Merge branch 'development' of https://github.com/0xProject/0x-monorepo into feature/website/v2-tweaks

11 files changed, 201 insertions, 132 deletions

diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
index 004c3892d..258443bca 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC20Proxy.sol
@@ -18,7 +18,6 @@
 
 pragma solidity 0.4.24;
 
-import "../../utils/LibBytes/LibBytes.sol";
 import "./MixinAuthorizable.sol";
 
 
@@ -59,15 +58,64 @@ contract ERC20Proxy is
                     mstore(96, 0)
                     revert(0, 100)
                 }
-                
-                /////// Token contract address ///////
-                // The token address is found as follows:
-                // * It is stored at offset 4 in `assetData` contents.
-                // * This is stored at offset 32 from `assetData`.
-                // * The offset to `assetData` from Params is stored at offset
-                //   4 in calldata.
-                // * The offset of Params in calldata is 4.
-                // So we read location 4 and add 32 + 4 + 4 to it.
+
+                // `transferFrom`.
+                // The function is marked `external`, so no abi decodeding is done for
+                // us. Instead, we expect the `calldata` memory to contain the
+                // following:
+                //
+                // | Area     | Offset | Length  | Contents                            |
+                // |----------|--------|---------|-------------------------------------|
+                // | Header   | 0      | 4       | function selector                   |
+                // | Params   |        | 4 * 32  | function parameters:                |
+                // |          | 4      |         |   1. offset to assetData (*)        |
+                // |          | 36     |         |   2. from                           |
+                // |          | 68     |         |   3. to                             |
+                // |          | 100    |         |   4. amount                         |
+                // | Data     |        |         | assetData:                          |
+                // |          | 132    | 32      | assetData Length                    |
+                // |          | 164    | **      | assetData Contents                  |
+                //
+                // (*): offset is computed from start of function parameters, so offset
+                //      by an additional 4 bytes in the calldata.
+                //
+                // (**): see table below to compute length of assetData Contents
+                //
+                // WARNING: The ABIv2 specification allows additional padding between
+                //          the Params and Data section. This will result in a larger
+                //          offset to assetData.
+
+                // Asset data itself is encoded as follows:
+                //
+                // | Area     | Offset | Length  | Contents                            |
+                // |----------|--------|---------|-------------------------------------|
+                // | Header   | 0      | 4       | function selector                   |
+                // | Params   |        | 1 * 32  | function parameters:                |
+                // |          | 4      | 12 + 20 |   1. token address                  |
+
+                // We construct calldata for the `token.transferFrom` ABI.
+                // The layout of this calldata is in the table below.
+                //
+                // | Area     | Offset | Length  | Contents                            |
+                // |----------|--------|---------|-------------------------------------|
+                // | Header   | 0      | 4       | function selector                   |
+                // | Params   |        | 3 * 32  | function parameters:                |
+                // |          | 4      |         |   1. from                           |
+                // |          | 36     |         |   2. to                             |
+                // |          | 68     |         |   3. amount                         |
+
+                /////// Read token address from calldata ///////
+                // * The token address is stored in `assetData`.
+                //
+                // * The "offset to assetData" is stored at offset 4 in the calldata (table 1).
+                //   [assetDataOffsetFromParams = calldataload(4)]
+                //
+                // * Notes that the "offset to assetData" is relative to the "Params" area of calldata;
+                //   add 4 bytes to account for the length of the "Header" area (table 1).
+                //   [assetDataOffsetFromHeader = assetDataOffsetFromParams + 4]
+                //
+                // * The "token address" is offset 32+4=36 bytes into "assetData" (tables 1 & 2).
+                //   [tokenOffset = assetDataOffsetFromHeader + 36 = calldataload(4) + 4 + 36]
                 let token := calldataload(add(calldataload(4), 40))
                 
                 /////// Setup Header Area ///////
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
index 9d0bc0f74..65b664b8b 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxy/ERC721Proxy.sol
@@ -18,7 +18,6 @@
 
 pragma solidity 0.4.24;
 
-import "../../utils/LibBytes/LibBytes.sol";
 import "./MixinAuthorizable.sol";
 
 
@@ -80,6 +79,8 @@ contract ERC721Proxy is
                 // (*): offset is computed from start of function parameters, so offset
                 //      by an additional 4 bytes in the calldata.
                 //
+                // (**): see table below to compute length of assetData Contents
+                //
                 // WARNING: The ABIv2 specification allows additional padding between
                 //          the Params and Data section. This will result in a larger
                 //          offset to assetData.
diff --git a/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol b/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol
index 8b7333646..4d00e92d3 100644
--- a/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol
+++ b/packages/contracts/src/2.0.0/protocol/AssetProxyOwner/AssetProxyOwner.sol
@@ -16,15 +16,18 @@
 
 */
 
-pragma solidity 0.4.10;
+pragma solidity 0.4.24;
 
 import "../../multisig/MultiSigWalletWithTimeLock.sol";
+import "../../utils/LibBytes/LibBytes.sol";
 
 
 contract AssetProxyOwner is
     MultiSigWalletWithTimeLock
 {
 
+    using LibBytes for bytes;
+
     event AssetProxyRegistration(address assetProxyContract, bool isRegistered);
 
     // Mapping of AssetProxy contract address =>
@@ -37,8 +40,14 @@ contract AssetProxyOwner is
     ///      on an approved AssetProxy contract.
     modifier validRemoveAuthorizedAddressAtIndexTx(uint256 transactionId) {
         Transaction storage tx = transactions[transactionId];
-        require(isAssetProxyRegistered[tx.destination]);
-        require(readBytes4(tx.data, 0) == REMOVE_AUTHORIZED_ADDRESS_AT_INDEX_SELECTOR);
+        require(
+            isAssetProxyRegistered[tx.destination],
+            "UNREGISTERED_ASSET_PROXY"
+        );
+        require(
+            tx.data.readBytes4(0) == REMOVE_AUTHORIZED_ADDRESS_AT_INDEX_SELECTOR,
+            "INVALID_FUNCTION_SELECTOR"
+        );
         _;
     }
 
@@ -48,7 +57,7 @@ contract AssetProxyOwner is
     /// @param _assetProxyContracts Array of AssetProxy contract addresses.
     /// @param _required Number of required confirmations.
     /// @param _secondsTimeLocked Duration needed after a transaction is confirmed and before it becomes executable, in seconds.
-    function AssetProxyOwner(
+    constructor (
         address[] memory _owners,
         address[] memory _assetProxyContracts,
         uint256 _required,
@@ -59,7 +68,10 @@ contract AssetProxyOwner is
     {
         for (uint256 i = 0; i < _assetProxyContracts.length; i++) {
             address assetProxy = _assetProxyContracts[i];
-            require(assetProxy != address(0));
+            require(
+                assetProxy != address(0),
+                "INVALID_ASSET_PROXY"
+            );
             isAssetProxyRegistered[assetProxy] = true;
         }
     }
@@ -74,7 +86,7 @@ contract AssetProxyOwner is
         notNull(assetProxyContract)
     {
         isAssetProxyRegistered[assetProxyContract] = isRegistered;
-        AssetProxyRegistration(assetProxyContract, isRegistered);
+        emit AssetProxyRegistration(assetProxyContract, isRegistered);
     }
 
     /// @dev Allows execution of `removeAuthorizedAddressAtIndex` without time lock.
@@ -89,31 +101,10 @@ contract AssetProxyOwner is
         tx.executed = true;
         // solhint-disable-next-line avoid-call-value
         if (tx.destination.call.value(tx.value)(tx.data))
-            Execution(transactionId);
+            emit Execution(transactionId);
         else {
-            ExecutionFailure(transactionId);
+            emit ExecutionFailure(transactionId);
             tx.executed = false;
         }
     }
-
-    /// @dev Reads an unpadded bytes4 value from a position in a byte array.
-    /// @param b Byte array containing a bytes4 value.
-    /// @param index Index in byte array of bytes4 value.
-    /// @return bytes4 value from byte array.
-    function readBytes4(
-        bytes memory b,
-        uint256 index
-    )
-        internal
-        returns (bytes4 result)
-    {
-        require(b.length >= index + 4);
-        assembly {
-            result := mload(add(b, 32))
-            // Solidity does not require us to clean the trailing bytes.
-            // We do it anyway
-            result := and(result, 0xFFFFFFFF00000000000000000000000000000000000000000000000000000000)
-        }
-        return result;
-    }
 }
diff --git a/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol b/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol
index 80475e6e3..e90b62f19 100644
--- a/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol
+++ b/packages/contracts/src/2.0.0/protocol/Exchange/MixinAssetProxyDispatcher.sol
@@ -19,7 +19,6 @@
 pragma solidity 0.4.24;
 
 import "../../utils/Ownable/Ownable.sol";
-import "../../utils/LibBytes/LibBytes.sol";
 import "./mixins/MAssetProxyDispatcher.sol";
 import "../AssetProxy/interfaces/IAssetProxy.sol";
 
@@ -28,7 +27,6 @@ contract MixinAssetProxyDispatcher is
     Ownable,
     MAssetProxyDispatcher
 {
-    using LibBytes for bytes;
     
     // Mapping from Asset Proxy Id's to their respective Asset Proxy
     mapping (bytes4 => IAssetProxy) public assetProxies;
@@ -90,7 +88,7 @@ contract MixinAssetProxyDispatcher is
                 "LENGTH_GREATER_THAN_3_REQUIRED"
             );
             
-            // Lookup assetProxy
+            // Lookup assetProxy. We do not use `LibBytes.readBytes4` for gas efficiency reasons.
             bytes4 assetProxyId;
             assembly {
                 assetProxyId := and(mload(
diff --git a/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol b/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
index 75e782d43..38ec42a72 100644
--- a/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
+++ b/packages/contracts/src/2.0.0/test/TestAssetProxyOwner/TestAssetProxyOwner.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.10;
+pragma solidity 0.4.24;
 
 import "../../protocol/AssetProxyOwner/AssetProxyOwner.sol";
 
@@ -26,7 +26,7 @@ contract TestAssetProxyOwner is
     AssetProxyOwner
 {
 
-    function TestAssetProxyOwner(
+    constructor (
         address[] memory _owners,
         address[] memory _assetProxyContracts,
         uint256 _required,
@@ -38,6 +38,7 @@ contract TestAssetProxyOwner is
     
     function testValidRemoveAuthorizedAddressAtIndexTx(uint256 id)
         public
+        view
         validRemoveAuthorizedAddressAtIndexTx(id)
         returns (bool)
     {
@@ -50,23 +51,9 @@ contract TestAssetProxyOwner is
     /// @return Successful if data is a call to `removeAuthorizedAddressAtIndex`.
     function isFunctionRemoveAuthorizedAddressAtIndex(bytes memory data)
         public
+        pure
         returns (bool)
     {
-        return readBytes4(data, 0) == REMOVE_AUTHORIZED_ADDRESS_AT_INDEX_SELECTOR;
-    }
-
-    /// @dev Reads an unpadded bytes4 value from a position in a byte array.
-    /// @param b Byte array containing a bytes4 value.
-    /// @param index Index in byte array of bytes4 value.
-    /// @return bytes4 value from byte array.
-    function publicReadBytes4(
-        bytes memory b,
-        uint256 index
-    )
-        public
-        returns (bytes4 result)
-    {
-        result = readBytes4(b, index);
-        return result;
+        return data.readBytes4(0) == REMOVE_AUTHORIZED_ADDRESS_AT_INDEX_SELECTOR;
     }
 }
diff --git a/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol b/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol
index 504e950a8..93873cbcc 100644
--- a/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol
+++ b/packages/contracts/src/2.0.0/utils/LibBytes/LibBytes.sol
@@ -467,8 +467,13 @@ library LibBytes {
             b.length >= index + 4,
             "GREATER_OR_EQUAL_TO_4_LENGTH_REQUIRED"
         );
+
+        // Arrays are prefixed by a 32 byte length field
+        index += 32;
+
+        // Read the bytes4 from array memory
         assembly {
-            result := mload(add(b, 32))
+            result := mload(add(b, index))
             // Solidity does not require us to clean the trailing bytes.
             // We do it anyway
             result := and(result, 0xFFFFFFFF00000000000000000000000000000000000000000000000000000000)
diff --git a/packages/contracts/test/exchange/signature_validator.ts b/packages/contracts/test/exchange/signature_validator.ts
index da2febfd8..b25483c4b 100644
--- a/packages/contracts/test/exchange/signature_validator.ts
+++ b/packages/contracts/test/exchange/signature_validator.ts
@@ -14,7 +14,7 @@ import { ValidatorContract } from '../../generated_contract_wrappers/validator';
 import { WalletContract } from '../../generated_contract_wrappers/wallet';
 import { addressUtils } from '../utils/address_utils';
 import { artifacts } from '../utils/artifacts';
-import { expectContractCallFailed, expectContractCallFailedWithoutReasonAsync } from '../utils/assertions';
+import { expectContractCallFailedAsync, expectContractCallFailedWithoutReasonAsync } from '../utils/assertions';
 import { chaiSetup } from '../utils/chai_setup';
 import { constants } from '../utils/constants';
 import { LogDecoder } from '../utils/log_decoder';
@@ -119,7 +119,7 @@ describe('MixinSignatureValidator', () => {
         it('should revert when signature is empty', async () => {
             const emptySignature = '0x';
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 signatureValidator.publicIsValidSignature.callAsync(
                     orderHashHex,
                     signedOrder.makerAddress,
@@ -133,7 +133,7 @@ describe('MixinSignatureValidator', () => {
             const unsupportedSignatureType = SignatureType.NSignatureTypes;
             const unsupportedSignatureHex = '0x' + Buffer.from([unsupportedSignatureType]).toString('hex');
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 signatureValidator.publicIsValidSignature.callAsync(
                     orderHashHex,
                     signedOrder.makerAddress,
@@ -146,7 +146,7 @@ describe('MixinSignatureValidator', () => {
         it('should revert when SignatureType=Illegal', async () => {
             const unsupportedSignatureHex = '0x' + Buffer.from([SignatureType.Illegal]).toString('hex');
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 signatureValidator.publicIsValidSignature.callAsync(
                     orderHashHex,
                     signedOrder.makerAddress,
@@ -173,7 +173,7 @@ describe('MixinSignatureValidator', () => {
             const signatureBuffer = Buffer.concat([fillerData, signatureType]);
             const signatureHex = ethUtil.bufferToHex(signatureBuffer);
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 signatureValidator.publicIsValidSignature.callAsync(
                     orderHashHex,
                     signedOrder.makerAddress,
@@ -339,7 +339,7 @@ describe('MixinSignatureValidator', () => {
                 ethUtil.toBuffer(`0x${SignatureType.Wallet}`),
             ]);
             const signatureHex = ethUtil.bufferToHex(signature);
-            await expectContractCallFailed(
+            await expectContractCallFailedAsync(
                 signatureValidator.publicIsValidSignature.callAsync(
                     orderHashHex,
                     maliciousWallet.address,
@@ -385,7 +385,7 @@ describe('MixinSignatureValidator', () => {
             const signature = Buffer.concat([validatorAddress, signatureType]);
             const signatureHex = ethUtil.bufferToHex(signature);
             const orderHashHex = orderHashUtils.getOrderHashHex(signedOrder);
-            await expectContractCallFailed(
+            await expectContractCallFailedAsync(
                 signatureValidator.publicIsValidSignature.callAsync(orderHashHex, signerAddress, signatureHex),
                 RevertReason.ValidatorError,
             );
diff --git a/packages/contracts/test/libraries/lib_bytes.ts b/packages/contracts/test/libraries/lib_bytes.ts
index 1c497a226..13640a761 100644
--- a/packages/contracts/test/libraries/lib_bytes.ts
+++ b/packages/contracts/test/libraries/lib_bytes.ts
@@ -9,7 +9,7 @@ import * as _ from 'lodash';
 
 import { TestLibBytesContract } from '../../generated_contract_wrappers/test_lib_bytes';
 import { artifacts } from '../utils/artifacts';
-import { expectContractCallFailed } from '../utils/assertions';
+import { expectContractCallFailedAsync } from '../utils/assertions';
 import { chaiSetup } from '../utils/chai_setup';
 import { constants } from '../utils/constants';
 import { typeEncodingUtils } from '../utils/type_encoding_utils';
@@ -41,6 +41,8 @@ describe('LibBytes', () => {
     const testBytes32B = '0x534877abd8443578526845cdfef020047528759477fedef87346527659aced32';
     const testUint256 = new BigNumber(testBytes32, 16);
     const testUint256B = new BigNumber(testBytes32B, 16);
+    const testBytes4 = '0xabcdef12';
+    const testByte = '0xab';
     let shortData: string;
     let shortTestBytes: string;
     let shortTestBytesAsBuffer: Buffer;
@@ -101,34 +103,47 @@ describe('LibBytes', () => {
 
     describe('popLastByte', () => {
         it('should revert if length is 0', async () => {
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicPopLastByte.callAsync(constants.NULL_BYTES),
                 RevertReason.LibBytesGreaterThanZeroLengthRequired,
             );
         });
-        it('should pop the last byte from the input and return it', async () => {
+        it('should pop the last byte from the input and return it when array holds more than 1 byte', async () => {
             const [newBytes, poppedByte] = await libBytes.publicPopLastByte.callAsync(byteArrayLongerThan32Bytes);
             const expectedNewBytes = byteArrayLongerThan32Bytes.slice(0, -2);
             const expectedPoppedByte = `0x${byteArrayLongerThan32Bytes.slice(-2)}`;
             expect(newBytes).to.equal(expectedNewBytes);
             expect(poppedByte).to.equal(expectedPoppedByte);
         });
+        it('should pop the last byte from the input and return it when array is exactly 1 byte', async () => {
+            const [newBytes, poppedByte] = await libBytes.publicPopLastByte.callAsync(testByte);
+            const expectedNewBytes = '0x';
+            expect(newBytes).to.equal(expectedNewBytes);
+            return expect(poppedByte).to.be.equal(testByte);
+        });
     });
 
     describe('popLast20Bytes', () => {
         it('should revert if length is less than 20', async () => {
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicPopLast20Bytes.callAsync(byteArrayShorterThan20Bytes),
                 RevertReason.LibBytesGreaterOrEqualTo20LengthRequired,
             );
         });
-        it('should pop the last 20 bytes from the input and return it', async () => {
+        it('should pop the last 20 bytes from the input and return it when array holds more than 20 bytes', async () => {
             const [newBytes, poppedAddress] = await libBytes.publicPopLast20Bytes.callAsync(byteArrayLongerThan32Bytes);
             const expectedNewBytes = byteArrayLongerThan32Bytes.slice(0, -40);
             const expectedPoppedAddress = `0x${byteArrayLongerThan32Bytes.slice(-40)}`;
             expect(newBytes).to.equal(expectedNewBytes);
             expect(poppedAddress).to.equal(expectedPoppedAddress);
         });
+        it('should pop the last 20 bytes from the input and return it when array is exactly 20 bytes', async () => {
+            const [newBytes, poppedAddress] = await libBytes.publicPopLast20Bytes.callAsync(testAddress);
+            const expectedNewBytes = '0x';
+            const expectedPoppedAddress = testAddress;
+            expect(newBytes).to.equal(expectedNewBytes);
+            expect(poppedAddress).to.equal(expectedPoppedAddress);
+        });
     });
 
     describe('equals', () => {
@@ -185,7 +200,7 @@ describe('LibBytes', () => {
 
     describe('deepCopyBytes', () => {
         it('should revert if dest is shorter than source', async () => {
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicDeepCopyBytes.callAsync(byteArrayShorterThan32Bytes, byteArrayLongerThan32Bytes),
                 RevertReason.LibBytesGreaterOrEqualToSourceBytesLengthRequired,
             );
@@ -238,7 +253,7 @@ describe('LibBytes', () => {
         it('should fail if the byte array is too short to hold an address', async () => {
             const shortByteArray = '0xabcdef';
             const offset = new BigNumber(0);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadAddress.callAsync(shortByteArray, offset),
                 RevertReason.LibBytesGreaterOrEqualTo20LengthRequired,
             );
@@ -246,7 +261,7 @@ describe('LibBytes', () => {
         it('should fail if the length between the offset and end of the byte array is too short to hold an address', async () => {
             const byteArray = testAddress;
             const badOffset = new BigNumber(ethUtil.toBuffer(byteArray).byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadAddress.callAsync(byteArray, badOffset),
                 RevertReason.LibBytesGreaterOrEqualTo20LengthRequired,
             );
@@ -282,7 +297,7 @@ describe('LibBytes', () => {
         });
         it('should fail if the byte array is too short to hold an address', async () => {
             const offset = new BigNumber(0);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicWriteAddress.callAsync(byteArrayShorterThan20Bytes, offset, testAddress),
                 RevertReason.LibBytesGreaterOrEqualTo20LengthRequired,
             );
@@ -290,7 +305,7 @@ describe('LibBytes', () => {
         it('should fail if the length between the offset and end of the byte array is too short to hold an address', async () => {
             const byteArray = byteArrayLongerThan32Bytes;
             const badOffset = new BigNumber(ethUtil.toBuffer(byteArray).byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicWriteAddress.callAsync(byteArray, badOffset, testAddress),
                 RevertReason.LibBytesGreaterOrEqualTo20LengthRequired,
             );
@@ -303,7 +318,7 @@ describe('LibBytes', () => {
             const bytes32 = await libBytes.publicReadBytes32.callAsync(testBytes32, testBytes32Offset);
             return expect(bytes32).to.be.equal(testBytes32);
         });
-        it('should successfully read bytes32 when it is offset in the array)', async () => {
+        it('should successfully read bytes32 when it is offset in the array', async () => {
             const bytes32ByteArrayBuffer = ethUtil.toBuffer(testBytes32);
             const prefixByteArrayBuffer = ethUtil.toBuffer('0xabcdef');
             const combinedByteArrayBuffer = Buffer.concat([prefixByteArrayBuffer, bytes32ByteArrayBuffer]);
@@ -314,14 +329,14 @@ describe('LibBytes', () => {
         });
         it('should fail if the byte array is too short to hold a bytes32', async () => {
             const offset = new BigNumber(0);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadBytes32.callAsync(byteArrayShorterThan32Bytes, offset),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
         });
         it('should fail if the length between the offset and end of the byte array is too short to hold a bytes32', async () => {
             const badOffset = new BigNumber(ethUtil.toBuffer(testBytes32).byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadBytes32.callAsync(testBytes32, badOffset),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
@@ -357,7 +372,7 @@ describe('LibBytes', () => {
         });
         it('should fail if the byte array is too short to hold a bytes32', async () => {
             const offset = new BigNumber(0);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicWriteBytes32.callAsync(byteArrayShorterThan32Bytes, offset, testBytes32),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
@@ -365,7 +380,7 @@ describe('LibBytes', () => {
         it('should fail if the length between the offset and end of the byte array is too short to hold a bytes32', async () => {
             const byteArray = byteArrayLongerThan32Bytes;
             const badOffset = new BigNumber(ethUtil.toBuffer(byteArray).byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicWriteBytes32.callAsync(byteArray, badOffset, testBytes32),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
@@ -393,7 +408,7 @@ describe('LibBytes', () => {
         });
         it('should fail if the byte array is too short to hold a uint256', async () => {
             const offset = new BigNumber(0);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadUint256.callAsync(byteArrayShorterThan32Bytes, offset),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
@@ -403,7 +418,7 @@ describe('LibBytes', () => {
             const testUint256AsBuffer = ethUtil.toBuffer(formattedTestUint256);
             const byteArray = ethUtil.bufferToHex(testUint256AsBuffer);
             const badOffset = new BigNumber(testUint256AsBuffer.byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadUint256.callAsync(byteArray, badOffset),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
@@ -443,7 +458,7 @@ describe('LibBytes', () => {
         });
         it('should fail if the byte array is too short to hold a uint256', async () => {
             const offset = new BigNumber(0);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicWriteUint256.callAsync(byteArrayShorterThan32Bytes, offset, testUint256),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
@@ -451,7 +466,7 @@ describe('LibBytes', () => {
         it('should fail if the length between the offset and end of the byte array is too short to hold a uint256', async () => {
             const byteArray = byteArrayLongerThan32Bytes;
             const badOffset = new BigNumber(ethUtil.toBuffer(byteArray).byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicWriteUint256.callAsync(byteArray, badOffset, testUint256),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
@@ -462,8 +477,9 @@ describe('LibBytes', () => {
         // AssertionError: expected promise to be rejected with an error including 'revert' but it was fulfilled with '0x08c379a0'
         it('should revert if byte array has a length < 4', async () => {
             const byteArrayLessThan4Bytes = '0x010101';
-            return expectContractCallFailed(
-                libBytes.publicReadBytes4.callAsync(byteArrayLessThan4Bytes, new BigNumber(0)),
+            const offset = new BigNumber(0);
+            return expectContractCallFailedAsync(
+                libBytes.publicReadBytes4.callAsync(byteArrayLessThan4Bytes, offset),
                 RevertReason.LibBytesGreaterOrEqualTo4LengthRequired,
             );
         });
@@ -472,6 +488,27 @@ describe('LibBytes', () => {
             const expectedFirst4Bytes = byteArrayLongerThan32Bytes.slice(0, 10);
             expect(first4Bytes).to.equal(expectedFirst4Bytes);
         });
+        it('should successfully read bytes4 when the bytes4 takes up the whole array', async () => {
+            const testBytes4Offset = new BigNumber(0);
+            const bytes4 = await libBytes.publicReadBytes4.callAsync(testBytes4, testBytes4Offset);
+            return expect(bytes4).to.be.equal(testBytes4);
+        });
+        it('should successfully read bytes4 when it is offset in the array', async () => {
+            const bytes4ByteArrayBuffer = ethUtil.toBuffer(testBytes4);
+            const prefixByteArrayBuffer = ethUtil.toBuffer('0xabcdef');
+            const combinedByteArrayBuffer = Buffer.concat([prefixByteArrayBuffer, bytes4ByteArrayBuffer]);
+            const combinedByteArray = ethUtil.bufferToHex(combinedByteArrayBuffer);
+            const testBytes4Offset = new BigNumber(prefixByteArrayBuffer.byteLength);
+            const bytes4 = await libBytes.publicReadBytes4.callAsync(combinedByteArray, testBytes4Offset);
+            return expect(bytes4).to.be.equal(testBytes4);
+        });
+        it('should fail if the length between the offset and end of the byte array is too short to hold a bytes4', async () => {
+            const badOffset = new BigNumber(ethUtil.toBuffer(testBytes4).byteLength);
+            return expectContractCallFailedAsync(
+                libBytes.publicReadBytes4.callAsync(testBytes4, badOffset),
+                RevertReason.LibBytesGreaterOrEqualTo4LengthRequired,
+            );
+        });
     });
 
     describe('readBytesWithLength', () => {
@@ -517,28 +554,28 @@ describe('LibBytes', () => {
         it('should fail if the byte array is too short to hold the length of a nested byte array', async () => {
             // The length of the nested array is 32 bytes. By storing less than 32 bytes, a length cannot be read.
             const offset = new BigNumber(0);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadBytesWithLength.callAsync(byteArrayShorterThan32Bytes, offset),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
         });
         it('should fail if we store a nested byte array length, without a nested byte array', async () => {
             const offset = new BigNumber(0);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadBytesWithLength.callAsync(testBytes32, offset),
                 RevertReason.LibBytesGreaterOrEqualToNestedBytesLengthRequired,
             );
         });
         it('should fail if the length between the offset and end of the byte array is too short to hold the length of a nested byte array', async () => {
             const badOffset = new BigNumber(ethUtil.toBuffer(byteArrayShorterThan32Bytes).byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadBytesWithLength.callAsync(byteArrayShorterThan32Bytes, badOffset),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
         });
         it('should fail if the length between the offset and end of the byte array is too short to hold the nested byte array', async () => {
             const badOffset = new BigNumber(ethUtil.toBuffer(testBytes32).byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicReadBytesWithLength.callAsync(testBytes32, badOffset),
                 RevertReason.LibBytesGreaterOrEqualTo32LengthRequired,
             );
@@ -546,7 +583,7 @@ describe('LibBytes', () => {
     });
 
     describe('writeBytesWithLength', () => {
-        it('should successfully write short, nested array of bytes when it takes up the whole array)', async () => {
+        it('should successfully write short, nested array of bytes when it takes up the whole array', async () => {
             const testBytesOffset = new BigNumber(0);
             const emptyByteArray = ethUtil.bufferToHex(new Buffer(shortTestBytesAsBuffer.byteLength));
             const bytesWritten = await libBytes.publicWriteBytesWithLength.callAsync(
@@ -650,15 +687,15 @@ describe('LibBytes', () => {
         it('should fail if the byte array is too short to hold the length of a nested byte array', async () => {
             const offset = new BigNumber(0);
             const emptyByteArray = ethUtil.bufferToHex(new Buffer(1));
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicWriteBytesWithLength.callAsync(emptyByteArray, offset, longData),
                 RevertReason.LibBytesGreaterOrEqualToNestedBytesLengthRequired,
             );
         });
-        it('should fail if the length between the offset and end of the byte array is too short to hold the length of a nested byte array)', async () => {
+        it('should fail if the length between the offset and end of the byte array is too short to hold the length of a nested byte array', async () => {
             const emptyByteArray = ethUtil.bufferToHex(new Buffer(shortTestBytesAsBuffer.byteLength));
             const badOffset = new BigNumber(ethUtil.toBuffer(shortTestBytesAsBuffer).byteLength);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 libBytes.publicWriteBytesWithLength.callAsync(emptyByteArray, badOffset, shortData),
                 RevertReason.LibBytesGreaterOrEqualToNestedBytesLengthRequired,
             );
diff --git a/packages/contracts/test/multisig/asset_proxy_owner.ts b/packages/contracts/test/multisig/asset_proxy_owner.ts
index 9515941ff..bb2b3b1a3 100644
--- a/packages/contracts/test/multisig/asset_proxy_owner.ts
+++ b/packages/contracts/test/multisig/asset_proxy_owner.ts
@@ -1,4 +1,5 @@
 import { BlockchainLifecycle } from '@0xproject/dev-utils';
+import { RevertReason } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import * as chai from 'chai';
 import { LogWithDecodedArgs } from 'ethereum-types';
@@ -14,9 +15,11 @@ import { MixinAuthorizableContract } from '../../generated_contract_wrappers/mix
 import { TestAssetProxyOwnerContract } from '../../generated_contract_wrappers/test_asset_proxy_owner';
 import { artifacts } from '../utils/artifacts';
 import {
-    expectContractCallFailedWithoutReasonAsync,
-    expectContractCreationFailedWithoutReason,
+    expectContractCallFailedAsync,
+    expectContractCreationFailedAsync,
+    expectTransactionFailedAsync,
     expectTransactionFailedWithoutReasonAsync,
+    sendTransactionResult,
 } from '../utils/assertions';
 import { increaseTimeAndMineBlockAsync } from '../utils/block_timestamp';
 import { chaiSetup } from '../utils/chai_setup';
@@ -109,8 +112,8 @@ describe('AssetProxyOwner', () => {
         });
         it('should throw if a null address is included in assetProxyContracts', async () => {
             const assetProxyContractAddresses = [erc20Proxy.address, constants.NULL_ADDRESS];
-            return expectContractCreationFailedWithoutReason(
-                AssetProxyOwnerContract.deployFrom0xArtifactAsync(
+            return expectContractCreationFailedAsync(
+                (AssetProxyOwnerContract.deployFrom0xArtifactAsync(
                     artifacts.AssetProxyOwner,
                     provider,
                     txDefaults,
@@ -118,7 +121,8 @@ describe('AssetProxyOwner', () => {
                     assetProxyContractAddresses,
                     REQUIRED_APPROVALS,
                     SECONDS_TIME_LOCKED,
-                ),
+                ) as any) as sendTransactionResult,
+                RevertReason.InvalidAssetProxy,
             );
         });
     });
@@ -148,25 +152,6 @@ describe('AssetProxyOwner', () => {
         });
     });
 
-    describe('readBytes4', () => {
-        it('should revert if byte array has a length < 4', async () => {
-            const byteArrayLessThan4Bytes = '0x010101';
-            return expectContractCallFailedWithoutReasonAsync(
-                testAssetProxyOwner.publicReadBytes4.callAsync(byteArrayLessThan4Bytes, new BigNumber(0)),
-            );
-        });
-        it('should return the first 4 bytes of a byte array of arbitrary length', async () => {
-            const byteArrayLongerThan32Bytes =
-                '0x0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef0123456789abcdef';
-            const first4Bytes = await testAssetProxyOwner.publicReadBytes4.callAsync(
-                byteArrayLongerThan32Bytes,
-                new BigNumber(0),
-            );
-            const expectedFirst4Bytes = byteArrayLongerThan32Bytes.slice(0, 10);
-            expect(first4Bytes).to.equal(expectedFirst4Bytes);
-        });
-    });
-
     describe('registerAssetProxy', () => {
         it('should throw if not called by multisig', async () => {
             const isRegistered = true;
@@ -300,8 +285,9 @@ describe('AssetProxyOwner', () => {
                 );
                 const log = submitTxRes.logs[0] as LogWithDecodedArgs<AssetProxyOwnerSubmissionEventArgs>;
                 const txId = log.args.transactionId;
-                return expectContractCallFailedWithoutReasonAsync(
+                return expectContractCallFailedAsync(
                     testAssetProxyOwner.testValidRemoveAuthorizedAddressAtIndexTx.callAsync(txId),
+                    RevertReason.InvalidFunctionSelector,
                 );
             });
 
@@ -335,8 +321,9 @@ describe('AssetProxyOwner', () => {
                 );
                 const log = submitTxRes.logs[0] as LogWithDecodedArgs<AssetProxyOwnerSubmissionEventArgs>;
                 const txId = log.args.transactionId;
-                return expectContractCallFailedWithoutReasonAsync(
+                return expectContractCallFailedAsync(
                     testAssetProxyOwner.testValidRemoveAuthorizedAddressAtIndexTx.callAsync(txId),
+                    RevertReason.UnregisteredAssetProxy,
                 );
             });
         });
@@ -377,10 +364,11 @@ describe('AssetProxyOwner', () => {
 
                 await multiSigWrapper.confirmTransactionAsync(txId, owners[1]);
 
-                return expectTransactionFailedWithoutReasonAsync(
+                return expectTransactionFailedAsync(
                     testAssetProxyOwner.executeRemoveAuthorizedAddressAtIndex.sendTransactionAsync(txId, {
                         from: owners[1],
                     }),
+                    RevertReason.UnregisteredAssetProxy,
                 );
             });
 
@@ -399,10 +387,11 @@ describe('AssetProxyOwner', () => {
 
                 await multiSigWrapper.confirmTransactionAsync(txId, owners[1]);
 
-                return expectTransactionFailedWithoutReasonAsync(
+                return expectTransactionFailedAsync(
                     testAssetProxyOwner.executeRemoveAuthorizedAddressAtIndex.sendTransactionAsync(txId, {
                         from: owners[1],
                     }),
+                    RevertReason.InvalidFunctionSelector,
                 );
             });
 
diff --git a/packages/contracts/test/tokens/unlimited_allowance_token.ts b/packages/contracts/test/tokens/unlimited_allowance_token.ts
index f2725b408..63680fe9b 100644
--- a/packages/contracts/test/tokens/unlimited_allowance_token.ts
+++ b/packages/contracts/test/tokens/unlimited_allowance_token.ts
@@ -5,7 +5,7 @@ import * as chai from 'chai';
 
 import { DummyERC20TokenContract } from '../../generated_contract_wrappers/dummy_erc20_token';
 import { artifacts } from '../utils/artifacts';
-import { expectContractCallFailed } from '../utils/assertions';
+import { expectContractCallFailedAsync } from '../utils/assertions';
 import { chaiSetup } from '../utils/chai_setup';
 import { constants } from '../utils/constants';
 import { provider, txDefaults, web3Wrapper } from '../utils/web3_wrapper';
@@ -54,7 +54,7 @@ describe('UnlimitedAllowanceToken', () => {
         it('should throw if owner has insufficient balance', async () => {
             const ownerBalance = await token.balanceOf.callAsync(owner);
             const amountToTransfer = ownerBalance.plus(1);
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 token.transfer.callAsync(spender, amountToTransfer, { from: owner }),
                 RevertReason.Erc20InsufficientBalance,
             );
@@ -93,7 +93,7 @@ describe('UnlimitedAllowanceToken', () => {
                 await token.approve.sendTransactionAsync(spender, amountToTransfer, { from: owner }),
                 constants.AWAIT_TRANSACTION_MINED_MS,
             );
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 token.transferFrom.callAsync(owner, spender, amountToTransfer, {
                     from: spender,
                 }),
@@ -109,7 +109,7 @@ describe('UnlimitedAllowanceToken', () => {
             const isSpenderAllowanceInsufficient = spenderAllowance.cmp(amountToTransfer) < 0;
             expect(isSpenderAllowanceInsufficient).to.be.true();
 
-            return expectContractCallFailed(
+            return expectContractCallFailedAsync(
                 token.transferFrom.callAsync(owner, spender, amountToTransfer, {
                     from: spender,
                 }),
diff --git a/packages/contracts/test/utils/assertions.ts b/packages/contracts/test/utils/assertions.ts
index 61df800c8..3361a751a 100644
--- a/packages/contracts/test/utils/assertions.ts
+++ b/packages/contracts/test/utils/assertions.ts
@@ -159,7 +159,7 @@ export async function expectTransactionFailedWithoutReasonAsync(p: sendTransacti
  * @returns a new Promise which will reject if the conditions are not met and
  * otherwise resolve with no value.
  */
-export async function expectContractCallFailed<T>(p: Promise<T>, reason: RevertReason): Promise<void> {
+export async function expectContractCallFailedAsync<T>(p: Promise<T>, reason: RevertReason): Promise<void> {
     return expect(p).to.be.rejectedWith(reason);
 }
 
@@ -180,7 +180,20 @@ export async function expectContractCallFailedWithoutReasonAsync<T>(p: Promise<T
  * @returns a new Promise which will reject if the conditions are not met and
  * otherwise resolve with no value.
  */
-export async function expectContractCreationFailedWithoutReason<T>(p: Promise<T>): Promise<void> {
+export async function expectContractCreationFailedAsync<T>(
+    p: sendTransactionResult,
+    reason: RevertReason,
+): Promise<void> {
+    return expectTransactionFailedAsync(p, reason);
+}
+
+/**
+ * Resolves if the contract creation/deployment fails without a revert reason.
+ * @param p a Promise resulting from a contract creation/deployment
+ * @returns a new Promise which will reject if the conditions are not met and
+ * otherwise resolve with no value.
+ */
+export async function expectContractCreationFailedWithoutReasonAsync<T>(p: Promise<T>): Promise<void> {
     const errMessage = await _getTransactionFailedErrorMessageAsync();
     return expect(p).to.be.rejectedWith(errMessage);
 }