LibSafeDowncast unit tests (#2143)

contracts/staking/contracts/test/TestLibSafeDowncast.sol

@@ -0,0 +1,41 @@
+/*
+
+  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;
+
+import "../src/libs/LibSafeDowncast.sol";
+
+
+contract TestLibSafeDowncast {
+
+    function downcastToUint96(uint256 a)
+        external
+        pure
+        returns (uint96)
+    {
+        return LibSafeDowncast.downcastToUint96(a);
+    }
+
+    function downcastToUint64(uint256 a)
+        external
+        pure
+        returns (uint64)
+    {
+        return LibSafeDowncast.downcastToUint64(a);
+    }
+}

contracts/staking/package.json

@@ -37,7 +37,7 @@
     },
     "config": {
         "abis:comment": "This list is auto-generated by contracts-gen. Don't edit manually.",
-        "abis": "./generated-artifacts/@(EthVault|IEthVault|IStaking|IStakingEvents|IStakingPoolRewardVault|IStakingProxy|IStorageInit|IStructs|IVaultCore|IZrxVault|LibFixedMath|LibFixedMathRichErrors|LibProxy|LibSafeDowncast|LibStakingRichErrors|MixinConstants|MixinDeploymentConstants|MixinEthVault|MixinExchangeFees|MixinExchangeManager|MixinParams|MixinScheduler|MixinStake|MixinStakeBalances|MixinStakeStorage|MixinStakingPool|MixinStakingPoolRewardVault|MixinStakingPoolRewards|MixinStorage|MixinVaultCore|MixinZrxVault|ReadOnlyProxy|Staking|StakingPoolRewardVault|StakingProxy|TestCobbDouglas|TestInitTarget|TestLibFixedMath|TestLibProxy|TestLibProxyReceiver|TestProtocolFees|TestProtocolFeesERC20Proxy|TestStaking|TestStakingProxy|TestStorageLayout|ZrxVault).json"
+        "abis": "./generated-artifacts/@(EthVault|IEthVault|IStaking|IStakingEvents|IStakingPoolRewardVault|IStakingProxy|IStorageInit|IStructs|IVaultCore|IZrxVault|LibFixedMath|LibFixedMathRichErrors|LibProxy|LibSafeDowncast|LibStakingRichErrors|MixinConstants|MixinDeploymentConstants|MixinEthVault|MixinExchangeFees|MixinExchangeManager|MixinParams|MixinScheduler|MixinStake|MixinStakeBalances|MixinStakeStorage|MixinStakingPool|MixinStakingPoolRewardVault|MixinStakingPoolRewards|MixinStorage|MixinVaultCore|MixinZrxVault|ReadOnlyProxy|Staking|StakingPoolRewardVault|StakingProxy|TestCobbDouglas|TestInitTarget|TestLibFixedMath|TestLibProxy|TestLibProxyReceiver|TestLibSafeDowncast|TestProtocolFees|TestProtocolFeesERC20Proxy|TestStaking|TestStakingProxy|TestStorageLayout|ZrxVault).json"
     },
     "repository": {
         "type": "git",

contracts/staking/src/artifacts.ts

@@ -45,6 +45,7 @@ import * as TestInitTarget from '../generated-artifacts/TestInitTarget.json';
 import * as TestLibFixedMath from '../generated-artifacts/TestLibFixedMath.json';
 import * as TestLibProxy from '../generated-artifacts/TestLibProxy.json';
 import * as TestLibProxyReceiver from '../generated-artifacts/TestLibProxyReceiver.json';
+import * as TestLibSafeDowncast from '../generated-artifacts/TestLibSafeDowncast.json';
 import * as TestProtocolFees from '../generated-artifacts/TestProtocolFees.json';
 import * as TestProtocolFeesERC20Proxy from '../generated-artifacts/TestProtocolFeesERC20Proxy.json';
 import * as TestStaking from '../generated-artifacts/TestStaking.json';
@@ -93,6 +94,7 @@ export const artifacts = {
     TestLibFixedMath: TestLibFixedMath as ContractArtifact,
     TestLibProxy: TestLibProxy as ContractArtifact,
     TestLibProxyReceiver: TestLibProxyReceiver as ContractArtifact,
+    TestLibSafeDowncast: TestLibSafeDowncast as ContractArtifact,
     TestProtocolFees: TestProtocolFees as ContractArtifact,
     TestProtocolFeesERC20Proxy: TestProtocolFeesERC20Proxy as ContractArtifact,
     TestStaking: TestStaking as ContractArtifact,

contracts/staking/src/wrappers.ts

@@ -43,6 +43,7 @@ export * from '../generated-wrappers/test_init_target';
 export * from '../generated-wrappers/test_lib_fixed_math';
 export * from '../generated-wrappers/test_lib_proxy';
 export * from '../generated-wrappers/test_lib_proxy_receiver';
+export * from '../generated-wrappers/test_lib_safe_downcast';
 export * from '../generated-wrappers/test_protocol_fees';
 export * from '../generated-wrappers/test_protocol_fees_erc20_proxy';
 export * from '../generated-wrappers/test_staking';

contracts/staking/test/unit_tests/lib_proxy_unit_test.ts

@@ -11,7 +11,7 @@ import { StakingRevertErrors } from '@0x/order-utils';
 
 import { artifacts, TestLibProxyContract, TestLibProxyReceiverContract } from '../../src';
 
-blockchainTests.resets.only('LibProxy', env => {
+blockchainTests.resets('LibProxy', env => {
     let proxy: TestLibProxyContract;
     let receiver: TestLibProxyReceiverContract;
 

contracts/staking/test/unit_tests/lib_safe_downcast_test.ts

@@ -0,0 +1,83 @@
+import { blockchainTests, expect, Numberish } from '@0x/contracts-test-utils';
+import { BigNumber, SafeMathRevertErrors } from '@0x/utils';
+
+import { artifacts, TestLibSafeDowncastContract } from '../../src/';
+
+blockchainTests('LibSafeDowncast', env => {
+    let testContract: TestLibSafeDowncastContract;
+
+    before(async () => {
+        testContract = await TestLibSafeDowncastContract.deployFrom0xArtifactAsync(
+            artifacts.TestLibSafeDowncast,
+            env.provider,
+            env.txDefaults,
+            artifacts,
+        );
+    });
+
+    const MAX_UINT_64 = new BigNumber(2).pow(64).minus(1);
+    const MAX_UINT_96 = new BigNumber(2).pow(96).minus(1);
+    const MAX_UINT_256 = new BigNumber(2).pow(256).minus(1);
+
+    describe('downcastToUint96', () => {
+        async function verifyCorrectDowncastAsync(n: Numberish): Promise<void> {
+            const actual = await testContract.downcastToUint96.callAsync(new BigNumber(n));
+            expect(actual).to.bignumber.eq(n);
+        }
+        function toDowncastError(n: Numberish): SafeMathRevertErrors.Uint256DowncastError {
+            return new SafeMathRevertErrors.Uint256DowncastError(
+                SafeMathRevertErrors.DowncastErrorCodes.ValueTooLargeToDowncastToUint96,
+                new BigNumber(n),
+            );
+        }
+
+        it('correctly downcasts 0', async () => {
+            return verifyCorrectDowncastAsync(0);
+        });
+        it('correctly downcasts 1337', async () => {
+            return verifyCorrectDowncastAsync(1337);
+        });
+        it('correctly downcasts MAX_UINT_96', async () => {
+            return verifyCorrectDowncastAsync(MAX_UINT_96);
+        });
+        it('reverts on MAX_UINT_96 + 1', async () => {
+            const n = MAX_UINT_96.plus(1);
+            return expect(verifyCorrectDowncastAsync(n)).to.revertWith(toDowncastError(n));
+        });
+        it('reverts on MAX_UINT_256', async () => {
+            const n = MAX_UINT_256;
+            return expect(verifyCorrectDowncastAsync(n)).to.revertWith(toDowncastError(n));
+        });
+    });
+
+    describe('downcastToUint64', () => {
+        async function verifyCorrectDowncastAsync(n: Numberish): Promise<void> {
+            const actual = await testContract.downcastToUint64.callAsync(new BigNumber(n));
+            expect(actual).to.bignumber.eq(n);
+        }
+        function toDowncastError(n: Numberish): SafeMathRevertErrors.Uint256DowncastError {
+            return new SafeMathRevertErrors.Uint256DowncastError(
+                SafeMathRevertErrors.DowncastErrorCodes.ValueTooLargeToDowncastToUint64,
+                new BigNumber(n),
+            );
+        }
+
+        it('correctly downcasts 0', async () => {
+            return verifyCorrectDowncastAsync(0);
+        });
+        it('correctly downcasts 1337', async () => {
+            return verifyCorrectDowncastAsync(1337);
+        });
+        it('correctly downcasts MAX_UINT_64', async () => {
+            return verifyCorrectDowncastAsync(MAX_UINT_64);
+        });
+        it('reverts on MAX_UINT_64 + 1', async () => {
+            const n = MAX_UINT_64.plus(1);
+            return expect(verifyCorrectDowncastAsync(n)).to.revertWith(toDowncastError(n));
+        });
+        it('reverts on MAX_UINT_256', async () => {
+            const n = MAX_UINT_256;
+            return expect(verifyCorrectDowncastAsync(n)).to.revertWith(toDowncastError(n));
+        });
+    });
+});

contracts/staking/test/utils/constants.ts

@@ -3,7 +3,6 @@ import { BigNumber } from '@0x/utils';
 
 const TWO_WEEKS = 14 * 24 * 60 * 60;
 export const constants = {
-    MAX_UINT_64: new BigNumber(2).pow(256).minus(1),
     TOKEN_MULTIPLIER: testConstants.DUMMY_TOKEN_DECIMALS,
     INITIAL_POOL_ID: '0x0000000000000000000000000000000100000000000000000000000000000000',
     SECOND_POOL_ID: '0x0000000000000000000000000000000200000000000000000000000000000000',

contracts/staking/tsconfig.json

@@ -43,6 +43,7 @@
         "generated-artifacts/TestLibFixedMath.json",
         "generated-artifacts/TestLibProxy.json",
         "generated-artifacts/TestLibProxyReceiver.json",
+        "generated-artifacts/TestLibSafeDowncast.json",
         "generated-artifacts/TestProtocolFees.json",
         "generated-artifacts/TestProtocolFeesERC20Proxy.json",
         "generated-artifacts/TestStaking.json",