Publish

- @0x/contracts-asset-proxy@3.3.0
 - @0x/contracts-broker@1.1.5
 - @0x/contracts-coordinator@3.1.6
 - @0x/contracts-dev-utils@1.3.4
 - @0x/contracts-erc1155@2.1.6
 - @0x/contracts-erc20-bridge-sampler@1.6.0
 - @0x/contracts-erc20@3.2.0
 - @0x/contracts-erc721@3.1.6
 - @0x/contracts-exchange-forwarder@4.2.6
 - @0x/contracts-exchange-libs@4.3.6
 - @0x/contracts-exchange@3.2.6
 - @0x/contracts-extensions@6.2.0
 - @0x/contracts-integrations@2.5.2
 - @0x/contracts-multisig@4.1.6
 - @0x/contracts-staking@2.0.13
 - @0x/contracts-test-utils@5.3.3
 - @0x/contracts-utils@4.5.0
 - @0x/contracts-zero-ex@0.1.1
 - 0x.js@9.1.6
 - @0x/abi-gen@5.3.0
 - @0x/assert@3.0.8
 - @0x/asset-swapper@4.5.0
 - @0x/base-contract@6.2.2
 - @0x/connect@6.0.8
 - @0x/contract-addresses@4.10.0
 - @0x/contract-artifacts@3.7.0
 - @0x/contract-wrappers-test@12.2.15
 - @0x/contract-wrappers@13.7.0
 - @0x/contracts-gen@2.0.9
 - @0x/dev-utils@3.2.2
 - ethereum-types@3.1.1
 - @0x/instant@1.0.52
 - @0x/json-schemas@5.0.8
 - @0x/migrations@6.3.0
 - @0x/monorepo-scripts@1.0.53
 - @0x/order-utils@10.2.5
 - @0x/orderbook@2.2.6
 - @0x/sol-compiler@4.1.0
 - @0x/sol-coverage@4.0.9
 - @0x/sol-doc@3.1.7
 - @0x/sol-profiler@4.0.9
 - @0x/sol-resolver@3.0.4
 - @0x/sol-trace@3.0.9
 - @0x/sol-tracing-utils@7.0.9
 - @0x/sra-spec@3.0.8
 - @0x/subproviders@6.1.0
 - @0x/types@3.1.3
 - @0x/typescript-typings@5.1.0
 - @0x/utils@5.5.0
 - @0x/web3-wrapper@7.1.0

.circleci/config.yml

@@ -38,17 +38,7 @@ jobs:
                   path: ~/repo/packages/abi-gen/test-cli/output
             - store_artifacts:
                   path: ~/repo/packages/contract-wrappers/generated_docs
-    test-contracts-ganache:
-        resource_class: medium+
-        docker:
-            - image: nikolaik/python-nodejs:python3.7-nodejs8
-        working_directory: ~/repo
-        steps:
-            - restore_cache:
-                  keys:
-                      - repo-{{ .Environment.CIRCLE_SHA1 }}
-            - run: yarn wsrun test:circleci @0x/contracts-multisig @0x/contracts-utils @0x/contracts-exchange-libs @0x/contracts-erc20 @0x/contracts-erc721 @0x/contracts-erc1155 @0x/contracts-extensions @0x/contracts-asset-proxy @0x/contracts-exchange @0x/contracts-exchange-forwarder @0x/contracts-coordinator @0x/contracts-staking
-    test-exchange-ganache-3.0:
+    test-exchange-ganache:
         resource_class: medium+
         docker:
             - image: nikolaik/python-nodejs:python3.7-nodejs8
@@ -58,7 +48,7 @@ jobs:
                   keys:
                       - repo-{{ .Environment.CIRCLE_SHA1 }}
             - run: yarn wsrun test:circleci @0x/contracts-exchange
-    test-integrations-ganache-3.0:
+    test-integrations-ganache:
         resource_class: medium+
         docker:
             - image: nikolaik/python-nodejs:python3.7-nodejs8
@@ -68,7 +58,7 @@ jobs:
                   keys:
                       - repo-{{ .Environment.CIRCLE_SHA1 }}
             - run: yarn wsrun test:circleci @0x/contracts-integrations
-    test-contracts-rest-ganache-3.0:
+    test-contracts-staking-ganache:
         resource_class: medium+
         docker:
             - image: nikolaik/python-nodejs:python3.7-nodejs8
@@ -77,11 +67,17 @@ jobs:
             - restore_cache:
                   keys:
                       - repo-{{ .Environment.CIRCLE_SHA1 }}
-            - run: yarn wsrun test:circleci @0x/contracts-multisig @0x/contracts-utils @0x/contracts-exchange-libs @0x/contracts-erc20 @0x/contracts-erc721 @0x/contracts-erc1155 @0x/contracts-asset-proxy @0x/contracts-exchange-forwarder @0x/contracts-staking @0x/contracts-coordinator @0x/contracts-erc20-bridge-sampler
-            # TODO(dorothy-zbornak): Re-enable after updating this package for
-            # 3.0. At that time, also remove exclusion from monorepo
-            # package.json's test script.
-            # - run: yarn wsrun test:circleci @0x/contracts-extensions
+            - run: yarn wsrun test:circleci @0x/contracts-staking
+    test-contracts-rest-ganache:
+        resource_class: medium+
+        docker:
+            - image: nikolaik/python-nodejs:python3.7-nodejs8
+        working_directory: ~/repo
+        steps:
+            - restore_cache:
+                  keys:
+                      - repo-{{ .Environment.CIRCLE_SHA1 }}
+            - run: yarn wsrun test:circleci @0x/contracts-multisig @0x/contracts-utils @0x/contracts-exchange-libs @0x/contracts-erc20 @0x/contracts-erc721 @0x/contracts-erc1155 @0x/contracts-asset-proxy @0x/contracts-exchange-forwarder @0x/contracts-coordinator @0x/contracts-erc20-bridge-sampler @0x/contracts-broker @0x/contracts-zero-ex
     test-publish:
         resource_class: medium+
         docker:
@@ -194,6 +190,8 @@ jobs:
         docker:
             - image: nikolaik/python-nodejs:python3.7-nodejs8
             - image: 0xorg/ganache-cli:6.0.0
+              environment:
+                  VERSION: '6.0.0'
             - image: 0xorg/mesh:0xV3
               environment:
                   ETHEREUM_RPC_URL: 'http://localhost:8545'
@@ -417,13 +415,16 @@ workflows:
     main:
         jobs:
             - build
-            - test-exchange-ganache-3.0:
+            - test-exchange-ganache:
                   requires:
                       - build
-            - test-integrations-ganache-3.0:
+            - test-integrations-ganache:
                   requires:
                       - build
-            - test-contracts-rest-ganache-3.0:
+            - test-contracts-staking-ganache:
+                  requires:
+                      - build
+            - test-contracts-rest-ganache:
                   requires:
                       - build
             - test-rest:
@@ -440,8 +441,9 @@ workflows:
                       - build
             - submit-coverage:
                   requires:
-                      - test-contracts-rest-ganache-3.0
-                      - test-exchange-ganache-3.0
+                      - test-contracts-rest-ganache
+                      - test-contracts-staking-ganache
+                      - test-exchange-ganache
                       - test-rest
                       - static-tests
             - test-python:

.gitignore

@@ -111,6 +111,8 @@ contracts/exchange-forwarder/generated-artifacts/
 contracts/exchange-forwarder/test/generated-artifacts/
 contracts/dev-utils/generated-artifacts/
 contracts/dev-utils/test/generated-artifacts/
+contracts/zero-ex/generated-artifacts/
+contracts/zero-ex/test/generated-artifacts/
 packages/sol-tracing-utils/test/fixtures/artifacts/
 python-packages/contract_artifacts/src/zero_ex/contract_artifacts/artifacts/
 
@@ -165,6 +167,8 @@ contracts/exchange-forwarder/generated-wrappers/
 contracts/exchange-forwarder/test/generated-wrappers/
 contracts/dev-utils/generated-wrappers/
 contracts/dev-utils/test/generated-wrappers/
+contracts/zero-ex/generated-wrappers/
+contracts/zero-ex/test/generated-wrappers/
 python-packages/contract_wrappers/src/zero_ex/contract_wrappers/*/__init__.py
 
 # solc-bin in sol-compiler

.prettierignore

@@ -64,6 +64,10 @@ lib
 /contracts/dev-utils/test/generated-wrappers
 /contracts/dev-utils/generated-artifacts
 /contracts/dev-utils/test/generated-artifacts
+/contracts/zero-ex/generated-wrappers
+/contracts/zero-ex/test/generated-wrappers
+/contracts/zero-ex/generated-artifacts
+/contracts/zero-ex/test/generated-artifacts
 /contracts/staking/build/
 /contracts/coordinator/build/
 /contracts/exchange/build/
@@ -91,3 +95,4 @@ packages/abi-gen/test-cli/fixtures/artifacts/AbiGenDummy.json
 packages/abi-gen/test-cli/fixtures/artifacts/LibDummy.json
 packages/abi-gen/test-cli/fixtures/artifacts/TestLibDummy.json
 packages/*/docs
+*.sol

contracts/asset-proxy/CHANGELOG.json

@@ -1,4 +1,65 @@
 [
+    {
+        "version": "3.3.0",
+        "changes": [
+            {
+                "note": "Use `LibERC20Token.approveIfBelow()` in DEX bridges for for approvals.",
+                "pr": 2512
+            },
+            {
+                "note": "Emit `ERC20BridgeTransfer` events in bridges.",
+                "pr": 2512
+            },
+            {
+                "note": "Change names of `ERC20BridgeTransfer` args to be less ambiguous.",
+                "pr": 2524
+            },
+            {
+                "note": "Added `MixinGasToken` allowing Gas Tokens to be freed",
+                "pr": 2523
+            },
+            {
+                "note": "Add `DexForwaderBridge` bridge contract.",
+                "pr": 2525
+            },
+            {
+                "note": "Add `UniswapV2Bridge` bridge contract.",
+                "pr": 2590
+            },
+            {
+                "note": "Add Gas Token freeing to `DexForwarderBridge` contract.",
+                "pr": 2536
+            }
+        ],
+        "timestamp": 1592969527
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "3.2.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "3.2.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "3.2.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "3.2.2",
@@ -42,7 +103,7 @@
             },
             {
                 "note": "Add `setOperators()` to `IDydx`",
-                "pr": "TODO"
+                "pr": 2462
             }
         ],
         "timestamp": 1581204851

contracts/asset-proxy/CHANGELOG.md

@@ -5,6 +5,28 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.3.0 - _June 24, 2020_
+
+    * Use `LibERC20Token.approveIfBelow()` in DEX bridges for for approvals. (#2512)
+    * Emit `ERC20BridgeTransfer` events in bridges. (#2512)
+    * Change names of `ERC20BridgeTransfer` args to be less ambiguous. (#2524)
+    * Added `MixinGasToken` allowing Gas Tokens to be freed (#2523)
+    * Add `DexForwaderBridge` bridge contract. (#2525)
+    * Add `UniswapV2Bridge` bridge contract. (#2590)
+    * Add Gas Token freeing to `DexForwarderBridge` contract. (#2536)
+
+## v3.2.5 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v3.2.4 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v3.2.3 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v3.2.2 - _February 25, 2020_
 
     * Dependencies updated
@@ -20,7 +42,7 @@ CHANGELOG
     * Fix broken tests. (#2462)
     * Remove dependency on `@0x/contracts-dev-utils` (#2462)
     * Add asset data decoding functions (#2462)
-    * Add `setOperators()` to `IDydx` (#TODO)
+    * Add `setOperators()` to `IDydx` (#2462)
 
 ## v3.1.3 - _February 6, 2020_
 

contracts/asset-proxy/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/asset-proxy/contracts/src/bridges/ChaiBridge.sol

@@ -35,7 +35,7 @@ contract ChaiBridge is
     /// @param from Address to transfer asset from.
     /// @param to Address to transfer asset to.
     /// @param amount Amount of asset to transfer.
-    /// @return success The magic bytes `0x37708e9b` if successful.
+    /// @return success The magic bytes `0xdc1600f3` if successful.
     function bridgeTransferFrom(
         address /* tokenAddress */,
         address from,

contracts/asset-proxy/contracts/src/bridges/CurveBridge.sol

@@ -26,6 +26,7 @@ import "@0x/contracts-exchange-libs/contracts/src/IWallet.sol";
 import "@0x/contracts-utils/contracts/src/DeploymentConstants.sol";
 import "../interfaces/IERC20Bridge.sol";
 import "../interfaces/ICurve.sol";
+import "./MixinGasToken.sol";
 
 
 // solhint-disable not-rely-on-time
@@ -33,54 +34,64 @@ import "../interfaces/ICurve.sol";
 contract CurveBridge is
     IERC20Bridge,
     IWallet,
-    DeploymentConstants
+    DeploymentConstants,
+    MixinGasToken
 {
+    struct CurveBridgeData {
+        address curveAddress;
+        int128 fromCoinIdx;
+        int128 toCoinIdx;
+        int128 version;
+    }
+
     /// @dev Callback for `ICurve`. Tries to buy `amount` of
     ///      `toTokenAddress` tokens by selling the entirety of the opposing asset
     ///      (DAI, USDC) to the Curve contract, then transfers the bought
     ///      tokens to `to`.
     /// @param toTokenAddress The token to give to `to` (i.e DAI, USDC, USDT).
+    /// @param from The maker (this contract).
     /// @param to The recipient of the bought tokens.
     /// @param amount Minimum amount of `toTokenAddress` tokens to buy.
     /// @param bridgeData The abi-encoeded "from" token address.
     /// @return success The magic bytes if successful.
     function bridgeTransferFrom(
         address toTokenAddress,
-        address /* from */,
+        address from,
         address to,
         uint256 amount,
         bytes calldata bridgeData
     )
         external
+        freesGasTokensFromCollector
         returns (bytes4 success)
     {
         // Decode the bridge data to get the Curve metadata.
-        (address curveAddress, int128 fromCoinIdx, int128 toCoinIdx, int128 version) = abi.decode(bridgeData, (address, int128, int128, int128));
-        ICurve exchange = ICurve(curveAddress);
+        CurveBridgeData memory data = abi.decode(bridgeData, (CurveBridgeData));
 
-        address fromTokenAddress = exchange.underlying_coins(fromCoinIdx);
+        address fromTokenAddress = ICurve(data.curveAddress).underlying_coins(data.fromCoinIdx);
         require(toTokenAddress != fromTokenAddress, "CurveBridge/INVALID_PAIR");
+        uint256 fromTokenBalance = IERC20Token(fromTokenAddress).balanceOf(address(this));
         // Grant an allowance to the exchange to spend `fromTokenAddress` token.
-        LibERC20Token.approve(fromTokenAddress, address(exchange), uint256(-1));
+        LibERC20Token.approveIfBelow(fromTokenAddress, data.curveAddress, fromTokenBalance);
 
         // Try to sell all of this contract's `fromTokenAddress` token balance.
-        if (version == 0) {
-            exchange.exchange_underlying(
-                fromCoinIdx,
-                toCoinIdx,
+        if (data.version == 0) {
+            ICurve(data.curveAddress).exchange_underlying(
+                data.fromCoinIdx,
+                data.toCoinIdx,
                 // dx
-                IERC20Token(fromTokenAddress).balanceOf(address(this)),
+                fromTokenBalance,
                 // min dy
                 amount,
                 // expires
                 block.timestamp + 1
             );
         } else {
-            exchange.exchange_underlying(
-                fromCoinIdx,
-                toCoinIdx,
+            ICurve(data.curveAddress).exchange_underlying(
+                data.fromCoinIdx,
+                data.toCoinIdx,
                 // dx
-                IERC20Token(fromTokenAddress).balanceOf(address(this)),
+                fromTokenBalance,
                 // min dy
                 amount
             );
@@ -89,6 +100,15 @@ contract CurveBridge is
         uint256 toTokenBalance = IERC20Token(toTokenAddress).balanceOf(address(this));
         // Transfer the converted `toToken`s to `to`.
         LibERC20Token.transfer(toTokenAddress, to, toTokenBalance);
+
+        emit ERC20BridgeTransfer(
+            fromTokenAddress,
+            toTokenAddress,
+            fromTokenBalance,
+            toTokenBalance,
+            from,
+            to
+        );
         return BRIDGE_SUCCESS;
     }
 

contracts/asset-proxy/contracts/src/bridges/DexForwarderBridge.sol

@@ -0,0 +1,201 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/interfaces/IERC20Token.sol";
+import "@0x/contracts-erc20/contracts/src/LibERC20Token.sol";
+import "@0x/contracts-exchange-libs/contracts/src/IWallet.sol";
+import "@0x/contracts-exchange-libs/contracts/src/LibMath.sol";
+import "@0x/contracts-utils/contracts/src/DeploymentConstants.sol";
+import "@0x/contracts-utils/contracts/src/LibBytes.sol";
+import "@0x/contracts-utils/contracts/src/LibSafeMath.sol";
+import "../interfaces/IERC20Bridge.sol";
+import "./MixinGasToken.sol";
+
+
+// solhint-disable space-after-comma, indent
+contract DexForwarderBridge is
+    IERC20Bridge,
+    IWallet,
+    DeploymentConstants,
+    MixinGasToken
+{
+    using LibSafeMath for uint256;
+
+    /// @dev Data needed to reconstruct a bridge call.
+    struct BridgeCall {
+        address target;
+        uint256 inputTokenAmount;
+        uint256 outputTokenAmount;
+        bytes bridgeData;
+    }
+
+    /// @dev Intermediate state variables used by `bridgeTransferFrom()`, in
+    ///      struct form to get around stack limits.
+    struct TransferFromState {
+        address inputToken;
+        uint256 initialInputTokenBalance;
+        uint256 callInputTokenAmount;
+        uint256 callOutputTokenAmount;
+        uint256 totalInputTokenSold;
+        BridgeCall[] calls;
+    }
+
+    /// @dev Spends this contract's entire balance of input tokens by forwarding
+    /// them to other bridges. Reverts if the entire balance is not spent.
+    /// @param outputToken The token being bought.
+    /// @param to The recipient of the bought tokens.
+    /// @param bridgeData The abi-encoded input token address.
+    /// @return success The magic bytes if successful.
+    function bridgeTransferFrom(
+        address outputToken,
+        address /* from */,
+        address to,
+        uint256 /* amount */,
+        bytes calldata bridgeData
+    )
+        external
+        freesGasTokensFromCollector
+        returns (bytes4 success)
+    {
+        require(msg.sender == _getERC20BridgeProxyAddress(), "DexForwarderBridge/SENDER_NOT_AUTHORIZED");
+        TransferFromState memory state;
+        (
+            state.inputToken,
+            state.calls
+        ) = abi.decode(bridgeData, (address, BridgeCall[]));
+
+        state.initialInputTokenBalance = IERC20Token(state.inputToken).balanceOf(address(this));
+
+        for (uint256 i = 0; i < state.calls.length; ++i) {
+            // Stop if the we've sold all our input tokens.
+            if (state.totalInputTokenSold >= state.initialInputTokenBalance) {
+                break;
+            }
+
+            // Compute token amounts.
+            state.callInputTokenAmount = LibSafeMath.min256(
+                state.calls[i].inputTokenAmount,
+                state.initialInputTokenBalance.safeSub(state.totalInputTokenSold)
+            );
+            state.callOutputTokenAmount = LibMath.getPartialAmountFloor(
+                state.callInputTokenAmount,
+                state.calls[i].inputTokenAmount,
+                state.calls[i].outputTokenAmount
+            );
+
+            // Execute the call in a new context so we can recoup transferred
+            // funds by reverting.
+            (bool didSucceed, ) = address(this)
+                .call(abi.encodeWithSelector(
+                    this.executeBridgeCall.selector,
+                    state.calls[i].target,
+                    to,
+                    state.inputToken,
+                    outputToken,
+                    state.callInputTokenAmount,
+                    state.callOutputTokenAmount,
+                    state.calls[i].bridgeData
+                ));
+
+            if (didSucceed) {
+                // Increase the amount of tokens sold.
+                state.totalInputTokenSold = state.totalInputTokenSold.safeAdd(
+                    state.callInputTokenAmount
+                );
+            }
+        }
+        // Revert if we were not able to sell our entire input token balance.
+        require(
+            state.totalInputTokenSold >= state.initialInputTokenBalance,
+            "DexForwarderBridge/INCOMPLETE_FILL"
+        );
+        // Always succeed.
+        return BRIDGE_SUCCESS;
+    }
+
+    /// @dev Transfers `inputToken` token to a bridge contract then calls
+    ///      its `bridgeTransferFrom()`. This is executed in separate context
+    ///      so we can revert the transfer on error. This can only be called
+    //       by this contract itself.
+    /// @param bridge The bridge contract.
+    /// @param to The recipient of `outputToken` tokens.
+    /// @param inputToken The input token.
+    /// @param outputToken The output token.
+    /// @param inputTokenAmount The amount of input tokens to transfer to `bridge`.
+    /// @param outputTokenAmount The amount of expected output tokens to be sent
+    ///        to `to` by `bridge`.
+    function executeBridgeCall(
+        address bridge,
+        address to,
+        address inputToken,
+        address outputToken,
+        uint256 inputTokenAmount,
+        uint256 outputTokenAmount,
+        bytes calldata bridgeData
+    )
+        external
+    {
+        // Must be called through `bridgeTransferFrom()`.
+        require(msg.sender == address(this), "DexForwarderBridge/ONLY_SELF");
+        // `bridge` must not be this contract.
+        require(bridge != address(this));
+
+        // Get the starting balance of output tokens for `to`.
+        uint256 initialRecipientBalance = IERC20Token(outputToken).balanceOf(to);
+
+        // Transfer input tokens to the bridge.
+        LibERC20Token.transfer(inputToken, bridge, inputTokenAmount);
+
+        // Call the bridge.
+        (bool didSucceed, bytes memory resultData) =
+            bridge.call(abi.encodeWithSelector(
+                IERC20Bridge(0).bridgeTransferFrom.selector,
+                outputToken,
+                bridge,
+                to,
+                outputTokenAmount,
+                bridgeData
+            ));
+
+        // Revert if the call failed or not enough tokens were bought.
+        // This will also undo the token transfer.
+        require(
+            didSucceed
+            && resultData.length == 32
+            && LibBytes.readBytes32(resultData, 0) == bytes32(BRIDGE_SUCCESS)
+            && IERC20Token(outputToken).balanceOf(to).safeSub(initialRecipientBalance) >= outputTokenAmount
+        );
+    }
+
+    /// @dev `SignatureType.Wallet` callback, so that this bridge can be the maker
+    ///      and sign for itself in orders. Always succeeds.
+    /// @return magicValue Magic success bytes, always.
+    function isValidSignature(
+        bytes32,
+        bytes calldata
+    )
+        external
+        view
+        returns (bytes4 magicValue)
+    {
+        return LEGACY_WALLET_MAGIC_VALUE;
+    }
+}

contracts/asset-proxy/contracts/src/bridges/DydxBridge.sol

@@ -50,7 +50,7 @@ contract DydxBridge is
     /// @param encodedBridgeData An abi-encoded `BridgeData` struct.
     /// @return success The magic bytes if successful.
     function bridgeTransferFrom(
-        address,
+        address, /* toTokenAddress */
         address from,
         address to,
         uint256 amount,
@@ -81,6 +81,7 @@ contract DydxBridge is
 
         // Run operation. This will revert on failure.
         IDydx(_getDydxAddress()).operate(accounts, actions);
+
         return BRIDGE_SUCCESS;
     }
 

contracts/asset-proxy/contracts/src/bridges/Eth2DaiBridge.sol

@@ -38,13 +38,14 @@ contract Eth2DaiBridge is
     ///      (DAI or WETH) to the Eth2Dai contract, then transfers the bought
     ///      tokens to `to`.
     /// @param toTokenAddress The token to give to `to` (either DAI or WETH).
+    /// @param from The maker (this contract).
     /// @param to The recipient of the bought tokens.
     /// @param amount Minimum amount of `toTokenAddress` tokens to buy.
     /// @param bridgeData The abi-encoeded "from" token address.
     /// @return success The magic bytes if successful.
     function bridgeTransferFrom(
         address toTokenAddress,
-        address /* from */,
+        address from,
         address to,
         uint256 amount,
         bytes calldata bridgeData
@@ -56,18 +57,28 @@ contract Eth2DaiBridge is
         (address fromTokenAddress) = abi.decode(bridgeData, (address));
 
         IEth2Dai exchange = IEth2Dai(_getEth2DaiAddress());
+        uint256 fromTokenBalance = IERC20Token(fromTokenAddress).balanceOf(address(this));
         // Grant an allowance to the exchange to spend `fromTokenAddress` token.
-        LibERC20Token.approve(fromTokenAddress, address(exchange), uint256(-1));
+        LibERC20Token.approveIfBelow(fromTokenAddress, address(exchange), fromTokenBalance);
 
         // Try to sell all of this contract's `fromTokenAddress` token balance.
         uint256 boughtAmount = exchange.sellAllAmount(
             fromTokenAddress,
-            IERC20Token(fromTokenAddress).balanceOf(address(this)),
+            fromTokenBalance,
             toTokenAddress,
             amount
         );
         // Transfer the converted `toToken`s to `to`.
         LibERC20Token.transfer(toTokenAddress, to, boughtAmount);
+
+        emit ERC20BridgeTransfer(
+            fromTokenAddress,
+            toTokenAddress,
+            fromTokenBalance,
+            boughtAmount,
+            from,
+            to
+        );
         return BRIDGE_SUCCESS;
     }
 

contracts/asset-proxy/contracts/src/bridges/KyberBridge.sol

@@ -66,13 +66,14 @@ contract KyberBridge is
     ///      to the `KyberNetworkProxy` contract, then transfers the bought
     ///      tokens to `to`.
     /// @param toTokenAddress The token to give to `to`.
+    /// @param from The maker (this contract).
     /// @param to The recipient of the bought tokens.
     /// @param amount Minimum amount of `toTokenAddress` tokens to buy.
     /// @param bridgeData The abi-encoeded "from" token address.
     /// @return success The magic bytes if successful.
     function bridgeTransferFrom(
         address toTokenAddress,
-        address /* from */,
+        address from,
         address to,
         uint256 amount,
         bytes calldata bridgeData
@@ -109,7 +110,11 @@ contract KyberBridge is
         } else if (state.fromTokenAddress != address(state.weth)) {
             // If the input token is not WETH, grant an allowance to the exchange
             // to spend them.
-            LibERC20Token.approve(state.fromTokenAddress, address(state.kyber), uint256(-1));
+            LibERC20Token.approveIfBelow(
+                state.fromTokenAddress,
+                address(state.kyber),
+                state.fromTokenBalance
+            );
         } else {
             // If the input token is WETH, unwrap it and attach it to the call.
             state.fromTokenAddress = KYBER_ETH_ADDRESS;
@@ -143,6 +148,15 @@ contract KyberBridge is
             state.weth.deposit.value(boughtAmount)();
             state.weth.transfer(to, boughtAmount);
         }
+
+        emit ERC20BridgeTransfer(
+            state.fromTokenAddress == KYBER_ETH_ADDRESS ? address(state.weth) : state.fromTokenAddress,
+            toTokenAddress,
+            state.fromTokenBalance,
+            boughtAmount,
+            from,
+            to
+        );
         return BRIDGE_SUCCESS;
     }
 

contracts/asset-proxy/contracts/src/bridges/MixinGasToken.sol

@@ -0,0 +1,55 @@
+/*
+
+  Copyright 2019 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.16;
+
+import "@0x/contracts-utils/contracts/src/DeploymentConstants.sol";
+import "../interfaces/IGasToken.sol";
+
+
+contract MixinGasToken is
+    DeploymentConstants
+{
+
+    /// @dev Frees gas tokens based on the amount of gas consumed in the function
+    modifier freesGasTokens {
+        uint256 gasBefore = gasleft();
+        _;
+        IGasToken gst = IGasToken(_getGstAddress());
+        if (address(gst) != address(0)) {
+            // (gasUsed + FREE_BASE) / (2 * REIMBURSE - FREE_TOKEN)
+            //            14154             24000        6870
+            uint256 value = (gasBefore - gasleft() + 14154) / 41130;
+            gst.freeUpTo(value);
+        }
+    }
+
+    /// @dev Frees gas tokens using the balance of `from`. Amount freed is based
+    ///     on the gas consumed in the function
+    modifier freesGasTokensFromCollector() {
+        uint256 gasBefore = gasleft();
+        _;
+        IGasToken gst = IGasToken(_getGstAddress());
+        if (address(gst) != address(0)) {
+            // (gasUsed + FREE_BASE) / (2 * REIMBURSE - FREE_TOKEN)
+            //            14154             24000        6870
+            uint256 value = (gasBefore - gasleft() + 14154) / 41130;
+            gst.freeFromUpTo(_getGstCollectorAddress(), value);
+        }
+    }
+}

contracts/asset-proxy/contracts/src/bridges/UniswapBridge.sol

@@ -38,10 +38,11 @@ contract UniswapBridge is
 {
     // Struct to hold `bridgeTransferFrom()` local variables in memory and to avoid
     // stack overflows.
-    struct WithdrawToState {
+    struct TransferState {
         IUniswapExchange exchange;
         uint256 fromTokenBalance;
         IEtherToken weth;
+        uint256 boughtAmount;
     }
 
     // solhint-disable no-empty-blocks
@@ -55,13 +56,14 @@ contract UniswapBridge is
     ///      `toTokenAddress` tokens by selling the entirety of the `fromTokenAddress`
     ///      token encoded in the bridge data.
     /// @param toTokenAddress The token to buy and transfer to `to`.
+    /// @param from The maker (this contract).
     /// @param to The recipient of the bought tokens.
     /// @param amount Minimum amount of `toTokenAddress` tokens to buy.
     /// @param bridgeData The abi-encoded "from" token address.
     /// @return success The magic bytes if successful.
     function bridgeTransferFrom(
         address toTokenAddress,
-        address /* from */,
+        address from,
         address to,
         uint256 amount,
         bytes calldata bridgeData
@@ -70,7 +72,7 @@ contract UniswapBridge is
         returns (bytes4 success)
     {
         // State memory object to avoid stack overflows.
-        WithdrawToState memory state;
+        TransferState memory state;
         // Decode the bridge data to get the `fromTokenAddress`.
         (address fromTokenAddress) = abi.decode(bridgeData, (address));
 
@@ -96,7 +98,7 @@ contract UniswapBridge is
             state.weth.withdraw(state.fromTokenBalance);
             // Buy as much of `toTokenAddress` token with ETH as possible and
             // transfer it to `to`.
-            state.exchange.ethToTokenTransferInput.value(state.fromTokenBalance)(
+            state.boughtAmount = state.exchange.ethToTokenTransferInput.value(state.fromTokenBalance)(
                 // Minimum buy amount.
                 amount,
                 // Expires after this block.
@@ -108,9 +110,9 @@ contract UniswapBridge is
         // Convert from a token to WETH.
         } else if (toTokenAddress == address(state.weth)) {
             // Grant the exchange an allowance.
-            _grantExchangeAllowance(state.exchange, fromTokenAddress);
+            _grantExchangeAllowance(state.exchange, fromTokenAddress, state.fromTokenBalance);
             // Buy as much ETH with `fromTokenAddress` token as possible.
-            uint256 ethBought = state.exchange.tokenToEthSwapInput(
+            state.boughtAmount = state.exchange.tokenToEthSwapInput(
                 // Sell all tokens we hold.
                 state.fromTokenBalance,
                 // Minimum buy amount.
@@ -119,17 +121,17 @@ contract UniswapBridge is
                 block.timestamp
             );
             // Wrap the ETH.
-            state.weth.deposit.value(ethBought)();
+            state.weth.deposit.value(state.boughtAmount)();
             // Transfer the WETH to `to`.
-            IEtherToken(toTokenAddress).transfer(to, ethBought);
+            IEtherToken(toTokenAddress).transfer(to, state.boughtAmount);
 
         // Convert from one token to another.
         } else {
             // Grant the exchange an allowance.
-            _grantExchangeAllowance(state.exchange, fromTokenAddress);
+            _grantExchangeAllowance(state.exchange, fromTokenAddress, state.fromTokenBalance);
             // Buy as much `toTokenAddress` token with `fromTokenAddress` token
             // and transfer it to `to`.
-            state.exchange.tokenToTokenTransferInput(
+            state.boughtAmount = state.exchange.tokenToTokenTransferInput(
                 // Sell all tokens we hold.
                 state.fromTokenBalance,
                 // Minimum buy amount.
@@ -144,6 +146,15 @@ contract UniswapBridge is
                 toTokenAddress
             );
         }
+
+        emit ERC20BridgeTransfer(
+            fromTokenAddress,
+            toTokenAddress,
+            state.fromTokenBalance,
+            state.boughtAmount,
+            from,
+            to
+        );
         return BRIDGE_SUCCESS;
     }
 
@@ -165,10 +176,19 @@ contract UniswapBridge is
     ///      on behalf of this contract.
     /// @param exchange The Uniswap token exchange.
     /// @param tokenAddress The token address for the exchange.
-    function _grantExchangeAllowance(IUniswapExchange exchange, address tokenAddress)
+    /// @param minimumAllowance The minimum necessary allowance.
+    function _grantExchangeAllowance(
+        IUniswapExchange exchange,
+        address tokenAddress,
+        uint256 minimumAllowance
+    )
         private
     {
-        LibERC20Token.approve(tokenAddress, address(exchange), uint256(-1));
+        LibERC20Token.approveIfBelow(
+            tokenAddress,
+            address(exchange),
+            minimumAllowance
+        );
     }
 
     /// @dev Retrieves the uniswap exchange for a given token pair.

contracts/asset-proxy/contracts/src/bridges/UniswapV2Bridge.sol

@@ -0,0 +1,135 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/interfaces/IERC20Token.sol";
+import "@0x/contracts-erc20/contracts/src/interfaces/IEtherToken.sol";
+import "@0x/contracts-erc20/contracts/src/LibERC20Token.sol";
+import "@0x/contracts-exchange-libs/contracts/src/IWallet.sol";
+import "@0x/contracts-utils/contracts/src/LibAddressArray.sol";
+import "@0x/contracts-utils/contracts/src/DeploymentConstants.sol";
+import "../interfaces/IUniswapV2Router01.sol";
+import "../interfaces/IERC20Bridge.sol";
+
+
+// solhint-disable space-after-comma
+// solhint-disable not-rely-on-time
+contract UniswapV2Bridge is
+    IERC20Bridge,
+    IWallet,
+    DeploymentConstants
+{
+    struct TransferState {
+        address[] path;
+        uint256 fromTokenBalance;
+    }
+
+    /// @dev Callback for `IERC20Bridge`. Tries to buy `amount` of
+    ///      `toTokenAddress` tokens by selling the entirety of the `fromTokenAddress`
+    ///      token encoded in the bridge data.
+    /// @param toTokenAddress The token to buy and transfer to `to`.
+    /// @param from The maker (this contract).
+    /// @param to The recipient of the bought tokens.
+    /// @param amount Minimum amount of `toTokenAddress` tokens to buy.
+    /// @param bridgeData The abi-encoded path of token addresses. Last element must be toTokenAddress
+    /// @return success The magic bytes if successful.
+    function bridgeTransferFrom(
+        address toTokenAddress,
+        address from,
+        address to,
+        uint256 amount,
+        bytes calldata bridgeData
+    )
+        external
+        returns (bytes4 success)
+    {
+        // hold variables to get around stack depth limitations
+        TransferState memory state;
+
+        // Decode the bridge data to get the `fromTokenAddress`.
+        // solhint-disable indent
+        state.path = abi.decode(bridgeData, (address[]));
+        // solhint-enable indent
+
+        require(state.path.length >= 2, "UniswapV2Bridge/PATH_LENGTH_MUST_BE_AT_LEAST_TWO");
+        require(state.path[state.path.length - 1] == toTokenAddress, "UniswapV2Bridge/LAST_ELEMENT_OF_PATH_MUST_MATCH_OUTPUT_TOKEN");
+
+        // Just transfer the tokens if they're the same.
+        if (state.path[0] == toTokenAddress) {
+            LibERC20Token.transfer(state.path[0], to, amount);
+            return BRIDGE_SUCCESS;
+        }
+
+        // Get our balance of `fromTokenAddress` token.
+        state.fromTokenBalance = IERC20Token(state.path[0]).balanceOf(address(this));
+
+        // Grant the Uniswap router an allowance.
+        LibERC20Token.approveIfBelow(
+            state.path[0],
+            _getUniswapV2Router01Address(),
+            state.fromTokenBalance
+        );
+
+        // Buy as much `toTokenAddress` token with `fromTokenAddress` token
+        // and transfer it to `to`.
+        IUniswapV2Router01 router = IUniswapV2Router01(_getUniswapV2Router01Address());
+        uint[] memory amounts = router.swapExactTokensForTokens(
+             // Sell all tokens we hold.
+            state.fromTokenBalance,
+             // Minimum buy amount.
+            amount,
+            // Convert `fromTokenAddress` to `toTokenAddress`.
+            state.path,
+            // Recipient is `to`.
+            to,
+            // Expires after this block.
+            block.timestamp
+        );
+
+        emit ERC20BridgeTransfer(
+            // input token
+            state.path[0],
+            // output token
+            toTokenAddress,
+            // input token amount
+            state.fromTokenBalance,
+            // output token amount
+            amounts[amounts.length - 1],
+            from,
+            to
+        );
+
+        return BRIDGE_SUCCESS;
+    }
+
+    /// @dev `SignatureType.Wallet` callback, so that this bridge can be the maker
+    ///      and sign for itself in orders. Always succeeds.
+    /// @return magicValue Success bytes, always.
+    function isValidSignature(
+        bytes32,
+        bytes calldata
+    )
+        external
+        view
+        returns (bytes4 magicValue)
+    {
+        return LEGACY_WALLET_MAGIC_VALUE;
+    }
+}

contracts/asset-proxy/contracts/src/interfaces/ICurve.sol

@@ -65,7 +65,6 @@ interface ICurve {
         returns (uint256 dy);
 
     /// @dev Get the amount of `fromToken` by buying `buyAmount` of `toToken`
-    ///      This function exists on later versions of Curve (USDC/DAI/USDT)
     /// @param i The token index being sold.
     /// @param j The token index being bought.
     /// @param buyAmount The amount of token being bought.

contracts/asset-proxy/contracts/src/interfaces/IERC20Bridge.sol

@@ -21,16 +21,32 @@ pragma solidity ^0.5.9;
 
 contract IERC20Bridge {
 
-    // @dev Result of a successful bridge call.
+    /// @dev Result of a successful bridge call.
     bytes4 constant internal BRIDGE_SUCCESS = 0xdc1600f3;
 
+    /// @dev Emitted when a trade occurs.
+    /// @param inputToken The token the bridge is converting from.
+    /// @param outputToken The token the bridge is converting to.
+    /// @param inputTokenAmount Amount of input token.
+    /// @param outputTokenAmount Amount of output token.
+    /// @param from The `from` address in `bridgeTransferFrom()`
+    /// @param to The `to` address in `bridgeTransferFrom()`
+    event ERC20BridgeTransfer(
+        address inputToken,
+        address outputToken,
+        uint256 inputTokenAmount,
+        uint256 outputTokenAmount,
+        address from,
+        address to
+    );
+
     /// @dev Transfers `amount` of the ERC20 `tokenAddress` from `from` to `to`.
     /// @param tokenAddress The address of the ERC20 token to transfer.
     /// @param from Address to transfer asset from.
     /// @param to Address to transfer asset to.
     /// @param amount Amount of asset to transfer.
     /// @param bridgeData Arbitrary asset data needed by the bridge contract.
-    /// @return success The magic bytes `0x37708e9b` if successful.
+    /// @return success The magic bytes `0xdc1600f3` if successful.
     function bridgeTransferFrom(
         address tokenAddress,
         address from,

contracts/asset-proxy/contracts/src/interfaces/IGasToken.sol

@@ -0,0 +1,40 @@
+/*
+
+  Copyright 2019 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.15;
+
+import "@0x/contracts-erc20/contracts/src/interfaces/IERC20Token.sol";
+
+
+contract IGasToken is IERC20Token {
+
+    /// @dev Frees up to `value` sub-tokens
+    /// @param value The amount of tokens to free
+    /// @return How many tokens were freed
+    function freeUpTo(uint256 value) external returns (uint256 freed);
+
+    /// @dev Frees up to `value` sub-tokens owned by `from`
+    /// @param from The owner of tokens to spend
+    /// @param value The amount of tokens to free
+    /// @return How many tokens were freed
+    function freeFromUpTo(address from, uint256 value) external returns (uint256 freed);
+
+    /// @dev Mints `value` amount of tokens
+    /// @param value The amount of tokens to mint
+    function mint(uint256 value) external;
+}

contracts/asset-proxy/contracts/src/interfaces/IUniswapV2Router01.sol

@@ -0,0 +1,40 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+
+
+interface IUniswapV2Router01 {
+
+    /// @dev Swaps an exact amount of input tokens for as many output tokens as possible, along the route determined by the path.
+    ///      The first element of path is the input token, the last is the output token, and any intermediate elements represent
+    ///      intermediate pairs to trade through (if, for example, a direct pair does not exist).
+    /// @param amountIn The amount of input tokens to send.
+    /// @param amountOutMin The minimum amount of output tokens that must be received for the transaction not to revert.
+    /// @param path An array of token addresses. path.length must be >= 2. Pools for each consecutive pair of addresses must exist and have liquidity.
+    /// @param to Recipient of the output tokens.
+    /// @param deadline Unix timestamp after which the transaction will revert.
+    /// @return amounts The input token amount and all subsequent output token amounts.
+    function swapExactTokensForTokens(
+        uint amountIn,
+        uint amountOutMin,
+        address[] calldata path,
+        address to,
+        uint deadline
+    ) external returns (uint[] memory amounts);
+}

contracts/asset-proxy/contracts/test/TestDexForwarderBridge.sol

@@ -0,0 +1,244 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+pragma experimental ABIEncoderV2;
+
+import "../src/bridges/DexForwarderBridge.sol";
+import "@0x/contracts-utils/contracts/src/LibSafeMath.sol";
+
+
+interface ITestDexForwarderBridge {
+    event BridgeTransferFromCalled(
+        address caller,
+        uint256 inputTokenBalance,
+        address inputToken,
+        address outputToken,
+        address from,
+        address to,
+        uint256 amount
+    );
+
+    event TokenTransferCalled(
+        address from,
+        address to,
+        uint256 amount
+    );
+
+    function emitBridgeTransferFromCalled(
+        address caller,
+        uint256 inputTokenBalance,
+        address inputToken,
+        address outputToken,
+        address from,
+        address to,
+        uint256 amount
+    ) external;
+
+    function emitTokenTransferCalled(
+        address from,
+        address to,
+        uint256 amount
+    ) external;
+}
+
+
+interface ITestDexForwarderBridgeTestToken {
+
+    function transfer(address to, uint256 amount)
+        external
+        returns (bool);
+
+    function mint(address to, uint256 amount)
+        external;
+
+    function balanceOf(address owner) external view returns (uint256);
+}
+
+
+contract TestDexForwarderBridgeTestBridge {
+
+    bytes4 private _returnCode;
+    string private _revertError;
+    uint256 private _transferAmount;
+    ITestDexForwarderBridge private _testContract;
+
+    constructor(bytes4 returnCode, string memory revertError) public {
+        _testContract = ITestDexForwarderBridge(msg.sender);
+        _returnCode = returnCode;
+        _revertError = revertError;
+    }
+
+    function setTransferAmount(uint256 amount) external {
+        _transferAmount = amount;
+    }
+
+    function bridgeTransferFrom(
+        address outputToken,
+        address from,
+        address to,
+        uint256 amount,
+        bytes memory bridgeData
+    )
+        public
+        returns (bytes4 success)
+    {
+        if (bytes(_revertError).length != 0) {
+            revert(_revertError);
+        }
+        address inputToken = abi.decode(bridgeData, (address));
+        _testContract.emitBridgeTransferFromCalled(
+            msg.sender,
+            ITestDexForwarderBridgeTestToken(inputToken).balanceOf(address(this)),
+            inputToken,
+            outputToken,
+            from,
+            to,
+            amount
+        );
+        ITestDexForwarderBridgeTestToken(outputToken).mint(to, _transferAmount);
+        return _returnCode;
+    }
+}
+
+
+contract TestDexForwarderBridgeTestToken {
+
+    using LibSafeMath for uint256;
+
+    mapping(address => uint256) public balanceOf;
+    ITestDexForwarderBridge private _testContract;
+
+    constructor() public {
+        _testContract = ITestDexForwarderBridge(msg.sender);
+    }
+
+    function transfer(address to, uint256 amount)
+        external
+        returns (bool)
+    {
+        balanceOf[msg.sender] = balanceOf[msg.sender].safeSub(amount);
+        balanceOf[to] = balanceOf[to].safeAdd(amount);
+        _testContract.emitTokenTransferCalled(msg.sender, to, amount);
+        return true;
+    }
+
+    function mint(address owner, uint256 amount)
+        external
+    {
+        balanceOf[owner] = balanceOf[owner].safeAdd(amount);
+    }
+
+    function setBalance(address owner, uint256 amount)
+        external
+    {
+        balanceOf[owner] = amount;
+    }
+}
+
+
+contract TestDexForwarderBridge is
+    ITestDexForwarderBridge,
+    DexForwarderBridge
+{
+    address private AUTHORIZED_ADDRESS; // solhint-disable-line var-name-mixedcase
+
+    function setAuthorized(address authorized)
+        public
+    {
+        AUTHORIZED_ADDRESS = authorized;
+    }
+
+    function createBridge(
+        bytes4 returnCode,
+        string memory revertError
+    )
+        public
+        returns (address bridge)
+    {
+        return address(new TestDexForwarderBridgeTestBridge(returnCode, revertError));
+    }
+
+    function createToken() public returns (address token) {
+        return address(new TestDexForwarderBridgeTestToken());
+    }
+
+    function setTokenBalance(address token, address owner, uint256 amount) public {
+        TestDexForwarderBridgeTestToken(token).setBalance(owner, amount);
+    }
+
+    function setBridgeTransferAmount(address bridge, uint256 amount) public {
+        TestDexForwarderBridgeTestBridge(bridge).setTransferAmount(amount);
+    }
+
+    function emitBridgeTransferFromCalled(
+        address caller,
+        uint256 inputTokenBalance,
+        address inputToken,
+        address outputToken,
+        address from,
+        address to,
+        uint256 amount
+    )
+        public
+    {
+        emit BridgeTransferFromCalled(
+            caller,
+            inputTokenBalance,
+            inputToken,
+            outputToken,
+            from,
+            to,
+            amount
+        );
+    }
+
+    function emitTokenTransferCalled(
+        address from,
+        address to,
+        uint256 amount
+    )
+        public
+    {
+        emit TokenTransferCalled(
+            from,
+            to,
+            amount
+        );
+    }
+
+    function balanceOf(address token, address owner) public view returns (uint256) {
+        return TestDexForwarderBridgeTestToken(token).balanceOf(owner);
+    }
+
+    function _getGstAddress()
+        internal
+        view
+        returns (address gst)
+    {
+        return address(0);
+    }
+
+    function _getERC20BridgeProxyAddress()
+        internal
+        view
+        returns (address erc20BridgeProxyAddress)
+    {
+        return AUTHORIZED_ADDRESS;
+    }
+}

contracts/asset-proxy/contracts/test/TestEth2DaiBridge.sol

@@ -110,6 +110,10 @@ contract TestToken {
         return true;
     }
 
+    function allowance(address, address) external view returns (uint256) {
+        return 0;
+    }
+
     /// @dev Retrieve the balance for `owner`.
     function balanceOf(address owner)
         external

contracts/asset-proxy/contracts/test/TestKyberBridge.sol

@@ -110,6 +110,10 @@ contract TestToken {
         return _testContract.wethDeposit.value(msg.value)(msg.sender);
     }
 
+    function allowance(address, address) external view returns (uint256) {
+        return 0;
+    }
+
     function balanceOf(address owner)
         external
         view

contracts/asset-proxy/contracts/test/TestUniswapBridge.sol

@@ -224,6 +224,10 @@ contract TestToken {
         TestEventsRaiser(msg.sender).raiseWethWithdraw(amount);
     }
 
+    function allowance(address, address) external view returns (uint256) {
+        return 0;
+    }
+
     /// @dev Retrieve the balance for `owner`.
     function balanceOf(address owner)
         external

contracts/asset-proxy/contracts/test/TestUniswapV2Bridge.sol

@@ -0,0 +1,253 @@
+/*
+
+  Copyright 2019 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-erc20/contracts/src/interfaces/IERC20Token.sol";
+import "@0x/contracts-utils/contracts/src/LibSafeMath.sol";
+import "@0x/contracts-utils/contracts/src/LibAddressArray.sol";
+import "../src/bridges/UniswapV2Bridge.sol";
+import "../src/interfaces/IUniswapV2Router01.sol";
+
+
+contract TestEventsRaiser {
+
+    event TokenTransfer(
+        address token,
+        address from,
+        address to,
+        uint256 amount
+    );
+
+    event TokenApprove(
+        address spender,
+        uint256 allowance
+    );
+
+    event SwapExactTokensForTokensInput(
+        uint amountIn,
+        uint amountOutMin,
+        address toTokenAddress,
+        address to,
+        uint deadline
+    );
+
+    function raiseTokenTransfer(
+        address from,
+        address to,
+        uint256 amount
+    )
+        external
+    {
+        emit TokenTransfer(
+            msg.sender,
+            from,
+            to,
+            amount
+        );
+    }
+
+    function raiseTokenApprove(address spender, uint256 allowance) external {
+        emit TokenApprove(spender, allowance);
+    }
+
+    function raiseSwapExactTokensForTokensInput(
+        uint amountIn,
+        uint amountOutMin,
+        address toTokenAddress,
+        address to,
+        uint deadline
+    ) external
+    {
+        emit SwapExactTokensForTokensInput(
+            amountIn,
+            amountOutMin,
+            toTokenAddress,
+            to,
+            deadline
+        );
+    }
+}
+
+
+/// @dev A minimalist ERC20 token.
+contract TestToken {
+
+    using LibSafeMath for uint256;
+
+    mapping (address => uint256) public balances;
+    string private _nextRevertReason;
+
+    /// @dev Set the balance for `owner`.
+    function setBalance(address owner, uint256 balance)
+        external
+        payable
+    {
+        balances[owner] = balance;
+    }
+
+    /// @dev Just emits a TokenTransfer event on the caller
+    function transfer(address to, uint256 amount)
+        external
+        returns (bool)
+    {
+        TestEventsRaiser(msg.sender).raiseTokenTransfer(msg.sender, to, amount);
+        return true;
+    }
+
+    /// @dev Just emits a TokenApprove event on the caller
+    function approve(address spender, uint256 allowance)
+        external
+        returns (bool)
+    {
+        TestEventsRaiser(msg.sender).raiseTokenApprove(spender, allowance);
+        return true;
+    }
+
+    function allowance(address, address) external view returns (uint256) {
+        return 0;
+    }
+
+    /// @dev Retrieve the balance for `owner`.
+    function balanceOf(address owner)
+        external
+        view
+        returns (uint256)
+    {
+        return balances[owner];
+    }
+}
+
+
+/// @dev Mock the UniswapV2Router01 contract
+contract TestRouter is
+    IUniswapV2Router01
+{
+    string private _nextRevertReason;
+
+    /// @dev Set the revert reason for `swapExactTokensForTokens`.
+    function setRevertReason(string calldata reason)
+        external
+    {
+        _nextRevertReason = reason;
+    }
+
+    function swapExactTokensForTokens(
+        uint amountIn,
+        uint amountOutMin,
+        address[] calldata path,
+        address to,
+        uint deadline
+    ) external returns (uint[] memory amounts)
+    {
+        _revertIfReasonExists();
+
+        amounts = new uint[](path.length);
+        amounts[0] = amountIn;
+        amounts[amounts.length - 1] = amountOutMin;
+
+        TestEventsRaiser(msg.sender).raiseSwapExactTokensForTokensInput(
+            // tokens sold
+            amountIn,
+            // tokens bought
+            amountOutMin,
+            // output token (toTokenAddress)
+            path[path.length - 1],
+            // recipient
+            to,
+            // deadline
+            deadline
+        );
+    }
+
+    function _revertIfReasonExists()
+        private
+        view
+    {
+        if (bytes(_nextRevertReason).length != 0) {
+            revert(_nextRevertReason);
+        }
+    }
+
+}
+
+
+/// @dev UniswapV2Bridge overridden to mock tokens and Uniswap router
+contract TestUniswapV2Bridge is
+    UniswapV2Bridge,
+    TestEventsRaiser
+{
+
+    // Token address to TestToken instance.
+    mapping (address => TestToken) private _testTokens;
+    // TestRouter instance.
+    TestRouter private _testRouter;
+
+    constructor() public {
+        _testRouter = new TestRouter();
+    }
+
+    function setRouterRevertReason(string calldata revertReason)
+        external
+    {
+        _testRouter.setRevertReason(revertReason);
+    }
+
+    /// @dev Sets the balance of this contract for an existing token.
+    ///      The wei attached will be the balance.
+    function setTokenBalance(address tokenAddress, uint256 balance)
+        external
+    {
+        TestToken token = _testTokens[tokenAddress];
+        token.setBalance(address(this), balance);
+    }
+
+    /// @dev Create a new token
+    /// @param tokenAddress The token address. If zero, one will be created.
+    function createToken(
+        address tokenAddress
+    )
+        external
+        returns (TestToken token)
+    {
+        token = TestToken(tokenAddress);
+        if (tokenAddress == address(0)) {
+            token = new TestToken();
+        }
+        _testTokens[address(token)] = token;
+
+        return token;
+    }
+
+    function getRouterAddress()
+        external
+        view
+        returns (address)
+    {
+        return address(_testRouter);
+    }
+
+    function _getUniswapV2Router01Address()
+        internal
+        view
+        returns (address)
+    {
+        return address(_testRouter);
+    }
+}

contracts/asset-proxy/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-asset-proxy",
-    "version": "3.2.2",
+    "version": "3.3.0",
     "engines": {
         "node": ">=6.12"
     },
@@ -38,7 +38,7 @@
         "docs:json": "typedoc --excludePrivate --excludeExternals --excludeProtected --ignoreCompilerErrors --target ES5 --tsconfig typedoc-tsconfig.json --json $JSON_FILE_PATH $PROJECT_FILES"
     },
     "config": {
-        "abis": "./test/generated-artifacts/@(ChaiBridge|CurveBridge|DydxBridge|ERC1155Proxy|ERC20BridgeProxy|ERC20Proxy|ERC721Proxy|Eth2DaiBridge|IAssetData|IAssetProxy|IAssetProxyDispatcher|IAuthorizable|IChai|ICurve|IDydx|IDydxBridge|IERC20Bridge|IEth2Dai|IKyberNetworkProxy|IUniswapExchange|IUniswapExchangeFactory|KyberBridge|MixinAssetProxyDispatcher|MixinAuthorizable|MultiAssetProxy|Ownable|StaticCallProxy|TestChaiBridge|TestDydxBridge|TestERC20Bridge|TestEth2DaiBridge|TestKyberBridge|TestStaticCallTarget|TestUniswapBridge|UniswapBridge).json",
+        "abis": "./test/generated-artifacts/@(ChaiBridge|CurveBridge|DexForwarderBridge|DydxBridge|ERC1155Proxy|ERC20BridgeProxy|ERC20Proxy|ERC721Proxy|Eth2DaiBridge|IAssetData|IAssetProxy|IAssetProxyDispatcher|IAuthorizable|IChai|ICurve|IDydx|IDydxBridge|IERC20Bridge|IEth2Dai|IGasToken|IKyberNetworkProxy|IUniswapExchange|IUniswapExchangeFactory|IUniswapV2Router01|KyberBridge|MixinAssetProxyDispatcher|MixinAuthorizable|MixinGasToken|MultiAssetProxy|Ownable|StaticCallProxy|TestChaiBridge|TestDexForwarderBridge|TestDydxBridge|TestERC20Bridge|TestEth2DaiBridge|TestKyberBridge|TestStaticCallTarget|TestUniswapBridge|TestUniswapV2Bridge|UniswapBridge|UniswapV2Bridge).json",
         "abis:comment": "This list is auto-generated by contracts-gen. Don't edit manually."
     },
     "repository": {
@@ -51,12 +51,13 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/protocol/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/dev-utils": "^3.2.1",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contract-wrappers": "^13.7.0",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/dev-utils": "^3.2.2",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
         "@types/lodash": "4.14.104",
@@ -78,17 +79,17 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1",
-        "@0x/contracts-erc1155": "^2.1.2",
-        "@0x/contracts-erc20": "^3.1.2",
-        "@0x/contracts-erc721": "^3.1.2",
-        "@0x/contracts-exchange-libs": "^4.3.2",
-        "@0x/order-utils": "^10.2.2",
-        "@0x/types": "^3.1.2",
-        "@0x/typescript-typings": "^5.0.2",
-        "@0x/utils": "^5.4.1",
-        "@0x/web3-wrapper": "^7.0.7",
-        "ethereum-types": "^3.1.0",
+        "@0x/base-contract": "^6.2.2",
+        "@0x/contracts-erc1155": "^2.1.6",
+        "@0x/contracts-erc20": "^3.2.0",
+        "@0x/contracts-erc721": "^3.1.6",
+        "@0x/contracts-exchange-libs": "^4.3.6",
+        "@0x/order-utils": "^10.2.5",
+        "@0x/types": "^3.1.3",
+        "@0x/typescript-typings": "^5.1.0",
+        "@0x/utils": "^5.5.0",
+        "@0x/web3-wrapper": "^7.1.0",
+        "ethereum-types": "^3.1.1",
         "lodash": "^4.17.11"
     },
     "publishConfig": {

contracts/asset-proxy/src/artifacts.ts

@@ -7,6 +7,7 @@ import { ContractArtifact } from 'ethereum-types';
 
 import * as ChaiBridge from '../generated-artifacts/ChaiBridge.json';
 import * as CurveBridge from '../generated-artifacts/CurveBridge.json';
+import * as DexForwarderBridge from '../generated-artifacts/DexForwarderBridge.json';
 import * as DydxBridge from '../generated-artifacts/DydxBridge.json';
 import * as ERC1155Proxy from '../generated-artifacts/ERC1155Proxy.json';
 import * as ERC20BridgeProxy from '../generated-artifacts/ERC20BridgeProxy.json';
@@ -23,23 +24,29 @@ import * as IDydx from '../generated-artifacts/IDydx.json';
 import * as IDydxBridge from '../generated-artifacts/IDydxBridge.json';
 import * as IERC20Bridge from '../generated-artifacts/IERC20Bridge.json';
 import * as IEth2Dai from '../generated-artifacts/IEth2Dai.json';
+import * as IGasToken from '../generated-artifacts/IGasToken.json';
 import * as IKyberNetworkProxy from '../generated-artifacts/IKyberNetworkProxy.json';
 import * as IUniswapExchange from '../generated-artifacts/IUniswapExchange.json';
 import * as IUniswapExchangeFactory from '../generated-artifacts/IUniswapExchangeFactory.json';
+import * as IUniswapV2Router01 from '../generated-artifacts/IUniswapV2Router01.json';
 import * as KyberBridge from '../generated-artifacts/KyberBridge.json';
 import * as MixinAssetProxyDispatcher from '../generated-artifacts/MixinAssetProxyDispatcher.json';
 import * as MixinAuthorizable from '../generated-artifacts/MixinAuthorizable.json';
+import * as MixinGasToken from '../generated-artifacts/MixinGasToken.json';
 import * as MultiAssetProxy from '../generated-artifacts/MultiAssetProxy.json';
 import * as Ownable from '../generated-artifacts/Ownable.json';
 import * as StaticCallProxy from '../generated-artifacts/StaticCallProxy.json';
 import * as TestChaiBridge from '../generated-artifacts/TestChaiBridge.json';
+import * as TestDexForwarderBridge from '../generated-artifacts/TestDexForwarderBridge.json';
 import * as TestDydxBridge from '../generated-artifacts/TestDydxBridge.json';
 import * as TestERC20Bridge from '../generated-artifacts/TestERC20Bridge.json';
 import * as TestEth2DaiBridge from '../generated-artifacts/TestEth2DaiBridge.json';
 import * as TestKyberBridge from '../generated-artifacts/TestKyberBridge.json';
 import * as TestStaticCallTarget from '../generated-artifacts/TestStaticCallTarget.json';
 import * as TestUniswapBridge from '../generated-artifacts/TestUniswapBridge.json';
+import * as TestUniswapV2Bridge from '../generated-artifacts/TestUniswapV2Bridge.json';
 import * as UniswapBridge from '../generated-artifacts/UniswapBridge.json';
+import * as UniswapV2Bridge from '../generated-artifacts/UniswapV2Bridge.json';
 export const artifacts = {
     MixinAssetProxyDispatcher: MixinAssetProxyDispatcher as ContractArtifact,
     MixinAuthorizable: MixinAuthorizable as ContractArtifact,
@@ -52,10 +59,13 @@ export const artifacts = {
     StaticCallProxy: StaticCallProxy as ContractArtifact,
     ChaiBridge: ChaiBridge as ContractArtifact,
     CurveBridge: CurveBridge as ContractArtifact,
+    DexForwarderBridge: DexForwarderBridge as ContractArtifact,
     DydxBridge: DydxBridge as ContractArtifact,
     Eth2DaiBridge: Eth2DaiBridge as ContractArtifact,
     KyberBridge: KyberBridge as ContractArtifact,
+    MixinGasToken: MixinGasToken as ContractArtifact,
     UniswapBridge: UniswapBridge as ContractArtifact,
+    UniswapV2Bridge: UniswapV2Bridge as ContractArtifact,
     IAssetData: IAssetData as ContractArtifact,
     IAssetProxy: IAssetProxy as ContractArtifact,
     IAssetProxyDispatcher: IAssetProxyDispatcher as ContractArtifact,
@@ -66,14 +76,18 @@ export const artifacts = {
     IDydxBridge: IDydxBridge as ContractArtifact,
     IERC20Bridge: IERC20Bridge as ContractArtifact,
     IEth2Dai: IEth2Dai as ContractArtifact,
+    IGasToken: IGasToken as ContractArtifact,
     IKyberNetworkProxy: IKyberNetworkProxy as ContractArtifact,
     IUniswapExchange: IUniswapExchange as ContractArtifact,
     IUniswapExchangeFactory: IUniswapExchangeFactory as ContractArtifact,
+    IUniswapV2Router01: IUniswapV2Router01 as ContractArtifact,
     TestChaiBridge: TestChaiBridge as ContractArtifact,
+    TestDexForwarderBridge: TestDexForwarderBridge as ContractArtifact,
     TestDydxBridge: TestDydxBridge as ContractArtifact,
     TestERC20Bridge: TestERC20Bridge as ContractArtifact,
     TestEth2DaiBridge: TestEth2DaiBridge as ContractArtifact,
     TestKyberBridge: TestKyberBridge as ContractArtifact,
     TestStaticCallTarget: TestStaticCallTarget as ContractArtifact,
     TestUniswapBridge: TestUniswapBridge as ContractArtifact,
+    TestUniswapV2Bridge: TestUniswapV2Bridge as ContractArtifact,
 };

contracts/asset-proxy/src/dex_forwarder_bridge.ts

@@ -0,0 +1,27 @@
+import { AbiEncoder, BigNumber } from '@0x/utils';
+
+export interface DexForwarderBridgeCall {
+    target: string;
+    inputTokenAmount: BigNumber;
+    outputTokenAmount: BigNumber;
+    bridgeData: string;
+}
+
+export interface DexForwaderBridgeData {
+    inputToken: string;
+    calls: DexForwarderBridgeCall[];
+}
+
+export const dexForwarderBridgeDataEncoder = AbiEncoder.create([
+    { name: 'inputToken', type: 'address' },
+    {
+        name: 'calls',
+        type: 'tuple[]',
+        components: [
+            { name: 'target', type: 'address' },
+            { name: 'inputTokenAmount', type: 'uint256' },
+            { name: 'outputTokenAmount', type: 'uint256' },
+            { name: 'bridgeData', type: 'bytes' },
+        ],
+    },
+]);

contracts/asset-proxy/src/index.ts

@@ -88,3 +88,4 @@ export {
 } from './asset_data';
 
 export * from './dydx_bridge_encoder';
+export * from './dex_forwarder_bridge';

contracts/asset-proxy/src/wrappers.ts

@@ -5,6 +5,7 @@
  */
 export * from '../generated-wrappers/chai_bridge';
 export * from '../generated-wrappers/curve_bridge';
+export * from '../generated-wrappers/dex_forwarder_bridge';
 export * from '../generated-wrappers/dydx_bridge';
 export * from '../generated-wrappers/erc1155_proxy';
 export * from '../generated-wrappers/erc20_bridge_proxy';
@@ -21,20 +22,26 @@ export * from '../generated-wrappers/i_dydx';
 export * from '../generated-wrappers/i_dydx_bridge';
 export * from '../generated-wrappers/i_erc20_bridge';
 export * from '../generated-wrappers/i_eth2_dai';
+export * from '../generated-wrappers/i_gas_token';
 export * from '../generated-wrappers/i_kyber_network_proxy';
 export * from '../generated-wrappers/i_uniswap_exchange';
 export * from '../generated-wrappers/i_uniswap_exchange_factory';
+export * from '../generated-wrappers/i_uniswap_v2_router01';
 export * from '../generated-wrappers/kyber_bridge';
 export * from '../generated-wrappers/mixin_asset_proxy_dispatcher';
 export * from '../generated-wrappers/mixin_authorizable';
+export * from '../generated-wrappers/mixin_gas_token';
 export * from '../generated-wrappers/multi_asset_proxy';
 export * from '../generated-wrappers/ownable';
 export * from '../generated-wrappers/static_call_proxy';
 export * from '../generated-wrappers/test_chai_bridge';
+export * from '../generated-wrappers/test_dex_forwarder_bridge';
 export * from '../generated-wrappers/test_dydx_bridge';
 export * from '../generated-wrappers/test_erc20_bridge';
 export * from '../generated-wrappers/test_eth2_dai_bridge';
 export * from '../generated-wrappers/test_kyber_bridge';
 export * from '../generated-wrappers/test_static_call_target';
 export * from '../generated-wrappers/test_uniswap_bridge';
+export * from '../generated-wrappers/test_uniswap_v2_bridge';
 export * from '../generated-wrappers/uniswap_bridge';
+export * from '../generated-wrappers/uniswap_v2_bridge';

contracts/asset-proxy/test/artifacts.ts

@@ -7,6 +7,7 @@ import { ContractArtifact } from 'ethereum-types';
 
 import * as ChaiBridge from '../test/generated-artifacts/ChaiBridge.json';
 import * as CurveBridge from '../test/generated-artifacts/CurveBridge.json';
+import * as DexForwarderBridge from '../test/generated-artifacts/DexForwarderBridge.json';
 import * as DydxBridge from '../test/generated-artifacts/DydxBridge.json';
 import * as ERC1155Proxy from '../test/generated-artifacts/ERC1155Proxy.json';
 import * as ERC20BridgeProxy from '../test/generated-artifacts/ERC20BridgeProxy.json';
@@ -23,23 +24,29 @@ import * as IDydx from '../test/generated-artifacts/IDydx.json';
 import * as IDydxBridge from '../test/generated-artifacts/IDydxBridge.json';
 import * as IERC20Bridge from '../test/generated-artifacts/IERC20Bridge.json';
 import * as IEth2Dai from '../test/generated-artifacts/IEth2Dai.json';
+import * as IGasToken from '../test/generated-artifacts/IGasToken.json';
 import * as IKyberNetworkProxy from '../test/generated-artifacts/IKyberNetworkProxy.json';
 import * as IUniswapExchange from '../test/generated-artifacts/IUniswapExchange.json';
 import * as IUniswapExchangeFactory from '../test/generated-artifacts/IUniswapExchangeFactory.json';
+import * as IUniswapV2Router01 from '../test/generated-artifacts/IUniswapV2Router01.json';
 import * as KyberBridge from '../test/generated-artifacts/KyberBridge.json';
 import * as MixinAssetProxyDispatcher from '../test/generated-artifacts/MixinAssetProxyDispatcher.json';
 import * as MixinAuthorizable from '../test/generated-artifacts/MixinAuthorizable.json';
+import * as MixinGasToken from '../test/generated-artifacts/MixinGasToken.json';
 import * as MultiAssetProxy from '../test/generated-artifacts/MultiAssetProxy.json';
 import * as Ownable from '../test/generated-artifacts/Ownable.json';
 import * as StaticCallProxy from '../test/generated-artifacts/StaticCallProxy.json';
 import * as TestChaiBridge from '../test/generated-artifacts/TestChaiBridge.json';
+import * as TestDexForwarderBridge from '../test/generated-artifacts/TestDexForwarderBridge.json';
 import * as TestDydxBridge from '../test/generated-artifacts/TestDydxBridge.json';
 import * as TestERC20Bridge from '../test/generated-artifacts/TestERC20Bridge.json';
 import * as TestEth2DaiBridge from '../test/generated-artifacts/TestEth2DaiBridge.json';
 import * as TestKyberBridge from '../test/generated-artifacts/TestKyberBridge.json';
 import * as TestStaticCallTarget from '../test/generated-artifacts/TestStaticCallTarget.json';
 import * as TestUniswapBridge from '../test/generated-artifacts/TestUniswapBridge.json';
+import * as TestUniswapV2Bridge from '../test/generated-artifacts/TestUniswapV2Bridge.json';
 import * as UniswapBridge from '../test/generated-artifacts/UniswapBridge.json';
+import * as UniswapV2Bridge from '../test/generated-artifacts/UniswapV2Bridge.json';
 export const artifacts = {
     MixinAssetProxyDispatcher: MixinAssetProxyDispatcher as ContractArtifact,
     MixinAuthorizable: MixinAuthorizable as ContractArtifact,
@@ -52,10 +59,13 @@ export const artifacts = {
     StaticCallProxy: StaticCallProxy as ContractArtifact,
     ChaiBridge: ChaiBridge as ContractArtifact,
     CurveBridge: CurveBridge as ContractArtifact,
+    DexForwarderBridge: DexForwarderBridge as ContractArtifact,
     DydxBridge: DydxBridge as ContractArtifact,
     Eth2DaiBridge: Eth2DaiBridge as ContractArtifact,
     KyberBridge: KyberBridge as ContractArtifact,
+    MixinGasToken: MixinGasToken as ContractArtifact,
     UniswapBridge: UniswapBridge as ContractArtifact,
+    UniswapV2Bridge: UniswapV2Bridge as ContractArtifact,
     IAssetData: IAssetData as ContractArtifact,
     IAssetProxy: IAssetProxy as ContractArtifact,
     IAssetProxyDispatcher: IAssetProxyDispatcher as ContractArtifact,
@@ -66,14 +76,18 @@ export const artifacts = {
     IDydxBridge: IDydxBridge as ContractArtifact,
     IERC20Bridge: IERC20Bridge as ContractArtifact,
     IEth2Dai: IEth2Dai as ContractArtifact,
+    IGasToken: IGasToken as ContractArtifact,
     IKyberNetworkProxy: IKyberNetworkProxy as ContractArtifact,
     IUniswapExchange: IUniswapExchange as ContractArtifact,
     IUniswapExchangeFactory: IUniswapExchangeFactory as ContractArtifact,
+    IUniswapV2Router01: IUniswapV2Router01 as ContractArtifact,
     TestChaiBridge: TestChaiBridge as ContractArtifact,
+    TestDexForwarderBridge: TestDexForwarderBridge as ContractArtifact,
     TestDydxBridge: TestDydxBridge as ContractArtifact,
     TestERC20Bridge: TestERC20Bridge as ContractArtifact,
     TestEth2DaiBridge: TestEth2DaiBridge as ContractArtifact,
     TestKyberBridge: TestKyberBridge as ContractArtifact,
     TestStaticCallTarget: TestStaticCallTarget as ContractArtifact,
     TestUniswapBridge: TestUniswapBridge as ContractArtifact,
+    TestUniswapV2Bridge: TestUniswapV2Bridge as ContractArtifact,
 };

contracts/asset-proxy/test/dex_forwarder_bridge.ts

@@ -0,0 +1,356 @@
+import { ContractTxFunctionObj } from '@0x/contract-wrappers';
+import {
+    blockchainTests,
+    constants,
+    expect,
+    filterLogsToArguments,
+    getRandomInteger,
+    randomAddress,
+    shortZip,
+} from '@0x/contracts-test-utils';
+import { BigNumber, hexUtils, NULL_ADDRESS } from '@0x/utils';
+import { DecodedLogs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { DexForwarderBridgeCall, dexForwarderBridgeDataEncoder } from '../src/dex_forwarder_bridge';
+
+import { artifacts } from './artifacts';
+import {
+    TestDexForwarderBridgeBridgeTransferFromCalledEventArgs as BtfCalledEventArgs,
+    TestDexForwarderBridgeContract,
+    TestDexForwarderBridgeEvents as TestEvents,
+} from './wrappers';
+
+const { ZERO_AMOUNT } = constants;
+
+blockchainTests.resets('DexForwarderBridge unit tests', env => {
+    let testContract: TestDexForwarderBridgeContract;
+    let inputToken: string;
+    let outputToken: string;
+    const BRIDGE_SUCCESS = '0xdc1600f3';
+    const BRIDGE_FAILURE = '0xffffffff';
+    const BRIDGE_REVERT_ERROR = 'oopsie';
+    const INCOMPLETE_FILL_REVERT = 'DexForwarderBridge/INCOMPLETE_FILL';
+    const NOT_AUTHORIZED_REVERT = 'DexForwarderBridge/SENDER_NOT_AUTHORIZED';
+    const DEFAULTS = {
+        toAddress: randomAddress(),
+    };
+
+    before(async () => {
+        testContract = await TestDexForwarderBridgeContract.deployFrom0xArtifactAsync(
+            artifacts.TestDexForwarderBridge,
+            env.provider,
+            env.txDefaults,
+            artifacts,
+        );
+        // Create test tokens.
+        [inputToken, outputToken] = [
+            await callAndTransactAsync(testContract.createToken()),
+            await callAndTransactAsync(testContract.createToken()),
+        ];
+        await callAndTransactAsync(testContract.setAuthorized(env.txDefaults.from as string));
+    });
+
+    async function callAndTransactAsync<TResult>(fnCall: ContractTxFunctionObj<TResult>): Promise<TResult> {
+        const result = await fnCall.callAsync();
+        await fnCall.awaitTransactionSuccessAsync({}, { shouldValidate: false });
+        return result;
+    }
+
+    function getRandomBridgeCall(
+        bridgeAddress: string,
+        fields: Partial<DexForwarderBridgeCall> = {},
+    ): DexForwarderBridgeCall {
+        return {
+            target: bridgeAddress,
+            inputTokenAmount: getRandomInteger(1, '100e18'),
+            outputTokenAmount: getRandomInteger(1, '100e18'),
+            bridgeData: hexUtils.leftPad(inputToken),
+            ...fields,
+        };
+    }
+
+    describe('bridgeTransferFrom()', () => {
+        let goodBridgeCalls: DexForwarderBridgeCall[];
+        let revertingBridgeCall: DexForwarderBridgeCall;
+        let failingBridgeCall: DexForwarderBridgeCall;
+        let allBridgeCalls: DexForwarderBridgeCall[];
+        let totalFillableOutputAmount: BigNumber;
+        let totalFillableInputAmount: BigNumber;
+        let recipientOutputBalance: BigNumber;
+
+        beforeEach(async () => {
+            goodBridgeCalls = [];
+            for (let i = 0; i < 4; ++i) {
+                goodBridgeCalls.push(await createBridgeCallAsync({ returnCode: BRIDGE_SUCCESS }));
+            }
+            revertingBridgeCall = await createBridgeCallAsync({ revertError: BRIDGE_REVERT_ERROR });
+            failingBridgeCall = await createBridgeCallAsync({ returnCode: BRIDGE_FAILURE });
+            allBridgeCalls = _.shuffle([failingBridgeCall, revertingBridgeCall, ...goodBridgeCalls]);
+
+            totalFillableInputAmount = BigNumber.sum(...goodBridgeCalls.map(c => c.inputTokenAmount));
+            totalFillableOutputAmount = BigNumber.sum(...goodBridgeCalls.map(c => c.outputTokenAmount));
+
+            // Grant the taker some output tokens.
+            await testContract.setTokenBalance(
+                outputToken,
+                DEFAULTS.toAddress,
+                (recipientOutputBalance = getRandomInteger(1, '100e18')),
+            );
+        });
+
+        async function setForwarderInputBalanceAsync(amount: BigNumber): Promise<void> {
+            await testContract
+                .setTokenBalance(inputToken, testContract.address, amount)
+                .awaitTransactionSuccessAsync({}, { shouldValidate: false });
+        }
+
+        async function createBridgeCallAsync(
+            opts: Partial<{
+                returnCode: string;
+                revertError: string;
+                callFields: Partial<DexForwarderBridgeCall>;
+                outputFillAmount: BigNumber;
+            }>,
+        ): Promise<DexForwarderBridgeCall> {
+            const { returnCode, revertError, callFields, outputFillAmount } = {
+                returnCode: BRIDGE_SUCCESS,
+                revertError: '',
+                ...opts,
+            };
+            const bridge = await callAndTransactAsync(testContract.createBridge(returnCode, revertError));
+            const call = getRandomBridgeCall(bridge, callFields);
+            await testContract
+                .setBridgeTransferAmount(call.target, outputFillAmount || call.outputTokenAmount)
+                .awaitTransactionSuccessAsync({}, { shouldValidate: false });
+            return call;
+        }
+
+        async function callBridgeTransferFromAsync(opts: {
+            bridgeData: string;
+            sellAmount?: BigNumber;
+            buyAmount?: BigNumber;
+        }): Promise<DecodedLogs> {
+            // Fund the forwarder with input tokens to sell.
+            await setForwarderInputBalanceAsync(opts.sellAmount || totalFillableInputAmount);
+            const call = testContract.bridgeTransferFrom(
+                outputToken,
+                testContract.address,
+                DEFAULTS.toAddress,
+                opts.buyAmount || totalFillableOutputAmount,
+                opts.bridgeData,
+            );
+            const returnCode = await call.callAsync();
+            if (returnCode !== BRIDGE_SUCCESS) {
+                throw new Error('Expected BRIDGE_SUCCESS');
+            }
+            const receipt = await call.awaitTransactionSuccessAsync({}, { shouldValidate: false });
+            // tslint:disable-next-line: no-unnecessary-type-assertion
+            return receipt.logs as DecodedLogs;
+        }
+
+        it('succeeds with no bridge calls and no input balance', async () => {
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls: [],
+            });
+            await callBridgeTransferFromAsync({ bridgeData, sellAmount: ZERO_AMOUNT });
+        });
+
+        it('succeeds with bridge calls and no input balance', async () => {
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls: allBridgeCalls,
+            });
+            await callBridgeTransferFromAsync({ bridgeData, sellAmount: ZERO_AMOUNT });
+        });
+
+        it('fails with no bridge calls and an input balance', async () => {
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls: [],
+            });
+            return expect(callBridgeTransferFromAsync({ bridgeData, sellAmount: new BigNumber(1) })).to.revertWith(
+                INCOMPLETE_FILL_REVERT,
+            );
+        });
+
+        it('fails if entire input token balance is not consumed', async () => {
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls: allBridgeCalls,
+            });
+            return expect(
+                callBridgeTransferFromAsync({
+                    bridgeData,
+                    sellAmount: totalFillableInputAmount.plus(1),
+                }),
+            ).to.revertWith(INCOMPLETE_FILL_REVERT);
+        });
+
+        it('fails if not authorized', async () => {
+            const calls = goodBridgeCalls.slice(0, 1);
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            await callAndTransactAsync(testContract.setAuthorized(NULL_ADDRESS));
+            return expect(callBridgeTransferFromAsync({ bridgeData, sellAmount: new BigNumber(1) })).to.revertWith(
+                NOT_AUTHORIZED_REVERT,
+            );
+        });
+
+        it('succeeds with one bridge call', async () => {
+            const calls = goodBridgeCalls.slice(0, 1);
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            await callBridgeTransferFromAsync({ bridgeData, sellAmount: calls[0].inputTokenAmount });
+        });
+
+        it('succeeds with many bridge calls', async () => {
+            const calls = goodBridgeCalls;
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            await callBridgeTransferFromAsync({ bridgeData });
+        });
+
+        it('swallows a failing bridge call', async () => {
+            const calls = _.shuffle([...goodBridgeCalls, failingBridgeCall]);
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            await callBridgeTransferFromAsync({ bridgeData });
+        });
+
+        it('consumes input tokens for output tokens', async () => {
+            const calls = allBridgeCalls;
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            await callBridgeTransferFromAsync({ bridgeData });
+            const currentBridgeInputBalance = await testContract
+                .balanceOf(inputToken, testContract.address)
+                .callAsync();
+            expect(currentBridgeInputBalance).to.bignumber.eq(0);
+            const currentRecipientOutputBalance = await testContract
+                .balanceOf(outputToken, DEFAULTS.toAddress)
+                .callAsync();
+            expect(currentRecipientOutputBalance).to.bignumber.eq(totalFillableOutputAmount);
+        });
+
+        it("transfers only up to each call's input amount to each bridge", async () => {
+            const calls = goodBridgeCalls;
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            const logs = await callBridgeTransferFromAsync({ bridgeData });
+            const btfs = filterLogsToArguments<BtfCalledEventArgs>(logs, TestEvents.BridgeTransferFromCalled);
+            for (const [call, btf] of shortZip(goodBridgeCalls, btfs)) {
+                expect(btf.inputTokenBalance).to.bignumber.eq(call.inputTokenAmount);
+            }
+        });
+
+        it('transfers only up to outstanding sell amount to each bridge', async () => {
+            // Prepend an extra bridge call.
+            const calls = [
+                await createBridgeCallAsync({
+                    callFields: {
+                        inputTokenAmount: new BigNumber(1),
+                        outputTokenAmount: new BigNumber(1),
+                    },
+                }),
+                ...goodBridgeCalls,
+            ];
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            const logs = await callBridgeTransferFromAsync({ bridgeData });
+            const btfs = filterLogsToArguments<BtfCalledEventArgs>(logs, TestEvents.BridgeTransferFromCalled);
+            expect(btfs).to.be.length(goodBridgeCalls.length + 1);
+            // The last call will receive 1 less token.
+            const lastCall = calls.slice(-1)[0];
+            const lastBtf = btfs.slice(-1)[0];
+            expect(lastBtf.inputTokenBalance).to.bignumber.eq(lastCall.inputTokenAmount.minus(1));
+        });
+
+        it('recoups funds from a bridge that fails', async () => {
+            // Prepend a call that will take the whole input amount but will
+            // fail.
+            const badCall = await createBridgeCallAsync({
+                callFields: { inputTokenAmount: totalFillableInputAmount },
+                returnCode: BRIDGE_FAILURE,
+            });
+            const calls = [badCall, ...goodBridgeCalls];
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            const logs = await callBridgeTransferFromAsync({ bridgeData });
+            const btfs = filterLogsToArguments<BtfCalledEventArgs>(logs, TestEvents.BridgeTransferFromCalled);
+            expect(btfs).to.be.length(goodBridgeCalls.length);
+        });
+
+        it('recoups funds from a bridge that reverts', async () => {
+            // Prepend a call that will take the whole input amount but will
+            // revert.
+            const badCall = await createBridgeCallAsync({
+                callFields: { inputTokenAmount: totalFillableInputAmount },
+                revertError: BRIDGE_REVERT_ERROR,
+            });
+            const calls = [badCall, ...goodBridgeCalls];
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            const logs = await callBridgeTransferFromAsync({ bridgeData });
+            const btfs = filterLogsToArguments<BtfCalledEventArgs>(logs, TestEvents.BridgeTransferFromCalled);
+            expect(btfs).to.be.length(goodBridgeCalls.length);
+        });
+
+        it('recoups funds from a bridge that under-pays', async () => {
+            // Prepend a call that will take the whole input amount but will
+            // underpay the output amount..
+            const badCall = await createBridgeCallAsync({
+                callFields: {
+                    inputTokenAmount: totalFillableInputAmount,
+                    outputTokenAmount: new BigNumber(2),
+                },
+                outputFillAmount: new BigNumber(1),
+            });
+            const calls = [badCall, ...goodBridgeCalls];
+            const bridgeData = dexForwarderBridgeDataEncoder.encode({
+                inputToken,
+                calls,
+            });
+            const logs = await callBridgeTransferFromAsync({ bridgeData });
+            const btfs = filterLogsToArguments<BtfCalledEventArgs>(logs, TestEvents.BridgeTransferFromCalled);
+            expect(btfs).to.be.length(goodBridgeCalls.length);
+        });
+    });
+
+    describe('executeBridgeCall()', () => {
+        it('cannot be called externally', async () => {
+            return expect(
+                testContract
+                    .executeBridgeCall(
+                        randomAddress(),
+                        randomAddress(),
+                        randomAddress(),
+                        randomAddress(),
+                        new BigNumber(1),
+                        new BigNumber(1),
+                        constants.NULL_BYTES,
+                    )
+                    .callAsync(),
+            ).to.revertWith('DexForwarderBridge/ONLY_SELF');
+        });
+    });
+});

contracts/asset-proxy/test/uniswapv2_bridge.ts

@@ -0,0 +1,216 @@
+import {
+    blockchainTests,
+    constants,
+    expect,
+    filterLogsToArguments,
+    getRandomInteger,
+    randomAddress,
+} from '@0x/contracts-test-utils';
+import { AssetProxyId } from '@0x/types';
+import { AbiEncoder, BigNumber, hexUtils } from '@0x/utils';
+import { DecodedLogs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { artifacts } from './artifacts';
+
+import {
+    TestUniswapV2BridgeContract,
+    TestUniswapV2BridgeEvents as ContractEvents,
+    TestUniswapV2BridgeSwapExactTokensForTokensInputEventArgs as SwapExactTokensForTokensArgs,
+    TestUniswapV2BridgeTokenApproveEventArgs as TokenApproveArgs,
+    TestUniswapV2BridgeTokenTransferEventArgs as TokenTransferArgs,
+} from './wrappers';
+
+blockchainTests.resets('UniswapV2 unit tests', env => {
+    const FROM_TOKEN_DECIMALS = 6;
+    const TO_TOKEN_DECIMALS = 18;
+    const FROM_TOKEN_BASE = new BigNumber(10).pow(FROM_TOKEN_DECIMALS);
+    const TO_TOKEN_BASE = new BigNumber(10).pow(TO_TOKEN_DECIMALS);
+    let testContract: TestUniswapV2BridgeContract;
+
+    before(async () => {
+        testContract = await TestUniswapV2BridgeContract.deployFrom0xArtifactAsync(
+            artifacts.TestUniswapV2Bridge,
+            env.provider,
+            env.txDefaults,
+            artifacts,
+        );
+    });
+
+    describe('isValidSignature()', () => {
+        it('returns success bytes', async () => {
+            const LEGACY_WALLET_MAGIC_VALUE = '0xb0671381';
+            const result = await testContract
+                .isValidSignature(hexUtils.random(), hexUtils.random(_.random(0, 32)))
+                .callAsync();
+            expect(result).to.eq(LEGACY_WALLET_MAGIC_VALUE);
+        });
+    });
+
+    describe('bridgeTransferFrom()', () => {
+        interface TransferFromOpts {
+            tokenAddressesPath: string[];
+            toAddress: string;
+            // Amount to pass into `bridgeTransferFrom()`
+            amount: BigNumber;
+            // Token balance of the bridge.
+            fromTokenBalance: BigNumber;
+            // Router reverts with this reason
+            routerRevertReason: string;
+        }
+
+        interface TransferFromResult {
+            opts: TransferFromOpts;
+            result: string;
+            logs: DecodedLogs;
+            blocktime: number;
+        }
+
+        function createTransferFromOpts(opts?: Partial<TransferFromOpts>): TransferFromOpts {
+            const amount = getRandomInteger(1, TO_TOKEN_BASE.times(100));
+            return {
+                tokenAddressesPath: Array(2).fill(constants.NULL_ADDRESS),
+                amount,
+                toAddress: randomAddress(),
+                fromTokenBalance: getRandomInteger(1, FROM_TOKEN_BASE.times(100)),
+                routerRevertReason: '',
+                ...opts,
+            };
+        }
+
+        const bridgeDataEncoder = AbiEncoder.create('(address[])');
+
+        async function transferFromAsync(opts?: Partial<TransferFromOpts>): Promise<TransferFromResult> {
+            const _opts = createTransferFromOpts(opts);
+
+            for (let i = 0; i < _opts.tokenAddressesPath.length; i++) {
+                const createFromTokenFn = testContract.createToken(_opts.tokenAddressesPath[i]);
+                _opts.tokenAddressesPath[i] = await createFromTokenFn.callAsync();
+                await createFromTokenFn.awaitTransactionSuccessAsync();
+            }
+
+            // Set the token balance for the token we're converting from.
+            await testContract
+                .setTokenBalance(_opts.tokenAddressesPath[0], _opts.fromTokenBalance)
+                .awaitTransactionSuccessAsync();
+
+            // Set revert reason for the router.
+            await testContract.setRouterRevertReason(_opts.routerRevertReason).awaitTransactionSuccessAsync();
+
+            // Call bridgeTransferFrom().
+            const bridgeTransferFromFn = testContract.bridgeTransferFrom(
+                // Output token
+                _opts.tokenAddressesPath[_opts.tokenAddressesPath.length - 1],
+                // Random maker address.
+                randomAddress(),
+                // Recipient address.
+                _opts.toAddress,
+                // Transfer amount.
+                _opts.amount,
+                // ABI-encode the input token address as the bridge data. // FIXME
+                bridgeDataEncoder.encode([_opts.tokenAddressesPath]),
+            );
+            const result = await bridgeTransferFromFn.callAsync();
+            const receipt = await bridgeTransferFromFn.awaitTransactionSuccessAsync();
+            return {
+                opts: _opts,
+                result,
+                logs: (receipt.logs as any) as DecodedLogs,
+                blocktime: await env.web3Wrapper.getBlockTimestampAsync(receipt.blockNumber),
+            };
+        }
+
+        it('returns magic bytes on success', async () => {
+            const { result } = await transferFromAsync();
+            expect(result).to.eq(AssetProxyId.ERC20Bridge);
+        });
+
+        it('performs transfer when both tokens are the same', async () => {
+            const createTokenFn = testContract.createToken(constants.NULL_ADDRESS);
+            const tokenAddress = await createTokenFn.callAsync();
+            await createTokenFn.awaitTransactionSuccessAsync();
+
+            const { opts, result, logs } = await transferFromAsync({
+                tokenAddressesPath: [tokenAddress, tokenAddress],
+            });
+            expect(result).to.eq(AssetProxyId.ERC20Bridge, 'asset proxy id');
+            const transfers = filterLogsToArguments<TokenTransferArgs>(logs, ContractEvents.TokenTransfer);
+
+            expect(transfers.length).to.eq(1);
+            expect(transfers[0].token).to.eq(tokenAddress, 'input token address');
+            expect(transfers[0].from).to.eq(testContract.address);
+            expect(transfers[0].to).to.eq(opts.toAddress, 'recipient address');
+            expect(transfers[0].amount).to.bignumber.eq(opts.amount, 'amount');
+        });
+
+        describe('token -> token', async () => {
+            it('calls UniswapV2Router01.swapExactTokensForTokens()', async () => {
+                const { opts, result, logs, blocktime } = await transferFromAsync();
+                expect(result).to.eq(AssetProxyId.ERC20Bridge, 'asset proxy id');
+                const transfers = filterLogsToArguments<SwapExactTokensForTokensArgs>(
+                    logs,
+                    ContractEvents.SwapExactTokensForTokensInput,
+                );
+
+                expect(transfers.length).to.eq(1);
+                expect(transfers[0].toTokenAddress).to.eq(
+                    opts.tokenAddressesPath[opts.tokenAddressesPath.length - 1],
+                    'output token address',
+                );
+                expect(transfers[0].to).to.eq(opts.toAddress, 'recipient address');
+                expect(transfers[0].amountIn).to.bignumber.eq(opts.fromTokenBalance, 'input token amount');
+                expect(transfers[0].amountOutMin).to.bignumber.eq(opts.amount, 'output token amount');
+                expect(transfers[0].deadline).to.bignumber.eq(blocktime, 'deadline');
+            });
+
+            it('sets allowance for "from" token', async () => {
+                const { logs } = await transferFromAsync();
+                const approvals = filterLogsToArguments<TokenApproveArgs>(logs, ContractEvents.TokenApprove);
+                const routerAddress = await testContract.getRouterAddress().callAsync();
+                expect(approvals.length).to.eq(1);
+                expect(approvals[0].spender).to.eq(routerAddress);
+                expect(approvals[0].allowance).to.bignumber.eq(constants.MAX_UINT256);
+            });
+
+            it('sets allowance for "from" token on subsequent calls', async () => {
+                const { opts } = await transferFromAsync();
+                const { logs } = await transferFromAsync(opts);
+                const approvals = filterLogsToArguments<TokenApproveArgs>(logs, ContractEvents.TokenApprove);
+                const routerAddress = await testContract.getRouterAddress().callAsync();
+                expect(approvals.length).to.eq(1);
+                expect(approvals[0].spender).to.eq(routerAddress);
+                expect(approvals[0].allowance).to.bignumber.eq(constants.MAX_UINT256);
+            });
+
+            it('fails if the router fails', async () => {
+                const revertReason = 'FOOBAR';
+                const tx = transferFromAsync({
+                    routerRevertReason: revertReason,
+                });
+                return expect(tx).to.eventually.be.rejectedWith(revertReason);
+            });
+        });
+        describe('token -> token -> token', async () => {
+            it('calls UniswapV2Router01.swapExactTokensForTokens()', async () => {
+                const { opts, result, logs, blocktime } = await transferFromAsync({
+                    tokenAddressesPath: Array(3).fill(constants.NULL_ADDRESS),
+                });
+                expect(result).to.eq(AssetProxyId.ERC20Bridge, 'asset proxy id');
+                const transfers = filterLogsToArguments<SwapExactTokensForTokensArgs>(
+                    logs,
+                    ContractEvents.SwapExactTokensForTokensInput,
+                );
+
+                expect(transfers.length).to.eq(1);
+                expect(transfers[0].toTokenAddress).to.eq(
+                    opts.tokenAddressesPath[opts.tokenAddressesPath.length - 1],
+                    'output token address',
+                );
+                expect(transfers[0].to).to.eq(opts.toAddress, 'recipient address');
+                expect(transfers[0].amountIn).to.bignumber.eq(opts.fromTokenBalance, 'input token amount');
+                expect(transfers[0].amountOutMin).to.bignumber.eq(opts.amount, 'output token amount');
+                expect(transfers[0].deadline).to.bignumber.eq(blocktime, 'deadline');
+            });
+        });
+    });
+});

contracts/asset-proxy/test/wrappers.ts

@@ -5,6 +5,7 @@
  */
 export * from '../test/generated-wrappers/chai_bridge';
 export * from '../test/generated-wrappers/curve_bridge';
+export * from '../test/generated-wrappers/dex_forwarder_bridge';
 export * from '../test/generated-wrappers/dydx_bridge';
 export * from '../test/generated-wrappers/erc1155_proxy';
 export * from '../test/generated-wrappers/erc20_bridge_proxy';
@@ -21,20 +22,26 @@ export * from '../test/generated-wrappers/i_dydx';
 export * from '../test/generated-wrappers/i_dydx_bridge';
 export * from '../test/generated-wrappers/i_erc20_bridge';
 export * from '../test/generated-wrappers/i_eth2_dai';
+export * from '../test/generated-wrappers/i_gas_token';
 export * from '../test/generated-wrappers/i_kyber_network_proxy';
 export * from '../test/generated-wrappers/i_uniswap_exchange';
 export * from '../test/generated-wrappers/i_uniswap_exchange_factory';
+export * from '../test/generated-wrappers/i_uniswap_v2_router01';
 export * from '../test/generated-wrappers/kyber_bridge';
 export * from '../test/generated-wrappers/mixin_asset_proxy_dispatcher';
 export * from '../test/generated-wrappers/mixin_authorizable';
+export * from '../test/generated-wrappers/mixin_gas_token';
 export * from '../test/generated-wrappers/multi_asset_proxy';
 export * from '../test/generated-wrappers/ownable';
 export * from '../test/generated-wrappers/static_call_proxy';
 export * from '../test/generated-wrappers/test_chai_bridge';
+export * from '../test/generated-wrappers/test_dex_forwarder_bridge';
 export * from '../test/generated-wrappers/test_dydx_bridge';
 export * from '../test/generated-wrappers/test_erc20_bridge';
 export * from '../test/generated-wrappers/test_eth2_dai_bridge';
 export * from '../test/generated-wrappers/test_kyber_bridge';
 export * from '../test/generated-wrappers/test_static_call_target';
 export * from '../test/generated-wrappers/test_uniswap_bridge';
+export * from '../test/generated-wrappers/test_uniswap_v2_bridge';
 export * from '../test/generated-wrappers/uniswap_bridge';
+export * from '../test/generated-wrappers/uniswap_v2_bridge';

contracts/asset-proxy/tsconfig.json

@@ -5,6 +5,7 @@
     "files": [
         "generated-artifacts/ChaiBridge.json",
         "generated-artifacts/CurveBridge.json",
+        "generated-artifacts/DexForwarderBridge.json",
         "generated-artifacts/DydxBridge.json",
         "generated-artifacts/ERC1155Proxy.json",
         "generated-artifacts/ERC20BridgeProxy.json",
@@ -21,25 +22,32 @@
         "generated-artifacts/IDydxBridge.json",
         "generated-artifacts/IERC20Bridge.json",
         "generated-artifacts/IEth2Dai.json",
+        "generated-artifacts/IGasToken.json",
         "generated-artifacts/IKyberNetworkProxy.json",
         "generated-artifacts/IUniswapExchange.json",
         "generated-artifacts/IUniswapExchangeFactory.json",
+        "generated-artifacts/IUniswapV2Router01.json",
         "generated-artifacts/KyberBridge.json",
         "generated-artifacts/MixinAssetProxyDispatcher.json",
         "generated-artifacts/MixinAuthorizable.json",
+        "generated-artifacts/MixinGasToken.json",
         "generated-artifacts/MultiAssetProxy.json",
         "generated-artifacts/Ownable.json",
         "generated-artifacts/StaticCallProxy.json",
         "generated-artifacts/TestChaiBridge.json",
+        "generated-artifacts/TestDexForwarderBridge.json",
         "generated-artifacts/TestDydxBridge.json",
         "generated-artifacts/TestERC20Bridge.json",
         "generated-artifacts/TestEth2DaiBridge.json",
         "generated-artifacts/TestKyberBridge.json",
         "generated-artifacts/TestStaticCallTarget.json",
         "generated-artifacts/TestUniswapBridge.json",
+        "generated-artifacts/TestUniswapV2Bridge.json",
         "generated-artifacts/UniswapBridge.json",
+        "generated-artifacts/UniswapV2Bridge.json",
         "test/generated-artifacts/ChaiBridge.json",
         "test/generated-artifacts/CurveBridge.json",
+        "test/generated-artifacts/DexForwarderBridge.json",
         "test/generated-artifacts/DydxBridge.json",
         "test/generated-artifacts/ERC1155Proxy.json",
         "test/generated-artifacts/ERC20BridgeProxy.json",
@@ -56,23 +64,29 @@
         "test/generated-artifacts/IDydxBridge.json",
         "test/generated-artifacts/IERC20Bridge.json",
         "test/generated-artifacts/IEth2Dai.json",
+        "test/generated-artifacts/IGasToken.json",
         "test/generated-artifacts/IKyberNetworkProxy.json",
         "test/generated-artifacts/IUniswapExchange.json",
         "test/generated-artifacts/IUniswapExchangeFactory.json",
+        "test/generated-artifacts/IUniswapV2Router01.json",
         "test/generated-artifacts/KyberBridge.json",
         "test/generated-artifacts/MixinAssetProxyDispatcher.json",
         "test/generated-artifacts/MixinAuthorizable.json",
+        "test/generated-artifacts/MixinGasToken.json",
         "test/generated-artifacts/MultiAssetProxy.json",
         "test/generated-artifacts/Ownable.json",
         "test/generated-artifacts/StaticCallProxy.json",
         "test/generated-artifacts/TestChaiBridge.json",
+        "test/generated-artifacts/TestDexForwarderBridge.json",
         "test/generated-artifacts/TestDydxBridge.json",
         "test/generated-artifacts/TestERC20Bridge.json",
         "test/generated-artifacts/TestEth2DaiBridge.json",
         "test/generated-artifacts/TestKyberBridge.json",
         "test/generated-artifacts/TestStaticCallTarget.json",
         "test/generated-artifacts/TestUniswapBridge.json",
-        "test/generated-artifacts/UniswapBridge.json"
+        "test/generated-artifacts/TestUniswapV2Bridge.json",
+        "test/generated-artifacts/UniswapBridge.json",
+        "test/generated-artifacts/UniswapV2Bridge.json"
     ],
     "exclude": ["./deploy/solc/solc_bin"]
 }

contracts/broker/CHANGELOG.json

@@ -1,4 +1,41 @@
 [
+    {
+        "version": "1.1.5",
+        "changes": [
+            {
+                "note": "Fix broken tests.",
+                "pr": 2591
+            }
+        ],
+        "timestamp": 1592969527
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "1.1.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "1.1.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "1.1.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "1.1.1",

contracts/broker/CHANGELOG.md

@@ -5,6 +5,22 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v1.1.5 - _June 24, 2020_
+
+    * Fix broken tests. (#2591)
+
+## v1.1.4 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v1.1.3 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v1.1.2 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v1.1.1 - _February 25, 2020_
 
     * Dependencies updated

contracts/broker/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/broker/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-broker",
-    "version": "1.1.1",
+    "version": "1.1.5",
     "engines": {
         "node": ">=6.12"
     },
@@ -51,20 +51,20 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/extensions/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-asset-proxy": "^3.2.2",
-        "@0x/contracts-erc20": "^3.1.2",
-        "@0x/contracts-erc721": "^3.1.2",
-        "@0x/contracts-exchange": "^3.2.2",
-        "@0x/contracts-exchange-libs": "^4.3.2",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contracts-asset-proxy": "^3.3.0",
+        "@0x/contracts-erc20": "^3.2.0",
+        "@0x/contracts-erc721": "^3.1.6",
+        "@0x/contracts-exchange": "^3.2.6",
+        "@0x/contracts-exchange-libs": "^4.3.6",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/types": "^3.1.2",
-        "@0x/web3-wrapper": "^7.0.7",
+        "@0x/types": "^3.1.3",
+        "@0x/web3-wrapper": "^7.1.0",
         "@types/lodash": "4.14.104",
         "@types/mocha": "^5.2.7",
         "@types/node": "*",
@@ -84,11 +84,11 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1",
-        "@0x/order-utils": "^10.2.2",
-        "@0x/typescript-typings": "^5.0.2",
-        "@0x/utils": "^5.4.1",
-        "ethereum-types": "^3.1.0"
+        "@0x/base-contract": "^6.2.2",
+        "@0x/order-utils": "^10.2.5",
+        "@0x/typescript-typings": "^5.1.0",
+        "@0x/utils": "^5.5.0",
+        "ethereum-types": "^3.1.1"
     },
     "publishConfig": {
         "access": "public"

contracts/broker/test/gods_unchained_validator_test.ts

@@ -44,13 +44,13 @@ blockchainTests.resets('GodsUnchainedValidator unit tests', env => {
             const tokenId = getRandomInteger(0, constants.MAX_UINT256);
             await godsUnchained.setTokenProperties(tokenId, proto.plus(1), quality).awaitTransactionSuccessAsync();
             const tx = validator.checkBrokerAsset(tokenId, propertyData).callAsync();
-            expect(tx).to.revertWith('PROTO_MISMATCH');
+            expect(tx).to.revertWith('GodsUnchainedValidator/PROTO_MISMATCH');
         });
         it("reverts if assetData quality doesn't match proeprtyData", async () => {
             const tokenId = getRandomInteger(0, constants.MAX_UINT256);
             await godsUnchained.setTokenProperties(tokenId, proto, quality.plus(1)).awaitTransactionSuccessAsync();
             const tx = validator.checkBrokerAsset(tokenId, propertyData).callAsync();
-            expect(tx).to.revertWith('QUALITY_MISMATCH');
+            expect(tx).to.revertWith('GodsUnchainedValidator/QUALITY_MISMATCH');
         });
     });
 });

contracts/coordinator/CHANGELOG.json

@@ -1,4 +1,40 @@
 [
+    {
+        "timestamp": 1592969527,
+        "version": "3.1.6",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "3.1.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "3.1.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "3.1.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "3.1.2",

contracts/coordinator/CHANGELOG.md

@@ -5,6 +5,22 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.1.6 - _June 24, 2020_
+
+    * Dependencies updated
+
+## v3.1.5 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v3.1.4 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v3.1.3 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v3.1.2 - _February 25, 2020_
 
     * Dependencies updated

contracts/coordinator/compiler.json

@@ -2,6 +2,7 @@
     "artifactsDir": "./test/generated-artifacts",
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/coordinator/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-coordinator",
-    "version": "3.1.2",
+    "version": "3.1.6",
     "engines": {
         "node": ">=6.12"
     },
@@ -52,19 +52,19 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/extensions/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-asset-proxy": "^3.2.2",
-        "@0x/contracts-dev-utils": "^1.3.0",
-        "@0x/contracts-erc20": "^3.1.2",
-        "@0x/contracts-exchange": "^3.2.2",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/dev-utils": "^3.2.1",
-        "@0x/order-utils": "^10.2.2",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contracts-asset-proxy": "^3.3.0",
+        "@0x/contracts-dev-utils": "^1.3.4",
+        "@0x/contracts-erc20": "^3.2.0",
+        "@0x/contracts-exchange": "^3.2.6",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/dev-utils": "^3.2.2",
+        "@0x/order-utils": "^10.2.5",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/web3-wrapper": "^7.0.7",
+        "@0x/web3-wrapper": "^7.1.0",
         "@types/lodash": "4.14.104",
         "@types/mocha": "^5.2.7",
         "@types/node": "*",
@@ -84,15 +84,15 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/assert": "^3.0.7",
-        "@0x/base-contract": "^6.2.1",
-        "@0x/contract-addresses": "^4.7.0",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/json-schemas": "^5.0.7",
-        "@0x/types": "^3.1.2",
-        "@0x/typescript-typings": "^5.0.2",
-        "@0x/utils": "^5.4.1",
-        "ethereum-types": "^3.1.0",
+        "@0x/assert": "^3.0.8",
+        "@0x/base-contract": "^6.2.2",
+        "@0x/contract-addresses": "^4.10.0",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/json-schemas": "^5.0.8",
+        "@0x/types": "^3.1.3",
+        "@0x/typescript-typings": "^5.1.0",
+        "@0x/utils": "^5.5.0",
+        "ethereum-types": "^3.1.1",
         "http-status-codes": "^1.3.2"
     },
     "publishConfig": {

contracts/dev-utils/CHANGELOG.json

@@ -1,4 +1,40 @@
 [
+    {
+        "timestamp": 1592969527,
+        "version": "1.3.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "1.3.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "1.3.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "1.3.1",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "version": "1.3.0",
         "changes": [

contracts/dev-utils/CHANGELOG.md

@@ -5,6 +5,22 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v1.3.4 - _June 24, 2020_
+
+    * Dependencies updated
+
+## v1.3.3 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v1.3.2 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v1.3.1 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v1.3.0 - _February 25, 2020_
 
     * Update `DevUtils` addresses in `DeploymentConstants` (#2493)

contracts/dev-utils/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/dev-utils/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-dev-utils",
-    "version": "1.3.0",
+    "version": "1.3.4",
     "engines": {
         "node": ">=6.12"
     },
@@ -41,19 +41,19 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/dev-utils/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/assert": "^3.0.7",
-        "@0x/contracts-asset-proxy": "^3.2.2",
-        "@0x/contracts-erc20": "^3.1.2",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/assert": "^3.0.8",
+        "@0x/contracts-asset-proxy": "^3.3.0",
+        "@0x/contracts-erc20": "^3.2.0",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/types": "^3.1.2",
-        "@0x/utils": "^5.4.1",
+        "@0x/types": "^3.1.3",
+        "@0x/utils": "^5.5.0",
         "@types/node": "*",
-        "ethereum-types": "^3.1.0",
+        "ethereum-types": "^3.1.1",
         "ethers": "~4.0.4",
         "npm-run-all": "^4.1.2",
         "shx": "^0.2.2",
@@ -64,7 +64,7 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1"
+        "@0x/base-contract": "^6.2.2"
     },
     "publishConfig": {
         "access": "public"

contracts/erc1155/CHANGELOG.json

@@ -1,4 +1,40 @@
 [
+    {
+        "timestamp": 1592969527,
+        "version": "2.1.6",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "2.1.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "2.1.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "2.1.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "2.1.2",

contracts/erc1155/CHANGELOG.md

@@ -5,6 +5,22 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v2.1.6 - _June 24, 2020_
+
+    * Dependencies updated
+
+## v2.1.5 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v2.1.4 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v2.1.3 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v2.1.2 - _February 25, 2020_
 
     * Dependencies updated

contracts/erc1155/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/erc1155/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-erc1155",
-    "version": "2.1.2",
+    "version": "2.1.6",
     "engines": {
         "node": ">=6.12"
     },
@@ -52,15 +52,15 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/tokens/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/dev-utils": "^3.2.1",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/dev-utils": "^3.2.2",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/types": "^3.1.2",
-        "@0x/typescript-typings": "^5.0.2",
+        "@0x/types": "^3.1.3",
+        "@0x/typescript-typings": "^5.1.0",
         "@types/lodash": "4.14.104",
         "@types/mocha": "^5.2.7",
         "@types/node": "*",
@@ -68,7 +68,7 @@
         "chai-as-promised": "^7.1.0",
         "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
-        "ethereum-types": "^3.1.0",
+        "ethereum-types": "^3.1.1",
         "make-promises-safe": "^1.1.0",
         "mocha": "^6.2.0",
         "npm-run-all": "^4.1.2",
@@ -80,10 +80,10 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/utils": "^5.4.1",
-        "@0x/web3-wrapper": "^7.0.7",
+        "@0x/base-contract": "^6.2.2",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/utils": "^5.5.0",
+        "@0x/web3-wrapper": "^7.1.0",
         "lodash": "^4.17.11"
     },
     "publishConfig": {

contracts/erc20-bridge-sampler/CHANGELOG.json

@@ -1,4 +1,66 @@
 [
+    {
+        "version": "1.6.0",
+        "changes": [
+            {
+                "note": "Pass in `DevUtils` address as a constructor parameter",
+                "pr": 2531
+            },
+            {
+                "note": "Sample `Curve` for buy amounts",
+                "pr": 2551
+            },
+            {
+                "note": "Added `sampleBuysFromKyberNetwork`",
+                "pr": 2551
+            },
+            {
+                "note": "Use `searchBestRate` in Kyber samples. Return 0 when Uniswap/Eth2Dai reserve",
+                "pr": 2575
+            },
+            {
+                "note": "Add UniswapV2",
+                "pr": 2595
+            },
+            {
+                "note": "Sample from MultiBridge",
+                "pr": 2593
+            }
+        ],
+        "timestamp": 1592969527
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "1.5.1",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "version": "1.5.0",
+        "changes": [
+            {
+                "note": "Add generic liquidity provider sampling",
+                "pr": 2487
+            },
+            {
+                "note": "Use liquidity provider registry in sampler",
+                "pr": 2499
+            }
+        ],
+        "timestamp": 1582837861
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "1.4.2",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "1.4.1",

contracts/erc20-bridge-sampler/CHANGELOG.md

@@ -5,6 +5,28 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v1.6.0 - _June 24, 2020_
+
+    * Pass in `DevUtils` address as a constructor parameter (#2531)
+    * Sample `Curve` for buy amounts (#2551)
+    * Added `sampleBuysFromKyberNetwork` (#2551)
+    * Use `searchBestRate` in Kyber samples. Return 0 when Uniswap/Eth2Dai reserve (#2575)
+    * Add UniswapV2 (#2595)
+    * Sample from MultiBridge (#2593)
+
+## v1.5.1 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v1.5.0 - _February 27, 2020_
+
+    * Add generic liquidity provider sampling (#2487)
+    * Use liquidity provider registry in sampler (#2499)
+
+## v1.4.2 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v1.4.1 - _February 25, 2020_
 
     * Dependencies updated

contracts/erc20-bridge-sampler/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/erc20-bridge-sampler/contracts/src/DummyLiquidityProvider.sol

@@ -0,0 +1,38 @@
+pragma solidity ^0.5.9;
+pragma experimental ABIEncoderV2;
+
+
+contract DummyLiquidityProvider
+{
+    /// @dev Quotes the amount of `makerToken` that would be obtained by
+    ///      selling `sellAmount` of `takerToken`.
+    /// @param sellAmount Amount of `takerToken` to sell.
+    /// @return makerTokenAmount Amount of `makerToken` that would be obtained.
+    function getSellQuote(
+        address, /* takerToken */
+        address, /* makerToken */
+        uint256 sellAmount
+    )
+        external
+        view
+        returns (uint256 makerTokenAmount)
+    {
+        makerTokenAmount = sellAmount - 1;
+    }
+
+    /// @dev Quotes the amount of `takerToken` that would need to be sold in
+    ///      order to obtain `buyAmount` of `makerToken`.
+    /// @param buyAmount Amount of `makerToken` to buy.
+    /// @return takerTokenAmount Amount of `takerToken` that would need to be sold.
+    function getBuyQuote(
+        address, /* takerToken */
+        address, /* makerToken */
+        uint256 buyAmount
+    )
+        external
+        view
+        returns (uint256 takerTokenAmount)
+    {
+        takerTokenAmount = buyAmount + 1;
+    }
+}

contracts/erc20-bridge-sampler/contracts/src/DummyLiquidityProviderRegistry.sol

@@ -0,0 +1,44 @@
+pragma solidity ^0.5.9;
+pragma experimental ABIEncoderV2;
+
+
+contract DummyLiquidityProviderRegistry
+{
+    address private constant NULL_ADDRESS = address(0x0);
+
+    mapping (address => mapping (address => address)) internal _gAddressBook;
+
+    /// @dev Sets address of pool for a market given market (xAsset, yAsset).
+    /// @param xToken First asset managed by pool.
+    /// @param yToken Second asset managed by pool.
+    /// @param poolAddress Address of pool.
+    function setLiquidityProviderForMarket(
+        address xToken,
+        address yToken,
+        address poolAddress
+    )
+        external
+    {
+        _gAddressBook[xToken][yToken] = poolAddress;
+        _gAddressBook[yToken][xToken] = poolAddress;
+    }
+
+    /// @dev Returns the address of pool for a market given market (xAsset, yAsset), or reverts if pool does not exist.
+    /// @param xToken First asset managed by pool.
+    /// @param yToken Second asset managed by pool.
+    /// @return Address of pool.
+    function getLiquidityProviderForMarket(
+        address xToken,
+        address yToken
+    )
+        external
+        view
+        returns (address poolAddress)
+    {
+        poolAddress = _gAddressBook[xToken][yToken];
+        require(
+            poolAddress != NULL_ADDRESS,
+            "Registry/MARKET_PAIR_NOT_SET"
+        );
+    }
+}

contracts/erc20-bridge-sampler/contracts/src/ERC20BridgeSampler.sol

@@ -24,12 +24,18 @@ import "@0x/contracts-erc20/contracts/src/LibERC20Token.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibOrder.sol";
 import "@0x/contracts-exchange-libs/contracts/src/LibMath.sol";
 import "@0x/contracts-utils/contracts/src/DeploymentConstants.sol";
+import "@0x/contracts-utils/contracts/src/LibBytes.sol";
 import "./IDevUtils.sol";
 import "./IERC20BridgeSampler.sol";
 import "./IEth2Dai.sol";
 import "./IKyberNetwork.sol";
+import "./IKyberNetworkProxy.sol";
 import "./IUniswapExchangeQuotes.sol";
 import "./ICurve.sol";
+import "./ILiquidityProvider.sol";
+import "./ILiquidityProviderRegistry.sol";
+import "./IUniswapV2Router01.sol";
+import "./IMultiBridge.sol";
 
 
 contract ERC20BridgeSampler is
@@ -42,11 +48,25 @@ contract ERC20BridgeSampler is
     uint256 constant internal KYBER_CALL_GAS = 1500e3; // 1.5m
     /// @dev Gas limit for Uniswap calls.
     uint256 constant internal UNISWAP_CALL_GAS = 150e3; // 150k
+    /// @dev Gas limit for UniswapV2 calls.
+    uint256 constant internal UNISWAPV2_CALL_GAS = 150e3; // 150k
     /// @dev Base gas limit for Eth2Dai calls.
     uint256 constant internal ETH2DAI_CALL_GAS = 1000e3; // 1m
     /// @dev Base gas limit for Curve calls. Some Curves have multiple tokens
     ///      So a reasonable ceil is 150k per token. Biggest Curve has 4 tokens.
     uint256 constant internal CURVE_CALL_GAS = 600e3; // 600k
+    /// @dev Default gas limit for liquidity provider calls.
+    uint256 constant internal DEFAULT_CALL_GAS = 400e3; // 400k
+    /// @dev The Kyber Uniswap Reserve address
+    address constant internal KYBER_UNIWAP_RESERVE = 0x31E085Afd48a1d6e51Cc193153d625e8f0514C7F;
+    /// @dev The Kyber Eth2Dai Reserve address
+    address constant internal KYBER_ETH2DAI_RESERVE = 0x1E158c0e93c30d24e918Ef83d1e0bE23595C3c0f;
+
+    address private _devUtilsAddress;
+
+    constructor(address devUtilsAddress) public {
+        _devUtilsAddress = devUtilsAddress;
+    }
 
     /// @dev Call multiple public functions on this contract in a single transaction.
     /// @param callDatas ABI-encoded call data for each function call.
@@ -82,6 +102,7 @@ contract ERC20BridgeSampler is
         returns (uint256[] memory orderFillableTakerAssetAmounts)
     {
         orderFillableTakerAssetAmounts = new uint256[](orders.length);
+        address devUtilsAddress = _devUtilsAddress;
         for (uint256 i = 0; i != orders.length; i++) {
             // Ignore orders with no signature or empty maker/taker amounts.
             if (orderSignatures[i].length == 0 ||
@@ -92,11 +113,11 @@ contract ERC20BridgeSampler is
             }
             // solhint-disable indent
             (bool didSucceed, bytes memory resultData) =
-                _getDevUtilsAddress()
+                devUtilsAddress
                     .staticcall
                     .gas(DEV_UTILS_CALL_GAS)
                     (abi.encodeWithSelector(
-                       IDevUtils(_getDevUtilsAddress()).getOrderRelevantState.selector,
+                       IDevUtils(devUtilsAddress).getOrderRelevantState.selector,
                        orders[i],
                        orderSignatures[i]
                     ));
@@ -171,36 +192,63 @@ contract ERC20BridgeSampler is
         returns (uint256[] memory makerTokenAmounts)
     {
         _assertValidPair(makerToken, takerToken);
-        address _takerToken = takerToken == _getWethAddress() ? KYBER_ETH_ADDRESS : takerToken;
-        address _makerToken = makerToken == _getWethAddress() ? KYBER_ETH_ADDRESS : makerToken;
-        uint256 takerTokenDecimals = _getTokenDecimals(takerToken);
-        uint256 makerTokenDecimals = _getTokenDecimals(makerToken);
         uint256 numSamples = takerTokenAmounts.length;
         makerTokenAmounts = new uint256[](numSamples);
+        address wethAddress = _getWethAddress();
+        uint256 value;
+        address reserve;
         for (uint256 i = 0; i < numSamples; i++) {
-            (bool didSucceed, bytes memory resultData) =
-                _getKyberNetworkProxyAddress().staticcall.gas(KYBER_CALL_GAS)(
-                    abi.encodeWithSelector(
-                        IKyberNetwork(0).getExpectedRate.selector,
-                        _takerToken,
-                        _makerToken,
-                        takerTokenAmounts[i]
-                    ));
-            uint256 rate = 0;
-            if (didSucceed) {
-                rate = abi.decode(resultData, (uint256));
+            if (takerToken == wethAddress || makerToken == wethAddress) {
+                // Direct ETH based trade
+                (value, reserve) = _sampleSellFromKyberNetwork(takerToken, makerToken, takerTokenAmounts[i]);
+                // If this fills on an on-chain reserve we remove it as that can introduce collisions
+                if (reserve == KYBER_UNIWAP_RESERVE || reserve == KYBER_ETH2DAI_RESERVE) {
+                    value = 0;
+                }
             } else {
-                break;
+                // Hop to ETH
+                (value, reserve) = _sampleSellFromKyberNetwork(takerToken, wethAddress, takerTokenAmounts[i]);
+                if (value != 0) {
+                    address otherReserve;
+                    (value, otherReserve) = _sampleSellFromKyberNetwork(wethAddress, makerToken, value);
+                    // If this fills on Eth2Dai it is ok as we queried a different market
+                    // If this fills on Uniswap on both legs then this is a hard collision
+                    if (reserve == KYBER_UNIWAP_RESERVE && reserve == otherReserve) {
+                        value = 0;
+                    }
+                }
             }
-            makerTokenAmounts[i] =
-                rate *
-                takerTokenAmounts[i] *
-                10 ** makerTokenDecimals /
-                10 ** takerTokenDecimals /
-                10 ** 18;
+            makerTokenAmounts[i] = value;
         }
     }
 
+    /// @dev Sample buy quotes from Kyber.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
+    /// @param opts `FakeBuyOptions` specifying target slippage and max iterations.
+    /// @return takerTokenAmounts Taker amounts sold at each maker token
+    ///         amount.
+    function sampleBuysFromKyberNetwork(
+        address takerToken,
+        address makerToken,
+        uint256[] memory makerTokenAmounts,
+        FakeBuyOptions memory opts
+    )
+        public
+        view
+        returns (uint256[] memory takerTokenAmounts)
+    {
+        return _sampleApproximateBuysFromSource(
+            takerToken,
+            makerToken,
+            makerTokenAmounts,
+            opts,
+            this.sampleSellsFromKyberNetwork.selector,
+            address(0) // PLP registry address
+        );
+    }
+
     /// @dev Sample sell quotes from Eth2Dai/Oasis.
     /// @param takerToken Address of the taker token (what to sell).
     /// @param makerToken Address of the maker token (what to buy).
@@ -238,6 +286,31 @@ contract ERC20BridgeSampler is
         }
     }
 
+    /// @dev Sample sell quotes from Eth2Dai/Oasis using a hop to an intermediate token.
+    ///      I.e WBTC/DAI via ETH or WBTC/ETH via DAI
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param intermediateToken Address of the token to hop to.
+    /// @param takerTokenAmounts Taker token sell amount for each sample.
+    /// @return makerTokenAmounts Maker amounts bought at each taker token
+    ///         amount.
+    function sampleSellsFromEth2DaiHop(
+        address takerToken,
+        address makerToken,
+        address intermediateToken,
+        uint256[] memory takerTokenAmounts
+    )
+        public
+        view
+        returns (uint256[] memory makerTokenAmounts)
+    {
+        if (makerToken == intermediateToken || takerToken == intermediateToken) {
+            return makerTokenAmounts;
+        }
+        uint256[] memory intermediateAmounts = sampleSellsFromEth2Dai(takerToken, intermediateToken, takerTokenAmounts);
+        makerTokenAmounts = sampleSellsFromEth2Dai(intermediateToken, makerToken, intermediateAmounts);
+    }
+
     /// @dev Sample buy quotes from Eth2Dai/Oasis.
     /// @param takerToken Address of the taker token (what to sell).
     /// @param makerToken Address of the maker token (what to buy).
@@ -431,6 +504,269 @@ contract ERC20BridgeSampler is
         }
     }
 
+    /// @dev Sample buy quotes from Curve.
+    /// @param curveAddress Address of the Curve contract.
+    /// @param fromTokenIdx Index of the taker token (what to sell).
+    /// @param toTokenIdx Index of the maker token (what to buy).
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
+    /// @return takerTokenAmounts Taker amounts sold at each maker token
+    ///         amount.
+    function sampleBuysFromCurve(
+        address curveAddress,
+        int128 fromTokenIdx,
+        int128 toTokenIdx,
+        uint256[] memory makerTokenAmounts
+    )
+        public
+        view
+        returns (uint256[] memory takerTokenAmounts)
+    {
+        uint256 numSamples = makerTokenAmounts.length;
+        takerTokenAmounts = new uint256[](numSamples);
+        for (uint256 i = 0; i < numSamples; i++) {
+            (bool didSucceed, bytes memory resultData) =
+                curveAddress.staticcall.gas(CURVE_CALL_GAS)(
+                    abi.encodeWithSelector(
+                        ICurve(0).get_dx_underlying.selector,
+                        fromTokenIdx,
+                        toTokenIdx,
+                        makerTokenAmounts[i]
+                    ));
+            uint256 sellAmount = 0;
+            if (didSucceed) {
+                sellAmount = abi.decode(resultData, (uint256));
+            } else {
+                break;
+            }
+            takerTokenAmounts[i] = sellAmount;
+        }
+    }
+
+    /// @dev Sample sell quotes from an arbitrary on-chain liquidity provider.
+    /// @param registryAddress Address of the liquidity provider registry contract.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param takerTokenAmounts Taker token sell amount for each sample.
+    /// @return makerTokenAmounts Maker amounts bought at each taker token
+    ///         amount.
+    function sampleSellsFromLiquidityProviderRegistry(
+        address registryAddress,
+        address takerToken,
+        address makerToken,
+        uint256[] memory takerTokenAmounts
+    )
+        public
+        view
+        returns (uint256[] memory makerTokenAmounts)
+    {
+        // Initialize array of maker token amounts.
+        uint256 numSamples = takerTokenAmounts.length;
+        makerTokenAmounts = new uint256[](numSamples);
+
+        // Query registry for provider address.
+        address providerAddress = getLiquidityProviderFromRegistry(
+            registryAddress,
+            takerToken,
+            makerToken
+        );
+        // If provider doesn't exist, return all zeros.
+        if (providerAddress == address(0)) {
+            return makerTokenAmounts;
+        }
+
+        for (uint256 i = 0; i < numSamples; i++) {
+            (bool didSucceed, bytes memory resultData) =
+                providerAddress.staticcall.gas(DEFAULT_CALL_GAS)(
+                    abi.encodeWithSelector(
+                        ILiquidityProvider(0).getSellQuote.selector,
+                        takerToken,
+                        makerToken,
+                        takerTokenAmounts[i]
+                    ));
+            uint256 buyAmount = 0;
+            if (didSucceed) {
+                buyAmount = abi.decode(resultData, (uint256));
+            } else {
+                // Exit early if the amount is too high for the liquidity provider to serve
+                break;
+            }
+            makerTokenAmounts[i] = buyAmount;
+        }
+    }
+
+    /// @dev Sample sell quotes from MultiBridge.
+    /// @param multibridge Address of the MultiBridge contract.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param intermediateToken The address of the intermediate token to
+    ///        use in an indirect route.
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param takerTokenAmounts Taker token sell amount for each sample.
+    /// @return makerTokenAmounts Maker amounts bought at each taker token
+    ///         amount.
+    function sampleSellsFromMultiBridge(
+        address multibridge,
+        address takerToken,
+        address intermediateToken,
+        address makerToken,
+        uint256[] memory takerTokenAmounts
+    )
+        public
+        view
+        returns (uint256[] memory makerTokenAmounts)
+    {
+        // Initialize array of maker token amounts.
+        uint256 numSamples = takerTokenAmounts.length;
+        makerTokenAmounts = new uint256[](numSamples);
+
+        // If no address provided, return all zeros.
+        if (multibridge == address(0)) {
+            return makerTokenAmounts;
+        }
+
+        for (uint256 i = 0; i < numSamples; i++) {
+            (bool didSucceed, bytes memory resultData) =
+                multibridge.staticcall.gas(DEFAULT_CALL_GAS)(
+                    abi.encodeWithSelector(
+                        IMultiBridge(0).getSellQuote.selector,
+                        takerToken,
+                        intermediateToken,
+                        makerToken,
+                        takerTokenAmounts[i]
+                    ));
+            uint256 buyAmount = 0;
+            if (didSucceed) {
+                buyAmount = abi.decode(resultData, (uint256));
+            } else {
+                // Exit early if the amount is too high for the liquidity provider to serve
+                break;
+            }
+            makerTokenAmounts[i] = buyAmount;
+        }
+    }
+
+    /// @dev Sample buy quotes from an arbitrary on-chain liquidity provider.
+    /// @param registryAddress Address of the liquidity provider registry contract.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
+    /// @param opts `FakeBuyOptions` specifying target slippage and max iterations.
+    /// @return takerTokenAmounts Taker amounts sold at each maker token
+    ///         amount.
+    function sampleBuysFromLiquidityProviderRegistry(
+        address registryAddress,
+        address takerToken,
+        address makerToken,
+        uint256[] memory makerTokenAmounts,
+        FakeBuyOptions memory opts
+    )
+        public
+        view
+        returns (uint256[] memory takerTokenAmounts)
+    {
+        return _sampleApproximateBuysFromSource(
+            takerToken,
+            makerToken,
+            makerTokenAmounts,
+            opts,
+            this.sampleSellsFromLiquidityProviderRegistry.selector,
+            registryAddress
+        );
+    }
+
+    /// @dev Returns the address of a liquidity provider for the given market
+    ///      (takerToken, makerToken), from a registry of liquidity providers.
+    ///      Returns address(0) if no such provider exists in the registry.
+    /// @param takerToken Taker asset managed by liquidity provider.
+    /// @param makerToken Maker asset managed by liquidity provider.
+    /// @return providerAddress Address of the liquidity provider.
+    function getLiquidityProviderFromRegistry(
+        address registryAddress,
+        address takerToken,
+        address makerToken
+    )
+        public
+        view
+        returns (address providerAddress)
+    {
+        bytes memory callData = abi.encodeWithSelector(
+            ILiquidityProviderRegistry(0).getLiquidityProviderForMarket.selector,
+            takerToken,
+            makerToken
+        );
+        (bool didSucceed, bytes memory returnData) = registryAddress.staticcall(callData);
+        if (didSucceed && returnData.length == 32) {
+            return LibBytes.readAddress(returnData, 12);
+        }
+    }
+
+    /// @dev Sample sell quotes from UniswapV2.
+    /// @param path Token route. Should be takerToken -> makerToken
+    /// @param takerTokenAmounts Taker token sell amount for each sample.
+    /// @return makerTokenAmounts Maker amounts bought at each taker token
+    ///         amount.
+    function sampleSellsFromUniswapV2(
+        address[] memory path,
+        uint256[] memory takerTokenAmounts
+    )
+        public
+        view
+        returns (uint256[] memory makerTokenAmounts)
+    {
+        uint256 numSamples = takerTokenAmounts.length;
+        makerTokenAmounts = new uint256[](numSamples);
+        for (uint256 i = 0; i < numSamples; i++) {
+            (bool didSucceed, bytes memory resultData) =
+                _getUniswapV2Router01Address().staticcall.gas(UNISWAPV2_CALL_GAS)(
+                    abi.encodeWithSelector(
+                        IUniswapV2Router01(0).getAmountsOut.selector,
+                        takerTokenAmounts[i],
+                        path
+                    ));
+            uint256 buyAmount = 0;
+            if (didSucceed) {
+                // solhint-disable-next-line indent
+                buyAmount = abi.decode(resultData, (uint256[]))[path.length - 1];
+            } else {
+                break;
+            }
+            makerTokenAmounts[i] = buyAmount;
+        }
+    }
+
+    /// @dev Sample buy quotes from UniswapV2.
+    /// @param path Token route. Should be takerToken -> makerToken.
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
+    /// @return takerTokenAmounts Taker amounts sold at each maker token
+    ///         amount.
+    function sampleBuysFromUniswapV2(
+        address[] memory path,
+        uint256[] memory makerTokenAmounts
+    )
+        public
+        view
+        returns (uint256[] memory takerTokenAmounts)
+    {
+        uint256 numSamples = makerTokenAmounts.length;
+        takerTokenAmounts = new uint256[](numSamples);
+        for (uint256 i = 0; i < numSamples; i++) {
+            (bool didSucceed, bytes memory resultData) =
+                _getUniswapV2Router01Address().staticcall.gas(UNISWAPV2_CALL_GAS)(
+                    abi.encodeWithSelector(
+                        IUniswapV2Router01(0).getAmountsIn.selector,
+                        makerTokenAmounts[i],
+                        path
+                    ));
+            uint256 sellAmount = 0;
+            if (didSucceed) {
+                // solhint-disable-next-line indent
+                sellAmount = abi.decode(resultData, (uint256[]))[0];
+            } else {
+                break;
+            }
+            takerTokenAmounts[i] = sellAmount;
+        }
+    }
+
     /// @dev Overridable way to get token decimals.
     /// @param tokenAddress Address of the token.
     /// @return decimals The decimal places for the token.
@@ -496,4 +832,178 @@ contract ERC20BridgeSampler is
     {
         require(makerToken != takerToken, "ERC20BridgeSampler/INVALID_TOKEN_PAIR");
     }
+
+    function _sampleSellForApproximateBuy(
+        address takerToken,
+        address makerToken,
+        uint256 takerTokenAmount,
+        bytes4 selector,
+        address plpRegistryAddress
+    )
+        private
+        view
+        returns (uint256 makerTokenAmount)
+    {
+        bytes memory callData;
+        uint256[] memory tmpTakerAmounts = new uint256[](1);
+        tmpTakerAmounts[0] = takerTokenAmount;
+        if (selector == this.sampleSellsFromKyberNetwork.selector) {
+            callData = abi.encodeWithSelector(
+                this.sampleSellsFromKyberNetwork.selector,
+                takerToken,
+                makerToken,
+                tmpTakerAmounts
+            );
+        } else {
+            callData = abi.encodeWithSelector(
+                this.sampleSellsFromLiquidityProviderRegistry.selector,
+                plpRegistryAddress,
+                takerToken,
+                makerToken,
+                tmpTakerAmounts
+            );
+        }
+        (bool success, bytes memory resultData) = address(this).staticcall(callData);
+        if (!success) {
+            return 0;
+        }
+        // solhint-disable indent
+        makerTokenAmount = abi.decode(resultData, (uint256[]))[0];
+    }
+
+    function _sampleApproximateBuysFromSource(
+        address takerToken,
+        address makerToken,
+        uint256[] memory makerTokenAmounts,
+        FakeBuyOptions memory opts,
+        bytes4 selector,
+        address plpRegistryAddress
+    )
+        private
+        view
+        returns (uint256[] memory takerTokenAmounts)
+    {
+        _assertValidPair(makerToken, takerToken);
+        if (makerTokenAmounts.length == 0) {
+            return takerTokenAmounts;
+        }
+        uint256 sellAmount;
+        uint256 buyAmount;
+        uint256 slippageFromTarget;
+        takerTokenAmounts = new uint256[](makerTokenAmounts.length);
+        sellAmount = _sampleSellForApproximateBuy(
+            makerToken,
+            takerToken,
+            makerTokenAmounts[0],
+            selector,
+            plpRegistryAddress
+        );
+
+        if (sellAmount == 0) {
+            return takerTokenAmounts;
+        }
+
+        buyAmount = _sampleSellForApproximateBuy(
+            takerToken,
+            makerToken,
+            sellAmount,
+            selector,
+            plpRegistryAddress
+        );
+        if (buyAmount == 0) {
+            return takerTokenAmounts;
+        }
+
+        for (uint256 i = 0; i < makerTokenAmounts.length; i++) {
+            for (uint256 iter = 0; iter < opts.maxIterations; iter++) {
+                // adjustedSellAmount = previousSellAmount * (target/actual) * JUMP_MULTIPLIER
+                sellAmount = LibMath.getPartialAmountCeil(
+                    makerTokenAmounts[i],
+                    buyAmount,
+                    sellAmount
+                );
+                sellAmount = LibMath.getPartialAmountCeil(
+                    (10000 + opts.targetSlippageBps),
+                    10000,
+                    sellAmount
+                );
+                uint256 _buyAmount = _sampleSellForApproximateBuy(
+                    takerToken,
+                    makerToken,
+                    sellAmount,
+                    selector,
+                    plpRegistryAddress
+                );
+                if (_buyAmount == 0) {
+                    break;
+                }
+                // We re-use buyAmount next iteration, only assign if it is
+                // non zero
+                buyAmount = _buyAmount;
+                // If we've reached our goal, exit early
+                if (buyAmount >= makerTokenAmounts[i]) {
+                    uint256 slippageFromTarget = (buyAmount - makerTokenAmounts[i]) * 10000 /
+                                                makerTokenAmounts[i];
+                    if (slippageFromTarget <= opts.targetSlippageBps) {
+                        break;
+                    }
+                }
+            }
+            // We do our best to close in on the requested amount, but we can either over buy or under buy and exit
+            // if we hit a max iteration limit
+            // We scale the sell amount to get the approximate target
+            takerTokenAmounts[i] = LibMath.getPartialAmountCeil(
+                makerTokenAmounts[i],
+                buyAmount,
+                sellAmount
+            );
+        }
+    }
+
+    function _sampleSellFromKyberNetwork(
+        address takerToken,
+        address makerToken,
+        uint256 takerTokenAmount
+    )
+        private
+        view
+        returns (uint256 makerTokenAmount, address reserve)
+    {
+        address _takerToken = takerToken == _getWethAddress() ? KYBER_ETH_ADDRESS : takerToken;
+        address _makerToken = makerToken == _getWethAddress() ? KYBER_ETH_ADDRESS : makerToken;
+        uint256 takerTokenDecimals = _getTokenDecimals(takerToken);
+        uint256 makerTokenDecimals = _getTokenDecimals(makerToken);
+        (bool didSucceed, bytes memory resultData) = _getKyberNetworkProxyAddress().staticcall.gas(DEFAULT_CALL_GAS)(
+            abi.encodeWithSelector(
+                IKyberNetworkProxy(0).kyberNetworkContract.selector
+            ));
+        if (!didSucceed) {
+            return (0, address(0));
+        }
+        address kyberNetworkContract = abi.decode(resultData, (address));
+        (didSucceed, resultData) =
+            kyberNetworkContract.staticcall.gas(KYBER_CALL_GAS)(
+                abi.encodeWithSelector(
+                    IKyberNetwork(0).searchBestRate.selector,
+                    _takerToken,
+                    _makerToken,
+                    takerTokenAmount,
+                    false // usePermissionless
+                ));
+        uint256 rate = 0;
+        address reserve;
+        if (didSucceed) {
+            (reserve, rate) = abi.decode(resultData, (address, uint256));
+        } else {
+            return (0, address(0));
+        }
+        makerTokenAmount =
+            rate *
+            takerTokenAmount *
+            10 ** makerTokenDecimals /
+            10 ** takerTokenDecimals /
+            10 ** 18;
+
+        return (makerTokenAmount, reserve);
+    }
 }

contracts/erc20-bridge-sampler/contracts/src/IERC20BridgeSampler.sol

@@ -24,6 +24,11 @@ import "@0x/contracts-exchange-libs/contracts/src/LibOrder.sol";
 
 interface IERC20BridgeSampler {
 
+    struct FakeBuyOptions {
+        uint256 targetSlippageBps;
+        uint256 maxIterations;
+    }
+
     /// @dev Call multiple public functions on this contract in a single transaction.
     /// @param callDatas ABI-encoded call data for each function call.
     /// @return callResults ABI-encoded results data for each call.
@@ -73,6 +78,23 @@ interface IERC20BridgeSampler {
         view
         returns (uint256[] memory makerTokenAmounts);
 
+    /// @dev Sample buy quotes from Kyber.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
+    /// @param opts `FakeBuyOptions` specifying target slippage and max iterations.
+    /// @return takerTokenAmounts Taker amounts sold at each maker token
+    ///         amount.
+    function sampleBuysFromKyberNetwork(
+        address takerToken,
+        address makerToken,
+        uint256[] calldata makerTokenAmounts,
+        FakeBuyOptions calldata opts
+    )
+        external
+        view
+        returns (uint256[] memory takerTokenAmounts);
+
     /// @dev Sample sell quotes from Eth2Dai/Oasis.
     /// @param takerToken Address of the taker token (what to sell).
     /// @param makerToken Address of the maker token (what to buy).
@@ -106,7 +128,7 @@ interface IERC20BridgeSampler {
     /// @dev Sample buy quotes from Uniswap.
     /// @param takerToken Address of the taker token (what to sell).
     /// @param makerToken Address of the maker token (what to buy).
-    /// @param makerTokenAmounts Maker token sell amount for each sample.
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
     /// @return takerTokenAmounts Taker amounts sold at each maker token
     ///         amount.
     function sampleBuysFromUniswap(
@@ -121,7 +143,7 @@ interface IERC20BridgeSampler {
     /// @dev Sample buy quotes from Eth2Dai/Oasis.
     /// @param takerToken Address of the taker token (what to sell).
     /// @param makerToken Address of the maker token (what to buy).
-    /// @param takerTokenAmounts Maker token sell amount for each sample.
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
     /// @return takerTokenAmounts Taker amounts sold at each maker token
     ///         amount.
     function sampleBuysFromEth2Dai(
@@ -149,4 +171,119 @@ interface IERC20BridgeSampler {
         external
         view
         returns (uint256[] memory makerTokenAmounts);
+
+    /// @dev Sample buy quotes from Curve.
+    /// @param curveAddress Address of the Curve contract.
+    /// @param fromTokenIdx Index of the taker token (what to sell).
+    /// @param toTokenIdx Index of the maker token (what to buy).
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
+    /// @return takerTokenAmounts Taker amounts sold at each maker token
+    ///         amount.
+    function sampleBuysFromCurve(
+        address curveAddress,
+        int128 fromTokenIdx,
+        int128 toTokenIdx,
+        uint256[] calldata makerTokenAmounts
+    )
+        external
+        view
+        returns (uint256[] memory takerTokenAmounts);
+
+    /// @dev Sample sell quotes from an arbitrary on-chain liquidity provider.
+    /// @param registryAddress Address of the liquidity provider registry contract.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param takerTokenAmounts Taker token sell amount for each sample.
+    /// @return makerTokenAmounts Maker amounts bought at each taker token
+    ///         amount.
+    function sampleSellsFromLiquidityProviderRegistry(
+        address registryAddress,
+        address takerToken,
+        address makerToken,
+        uint256[] calldata takerTokenAmounts
+    )
+        external
+        view
+        returns (uint256[] memory makerTokenAmounts);
+
+    /// @dev Sample sell quotes from MultiBridge.
+    /// @param multibridge Address of the MultiBridge contract.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param intermediateToken The address of the intermediate token to
+    ///        use in an indirect route.
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param takerTokenAmounts Taker token sell amount for each sample.
+    /// @return makerTokenAmounts Maker amounts bought at each taker token
+    ///         amount.
+    function sampleSellsFromMultiBridge(
+        address multibridge,
+        address takerToken,
+        address intermediateToken,
+        address makerToken,
+        uint256[] calldata takerTokenAmounts
+    )
+        external
+        view
+        returns (uint256[] memory makerTokenAmounts);
+
+    /// @dev Sample buy quotes from an arbitrary on-chain liquidity provider.
+    /// @param registryAddress Address of the liquidity provider registry contract.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
+    /// @param opts `FakeBuyOptions` specifying target slippage and max iterations.
+    /// @return takerTokenAmounts Taker amounts sold at each maker token
+    ///         amount.
+    function sampleBuysFromLiquidityProviderRegistry(
+        address registryAddress,
+        address takerToken,
+        address makerToken,
+        uint256[] calldata makerTokenAmounts,
+        FakeBuyOptions calldata opts
+
+    )
+        external
+        view
+        returns (uint256[] memory takerTokenAmounts);
+
+    /// @dev Returns the address of a liquidity provider for the given market
+    ///      (takerToken, makerToken), from a registry of liquidity providers.
+    ///      Returns address(0) if no such provider exists in the registry.
+    /// @param takerToken Taker asset managed by liquidity provider.
+    /// @param makerToken Maker asset managed by liquidity provider.
+    /// @return providerAddress Address of the liquidity provider.
+    function getLiquidityProviderFromRegistry(
+        address registryAddress,
+        address takerToken,
+        address makerToken
+    )
+        external
+        view
+        returns (address providerAddress);
+
+    /// @dev Sample sell quotes from UniswapV2.
+    /// @param path Token route.
+    /// @param takerTokenAmounts Taker token sell amount for each sample.
+    /// @return makerTokenAmounts Maker amounts bought at each taker token
+    ///         amount.
+    function sampleSellsFromUniswapV2(
+        address[] calldata path,
+        uint256[] calldata takerTokenAmounts
+    )
+        external
+        view
+        returns (uint256[] memory makerTokenAmounts);
+
+    /// @dev Sample buy quotes from UniswapV2.
+    /// @param path Token route.
+    /// @param makerTokenAmounts Maker token buy amount for each sample.
+    /// @return takerTokenAmounts Taker amounts sold at each maker token
+    ///         amount.
+    function sampleBuysFromUniswapV2(
+        address[] calldata path,
+        uint256[] calldata makerTokenAmounts
+    )
+        external
+        view
+        returns (uint256[] memory takerTokenAmounts);
 }

contracts/erc20-bridge-sampler/contracts/src/IKyberNetwork.sol

@@ -21,12 +21,13 @@ pragma solidity ^0.5.9;
 
 interface IKyberNetwork {
 
-    function getExpectedRate(
+    function searchBestRate(
         address fromToken,
         address toToken,
-        uint256 fromAmount
+        uint256 fromAmount,
+        bool usePermissionless
     )
         external
         view
-        returns (uint256 expectedRate, uint256 slippageRate);
+        returns (address reserve, uint256 expectedRate);
 }

contracts/erc20-bridge-sampler/contracts/src/IKyberNetworkProxy.sol

@@ -0,0 +1,34 @@
+/*
+
+  Copyright 2019 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+
+
+interface IKyberNetworkProxy {
+
+    function kyberNetworkContract() external view returns (address);
+
+    function getExpectedRate(
+        address fromToken,
+        address toToken,
+        uint256 fromAmount
+    )
+        external
+        view
+        returns (uint256 expectedRate, uint256 slippageRate);
+}

contracts/erc20-bridge-sampler/contracts/src/ILiquidityProvider.sol

@@ -0,0 +1,70 @@
+/*
+
+  Copyright 2019 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+
+
+interface ILiquidityProvider {
+
+    /// @dev Transfers `amount` of the ERC20 `tokenAddress` from `from` to `to`.
+    /// @param tokenAddress The address of the ERC20 token to transfer.
+    /// @param from Address to transfer asset from.
+    /// @param to Address to transfer asset to.
+    /// @param amount Amount of asset to transfer.
+    /// @param bridgeData Arbitrary asset data needed by the bridge contract.
+    /// @return success The magic bytes `0xdc1600f3` if successful.
+    function bridgeTransferFrom(
+        address tokenAddress,
+        address from,
+        address to,
+        uint256 amount,
+        bytes calldata bridgeData
+    )
+        external
+        returns (bytes4 success);
+
+    /// @dev Quotes the amount of `makerToken` that would be obtained by
+    ///      selling `sellAmount` of `takerToken`.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param sellAmount Amount of `takerToken` to sell.
+    /// @return makerTokenAmount Amount of `makerToken` that would be obtained.
+    function getSellQuote(
+        address takerToken,
+        address makerToken,
+        uint256 sellAmount
+    )
+        external
+        view
+        returns (uint256 makerTokenAmount);
+
+    /// @dev Quotes the amount of `takerToken` that would need to be sold in
+    ///      order to obtain `buyAmount` of `makerToken`.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param buyAmount Amount of `makerToken` to buy.
+    /// @return takerTokenAmount Amount of `takerToken` that would need to be sold.
+    function getBuyQuote(
+        address takerToken,
+        address makerToken,
+        uint256 buyAmount
+    )
+        external
+        view
+        returns (uint256 takerTokenAmount);
+}

contracts/erc20-bridge-sampler/contracts/src/ILiquidityProviderRegistry.sol

@@ -0,0 +1,36 @@
+/*
+
+  Copyright 2019 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+
+
+interface ILiquidityProviderRegistry {
+
+    /// @dev Returns the address of a liquidity provider for the given market
+    ///      (takerToken, makerToken), reverting if the pool does not exist.
+    /// @param takerToken Taker asset managed by liquidity provider.
+    /// @param makerToken Maker asset managed by liquidity provider.
+    /// @return Address of the liquidity provider.
+    function getLiquidityProviderForMarket(
+        address takerToken,
+        address makerToken
+    )
+        external
+        view
+        returns (address providerAddress);
+}

contracts/erc20-bridge-sampler/contracts/src/IMultiBridge.sol

@@ -0,0 +1,58 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+
+
+interface IMultiBridge {
+
+    /// @dev Transfers `amount` of the ERC20 `tokenAddress` from `from` to `to`.
+    /// @param tokenAddress The address of the ERC20 token to transfer.
+    /// @param from Address to transfer asset from.
+    /// @param to Address to transfer asset to.
+    /// @param amount Amount of asset to transfer.
+    /// @param bridgeData Arbitrary asset data needed by the bridge contract.
+    /// @return success The magic bytes `0xdc1600f3` if successful.
+    function bridgeTransferFrom(
+        address tokenAddress,
+        address from,
+        address to,
+        uint256 amount,
+        bytes calldata bridgeData
+    )
+        external
+        returns (bytes4 success);
+
+    /// @dev Quotes the amount of `makerToken` that would be obtained by
+    ///      selling `sellAmount` of `takerToken`.
+    /// @param takerToken Address of the taker token (what to sell).
+    /// @param intermediateToken The address of the intermediate token to
+    ///        use in an indirect route.
+    /// @param makerToken Address of the maker token (what to buy).
+    /// @param sellAmount Amount of `takerToken` to sell.
+    /// @return makerTokenAmount Amount of `makerToken` that would be obtained.
+    function getSellQuote(
+        address takerToken,
+        address intermediateToken,
+        address makerToken,
+        uint256 sellAmount
+    )
+        external
+        view
+        returns (uint256 makerTokenAmount);
+}

contracts/erc20-bridge-sampler/contracts/src/IUniswapV2Router01.sol

@@ -0,0 +1,33 @@
+/*
+
+  Copyright 2019 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.5.9;
+
+
+interface IUniswapV2Router01 {
+
+    function getAmountsOut(uint256 amountIn, address[] calldata path)
+        external
+        view
+        returns (uint256[] memory amounts);
+
+    function getAmountsIn(uint256 amountOut, address[] calldata path)
+        external
+        view
+        returns (uint256[] memory amounts);
+}

contracts/erc20-bridge-sampler/contracts/test/TestERC20BridgeSampler.sol

@@ -24,7 +24,8 @@ import "@0x/contracts-exchange-libs/contracts/src/LibOrder.sol";
 import "../src/ERC20BridgeSampler.sol";
 import "../src/IEth2Dai.sol";
 import "../src/IDevUtils.sol";
-import "../src/IKyberNetwork.sol";
+import "../src/IKyberNetworkProxy.sol";
+import "../src/IUniswapV2Router01.sol";
 
 
 library LibDeterministicQuotes {
@@ -194,6 +195,55 @@ contract TestERC20BridgeSamplerUniswapExchange is
 }
 
 
+contract TestERC20BridgeSamplerUniswapV2Router01 is
+    IUniswapV2Router01,
+    DeploymentConstants,
+    FailTrigger
+{
+    bytes32 constant private SALT = 0xadc7fcb33c735913b8635927e66896b356a53a912ab2ceff929e60a04b53b3c1;
+
+    // Deterministic `IUniswapV2Router01.getAmountsOut()`.
+    function getAmountsOut(uint256 amountIn, address[] calldata path)
+        external
+        view
+        returns (uint256[] memory amounts)
+    {
+        require(path.length >= 2, "PATH_TOO_SHORT");
+        _revertIfShouldFail();
+        amounts = new uint256[](path.length);
+        amounts[0] = amountIn;
+        for (uint256 i = 0; i < path.length - 1; ++i) {
+            amounts[i + 1] = LibDeterministicQuotes.getDeterministicSellQuote(
+                SALT,
+                path[i],
+                path[i + 1],
+                amounts[i]
+            );
+        }
+    }
+
+    // Deterministic `IUniswapV2Router01.getAmountsInt()`.
+    function getAmountsIn(uint256 amountOut, address[] calldata path)
+        external
+        view
+        returns (uint256[] memory amounts)
+    {
+        require(path.length >= 2, "PATH_TOO_SHORT");
+        _revertIfShouldFail();
+        amounts = new uint256[](path.length);
+        amounts[path.length - 1] = amountOut;
+        for (uint256 i = path.length - 1; i > 0; --i) {
+            amounts[i - 1] = LibDeterministicQuotes.getDeterministicBuyQuote(
+                SALT,
+                path[i - 1],
+                path[i],
+                amounts[i]
+            );
+        }
+    }
+}
+
+
 contract TestERC20BridgeSamplerKyberNetwork is
     IKyberNetwork,
     DeploymentConstants,
@@ -202,7 +252,30 @@ contract TestERC20BridgeSamplerKyberNetwork is
     bytes32 constant private SALT = 0x0ff3ca9d46195c39f9a12afb74207b4970349fb3cfb1e459bbf170298d326bc7;
     address constant public ETH_ADDRESS = 0xEeeeeEeeeEeEeeEeEeEeeEEEeeeeEeeeeeeeEEeE;
 
-    // Deterministic `IKyberNetwork.getExpectedRate()`.
+    function kyberNetworkContract()
+        external
+        view
+        returns (address)
+    {
+        return address(this);
+    }
+
+    // IKyberNetwork not exposed via IKyberNetworkProxy
+    function searchBestRate(
+        address fromToken,
+        address toToken,
+        uint256 fromAmount,
+        bool  // usePermissionless
+    )
+        external
+        view
+        returns (address reserve, uint256 expectedRate)
+    {
+        (expectedRate, ) = this.getExpectedRate(fromToken, toToken, fromAmount);
+        return (address(this), expectedRate);
+    }
+
+    // Deterministic `IKyberNetworkProxy.getExpectedRate()`.
     function getExpectedRate(
         address fromToken,
         address toToken,
@@ -302,13 +375,15 @@ contract TestERC20BridgeSampler is
     FailTrigger
 {
     TestERC20BridgeSamplerUniswapExchangeFactory public uniswap;
+    TestERC20BridgeSamplerUniswapV2Router01 public uniswapV2Router;
     TestERC20BridgeSamplerEth2Dai public eth2Dai;
     TestERC20BridgeSamplerKyberNetwork public kyber;
 
     uint8 private constant MAX_ORDER_STATUS = uint8(LibOrder.OrderStatus.CANCELLED) + 1;
 
-    constructor() public {
+    constructor() public ERC20BridgeSampler(address(this)) {
         uniswap = new TestERC20BridgeSamplerUniswapExchangeFactory();
+        uniswapV2Router = new TestERC20BridgeSamplerUniswapV2Router01();
         eth2Dai = new TestERC20BridgeSamplerEth2Dai();
         kyber = new TestERC20BridgeSamplerKyberNetwork();
     }
@@ -327,6 +402,7 @@ contract TestERC20BridgeSampler is
         bytes memory
     )
         public
+        pure
         returns (
             LibOrder.OrderInfo memory orderInfo,
             uint256 fillableTakerAssetAmount,
@@ -357,15 +433,6 @@ contract TestERC20BridgeSampler is
         return LibDeterministicQuotes.getDeterministicTokenDecimals(tokenAddress);
     }
 
-    // Overriden to point to a this contract.
-    function _getDevUtilsAddress()
-        internal
-        view
-        returns (address devUtilAddress)
-    {
-        return address(this);
-    }
-
     // Overriden to point to a custom contract.
     function _getEth2DaiAddress()
         internal
@@ -384,6 +451,15 @@ contract TestERC20BridgeSampler is
         return address(uniswap);
     }
 
+    // Overriden to point to a custom contract.
+    function _getUniswapV2Router01Address()
+        internal
+        view
+        returns (address uniswapV2RouterAddress)
+    {
+        return address(uniswapV2Router);
+    }
+
     // Overriden to point to a custom contract.
     function _getKyberNetworkProxyAddress()
         internal

contracts/erc20-bridge-sampler/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-erc20-bridge-sampler",
-    "version": "1.4.1",
+    "version": "1.6.0",
     "engines": {
         "node": ">=6.12"
     },
@@ -36,9 +36,9 @@
         "compile:truffle": "truffle compile"
     },
     "config": {
-        "publicInterfaceContracts": "ERC20BridgeSampler,IERC20BridgeSampler",
+        "publicInterfaceContracts": "ERC20BridgeSampler,IERC20BridgeSampler,ILiquidityProvider,ILiquidityProviderRegistry,DummyLiquidityProviderRegistry,DummyLiquidityProvider",
         "abis:comment": "This list is auto-generated by contracts-gen. Don't edit manually.",
-        "abis": "./test/generated-artifacts/@(ERC20BridgeSampler|ICurve|IDevUtils|IERC20BridgeSampler|IEth2Dai|IKyberNetwork|IUniswapExchangeQuotes|TestERC20BridgeSampler).json"
+        "abis": "./test/generated-artifacts/@(DummyLiquidityProvider|DummyLiquidityProviderRegistry|ERC20BridgeSampler|ICurve|IDevUtils|IERC20BridgeSampler|IEth2Dai|IKyberNetwork|IKyberNetworkProxy|ILiquidityProvider|ILiquidityProviderRegistry|IMultiBridge|IUniswapExchangeQuotes|IUniswapV2Router01|TestERC20BridgeSampler).json"
     },
     "repository": {
         "type": "git",
@@ -50,18 +50,18 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/protocol/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-asset-proxy": "^3.2.2",
-        "@0x/contracts-erc20": "^3.1.2",
-        "@0x/contracts-exchange": "^3.2.2",
-        "@0x/contracts-exchange-libs": "^4.3.2",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/dev-utils": "^3.2.1",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contracts-asset-proxy": "^3.3.0",
+        "@0x/contracts-erc20": "^3.2.0",
+        "@0x/contracts-exchange": "^3.2.6",
+        "@0x/contracts-exchange-libs": "^4.3.6",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/dev-utils": "^3.2.2",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/web3-wrapper": "^7.0.7",
+        "@0x/web3-wrapper": "^7.1.0",
         "@types/lodash": "4.14.104",
         "@types/mocha": "^5.2.7",
         "@types/node": "*",
@@ -79,11 +79,11 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1",
-        "@0x/types": "^3.1.2",
-        "@0x/typescript-typings": "^5.0.2",
-        "@0x/utils": "^5.4.1",
-        "ethereum-types": "^3.1.0",
+        "@0x/base-contract": "^6.2.2",
+        "@0x/types": "^3.1.3",
+        "@0x/typescript-typings": "^5.1.0",
+        "@0x/utils": "^5.5.0",
+        "ethereum-types": "^3.1.1",
         "lodash": "^4.17.11"
     },
     "publishConfig": {

contracts/erc20-bridge-sampler/src/artifacts.ts

@@ -5,9 +5,17 @@
  */
 import { ContractArtifact } from 'ethereum-types';
 
+import * as DummyLiquidityProvider from '../generated-artifacts/DummyLiquidityProvider.json';
+import * as DummyLiquidityProviderRegistry from '../generated-artifacts/DummyLiquidityProviderRegistry.json';
 import * as ERC20BridgeSampler from '../generated-artifacts/ERC20BridgeSampler.json';
 import * as IERC20BridgeSampler from '../generated-artifacts/IERC20BridgeSampler.json';
+import * as ILiquidityProvider from '../generated-artifacts/ILiquidityProvider.json';
+import * as ILiquidityProviderRegistry from '../generated-artifacts/ILiquidityProviderRegistry.json';
 export const artifacts = {
     ERC20BridgeSampler: ERC20BridgeSampler as ContractArtifact,
     IERC20BridgeSampler: IERC20BridgeSampler as ContractArtifact,
+    ILiquidityProvider: ILiquidityProvider as ContractArtifact,
+    ILiquidityProviderRegistry: ILiquidityProviderRegistry as ContractArtifact,
+    DummyLiquidityProviderRegistry: DummyLiquidityProviderRegistry as ContractArtifact,
+    DummyLiquidityProvider: DummyLiquidityProvider as ContractArtifact,
 };

contracts/erc20-bridge-sampler/src/wrappers.ts

@@ -3,5 +3,9 @@
  * Warning: This file is auto-generated by contracts-gen. Don't edit manually.
  * -----------------------------------------------------------------------------
  */
+export * from '../generated-wrappers/dummy_liquidity_provider';
+export * from '../generated-wrappers/dummy_liquidity_provider_registry';
 export * from '../generated-wrappers/erc20_bridge_sampler';
 export * from '../generated-wrappers/i_erc20_bridge_sampler';
+export * from '../generated-wrappers/i_liquidity_provider';
+export * from '../generated-wrappers/i_liquidity_provider_registry';

contracts/erc20-bridge-sampler/test/artifacts.ts

@@ -5,21 +5,35 @@
  */
 import { ContractArtifact } from 'ethereum-types';
 
+import * as DummyLiquidityProvider from '../test/generated-artifacts/DummyLiquidityProvider.json';
+import * as DummyLiquidityProviderRegistry from '../test/generated-artifacts/DummyLiquidityProviderRegistry.json';
 import * as ERC20BridgeSampler from '../test/generated-artifacts/ERC20BridgeSampler.json';
 import * as ICurve from '../test/generated-artifacts/ICurve.json';
 import * as IDevUtils from '../test/generated-artifacts/IDevUtils.json';
 import * as IERC20BridgeSampler from '../test/generated-artifacts/IERC20BridgeSampler.json';
 import * as IEth2Dai from '../test/generated-artifacts/IEth2Dai.json';
 import * as IKyberNetwork from '../test/generated-artifacts/IKyberNetwork.json';
+import * as IKyberNetworkProxy from '../test/generated-artifacts/IKyberNetworkProxy.json';
+import * as ILiquidityProvider from '../test/generated-artifacts/ILiquidityProvider.json';
+import * as ILiquidityProviderRegistry from '../test/generated-artifacts/ILiquidityProviderRegistry.json';
+import * as IMultiBridge from '../test/generated-artifacts/IMultiBridge.json';
 import * as IUniswapExchangeQuotes from '../test/generated-artifacts/IUniswapExchangeQuotes.json';
+import * as IUniswapV2Router01 from '../test/generated-artifacts/IUniswapV2Router01.json';
 import * as TestERC20BridgeSampler from '../test/generated-artifacts/TestERC20BridgeSampler.json';
 export const artifacts = {
+    DummyLiquidityProvider: DummyLiquidityProvider as ContractArtifact,
+    DummyLiquidityProviderRegistry: DummyLiquidityProviderRegistry as ContractArtifact,
     ERC20BridgeSampler: ERC20BridgeSampler as ContractArtifact,
     ICurve: ICurve as ContractArtifact,
     IDevUtils: IDevUtils as ContractArtifact,
     IERC20BridgeSampler: IERC20BridgeSampler as ContractArtifact,
     IEth2Dai: IEth2Dai as ContractArtifact,
     IKyberNetwork: IKyberNetwork as ContractArtifact,
+    IKyberNetworkProxy: IKyberNetworkProxy as ContractArtifact,
+    ILiquidityProvider: ILiquidityProvider as ContractArtifact,
+    ILiquidityProviderRegistry: ILiquidityProviderRegistry as ContractArtifact,
+    IMultiBridge: IMultiBridge as ContractArtifact,
     IUniswapExchangeQuotes: IUniswapExchangeQuotes as ContractArtifact,
+    IUniswapV2Router01: IUniswapV2Router01 as ContractArtifact,
     TestERC20BridgeSampler: TestERC20BridgeSampler as ContractArtifact,
 };

contracts/erc20-bridge-sampler/test/erc20-bridge-sampler.ts

@@ -11,7 +11,11 @@ import { BigNumber, hexUtils } from '@0x/utils';
 import * as _ from 'lodash';
 
 import { artifacts } from './artifacts';
-import { TestERC20BridgeSamplerContract } from './wrappers';
+import {
+    DummyLiquidityProviderContract,
+    DummyLiquidityProviderRegistryContract,
+    TestERC20BridgeSamplerContract,
+} from './wrappers';
 
 blockchainTests('erc20-bridge-sampler', env => {
     let testContract: TestERC20BridgeSamplerContract;
@@ -24,10 +28,15 @@ blockchainTests('erc20-bridge-sampler', env => {
     const KYBER_SALT = '0x0ff3ca9d46195c39f9a12afb74207b4970349fb3cfb1e459bbf170298d326bc7';
     const ETH2DAI_SALT = '0xb713b61bb9bb2958a0f5d1534b21e94fc68c4c0c034b0902ed844f2f6cd1b4f7';
     const UNISWAP_BASE_SALT = '0x1d6a6a0506b0b4a554b907a4c29d9f4674e461989d9c1921feb17b26716385ab';
+    const UNISWAP_V2_SALT = '0xadc7fcb33c735913b8635927e66896b356a53a912ab2ceff929e60a04b53b3c1';
     const ERC20_PROXY_ID = '0xf47261b0';
     const INVALID_TOKEN_PAIR_ERROR = 'ERC20BridgeSampler/INVALID_TOKEN_PAIR';
     const MAKER_TOKEN = randomAddress();
     const TAKER_TOKEN = randomAddress();
+    const FAKE_BUY_OPTS = {
+        targetSlippageBps: new BigNumber(5),
+        maxIterations: new BigNumber(5),
+    };
 
     before(async () => {
         testContract = await TestERC20BridgeSamplerContract.deployFrom0xArtifactAsync(
@@ -165,8 +174,15 @@ blockchainTests('erc20-bridge-sampler', env => {
         for (const source of sources) {
             const sampleOutputs = [];
             for (const amount of sampleAmounts) {
-                if (source === 'Eth2Dai') {
-                    sampleOutputs.push(getDeterministicBuyQuote(ETH2DAI_SALT, sellToken, buyToken, amount));
+                if (source === 'Kyber' || source === 'Eth2Dai') {
+                    sampleOutputs.push(
+                        getDeterministicBuyQuote(
+                            source === 'Kyber' ? KYBER_SALT : ETH2DAI_SALT,
+                            sellToken,
+                            buyToken,
+                            amount,
+                        ),
+                    );
                 } else if (source === 'Uniswap') {
                     sampleOutputs.push(getDeterministicUniswapBuyQuote(sellToken, buyToken, amount));
                 }
@@ -176,6 +192,22 @@ blockchainTests('erc20-bridge-sampler', env => {
         return quotes;
     }
 
+    function getDeterministicUniswapV2SellQuote(path: string[], sellAmount: BigNumber): BigNumber {
+        let bought = sellAmount;
+        for (let i = 0; i < path.length - 1; ++i) {
+            bought = getDeterministicSellQuote(UNISWAP_V2_SALT, path[i], path[i + 1], bought);
+        }
+        return bought;
+    }
+
+    function getDeterministicUniswapV2BuyQuote(path: string[], buyAmount: BigNumber): BigNumber {
+        let sold = buyAmount;
+        for (let i = path.length - 1; i > 0; --i) {
+            sold = getDeterministicBuyQuote(UNISWAP_V2_SALT, path[i - 1], path[i], sold);
+        }
+        return sold;
+    }
+
     function getDeterministicFillableTakerAssetAmount(order: Order): BigNumber {
         const hash = getPackedHash(hexUtils.leftPad(order.salt));
         const orderStatus = new BigNumber(hash).mod(100).toNumber() > 90 ? 5 : 3;
@@ -200,7 +232,7 @@ blockchainTests('erc20-bridge-sampler', env => {
 
     function getSampleAmounts(tokenAddress: string, count?: number): BigNumber[] {
         const tokenDecimals = getDeterministicTokenDecimals(tokenAddress);
-        const _upperLimit = getRandomPortion(getRandomInteger(1, 1000).times(10 ** tokenDecimals));
+        const _upperLimit = getRandomPortion(getRandomInteger(1000, 50000).times(10 ** tokenDecimals));
         const _count = count || _.random(1, 16);
         const d = _upperLimit.div(_count);
         return _.times(_count, i => d.times((i + 1) / _count).integerValue());
@@ -326,9 +358,10 @@ blockchainTests('erc20-bridge-sampler', env => {
             expect(quotes).to.deep.eq([]);
         });
 
-        it('can quote token - token', async () => {
+        it('can quote token -> token', async () => {
             const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
-            const [expectedQuotes] = getDeterministicSellQuotes(TAKER_TOKEN, MAKER_TOKEN, ['Kyber'], sampleAmounts);
+            const [takerToEthQuotes] = getDeterministicSellQuotes(TAKER_TOKEN, WETH_ADDRESS, ['Kyber'], sampleAmounts);
+            const [expectedQuotes] = getDeterministicSellQuotes(WETH_ADDRESS, MAKER_TOKEN, ['Kyber'], takerToEthQuotes);
             const quotes = await testContract
                 .sampleSellsFromKyberNetwork(TAKER_TOKEN, MAKER_TOKEN, sampleAmounts)
                 .callAsync();
@@ -384,6 +417,109 @@ blockchainTests('erc20-bridge-sampler', env => {
         });
     });
 
+    blockchainTests.resets('sampleBuysFromKyberNetwork()', () => {
+        const ACCEPTABLE_SLIPPAGE = 0.0005;
+        before(async () => {
+            await testContract.createTokenExchanges([MAKER_TOKEN, TAKER_TOKEN]).awaitTransactionSuccessAsync();
+        });
+
+        it('throws if tokens are the same', async () => {
+            const tx = testContract.sampleBuysFromKyberNetwork(MAKER_TOKEN, MAKER_TOKEN, [], FAKE_BUY_OPTS).callAsync();
+            return expect(tx).to.revertWith(INVALID_TOKEN_PAIR_ERROR);
+        });
+
+        it('can return no quotes', async () => {
+            const quotes = await testContract
+                .sampleBuysFromKyberNetwork(TAKER_TOKEN, MAKER_TOKEN, [], FAKE_BUY_OPTS)
+                .callAsync();
+            expect(quotes).to.deep.eq([]);
+        });
+        const expectQuotesWithinRange = (
+            quotes: BigNumber[],
+            expectedQuotes: BigNumber[],
+            maxSlippage: BigNumber | number,
+        ) => {
+            quotes.forEach((_q, i) => {
+                // If we're within 1 base unit of a low decimal token
+                // then that's as good as we're going to get (and slippage is "high")
+                if (
+                    expectedQuotes[i].isZero() ||
+                    BigNumber.max(expectedQuotes[i], quotes[i])
+                        .minus(BigNumber.min(expectedQuotes[i], quotes[i]))
+                        .eq(1)
+                ) {
+                    return;
+                }
+                const slippage = quotes[i]
+                    .dividedBy(expectedQuotes[i])
+                    .minus(1)
+                    .decimalPlaces(4);
+                expect(slippage, `quote[${i}]: ${slippage} ${quotes[i]} ${expectedQuotes[i]}`).to.be.bignumber.gte(0);
+                expect(slippage, `quote[${i}] ${slippage} ${quotes[i]} ${expectedQuotes[i]}`).to.be.bignumber.lte(
+                    new BigNumber(maxSlippage),
+                );
+            });
+        };
+
+        it('can quote token -> token', async () => {
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const [ethToMakerQuotes] = getDeterministicBuyQuotes(WETH_ADDRESS, MAKER_TOKEN, ['Kyber'], sampleAmounts);
+            const [expectedQuotes] = getDeterministicBuyQuotes(TAKER_TOKEN, WETH_ADDRESS, ['Kyber'], ethToMakerQuotes);
+            const quotes = await testContract
+                .sampleBuysFromKyberNetwork(TAKER_TOKEN, MAKER_TOKEN, sampleAmounts, FAKE_BUY_OPTS)
+                .callAsync();
+            expectQuotesWithinRange(quotes, expectedQuotes, ACCEPTABLE_SLIPPAGE);
+        });
+
+        it('returns zero if token -> token fails', async () => {
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const expectedQuotes = _.times(sampleAmounts.length, () => constants.ZERO_AMOUNT);
+            await enableFailTriggerAsync();
+            const quotes = await testContract
+                .sampleBuysFromKyberNetwork(TAKER_TOKEN, MAKER_TOKEN, sampleAmounts, FAKE_BUY_OPTS)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+
+        it('can quote token -> ETH', async () => {
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const [expectedQuotes] = getDeterministicBuyQuotes(TAKER_TOKEN, WETH_ADDRESS, ['Kyber'], sampleAmounts);
+            const quotes = await testContract
+                .sampleBuysFromKyberNetwork(TAKER_TOKEN, WETH_ADDRESS, sampleAmounts, FAKE_BUY_OPTS)
+                .callAsync();
+            expectQuotesWithinRange(quotes, expectedQuotes, ACCEPTABLE_SLIPPAGE);
+        });
+
+        it('returns zero if token -> ETH fails', async () => {
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const expectedQuotes = _.times(sampleAmounts.length, () => constants.ZERO_AMOUNT);
+            await enableFailTriggerAsync();
+            const quotes = await testContract
+                .sampleBuysFromKyberNetwork(TAKER_TOKEN, WETH_ADDRESS, sampleAmounts, FAKE_BUY_OPTS)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+
+        it('can quote ETH -> token', async () => {
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const [expectedQuotes] = getDeterministicBuyQuotes(WETH_ADDRESS, TAKER_TOKEN, ['Kyber'], sampleAmounts);
+            const quotes = await testContract
+                .sampleBuysFromKyberNetwork(WETH_ADDRESS, TAKER_TOKEN, sampleAmounts, FAKE_BUY_OPTS)
+                .callAsync();
+            expectQuotesWithinRange(quotes, expectedQuotes, ACCEPTABLE_SLIPPAGE);
+        });
+
+        it('returns zero if ETH -> token fails', async () => {
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const expectedQuotes = _.times(sampleAmounts.length, () => constants.ZERO_AMOUNT);
+            await enableFailTriggerAsync();
+            const quotes = await testContract
+                .sampleBuysFromKyberNetwork(WETH_ADDRESS, TAKER_TOKEN, sampleAmounts, FAKE_BUY_OPTS)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+    });
+
     blockchainTests.resets('sampleSellsFromEth2Dai()', () => {
         before(async () => {
             await testContract.createTokenExchanges([MAKER_TOKEN, TAKER_TOKEN]).awaitTransactionSuccessAsync();
@@ -716,6 +852,177 @@ blockchainTests('erc20-bridge-sampler', env => {
         });
     });
 
+    describe('getLiquidityProviderFromRegistry', () => {
+        const xAsset = randomAddress();
+        const yAsset = randomAddress();
+        const sampleAmounts = getSampleAmounts(yAsset);
+        let liquidityProvider: DummyLiquidityProviderContract;
+        let registryContract: DummyLiquidityProviderRegistryContract;
+
+        before(async () => {
+            liquidityProvider = await DummyLiquidityProviderContract.deployFrom0xArtifactAsync(
+                artifacts.DummyLiquidityProvider,
+                env.provider,
+                env.txDefaults,
+                {},
+            );
+
+            registryContract = await DummyLiquidityProviderRegistryContract.deployFrom0xArtifactAsync(
+                artifacts.DummyLiquidityProviderRegistry,
+                env.provider,
+                env.txDefaults,
+                {},
+            );
+            await registryContract
+                .setLiquidityProviderForMarket(xAsset, yAsset, liquidityProvider.address)
+                .awaitTransactionSuccessAsync();
+        });
+
+        it('should be able to get the liquidity provider', async () => {
+            const xyLiquidityProvider = await testContract
+                .getLiquidityProviderFromRegistry(registryContract.address, xAsset, yAsset)
+                .callAsync();
+            const yxLiquidityProvider = await testContract
+                .getLiquidityProviderFromRegistry(registryContract.address, yAsset, xAsset)
+                .callAsync();
+            const unknownLiquidityProvider = await testContract
+                .getLiquidityProviderFromRegistry(registryContract.address, yAsset, randomAddress())
+                .callAsync();
+
+            expect(xyLiquidityProvider).to.eq(liquidityProvider.address);
+            expect(yxLiquidityProvider).to.eq(liquidityProvider.address);
+            expect(unknownLiquidityProvider).to.eq(constants.NULL_ADDRESS);
+        });
+
+        it('should be able to query sells from the liquidity provider', async () => {
+            const result = await testContract
+                .sampleSellsFromLiquidityProviderRegistry(registryContract.address, yAsset, xAsset, sampleAmounts)
+                .callAsync();
+            result.forEach((value, idx) => {
+                expect(value).is.bignumber.eql(sampleAmounts[idx].minus(1));
+            });
+        });
+
+        it('should be able to query buys from the liquidity provider', async () => {
+            const result = await testContract
+                .sampleBuysFromLiquidityProviderRegistry(
+                    registryContract.address,
+                    yAsset,
+                    xAsset,
+                    sampleAmounts,
+                    FAKE_BUY_OPTS,
+                )
+                .callAsync();
+            result.forEach((value, idx) => {
+                expect(value).is.bignumber.eql(sampleAmounts[idx].plus(1));
+            });
+        });
+
+        it('should just return zeros if the liquidity provider cannot be found', async () => {
+            const result = await testContract
+                .sampleBuysFromLiquidityProviderRegistry(
+                    registryContract.address,
+                    yAsset,
+                    randomAddress(),
+                    sampleAmounts,
+                    FAKE_BUY_OPTS,
+                )
+                .callAsync();
+            result.forEach(value => {
+                expect(value).is.bignumber.eql(constants.ZERO_AMOUNT);
+            });
+        });
+
+        it('should just return zeros if the registry does not exist', async () => {
+            const result = await testContract
+                .sampleBuysFromLiquidityProviderRegistry(randomAddress(), yAsset, xAsset, sampleAmounts, FAKE_BUY_OPTS)
+                .callAsync();
+            result.forEach(value => {
+                expect(value).is.bignumber.eql(constants.ZERO_AMOUNT);
+            });
+        });
+    });
+
+    blockchainTests.resets('sampleSellsFromUniswapV2()', () => {
+        function predictSellQuotes(path: string[], sellAmounts: BigNumber[]): BigNumber[] {
+            return sellAmounts.map(a => getDeterministicUniswapV2SellQuote(path, a));
+        }
+
+        it('can return no quotes', async () => {
+            const quotes = await testContract.sampleSellsFromUniswapV2([TAKER_TOKEN, MAKER_TOKEN], []).callAsync();
+            expect(quotes).to.deep.eq([]);
+        });
+
+        it('can quote token -> token', async () => {
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const expectedQuotes = predictSellQuotes([TAKER_TOKEN, MAKER_TOKEN], sampleAmounts);
+            const quotes = await testContract
+                .sampleSellsFromUniswapV2([TAKER_TOKEN, MAKER_TOKEN], sampleAmounts)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+
+        it('returns zero if token -> token fails', async () => {
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const expectedQuotes = _.times(sampleAmounts.length, () => constants.ZERO_AMOUNT);
+            await enableFailTriggerAsync();
+            const quotes = await testContract
+                .sampleSellsFromUniswapV2([TAKER_TOKEN, MAKER_TOKEN], sampleAmounts)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+
+        it('can quote token -> token -> token', async () => {
+            const intermediateToken = randomAddress();
+            const sampleAmounts = getSampleAmounts(TAKER_TOKEN);
+            const expectedQuotes = predictSellQuotes([TAKER_TOKEN, intermediateToken, MAKER_TOKEN], sampleAmounts);
+            const quotes = await testContract
+                .sampleSellsFromUniswapV2([TAKER_TOKEN, intermediateToken, MAKER_TOKEN], sampleAmounts)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+    });
+
+    blockchainTests.resets('sampleBuysFromUniswapV2()', () => {
+        function predictBuyQuotes(path: string[], buyAmounts: BigNumber[]): BigNumber[] {
+            return buyAmounts.map(a => getDeterministicUniswapV2BuyQuote(path, a));
+        }
+
+        it('can return no quotes', async () => {
+            const quotes = await testContract.sampleBuysFromUniswapV2([TAKER_TOKEN, MAKER_TOKEN], []).callAsync();
+            expect(quotes).to.deep.eq([]);
+        });
+
+        it('can quote token -> token', async () => {
+            const sampleAmounts = getSampleAmounts(MAKER_TOKEN);
+            const expectedQuotes = predictBuyQuotes([TAKER_TOKEN, MAKER_TOKEN], sampleAmounts);
+            const quotes = await testContract
+                .sampleBuysFromUniswapV2([TAKER_TOKEN, MAKER_TOKEN], sampleAmounts)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+
+        it('returns zero if token -> token fails', async () => {
+            const sampleAmounts = getSampleAmounts(MAKER_TOKEN);
+            const expectedQuotes = _.times(sampleAmounts.length, () => constants.ZERO_AMOUNT);
+            await enableFailTriggerAsync();
+            const quotes = await testContract
+                .sampleBuysFromUniswapV2([TAKER_TOKEN, MAKER_TOKEN], sampleAmounts)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+
+        it('can quote token -> token -> token', async () => {
+            const intermediateToken = randomAddress();
+            const sampleAmounts = getSampleAmounts(MAKER_TOKEN);
+            const expectedQuotes = predictBuyQuotes([TAKER_TOKEN, intermediateToken, MAKER_TOKEN], sampleAmounts);
+            const quotes = await testContract
+                .sampleBuysFromUniswapV2([TAKER_TOKEN, intermediateToken, MAKER_TOKEN], sampleAmounts)
+                .callAsync();
+            expect(quotes).to.deep.eq(expectedQuotes);
+        });
+    });
+
     describe('batchCall()', () => {
         it('can call one function', async () => {
             const orders = createOrders(MAKER_TOKEN, TAKER_TOKEN);

contracts/erc20-bridge-sampler/test/wrappers.ts

@@ -3,11 +3,18 @@
  * Warning: This file is auto-generated by contracts-gen. Don't edit manually.
  * -----------------------------------------------------------------------------
  */
+export * from '../test/generated-wrappers/dummy_liquidity_provider';
+export * from '../test/generated-wrappers/dummy_liquidity_provider_registry';
 export * from '../test/generated-wrappers/erc20_bridge_sampler';
 export * from '../test/generated-wrappers/i_curve';
 export * from '../test/generated-wrappers/i_dev_utils';
 export * from '../test/generated-wrappers/i_erc20_bridge_sampler';
 export * from '../test/generated-wrappers/i_eth2_dai';
 export * from '../test/generated-wrappers/i_kyber_network';
+export * from '../test/generated-wrappers/i_kyber_network_proxy';
+export * from '../test/generated-wrappers/i_liquidity_provider';
+export * from '../test/generated-wrappers/i_liquidity_provider_registry';
+export * from '../test/generated-wrappers/i_multi_bridge';
 export * from '../test/generated-wrappers/i_uniswap_exchange_quotes';
+export * from '../test/generated-wrappers/i_uniswap_v2_router01';
 export * from '../test/generated-wrappers/test_erc20_bridge_sampler';

contracts/erc20-bridge-sampler/tsconfig.json

@@ -3,15 +3,26 @@
     "compilerOptions": { "outDir": "lib", "rootDir": ".", "resolveJsonModule": true },
     "include": ["./src/**/*", "./test/**/*", "./generated-wrappers/**/*"],
     "files": [
+        "generated-artifacts/DummyLiquidityProvider.json",
+        "generated-artifacts/DummyLiquidityProviderRegistry.json",
         "generated-artifacts/ERC20BridgeSampler.json",
         "generated-artifacts/IERC20BridgeSampler.json",
+        "generated-artifacts/ILiquidityProvider.json",
+        "generated-artifacts/ILiquidityProviderRegistry.json",
+        "test/generated-artifacts/DummyLiquidityProvider.json",
+        "test/generated-artifacts/DummyLiquidityProviderRegistry.json",
         "test/generated-artifacts/ERC20BridgeSampler.json",
         "test/generated-artifacts/ICurve.json",
         "test/generated-artifacts/IDevUtils.json",
         "test/generated-artifacts/IERC20BridgeSampler.json",
         "test/generated-artifacts/IEth2Dai.json",
         "test/generated-artifacts/IKyberNetwork.json",
+        "test/generated-artifacts/IKyberNetworkProxy.json",
+        "test/generated-artifacts/ILiquidityProvider.json",
+        "test/generated-artifacts/ILiquidityProviderRegistry.json",
+        "test/generated-artifacts/IMultiBridge.json",
         "test/generated-artifacts/IUniswapExchangeQuotes.json",
+        "test/generated-artifacts/IUniswapV2Router01.json",
         "test/generated-artifacts/TestERC20BridgeSampler.json"
     ],
     "exclude": ["./deploy/solc/solc_bin"]

contracts/erc20/CHANGELOG.json

@@ -1,4 +1,49 @@
 [
+    {
+        "version": "3.2.0",
+        "changes": [
+            {
+                "note": "Add `LibERC20Token.approveIfBelow()`",
+                "pr": 2512
+            },
+            {
+                "note": "Add solidity 0.6 contracts",
+                "pr": 2545
+            },
+            {
+                "note": "Update `LibERC20TokenV06` comments.",
+                "pr": 2597
+            }
+        ],
+        "timestamp": 1592969527
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "3.1.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "3.1.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "3.1.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "3.1.2",

contracts/erc20/CHANGELOG.md

@@ -5,6 +5,24 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.2.0 - _June 24, 2020_
+
+    * Add `LibERC20Token.approveIfBelow()` (#2512)
+    * Add solidity 0.6 contracts (#2545)
+    * Update `LibERC20TokenV06` comments. (#2597)
+
+## v3.1.5 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v3.1.4 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v3.1.3 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v3.1.2 - _February 25, 2020_
 
     * Dependencies updated

contracts/erc20/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/erc20/contracts/src/LibERC20Token.sol

@@ -47,6 +47,25 @@ library LibERC20Token {
         _callWithOptionalBooleanResult(token, callData);
     }
 
+    /// @dev Calls `IERC20Token(token).approve()` and sets the allowance to the
+    ///      maximum if the current approval is not already >= an amount.
+    ///      Reverts if `false` is returned or if the return
+    ///      data length is nonzero and not 32 bytes.
+    /// @param token The address of the token contract.
+    /// @param spender The address that receives an allowance.
+    /// @param amount The minimum allowance needed.
+    function approveIfBelow(
+        address token,
+        address spender,
+        uint256 amount
+    )
+        internal
+    {
+        if (IERC20Token(token).allowance(address(this), spender) < amount) {
+            approve(token, spender, uint256(-1));
+        }
+    }
+
     /// @dev Calls `IERC20Token(token).transfer()`.
     ///      Reverts if `false` is returned or if the return
     ///      data length is nonzero and not 32 bytes.

contracts/erc20/contracts/src/v06/IERC20TokenV06.sol

@@ -0,0 +1,95 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+
+
+interface IERC20TokenV06 {
+
+    // solhint-disable no-simple-event-func-name
+    event Transfer(
+        address indexed from,
+        address indexed to,
+        uint256 value
+    );
+
+    event Approval(
+        address indexed owner,
+        address indexed spender,
+        uint256 value
+    );
+
+    /// @dev send `value` token to `to` from `msg.sender`
+    /// @param to The address of the recipient
+    /// @param value The amount of token to be transferred
+    /// @return True if transfer was successful
+    function transfer(address to, uint256 value)
+        external
+        returns (bool);
+
+    /// @dev send `value` token to `to` from `from` on the condition it is approved by `from`
+    /// @param from The address of the sender
+    /// @param to The address of the recipient
+    /// @param value The amount of token to be transferred
+    /// @return True if transfer was successful
+    function transferFrom(
+        address from,
+        address to,
+        uint256 value
+    )
+        external
+        returns (bool);
+
+    /// @dev `msg.sender` approves `spender` to spend `value` tokens
+    /// @param spender The address of the account able to transfer the tokens
+    /// @param value The amount of wei to be approved for transfer
+    /// @return Always true if the call has enough gas to complete execution
+    function approve(address spender, uint256 value)
+        external
+        returns (bool);
+
+    /// @dev Query total supply of token
+    /// @return Total supply of token
+    function totalSupply()
+        external
+        view
+        returns (uint256);
+
+    /// @dev Get the balance of `owner`.
+    /// @param owner The address from which the balance will be retrieved
+    /// @return Balance of owner
+    function balanceOf(address owner)
+        external
+        view
+        returns (uint256);
+
+    /// @dev Get the allowance for `spender` to spend from `owner`.
+    /// @param owner The address of the account owning tokens
+    /// @param spender The address of the account able to transfer the tokens
+    /// @return Amount of remaining tokens allowed to spent
+    function allowance(address owner, address spender)
+        external
+        view
+        returns (uint256);
+
+    /// @dev Get the number of decimals this token has.
+    function decimals()
+        external
+        view
+        returns (uint8);
+}

contracts/erc20/contracts/src/v06/IEtherTokenV06.sol

@@ -0,0 +1,32 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+
+import "./IERC20TokenV06.sol";
+
+
+interface IEtherTokenV06 is
+    IERC20TokenV06
+{
+    /// @dev Wrap ether.
+    function deposit() external payable;
+
+    /// @dev Unwrap ether.
+    function withdraw(uint256 amount) external;
+}

contracts/erc20/contracts/src/v06/LibERC20TokenV06.sol

@@ -0,0 +1,208 @@
+/*
+
+  Copyright 2020 ZeroEx Intl.
+
+  Licensed under the Apache License, Version 2.0 (the "License");
+  you may not use this file except in compliance with the License.
+  You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+  Unless required by applicable law or agreed to in writing, software
+  distributed under the License is distributed on an "AS IS" BASIS,
+  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+  See the License for the specific language governing permissions and
+  limitations under the License.
+
+*/
+
+pragma solidity ^0.6.5;
+
+import "@0x/contracts-utils/contracts/src/v06/errors/LibRichErrorsV06.sol";
+import "@0x/contracts-utils/contracts/src/v06/LibBytesV06.sol";
+import "./IERC20TokenV06.sol";
+
+
+library LibERC20TokenV06 {
+    bytes constant private DECIMALS_CALL_DATA = hex"313ce567";
+
+    /// @dev Calls `IERC20TokenV06(token).approve()`.
+    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
+    /// @param token The address of the token contract.
+    /// @param spender The address that receives an allowance.
+    /// @param allowance The allowance to set.
+    function compatApprove(
+        IERC20TokenV06 token,
+        address spender,
+        uint256 allowance
+    )
+        internal
+    {
+        bytes memory callData = abi.encodeWithSelector(
+            token.approve.selector,
+            spender,
+            allowance
+        );
+        _callWithOptionalBooleanResult(address(token), callData);
+    }
+
+    /// @dev Calls `IERC20TokenV06(token).approve()` and sets the allowance to the
+    ///      maximum if the current approval is not already >= an amount.
+    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
+    /// @param token The address of the token contract.
+    /// @param spender The address that receives an allowance.
+    /// @param amount The minimum allowance needed.
+    function approveIfBelow(
+        IERC20TokenV06 token,
+        address spender,
+        uint256 amount
+    )
+        internal
+    {
+        if (token.allowance(address(this), spender) < amount) {
+            compatApprove(token, spender, uint256(-1));
+        }
+    }
+
+    /// @dev Calls `IERC20TokenV06(token).transfer()`.
+    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
+    /// @param token The address of the token contract.
+    /// @param to The address that receives the tokens
+    /// @param amount Number of tokens to transfer.
+    function compatTransfer(
+        IERC20TokenV06 token,
+        address to,
+        uint256 amount
+    )
+        internal
+    {
+        bytes memory callData = abi.encodeWithSelector(
+            token.transfer.selector,
+            to,
+            amount
+        );
+        _callWithOptionalBooleanResult(address(token), callData);
+    }
+
+    /// @dev Calls `IERC20TokenV06(token).transferFrom()`.
+    ///      Reverts if the result fails `isSuccessfulResult()` or the call reverts.
+    /// @param token The address of the token contract.
+    /// @param from The owner of the tokens.
+    /// @param to The address that receives the tokens
+    /// @param amount Number of tokens to transfer.
+    function compatTransferFrom(
+        IERC20TokenV06 token,
+        address from,
+        address to,
+        uint256 amount
+    )
+        internal
+    {
+        bytes memory callData = abi.encodeWithSelector(
+            token.transferFrom.selector,
+            from,
+            to,
+            amount
+        );
+        _callWithOptionalBooleanResult(address(token), callData);
+    }
+
+    /// @dev Retrieves the number of decimals for a token.
+    ///      Returns `18` if the call reverts.
+    /// @param token The address of the token contract.
+    /// @return tokenDecimals The number of decimals places for the token.
+    function compatDecimals(IERC20TokenV06 token)
+        internal
+        view
+        returns (uint8 tokenDecimals)
+    {
+        tokenDecimals = 18;
+        (bool didSucceed, bytes memory resultData) = address(token).staticcall(DECIMALS_CALL_DATA);
+        if (didSucceed && resultData.length == 32) {
+            tokenDecimals = uint8(LibBytesV06.readUint256(resultData, 0));
+        }
+    }
+
+    /// @dev Retrieves the allowance for a token, owner, and spender.
+    ///      Returns `0` if the call reverts.
+    /// @param token The address of the token contract.
+    /// @param owner The owner of the tokens.
+    /// @param spender The address the spender.
+    /// @return allowance_ The allowance for a token, owner, and spender.
+    function compatAllowance(IERC20TokenV06 token, address owner, address spender)
+        internal
+        view
+        returns (uint256 allowance_)
+    {
+        (bool didSucceed, bytes memory resultData) = address(token).staticcall(
+            abi.encodeWithSelector(
+                token.allowance.selector,
+                owner,
+                spender
+            )
+        );
+        if (didSucceed && resultData.length == 32) {
+            allowance_ = LibBytesV06.readUint256(resultData, 0);
+        }
+    }
+
+    /// @dev Retrieves the balance for a token owner.
+    ///      Returns `0` if the call reverts.
+    /// @param token The address of the token contract.
+    /// @param owner The owner of the tokens.
+    /// @return balance The token balance of an owner.
+    function compatBalanceOf(IERC20TokenV06 token, address owner)
+        internal
+        view
+        returns (uint256 balance)
+    {
+        (bool didSucceed, bytes memory resultData) = address(token).staticcall(
+            abi.encodeWithSelector(
+                token.balanceOf.selector,
+                owner
+            )
+        );
+        if (didSucceed && resultData.length == 32) {
+            balance = LibBytesV06.readUint256(resultData, 0);
+        }
+    }
+
+    /// @dev Check if the data returned by a non-static call to an ERC20 token
+    ///      is a successful result. Supported functions are `transfer()`,
+    ///      `transferFrom()`, and `approve()`.
+    /// @param resultData The raw data returned by a non-static call to the ERC20 token.
+    /// @return isSuccessful Whether the result data indicates success.
+    function isSuccessfulResult(bytes memory resultData)
+        internal
+        pure
+        returns (bool isSuccessful)
+    {
+        if (resultData.length == 0) {
+            return true;
+        }
+        if (resultData.length == 32) {
+            uint256 result = LibBytesV06.readUint256(resultData, 0);
+            if (result == 1) {
+                return true;
+            }
+        }
+    }
+
+    /// @dev Executes a call on address `target` with calldata `callData`
+    ///      and asserts that either nothing was returned or a single boolean
+    ///      was returned equal to `true`.
+    /// @param target The call target.
+    /// @param callData The abi-encoded call data.
+    function _callWithOptionalBooleanResult(
+        address target,
+        bytes memory callData
+    )
+        private
+    {
+        (bool didSucceed, bytes memory resultData) = target.call(callData);
+        if (didSucceed && isSuccessfulResult(resultData)) {
+            return;
+        }
+        LibRichErrorsV06.rrevert(resultData);
+    }
+}

contracts/erc20/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-erc20",
-    "version": "3.1.2",
+    "version": "3.2.0",
     "engines": {
         "node": ">=6.12"
     },
@@ -38,7 +38,7 @@
     },
     "config": {
         "publicInterfaceContracts": "DummyERC20Token,ERC20Token,WETH9,ZRXToken,DummyNoReturnERC20Token,DummyMultipleReturnERC20Token",
-        "abis": "./test/generated-artifacts/@(DummyERC20Token|DummyMultipleReturnERC20Token|DummyNoReturnERC20Token|ERC20Token|IERC20Token|IEtherToken|LibERC20Token|MintableERC20Token|TestLibERC20Token|TestLibERC20TokenTarget|UnlimitedAllowanceERC20Token|UntransferrableDummyERC20Token|WETH9|ZRXToken).json",
+        "abis": "./test/generated-artifacts/@(DummyERC20Token|DummyMultipleReturnERC20Token|DummyNoReturnERC20Token|ERC20Token|IERC20Token|IERC20TokenV06|IEtherToken|IEtherTokenV06|LibERC20Token|LibERC20TokenV06|MintableERC20Token|TestLibERC20Token|TestLibERC20TokenTarget|UnlimitedAllowanceERC20Token|UntransferrableDummyERC20Token|WETH9|ZRXToken).json",
         "abis:comment": "This list is auto-generated by contracts-gen. Don't edit manually."
     },
     "repository": {
@@ -51,18 +51,18 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/tokens/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/dev-utils": "^3.2.1",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/dev-utils": "^3.2.2",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/types": "^3.1.2",
-        "@0x/typescript-typings": "^5.0.2",
-        "@0x/utils": "^5.4.1",
-        "@0x/web3-wrapper": "^7.0.7",
+        "@0x/types": "^3.1.3",
+        "@0x/typescript-typings": "^5.1.0",
+        "@0x/utils": "^5.5.0",
+        "@0x/web3-wrapper": "^7.1.0",
         "@types/lodash": "4.14.104",
         "@types/mocha": "^5.2.7",
         "@types/node": "*",
@@ -70,7 +70,7 @@
         "chai-as-promised": "^7.1.0",
         "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
-        "ethereum-types": "^3.1.0",
+        "ethereum-types": "^3.1.1",
         "lodash": "^4.17.11",
         "make-promises-safe": "^1.1.0",
         "mocha": "^6.2.0",
@@ -82,7 +82,7 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1"
+        "@0x/base-contract": "^6.2.2"
     },
     "publishConfig": {
         "access": "public"

contracts/erc20/test/artifacts.ts

@@ -10,8 +10,11 @@ import * as DummyMultipleReturnERC20Token from '../test/generated-artifacts/Dumm
 import * as DummyNoReturnERC20Token from '../test/generated-artifacts/DummyNoReturnERC20Token.json';
 import * as ERC20Token from '../test/generated-artifacts/ERC20Token.json';
 import * as IERC20Token from '../test/generated-artifacts/IERC20Token.json';
+import * as IERC20TokenV06 from '../test/generated-artifacts/IERC20TokenV06.json';
 import * as IEtherToken from '../test/generated-artifacts/IEtherToken.json';
+import * as IEtherTokenV06 from '../test/generated-artifacts/IEtherTokenV06.json';
 import * as LibERC20Token from '../test/generated-artifacts/LibERC20Token.json';
+import * as LibERC20TokenV06 from '../test/generated-artifacts/LibERC20TokenV06.json';
 import * as MintableERC20Token from '../test/generated-artifacts/MintableERC20Token.json';
 import * as TestLibERC20Token from '../test/generated-artifacts/TestLibERC20Token.json';
 import * as TestLibERC20TokenTarget from '../test/generated-artifacts/TestLibERC20TokenTarget.json';
@@ -28,6 +31,9 @@ export const artifacts = {
     ZRXToken: (ZRXToken as any) as ContractArtifact,
     IERC20Token: IERC20Token as ContractArtifact,
     IEtherToken: IEtherToken as ContractArtifact,
+    IERC20TokenV06: IERC20TokenV06 as ContractArtifact,
+    IEtherTokenV06: IEtherTokenV06 as ContractArtifact,
+    LibERC20TokenV06: LibERC20TokenV06 as ContractArtifact,
     DummyERC20Token: DummyERC20Token as ContractArtifact,
     DummyMultipleReturnERC20Token: DummyMultipleReturnERC20Token as ContractArtifact,
     DummyNoReturnERC20Token: DummyNoReturnERC20Token as ContractArtifact,

contracts/erc20/test/wrappers.ts

@@ -8,8 +8,11 @@ export * from '../test/generated-wrappers/dummy_multiple_return_erc20_token';
 export * from '../test/generated-wrappers/dummy_no_return_erc20_token';
 export * from '../test/generated-wrappers/erc20_token';
 export * from '../test/generated-wrappers/i_erc20_token';
+export * from '../test/generated-wrappers/i_erc20_token_v06';
 export * from '../test/generated-wrappers/i_ether_token';
+export * from '../test/generated-wrappers/i_ether_token_v06';
 export * from '../test/generated-wrappers/lib_erc20_token';
+export * from '../test/generated-wrappers/lib_erc20_token_v06';
 export * from '../test/generated-wrappers/mintable_erc20_token';
 export * from '../test/generated-wrappers/test_lib_erc20_token';
 export * from '../test/generated-wrappers/test_lib_erc20_token_target';

contracts/erc20/tsconfig.json

@@ -14,8 +14,11 @@
         "test/generated-artifacts/DummyNoReturnERC20Token.json",
         "test/generated-artifacts/ERC20Token.json",
         "test/generated-artifacts/IERC20Token.json",
+        "test/generated-artifacts/IERC20TokenV06.json",
         "test/generated-artifacts/IEtherToken.json",
+        "test/generated-artifacts/IEtherTokenV06.json",
         "test/generated-artifacts/LibERC20Token.json",
+        "test/generated-artifacts/LibERC20TokenV06.json",
         "test/generated-artifacts/MintableERC20Token.json",
         "test/generated-artifacts/TestLibERC20Token.json",
         "test/generated-artifacts/TestLibERC20TokenTarget.json",

contracts/erc721/CHANGELOG.json

@@ -1,4 +1,40 @@
 [
+    {
+        "timestamp": 1592969527,
+        "version": "3.1.6",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "3.1.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "3.1.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "3.1.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "3.1.2",

contracts/erc721/CHANGELOG.md

@@ -5,6 +5,22 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.1.6 - _June 24, 2020_
+
+    * Dependencies updated
+
+## v3.1.5 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v3.1.4 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v3.1.3 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v3.1.2 - _February 25, 2020_
 
     * Dependencies updated

contracts/erc721/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/erc721/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-erc721",
-    "version": "3.1.2",
+    "version": "3.1.6",
     "engines": {
         "node": ">=6.12"
     },
@@ -52,18 +52,18 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/tokens/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/dev-utils": "^3.2.1",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/dev-utils": "^3.2.2",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/types": "^3.1.2",
-        "@0x/typescript-typings": "^5.0.2",
-        "@0x/utils": "^5.4.1",
-        "@0x/web3-wrapper": "^7.0.7",
+        "@0x/types": "^3.1.3",
+        "@0x/typescript-typings": "^5.1.0",
+        "@0x/utils": "^5.5.0",
+        "@0x/web3-wrapper": "^7.1.0",
         "@types/lodash": "4.14.104",
         "@types/mocha": "^5.2.7",
         "@types/node": "*",
@@ -71,7 +71,7 @@
         "chai-as-promised": "^7.1.0",
         "chai-bignumber": "^3.0.0",
         "dirty-chai": "^2.0.1",
-        "ethereum-types": "^3.1.0",
+        "ethereum-types": "^3.1.1",
         "lodash": "^4.17.11",
         "make-promises-safe": "^1.1.0",
         "mocha": "^6.2.0",
@@ -84,7 +84,7 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1"
+        "@0x/base-contract": "^6.2.2"
     },
     "publishConfig": {
         "access": "public"

contracts/exchange-forwarder/CHANGELOG.json

@@ -1,4 +1,40 @@
 [
+    {
+        "timestamp": 1592969527,
+        "version": "4.2.6",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "4.2.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "4.2.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "4.2.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "4.2.2",

contracts/exchange-forwarder/CHANGELOG.md

@@ -5,6 +5,22 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v4.2.6 - _June 24, 2020_
+
+    * Dependencies updated
+
+## v4.2.5 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v4.2.4 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v4.2.3 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v4.2.2 - _February 25, 2020_
 
     * Dependencies updated

contracts/exchange-forwarder/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/exchange-forwarder/contracts/src/Forwarder.sol

@@ -151,6 +151,72 @@ contract Forwarder is
         _unwrapAndTransferEth(wethRemaining);
     }
 
+    /// @dev Purchases as much of orders' makerAssets as possible by selling the specified amount of ETH
+    ///      accounting for order and forwarder fees. This functions throws if ethSellAmount was not reached.
+    /// @param orders Array of order specifications used containing desired makerAsset and WETH as takerAsset.
+    /// @param ethSellAmount Desired amount of ETH to sell.
+    /// @param signatures Proofs that orders have been created by makers.
+    /// @param ethFeeAmounts Amounts of ETH, denominated in Wei, that are paid to corresponding feeRecipients.
+    /// @param feeRecipients Addresses that will receive ETH when orders are filled.
+    /// @return wethSpentAmount Amount of WETH spent on the given set of orders.
+    /// @return makerAssetAcquiredAmount Amount of maker asset acquired from the given set of orders.
+    function marketSellAmountWithEth(
+        LibOrder.Order[] memory orders,
+        uint256 ethSellAmount,
+        bytes[] memory signatures,
+        uint256[] memory ethFeeAmounts,
+        address payable[] memory feeRecipients
+    )
+        public
+        payable
+        returns (
+            uint256 wethSpentAmount,
+            uint256 makerAssetAcquiredAmount
+        )
+    {
+        if (ethSellAmount > msg.value) {
+            LibRichErrors.rrevert(LibForwarderRichErrors.CompleteSellFailedError(
+                ethSellAmount,
+                msg.value
+            ));
+        }
+        // Pay ETH affiliate fees to all feeRecipient addresses
+        uint256 wethRemaining = _transferEthFeesAndWrapRemaining(
+            ethFeeAmounts,
+            feeRecipients
+        );
+        // Need enough remaining to ensure we can sell ethSellAmount
+        if (wethRemaining < ethSellAmount) {
+            LibRichErrors.rrevert(LibForwarderRichErrors.OverspentWethError(
+                wethRemaining,
+                ethSellAmount
+            ));
+        }
+        // Spends up to ethSellAmount to fill orders, transfers purchased assets to msg.sender,
+        // and pays WETH order fees.
+        (
+            wethSpentAmount,
+            makerAssetAcquiredAmount
+        ) = _marketSellExactAmountNoThrow(
+            orders,
+            ethSellAmount,
+            signatures
+        );
+        // Ensure we sold the specified amount (note: wethSpentAmount includes fees)
+        if (wethSpentAmount < ethSellAmount) {
+            LibRichErrors.rrevert(LibForwarderRichErrors.CompleteSellFailedError(
+                ethSellAmount,
+                wethSpentAmount
+            ));
+        }
+
+        // Calculate amount of WETH that hasn't been spent.
+        wethRemaining = wethRemaining.safeSub(wethSpentAmount);
+
+        // Refund remaining ETH to msg.sender.
+        _unwrapAndTransferEth(wethRemaining);
+    }
+
     /// @dev Attempt to buy makerAssetBuyAmount of makerAsset by selling ETH provided with transaction.
     ///      The Forwarder may *fill* more than makerAssetBuyAmount of the makerAsset so that it can
     ///      pay takerFees where takerFeeAssetData == makerAssetData (i.e. percentage fees).

contracts/exchange-forwarder/contracts/src/MixinExchangeWrapper.sol

@@ -53,6 +53,7 @@ contract MixinExchangeWrapper {
     //     ")"
     // )));
     bytes4 constant public EXCHANGE_V2_ORDER_ID = 0x770501f8;
+    bytes4 constant internal ERC20_BRIDGE_PROXY_ID = 0xdc1600f3;
 
      // solhint-disable var-name-mixedcase
     IExchange internal EXCHANGE;
@@ -73,6 +74,12 @@ contract MixinExchangeWrapper {
         EXCHANGE_V2 = IExchangeV2(_exchangeV2);
     }
 
+    struct SellFillResults {
+        uint256 wethSpentAmount;
+        uint256 makerAssetAcquiredAmount;
+        uint256 protocolFeePaid;
+    }
+
     /// @dev Fills the input order.
     ///      Returns false if the transaction would otherwise revert.
     /// @param order Order struct containing order specifications.
@@ -115,11 +122,16 @@ contract MixinExchangeWrapper {
         uint256 remainingTakerAssetFillAmount
     )
         internal
-        returns (
-            uint256 wethSpentAmount,
-            uint256 makerAssetAcquiredAmount
-        )
+        returns (SellFillResults memory sellFillResults)
     {
+        // If the maker asset is ERC20Bridge, take a snapshot of the Forwarder contract's balance.
+        bytes4 makerAssetProxyId = order.makerAssetData.readBytes4(0);
+        address tokenAddress;
+        uint256 balanceBefore;
+        if (makerAssetProxyId == ERC20_BRIDGE_PROXY_ID) {
+            tokenAddress = order.makerAssetData.readAddress(16);
+            balanceBefore = IERC20Token(tokenAddress).balanceOf(address(this));
+        }
         // No taker fee or percentage fee
         if (
             order.takerFee == 0 ||
@@ -132,11 +144,11 @@ contract MixinExchangeWrapper {
                 signature
             );
 
-            wethSpentAmount = singleFillResults.takerAssetFilledAmount
-                .safeAdd(singleFillResults.protocolFeePaid);
+            sellFillResults.wethSpentAmount = singleFillResults.takerAssetFilledAmount;
+            sellFillResults.protocolFeePaid = singleFillResults.protocolFeePaid;
 
             // Subtract fee from makerAssetFilledAmount for the net amount acquired.
-            makerAssetAcquiredAmount = singleFillResults.makerAssetFilledAmount
+            sellFillResults.makerAssetAcquiredAmount = singleFillResults.makerAssetFilledAmount
                 .safeSub(singleFillResults.takerFeePaid);
 
         // WETH fee
@@ -157,18 +169,27 @@ contract MixinExchangeWrapper {
             );
 
             // WETH is also spent on the taker fee, so we add it here.
-            wethSpentAmount = singleFillResults.takerAssetFilledAmount
-                .safeAdd(singleFillResults.takerFeePaid)
-                .safeAdd(singleFillResults.protocolFeePaid);
-
-            makerAssetAcquiredAmount = singleFillResults.makerAssetFilledAmount;
+            sellFillResults.wethSpentAmount = singleFillResults.takerAssetFilledAmount
+                .safeAdd(singleFillResults.takerFeePaid);
+            sellFillResults.makerAssetAcquiredAmount = singleFillResults.makerAssetFilledAmount;
+            sellFillResults.protocolFeePaid = singleFillResults.protocolFeePaid;
 
         // Unsupported fee
         } else {
             LibRichErrors.rrevert(LibForwarderRichErrors.UnsupportedFeeError(order.takerFeeAssetData));
         }
 
-        return (wethSpentAmount, makerAssetAcquiredAmount);
+        // Account for the ERC20Bridge transfering more of the maker asset than expected.
+        if (makerAssetProxyId == ERC20_BRIDGE_PROXY_ID) {
+            uint256 balanceAfter = IERC20Token(tokenAddress).balanceOf(address(this));
+            sellFillResults.makerAssetAcquiredAmount = LibSafeMath.max256(
+                balanceAfter.safeSub(balanceBefore),
+                sellFillResults.makerAssetAcquiredAmount
+            );
+        }
+
+        order.makerAssetData.transferOut(sellFillResults.makerAssetAcquiredAmount);
+        return sellFillResults;
     }
 
     /// @dev Synchronously executes multiple calls of fillOrder until total amount of WETH has been sold by taker.
@@ -189,7 +210,6 @@ contract MixinExchangeWrapper {
         )
     {
         uint256 protocolFee = tx.gasprice.safeMul(EXCHANGE.protocolFeeMultiplier());
-        bytes4 erc20BridgeProxyId = IAssetData(address(0)).ERC20Bridge.selector;
 
         for (uint256 i = 0; i != orders.length; i++) {
             // Preemptively skip to avoid division by zero in _marketSellSingleOrder
@@ -199,42 +219,27 @@ contract MixinExchangeWrapper {
 
             // The remaining amount of WETH to sell
             uint256 remainingTakerAssetFillAmount = wethSellAmount
-                .safeSub(totalWethSpentAmount)
-                .safeSub(_isV2Order(orders[i]) ? 0 : protocolFee);
-
-            // If the maker asset is ERC20Bridge, take a snapshot of the Forwarder contract's balance.
-            bytes4 makerAssetProxyId = orders[i].makerAssetData.readBytes4(0);
-            address tokenAddress;
-            uint256 balanceBefore;
-            if (makerAssetProxyId == erc20BridgeProxyId) {
-                tokenAddress = orders[i].makerAssetData.readAddress(16);
-                balanceBefore = IERC20Token(tokenAddress).balanceOf(address(this));
+                .safeSub(totalWethSpentAmount);
+            uint256 currentProtocolFee = _isV2Order(orders[i]) ? 0 : protocolFee;
+            if (remainingTakerAssetFillAmount > currentProtocolFee) {
+                // Do not count the protocol fee as part of the fill amount.
+                remainingTakerAssetFillAmount = remainingTakerAssetFillAmount.safeSub(currentProtocolFee);
+            } else {
+                // Stop if we don't have at least enough ETH to pay another protocol fee.
+                break;
             }
 
-            (
-                uint256 wethSpentAmount,
-                uint256 makerAssetAcquiredAmount
-            ) = _marketSellSingleOrder(
+            SellFillResults memory sellFillResults = _marketSellSingleOrder(
                 orders[i],
                 signatures[i],
                 remainingTakerAssetFillAmount
             );
 
-            // Account for the ERC20Bridge transfering more of the maker asset than expected.
-            if (makerAssetProxyId == erc20BridgeProxyId) {
-                uint256 balanceAfter = IERC20Token(tokenAddress).balanceOf(address(this));
-                makerAssetAcquiredAmount = LibSafeMath.max256(
-                    balanceAfter.safeSub(balanceBefore),
-                    makerAssetAcquiredAmount
-                );
-            }
-
-            orders[i].makerAssetData.transferOut(makerAssetAcquiredAmount);
-
             totalWethSpentAmount = totalWethSpentAmount
-                .safeAdd(wethSpentAmount);
+                .safeAdd(sellFillResults.wethSpentAmount)
+                .safeAdd(sellFillResults.protocolFeePaid);
             totalMakerAssetAcquiredAmount = totalMakerAssetAcquiredAmount
-                .safeAdd(makerAssetAcquiredAmount);
+                .safeAdd(sellFillResults.makerAssetAcquiredAmount);
 
             // Stop execution if the entire amount of WETH has been sold
             if (totalWethSpentAmount >= wethSellAmount) {
@@ -243,6 +248,56 @@ contract MixinExchangeWrapper {
         }
     }
 
+    /// @dev Synchronously executes multiple calls of fillOrder until total amount of WETH (exclusive of protocol fee)
+    ///      has been sold by taker.
+    /// @param orders Array of order specifications.
+    /// @param wethSellAmount Desired amount of WETH to sell.
+    /// @param signatures Proofs that orders have been signed by makers.
+    /// @return totalWethSpentAmount Total amount of WETH spent on the given orders.
+    /// @return totalMakerAssetAcquiredAmount Total amount of maker asset acquired from the given orders.
+    function _marketSellExactAmountNoThrow(
+        LibOrder.Order[] memory orders,
+        uint256 wethSellAmount,
+        bytes[] memory signatures
+    )
+        internal
+        returns (
+            uint256 totalWethSpentAmount,
+            uint256 totalMakerAssetAcquiredAmount
+        )
+    {
+        uint256 totalProtocolFeePaid;
+
+        for (uint256 i = 0; i != orders.length; i++) {
+            // Preemptively skip to avoid division by zero in _marketSellSingleOrder
+            if (orders[i].makerAssetAmount == 0 || orders[i].takerAssetAmount == 0) {
+                continue;
+            }
+
+            // The remaining amount of WETH to sell
+            uint256 remainingTakerAssetFillAmount = wethSellAmount
+                .safeSub(totalWethSpentAmount);
+
+            SellFillResults memory sellFillResults = _marketSellSingleOrder(
+                orders[i],
+                signatures[i],
+                remainingTakerAssetFillAmount
+            );
+
+            totalWethSpentAmount = totalWethSpentAmount
+                .safeAdd(sellFillResults.wethSpentAmount);
+            totalMakerAssetAcquiredAmount = totalMakerAssetAcquiredAmount
+                .safeAdd(sellFillResults.makerAssetAcquiredAmount);
+            totalProtocolFeePaid = totalProtocolFeePaid.safeAdd(sellFillResults.protocolFeePaid);
+
+            // Stop execution if the entire amount of WETH has been sold
+            if (totalWethSpentAmount >= wethSellAmount) {
+                break;
+            }
+        }
+        totalWethSpentAmount = totalWethSpentAmount.safeAdd(totalProtocolFeePaid);
+    }
+
     /// @dev Executes a single call of fillOrder according to the makerAssetBuyAmount and
     ///      the amount already bought.
     /// @param order A single order specification.
@@ -338,8 +393,6 @@ contract MixinExchangeWrapper {
             uint256 totalMakerAssetAcquiredAmount
         )
     {
-        bytes4 erc20BridgeProxyId = IAssetData(address(0)).ERC20Bridge.selector;
-
         uint256 ordersLength = orders.length;
         for (uint256 i = 0; i != ordersLength; i++) {
             // Preemptively skip to avoid division by zero in _marketBuySingleOrder
@@ -354,7 +407,7 @@ contract MixinExchangeWrapper {
             bytes4 makerAssetProxyId = orders[i].makerAssetData.readBytes4(0);
             address tokenAddress;
             uint256 balanceBefore;
-            if (makerAssetProxyId == erc20BridgeProxyId) {
+            if (makerAssetProxyId == ERC20_BRIDGE_PROXY_ID) {
                 tokenAddress = orders[i].makerAssetData.readAddress(16);
                 balanceBefore = IERC20Token(tokenAddress).balanceOf(address(this));
             }
@@ -369,7 +422,7 @@ contract MixinExchangeWrapper {
             );
 
             // Account for the ERC20Bridge transfering more of the maker asset than expected.
-            if (makerAssetProxyId == erc20BridgeProxyId) {
+            if (makerAssetProxyId == ERC20_BRIDGE_PROXY_ID) {
                 uint256 balanceAfter = IERC20Token(tokenAddress).balanceOf(address(this));
                 makerAssetAcquiredAmount = LibSafeMath.max256(
                     balanceAfter.safeSub(balanceBefore),

contracts/exchange-forwarder/contracts/src/libs/LibForwarderRichErrors.sol

@@ -29,6 +29,10 @@ library LibForwarderRichErrors {
     bytes4 internal constant COMPLETE_BUY_FAILED_ERROR_SELECTOR =
         0x91353a0c;
 
+    // bytes4(keccak256("CompleteSellFailedError(uint256,uint256)"))
+    bytes4 internal constant COMPLETE_SELL_FAILED_ERROR_SELECTOR =
+        0x450a0219;
+
     // bytes4(keccak256("UnsupportedFeeError(bytes)"))
     bytes4 internal constant UNSUPPORTED_FEE_ERROR_SELECTOR =
         0x31360af1;
@@ -61,6 +65,21 @@ library LibForwarderRichErrors {
         );
     }
 
+    function CompleteSellFailedError(
+        uint256 expectedAssetSellAmount,
+        uint256 actualAssetSellAmount
+    )
+        internal
+        pure
+        returns (bytes memory)
+    {
+        return abi.encodeWithSelector(
+            COMPLETE_SELL_FAILED_ERROR_SELECTOR,
+            expectedAssetSellAmount,
+            actualAssetSellAmount
+        );
+    }
+
     function UnsupportedFeeError(
         bytes memory takerFeeAssetData
     )

contracts/exchange-forwarder/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-exchange-forwarder",
-    "version": "4.2.2",
+    "version": "4.2.6",
     "engines": {
         "node": ">=6.12"
     },
@@ -52,25 +52,25 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/extensions/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-asset-proxy": "^3.2.2",
-        "@0x/contracts-dev-utils": "^1.3.0",
-        "@0x/contracts-erc1155": "^2.1.2",
-        "@0x/contracts-erc20": "^3.1.2",
-        "@0x/contracts-erc721": "^3.1.2",
-        "@0x/contracts-exchange": "^3.2.2",
-        "@0x/contracts-exchange-libs": "^4.3.2",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/dev-utils": "^3.2.1",
-        "@0x/order-utils": "^10.2.2",
-        "@0x/sol-compiler": "^4.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contracts-asset-proxy": "^3.3.0",
+        "@0x/contracts-dev-utils": "^1.3.4",
+        "@0x/contracts-erc1155": "^2.1.6",
+        "@0x/contracts-erc20": "^3.2.0",
+        "@0x/contracts-erc721": "^3.1.6",
+        "@0x/contracts-exchange": "^3.2.6",
+        "@0x/contracts-exchange-libs": "^4.3.6",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/dev-utils": "^3.2.2",
+        "@0x/order-utils": "^10.2.5",
+        "@0x/sol-compiler": "^4.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/types": "^3.1.2",
-        "@0x/utils": "^5.4.1",
-        "@0x/web3-wrapper": "^7.0.7",
+        "@0x/types": "^3.1.3",
+        "@0x/utils": "^5.5.0",
+        "@0x/web3-wrapper": "^7.1.0",
         "@types/lodash": "4.14.104",
         "@types/mocha": "^5.2.7",
         "@types/node": "*",
@@ -90,9 +90,9 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1",
-        "@0x/typescript-typings": "^5.0.2",
-        "ethereum-types": "^3.1.0"
+        "@0x/base-contract": "^6.2.2",
+        "@0x/typescript-typings": "^5.1.0",
+        "ethereum-types": "^3.1.1"
     },
     "publishConfig": {
         "access": "public"

contracts/exchange-libs/CHANGELOG.json

@@ -1,4 +1,40 @@
 [
+    {
+        "timestamp": 1592969527,
+        "version": "4.3.6",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "4.3.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "4.3.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "4.3.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "4.3.2",

contracts/exchange-libs/CHANGELOG.md

@@ -5,6 +5,22 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v4.3.6 - _June 24, 2020_
+
+    * Dependencies updated
+
+## v4.3.5 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v4.3.4 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v4.3.3 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v4.3.2 - _February 25, 2020_
 
     * Dependencies updated

contracts/exchange-libs/compiler.json

@@ -3,6 +3,7 @@
     "contractsDir": "./contracts",
     "useDockerisedSolc": false,
     "isOfflineMode": false,
+    "shouldSaveStandardInput": true,
     "compilerSettings": {
         "evmVersion": "istanbul",
         "optimizer": {

contracts/exchange-libs/package.json

@@ -1,6 +1,6 @@
 {
     "name": "@0x/contracts-exchange-libs",
-    "version": "4.3.2",
+    "version": "4.3.6",
     "engines": {
         "node": ">=6.12"
     },
@@ -52,14 +52,14 @@
     },
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/libs/README.md",
     "devDependencies": {
-        "@0x/abi-gen": "^5.2.1",
-        "@0x/contracts-gen": "^2.0.8",
-        "@0x/dev-utils": "^3.2.1",
-        "@0x/sol-compiler": "^4.0.8",
-        "@0x/subproviders": "^6.0.8",
+        "@0x/abi-gen": "^5.3.0",
+        "@0x/contracts-gen": "^2.0.9",
+        "@0x/dev-utils": "^3.2.2",
+        "@0x/sol-compiler": "^4.1.0",
+        "@0x/subproviders": "^6.1.0",
         "@0x/ts-doc-gen": "^0.0.22",
         "@0x/tslint-config": "^4.0.0",
-        "@0x/web3-wrapper": "^7.0.7",
+        "@0x/web3-wrapper": "^7.1.0",
         "@types/lodash": "4.14.104",
         "@types/mocha": "^5.2.7",
         "@types/node": "*",
@@ -80,14 +80,14 @@
         "typescript": "3.0.1"
     },
     "dependencies": {
-        "@0x/base-contract": "^6.2.1",
-        "@0x/contracts-test-utils": "^5.3.0",
-        "@0x/contracts-utils": "^4.4.0",
-        "@0x/order-utils": "^10.2.2",
-        "@0x/types": "^3.1.2",
-        "@0x/typescript-typings": "^5.0.2",
-        "@0x/utils": "^5.4.1",
-        "ethereum-types": "^3.1.0"
+        "@0x/base-contract": "^6.2.2",
+        "@0x/contracts-test-utils": "^5.3.3",
+        "@0x/contracts-utils": "^4.5.0",
+        "@0x/order-utils": "^10.2.5",
+        "@0x/types": "^3.1.3",
+        "@0x/typescript-typings": "^5.1.0",
+        "@0x/utils": "^5.5.0",
+        "ethereum-types": "^3.1.1"
     },
     "publishConfig": {
         "access": "public"

contracts/exchange/CHANGELOG.json

@@ -1,4 +1,40 @@
 [
+    {
+        "timestamp": 1592969527,
+        "version": "3.2.6",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1583220306,
+        "version": "3.2.5",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582837861,
+        "version": "3.2.4",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
+    {
+        "timestamp": 1582677073,
+        "version": "3.2.3",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
+    },
     {
         "timestamp": 1582623685,
         "version": "3.2.2",

contracts/exchange/CHANGELOG.md

@@ -5,6 +5,22 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v3.2.6 - _June 24, 2020_
+
+    * Dependencies updated
+
+## v3.2.5 - _March 3, 2020_
+
+    * Dependencies updated
+
+## v3.2.4 - _February 27, 2020_
+
+    * Dependencies updated
+
+## v3.2.3 - _February 26, 2020_
+
+    * Dependencies updated
+
 ## v3.2.2 - _February 25, 2020_
 
     * Dependencies updated