fix: Support Multiple Shells (#17)

* fix: Support Multiple Shells

* CHANGEGLOG

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

@@ -51,16 +51,15 @@ contract ShellBridge is
         external
         returns (bytes4 success)
     {
-        // Decode the bridge data to get the `fromTokenAddress`.
-        (address fromTokenAddress) = abi.decode(bridgeData, (address));
+        // Decode the bridge data to get the `fromTokenAddress` and `pool`.
+        (address fromTokenAddress, address pool) = abi.decode(bridgeData, (address, address));
 
         uint256 fromTokenBalance = IERC20Token(fromTokenAddress).balanceOf(address(this));
-        IShell exchange = IShell(_getShellAddress());
         // Grant an allowance to the exchange to spend `fromTokenAddress` token.
-        LibERC20Token.approveIfBelow(fromTokenAddress, address(exchange), fromTokenBalance);
+        LibERC20Token.approveIfBelow(fromTokenAddress, pool, fromTokenBalance);
 
         // Try to sell all of this contract's `fromTokenAddress` token balance.
-        uint256 boughtAmount = exchange.originSwap(
+        uint256 boughtAmount = IShell(pool).originSwap(
             fromTokenAddress,
             toTokenAddress,
             fromTokenBalance,

contracts/utils/contracts/src/DeploymentConstants.sol

@@ -56,8 +56,6 @@ contract DeploymentConstants {
     address constant private MUSD_ADDRESS = 0xe2f2a5C287993345a840Db3B0845fbC70f5935a5;
     /// @dev Mainnet address of the Mooniswap Registry contract
     address constant private MOONISWAP_REGISTRY = 0x71CD6666064C3A1354a3B4dca5fA1E2D3ee7D303;
-    /// @dev Mainnet address of the Shell contract
-    address constant private SHELL_CONTRACT = 0x2E703D658f8dd21709a7B458967aB4081F8D3d05;
     /// @dev Mainnet address of the DODO Registry (ZOO) contract
     address constant private DODO_REGISTRY = 0x3A97247DF274a17C59A3bd12735ea3FcDFb49950;
     /// @dev Mainnet address of the DODO Helper contract
@@ -303,16 +301,6 @@ contract DeploymentConstants {
         return MOONISWAP_REGISTRY;
     }
 
-    /// @dev An overridable way to retrieve the Shell contract address.
-    /// @return registry The Shell contract address.
-    function _getShellAddress()
-        internal
-        view
-        returns (address)
-    {
-        return SHELL_CONTRACT;
-    }
-
     /// @dev An overridable way to retrieve the DODO Registry contract address.
     /// @return registry The DODO Registry contract address.
     function _getDODORegistryAddress()

contracts/zero-ex/contracts/src/transformers/bridges/BridgeAdapter.sol

@@ -89,7 +89,7 @@ contract BridgeAdapter is
         MixinMooniswap(addresses)
         MixinMStable(addresses)
         MixinOasis(addresses)
-        MixinShell(addresses)
+        MixinShell()
         MixinSushiswap(addresses)
         MixinUniswap(addresses)
         MixinUniswapV2(addresses)

contracts/zero-ex/contracts/src/transformers/bridges/mixins/MixinAdapterAddresses.sol

@@ -44,7 +44,6 @@ contract MixinAdapterAddresses
         address uniswapV2Router;
         address uniswapExchangeFactory;
         address mStable;
-        address shell;
         address dodoHelper;
         // Other
         address weth;

contracts/zero-ex/contracts/src/transformers/bridges/mixins/MixinShell.sol

@@ -44,15 +44,6 @@ contract MixinShell is
 {
     using LibERC20TokenV06 for IERC20TokenV06;
 
-    /// @dev Mainnet address of the `Shell` contract.
-    IShell private immutable SHELL;
-
-    constructor(AdapterAddresses memory addresses)
-        public
-    {
-        SHELL = IShell(addresses.shell);
-    }
-
     function _tradeShell(
         IERC20TokenV06 buyToken,
         uint256 sellAmount,
@@ -61,15 +52,15 @@ contract MixinShell is
         internal
         returns (uint256 boughtAmount)
     {
-        (address fromTokenAddress) = abi.decode(bridgeData, (address));
+        (address fromTokenAddress, address pool) = abi.decode(bridgeData, (address, address));
 
         // Grant the Shell contract an allowance to sell the first token.
         IERC20TokenV06(fromTokenAddress).approveIfBelow(
-            address(SHELL),
+            pool,
             sellAmount
         );
 
-        boughtAmount = SHELL.originSwap(
+        boughtAmount = IShell(pool).originSwap(
             fromTokenAddress,
             address(buyToken),
              // Sell all tokens we hold.

contracts/zero-ex/test/transformers/fill_quote_transformer_test.ts

@@ -77,7 +77,6 @@ blockchainTests.resets('FillQuoteTransformer', env => {
                 mStable: NULL_ADDRESS,
                 weth: NULL_ADDRESS,
                 shellBridge: NULL_ADDRESS,
-                shell: NULL_ADDRESS,
                 creamBridge: NULL_ADDRESS,
                 dodoBridge: NULL_ADDRESS,
                 dodoHelper: NULL_ADDRESS,