Merge LibMem and LibBytes

11 files changed, 322 insertions, 399 deletions

diff --git a/packages/contracts/compiler.json b/packages/contracts/compiler.json
index 38580f4dc..f1646e79e 100644
--- a/packages/contracts/compiler.json
+++ b/packages/contracts/compiler.json
@@ -33,7 +33,6 @@
         "TestAssetDataDecoders",
         "TestAssetProxyDispatcher",
         "TestLibBytes",
-        "TestLibMem",
         "TestLibs",
         "TestSignatureValidator",
         "TestValidator",
diff --git a/packages/contracts/package.json b/packages/contracts/package.json
index 3bb66067d..87f88a8eb 100644
--- a/packages/contracts/package.json
+++ b/packages/contracts/package.json
@@ -34,7 +34,7 @@
     },
     "config": {
         "abis":
-            "../migrations/artifacts/2.0.0/@(AssetProxyOwner|DummyERC20Token|DummyERC721Receiver|DummyERC721Token|ERC20Proxy|ERC721Proxy|Exchange|ExchangeWrapper|MixinAuthorizable|MultiSigWallet|MultiSigWalletWithTimeLock|TestAssetDataDecoders|TestAssetProxyDispatcher|TestLibBytes|TestLibMem|TestLibs|TestSignatureValidator|TestValidator|TestWallet|TokenRegistry|Whitelist|WETH9|ZRXToken).json"
+            "../migrations/artifacts/2.0.0/@(AssetProxyOwner|DummyERC20Token|DummyERC721Receiver|DummyERC721Token|ERC20Proxy|ERC721Proxy|Exchange|ExchangeWrapper|MixinAuthorizable|MultiSigWallet|MultiSigWalletWithTimeLock|TestAssetDataDecoders|TestAssetProxyDispatcher|TestLibBytes|TestLibs|TestSignatureValidator|TestValidator|TestWallet|TokenRegistry|Whitelist|WETH9|ZRXToken).json"
     },
     "repository": {
         "type": "git",
diff --git a/packages/contracts/src/contracts/current/test/TestLibBytes/TestLibBytes.sol b/packages/contracts/src/contracts/current/test/TestLibBytes/TestLibBytes.sol
index 6f1898acd..d9b246b29 100644
--- a/packages/contracts/src/contracts/current/test/TestLibBytes/TestLibBytes.sol
+++ b/packages/contracts/src/contracts/current/test/TestLibBytes/TestLibBytes.sol
@@ -221,4 +221,34 @@ contract TestLibBytes is
         writeBytes(b, index, input);
         return b;
     }
+    
+    /// @dev Copies a block of memory from one location to another.
+    /// @param mem Memory contents we want to apply memCopy to
+    /// @param dest Destination offset into <mem>.
+    /// @param source Source offset into <mem>.
+    /// @param length Length of bytes to copy from <source> to <dest>
+    /// @return mem Memory contents after calling memCopy.
+    function testMemcpy(
+        bytes mem,
+        uint256 dest,
+        uint256 source,
+        uint256 length
+    )
+        public // not external, we need input in memory
+        pure
+        returns (bytes)
+    {
+        // Sanity check. Overflows are not checked.
+        require(source + length <= mem.length);
+        require(dest + length <= mem.length);
+
+        // Get pointer to memory contents
+        uint256 offset = getMemAddress(mem) + 32;
+
+        // Execute memCopy adjusted for memory array location
+        memCopy(offset + dest, offset + source, length);
+
+        // Return modified memory contents
+        return mem;
+    }
 }
diff --git a/packages/contracts/src/contracts/current/test/TestLibMem/TestLibMem.sol b/packages/contracts/src/contracts/current/test/TestLibMem/TestLibMem.sol
deleted file mode 100644
index b7e2e06b8..000000000
--- a/packages/contracts/src/contracts/current/test/TestLibMem/TestLibMem.sol
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
-
-  Copyright 2018 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 ^0.4.24;
-
-import "../../utils/LibMem/LibMem.sol";
-
-contract TestLibMem is
-    LibMem
-{
-
-    /// @dev Copies a block of memory from one location to another.
-    /// @param mem Memory contents we want to apply memCopy to
-    /// @param dest Destination offset into <mem>.
-    /// @param source Source offset into <mem>.
-    /// @param length Length of bytes to copy from <source> to <dest>
-    /// @return mem Memory contents after calling memCopy.
-    function testMemcpy(
-        bytes mem,
-        uint256 dest,
-        uint256 source,
-        uint256 length
-    )
-        public // not external, we need input in memory
-        pure
-        returns (bytes)
-    {
-        // Sanity check. Overflows are not checked.
-        require(source + length <= mem.length);
-        require(dest + length <= mem.length);
-
-        // Get pointer to memory contents
-        uint256 offset = getMemAddress(mem) + 32;
-
-        // Execute memCopy adjusted for memory array location
-        memCopy(offset + dest, offset + source, length);
-
-        // Return modified memory contents
-        return mem;
-    }
-}
diff --git a/packages/contracts/src/contracts/current/utils/LibBytes/LibBytes.sol b/packages/contracts/src/contracts/current/utils/LibBytes/LibBytes.sol
index 10d7ce41a..cb63e38e6 100644
--- a/packages/contracts/src/contracts/current/utils/LibBytes/LibBytes.sol
+++ b/packages/contracts/src/contracts/current/utils/LibBytes/LibBytes.sol
@@ -18,11 +18,7 @@
 
 pragma solidity ^0.4.24;
 
-import "../LibMem/LibMem.sol";
-
-contract LibBytes is
-    LibMem
-{
+contract LibBytes {
 
     // Revert reasons
     string constant GREATER_THAN_ZERO_LENGTH_REQUIRED = "GREATER_THAN_ZERO_LENGTH_REQUIRED";
@@ -32,6 +28,125 @@ contract LibBytes is
     string constant GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED = "GREATER_OR_EQUAL_TO_NESTED_BYTES_LENGTH_REQUIRED";
     string constant GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED = "GREATER_OR_EQUAL_TO_SOURCE_BYTES_LENGTH_REQUIRED";
 
+    /// @dev Gets the memory address for a byte array.
+    /// @param input Byte array to lookup.
+    /// @return memoryAddress Memory address of byte array.
+    function getMemAddress(bytes memory input)
+        internal
+        pure
+        returns (uint256 memoryAddress)
+    {
+        assembly {
+            memoryAddress := input
+        }
+        return memoryAddress;
+    }
+
+    /// @dev Copies `length` bytes from memory location `source` to `dest`.
+    /// @param dest memory address to copy bytes to.
+    /// @param source memory address to copy bytes from.
+    /// @param length number of bytes to copy.
+    function memCopy(
+        uint256 dest,
+        uint256 source,
+        uint256 length
+    )
+        internal
+        pure
+    {
+        if (length < 32) {
+            // Handle a partial word by reading destination and masking
+            // off the bits we are interested in.
+            // This correctly handles overlap, zero lengths and source == dest
+            assembly {
+                let mask := sub(exp(256, sub(32, length)), 1)
+                let s := and(mload(source), not(mask))
+                let d := and(mload(dest), mask)
+                mstore(dest, or(s, d))
+            }
+        } else {
+            // Skip the O(length) loop when source == dest.
+            if (source == dest) {
+                return;
+            }
+
+            // For large copies we copy whole words at a time. The final
+            // word is aligned to the end of the range (instead of after the
+            // previous) to handle partial words. So a copy will look like this:
+            //
+            //  ####
+            //      ####
+            //          ####
+            //            ####
+            //
+            // We handle overlap in the source and destination range by
+            // changing the copying direction. This prevents us from
+            // overwriting parts of source that we still need to copy.
+            //
+            // This correctly handles source == dest
+            //
+            if (source > dest) {
+                assembly {
+                    // We subtract 32 from `sEnd` and `dEnd` because it
+                    // is easier to compare with in the loop, and these
+                    // are also the addresses we need for copying the
+                    // last bytes.
+                    length := sub(length, 32)
+                    let sEnd := add(source, length)
+                    let dEnd := add(dest, length)
+
+                    // Remember the last 32 bytes of source
+                    // This needs to be done here and not after the loop
+                    // because we may have overwritten the last bytes in
+                    // source already due to overlap.
+                    let last := mload(sEnd)
+
+                    // Copy whole words front to back
+                    // Note: the first check is always true,
+                    // this could have been a do-while loop.
+                    for {} lt(source, sEnd) {} {
+                        mstore(dest, mload(source))
+                        source := add(source, 32)
+                        dest := add(dest, 32)
+                    }
+                    
+                    // Write the last 32 bytes
+                    mstore(dEnd, last)
+                }
+            } else {
+                assembly {
+                    // We subtract 32 from `sEnd` and `dEnd` because those
+                    // are the starting points when copying a word at the end.
+                    length := sub(length, 32)
+                    let sEnd := add(source, length)
+                    let dEnd := add(dest, length)
+
+                    // Remember the first 32 bytes of source
+                    // This needs to be done here and not after the loop
+                    // because we may have overwritten the first bytes in
+                    // source already due to overlap.
+                    let first := mload(source)
+
+                    // Copy whole words back to front
+                    // We use a signed comparisson here to allow dEnd to become
+                    // negative (happens when source and dest < 32). Valid
+                    // addresses in local memory will never be larger than
+                    // 2**255, so they can be safely re-interpreted as signed.
+                    // Note: the first check is always true,
+                    // this could have been a do-while loop.
+                    for {} slt(dest, dEnd) {} {
+                        mstore(dEnd, mload(sEnd))
+                        sEnd := sub(sEnd, 32)
+                        dEnd := sub(dEnd, 32)
+                    }
+                    
+                    // Write the first 32 bytes
+                    mstore(dest, first)
+                }
+            }
+        }
+    }
+
     /// @dev Pops the last byte off of a byte array by modifying its length.
     /// @param b Byte array that will be modified.
     /// @return The byte that was popped off.
diff --git a/packages/contracts/src/contracts/current/utils/LibMem/LibMem.sol b/packages/contracts/src/contracts/current/utils/LibMem/LibMem.sol
deleted file mode 100644
index 97fb5fb0f..000000000
--- a/packages/contracts/src/contracts/current/utils/LibMem/LibMem.sol
+++ /dev/null
@@ -1,142 +0,0 @@
-/*
-
-  Copyright 2018 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 ^0.4.24;
-
-contract LibMem
-{
-
-    /// @dev Gets the memory address for a byte array.
-    /// @param input Byte array to lookup.
-    /// @return memoryAddress Memory address of byte array.
-    function getMemAddress(bytes memory input)
-        internal
-        pure
-        returns (uint256 memoryAddress)
-    {
-        assembly {
-            memoryAddress := input
-        }
-        return memoryAddress;
-    }
-
-    /// @dev Copies `length` bytes from memory location `source` to `dest`.
-    /// @param dest memory address to copy bytes to.
-    /// @param source memory address to copy bytes from.
-    /// @param length number of bytes to copy.
-    function memCopy(
-        uint256 dest,
-        uint256 source,
-        uint256 length
-    )
-        internal
-        pure
-    {
-        if (length < 32) {
-            // Handle a partial word by reading destination and masking
-            // off the bits we are interested in.
-            // This correctly handles overlap, zero lengths and source == dest
-            assembly {
-                let mask := sub(exp(256, sub(32, length)), 1)
-                let s := and(mload(source), not(mask))
-                let d := and(mload(dest), mask)
-                mstore(dest, or(s, d))
-            }
-        } else {
-            // Skip the O(length) loop when source == dest.
-            if (source == dest) {
-                return;
-            }
-
-            // For large copies we copy whole words at a time. The final
-            // word is aligned to the end of the range (instead of after the
-            // previous) to handle partial words. So a copy will look like this:
-            //
-            //  ####
-            //      ####
-            //          ####
-            //            ####
-            //
-            // We handle overlap in the source and destination range by
-            // changing the copying direction. This prevents us from
-            // overwriting parts of source that we still need to copy.
-            //
-            // This correctly handles source == dest
-            //
-            if (source > dest) {
-                assembly {
-                    // We subtract 32 from `sEnd` and `dEnd` because it
-                    // is easier to compare with in the loop, and these
-                    // are also the addresses we need for copying the
-                    // last bytes.
-                    length := sub(length, 32)
-                    let sEnd := add(source, length)
-                    let dEnd := add(dest, length)
-
-                    // Remember the last 32 bytes of source
-                    // This needs to be done here and not after the loop
-                    // because we may have overwritten the last bytes in
-                    // source already due to overlap.
-                    let last := mload(sEnd)
-
-                    // Copy whole words front to back
-                    // Note: the first check is always true,
-                    // this could have been a do-while loop.
-                    for {} lt(source, sEnd) {} {
-                        mstore(dest, mload(source))
-                        source := add(source, 32)
-                        dest := add(dest, 32)
-                    }
-                    
-                    // Write the last 32 bytes
-                    mstore(dEnd, last)
-                }
-            } else {
-                assembly {
-                    // We subtract 32 from `sEnd` and `dEnd` because those
-                    // are the starting points when copying a word at the end.
-                    length := sub(length, 32)
-                    let sEnd := add(source, length)
-                    let dEnd := add(dest, length)
-
-                    // Remember the first 32 bytes of source
-                    // This needs to be done here and not after the loop
-                    // because we may have overwritten the first bytes in
-                    // source already due to overlap.
-                    let first := mload(source)
-
-                    // Copy whole words back to front
-                    // We use a signed comparisson here to allow dEnd to become
-                    // negative (happens when source and dest < 32). Valid
-                    // addresses in local memory will never be larger than
-                    // 2**255, so they can be safely re-interpreted as signed.
-                    // Note: the first check is always true,
-                    // this could have been a do-while loop.
-                    for {} slt(dest, dEnd) {} {
-                        mstore(dEnd, mload(sEnd))
-                        sEnd := sub(sEnd, 32)
-                        dEnd := sub(dEnd, 32)
-                    }
-                    
-                    // Write the first 32 bytes
-                    mstore(dest, first)
-                }
-            }
-        }
-    }
-}
diff --git a/packages/contracts/src/utils/artifacts.ts b/packages/contracts/src/utils/artifacts.ts
index 4375d87c6..fa18cc9d2 100644
--- a/packages/contracts/src/utils/artifacts.ts
+++ b/packages/contracts/src/utils/artifacts.ts
@@ -14,7 +14,6 @@ import * as MultiSigWalletWithTimeLock from '../artifacts/MultiSigWalletWithTime
 import * as TestAssetDataDecoders from '../artifacts/TestAssetDataDecoders.json';
 import * as TestAssetProxyDispatcher from '../artifacts/TestAssetProxyDispatcher.json';
 import * as TestLibBytes from '../artifacts/TestLibBytes.json';
-import * as TestLibMem from '../artifacts/TestLibMem.json';
 import * as TestLibs from '../artifacts/TestLibs.json';
 import * as TestSignatureValidator from '../artifacts/TestSignatureValidator.json';
 import * as TestValidator from '../artifacts/TestValidator.json';
@@ -40,7 +39,6 @@ export const artifacts = {
     TestAssetProxyDispatcher: (TestAssetProxyDispatcher as any) as ContractArtifact,
     TestAssetDataDecoders: (TestAssetDataDecoders as any) as ContractArtifact,
     TestLibBytes: (TestLibBytes as any) as ContractArtifact,
-    TestLibMem: (TestLibMem as any) as ContractArtifact,
     TestLibs: (TestLibs as any) as ContractArtifact,
     TestSignatureValidator: (TestSignatureValidator as any) as ContractArtifact,
     TestValidator: (TestValidator as any) as ContractArtifact,
diff --git a/packages/contracts/src/utils/types.ts b/packages/contracts/src/utils/types.ts
index 7a1f92afd..5dfac64fc 100644
--- a/packages/contracts/src/utils/types.ts
+++ b/packages/contracts/src/utils/types.ts
@@ -92,7 +92,6 @@ export enum ContractName {
     Arbitrage = 'Arbitrage',
     TestAssetDataDecoders = 'TestAssetDataDecoders',
     TestAssetProxyDispatcher = 'TestAssetProxyDispatcher',
-    TestLibMem = 'TestLibMem',
     TestLibs = 'TestLibs',
     TestSignatureValidator = 'TestSignatureValidator',
     ERC20Proxy = 'ERC20Proxy',
diff --git a/packages/contracts/test/asset_proxy/decoder.ts b/packages/contracts/test/asset_proxy/decoder.ts
index 875d55daa..98d18aa38 100644
--- a/packages/contracts/test/asset_proxy/decoder.ts
+++ b/packages/contracts/test/asset_proxy/decoder.ts
@@ -27,7 +27,6 @@ describe('TestAssetDataDecoders', () => {
         // Setup accounts & addresses
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
         testAddress = accounts[0];
-        // Deploy TestLibMem
         testAssetProxyDecoder = await TestAssetDataDecodersContract.deployFrom0xArtifactAsync(
             artifacts.TestAssetDataDecoders,
             provider,
diff --git a/packages/contracts/test/libraries/lib_bytes.ts b/packages/contracts/test/libraries/lib_bytes.ts
index a31a4789c..b378bb036 100644
--- a/packages/contracts/test/libraries/lib_bytes.ts
+++ b/packages/contracts/test/libraries/lib_bytes.ts
@@ -17,6 +17,12 @@ chaiSetup.configure();
 const expect = chai.expect;
 const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
 
+// BUG: Ideally we would use Buffer.from(memory).toString('hex')
+// https://github.com/Microsoft/TypeScript/issues/23155
+const toHex = (buf: Uint8Array): string => buf.reduce((a, v) => a + ('00' + v.toString(16)).slice(-2), '0x');
+
+const fromHex = (str: string): Uint8Array => Uint8Array.from(Buffer.from(str.slice(2), 'hex'));
+
 describe('LibBytes', () => {
     let libBytes: TestLibBytesContract;
     const byteArrayShorterThan32Bytes = '0x012345';
@@ -617,5 +623,170 @@ describe('LibBytes', () => {
             );
         });
     });
+
+    describe('memCopy', () => {
+        // Create memory 0x000102...FF
+        const memSize = 256;
+        const memory = new Uint8Array(memSize).map((_, i) => i);
+        const memHex = toHex(memory);
+
+        // Reference implementation to test against
+        const refMemcpy = (mem: Uint8Array, dest: number, source: number, length: number): Uint8Array =>
+            Uint8Array.from(mem).copyWithin(dest, source, source + length);
+
+        // Test vectors: destination, source, length, job description
+        type Tests = Array<[number, number, number, string]>;
+
+        const test = (tests: Tests) =>
+            tests.forEach(([dest, source, length, job]) =>
+                it(job, async () => {
+                    const expected = refMemcpy(memory, dest, source, length);
+                    const resultStr = await libBytes.testMemcpy.callAsync(
+                        memHex,
+                        new BigNumber(dest),
+                        new BigNumber(source),
+                        new BigNumber(length),
+                    );
+                    const result = fromHex(resultStr);
+                    expect(result).to.deep.equal(expected);
+                }),
+            );
+
+        test([[0, 0, 0, 'copies zero bytes with overlap']]);
+
+        describe('copies forward', () =>
+            test([
+                [128, 0, 0, 'zero bytes'],
+                [128, 0, 1, 'one byte'],
+                [128, 0, 11, 'eleven bytes'],
+                [128, 0, 31, 'thirty-one bytes'],
+                [128, 0, 32, 'one word'],
+                [128, 0, 64, 'two words'],
+                [128, 0, 96, 'three words'],
+                [128, 0, 33, 'one word and one byte'],
+                [128, 0, 72, 'two words and eight bytes'],
+                [128, 0, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies forward within one word', () =>
+            test([
+                [16, 0, 0, 'zero bytes'],
+                [16, 0, 1, 'one byte'],
+                [16, 0, 11, 'eleven bytes'],
+                [16, 0, 16, 'sixteen bytes'],
+            ]));
+
+        describe('copies forward with one byte overlap', () =>
+            test([
+                [0, 0, 1, 'one byte'],
+                [10, 0, 11, 'eleven bytes'],
+                [30, 0, 31, 'thirty-one bytes'],
+                [31, 0, 32, 'one word'],
+                [32, 0, 33, 'one word and one byte'],
+                [71, 0, 72, 'two words and eight bytes'],
+                [99, 0, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies forward with thirty-one bytes overlap', () =>
+            test([
+                [0, 0, 31, 'thirty-one bytes'],
+                [1, 0, 32, 'one word'],
+                [2, 0, 33, 'one word and one byte'],
+                [41, 0, 72, 'two words and eight bytes'],
+                [69, 0, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies forward with one word overlap', () =>
+            test([
+                [0, 0, 32, 'one word'],
+                [1, 0, 33, 'one word and one byte'],
+                [41, 0, 72, 'two words and eight bytes'],
+                [69, 0, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies forward with one word and one byte overlap', () =>
+            test([
+                [0, 0, 33, 'one word and one byte'],
+                [40, 0, 72, 'two words and eight bytes'],
+                [68, 0, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies forward with two words overlap', () =>
+            test([
+                [0, 0, 64, 'two words'],
+                [8, 0, 72, 'two words and eight bytes'],
+                [36, 0, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies forward within one word and one byte overlap', () =>
+            test([[0, 0, 1, 'one byte'], [10, 0, 11, 'eleven bytes'], [15, 0, 16, 'sixteen bytes']]));
+
+        describe('copies backward', () =>
+            test([
+                [0, 128, 0, 'zero bytes'],
+                [0, 128, 1, 'one byte'],
+                [0, 128, 11, 'eleven bytes'],
+                [0, 128, 31, 'thirty-one bytes'],
+                [0, 128, 32, 'one word'],
+                [0, 128, 64, 'two words'],
+                [0, 128, 96, 'three words'],
+                [0, 128, 33, 'one word and one byte'],
+                [0, 128, 72, 'two words and eight bytes'],
+                [0, 128, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies backward within one word', () =>
+            test([
+                [0, 16, 0, 'zero bytes'],
+                [0, 16, 1, 'one byte'],
+                [0, 16, 11, 'eleven bytes'],
+                [0, 16, 16, 'sixteen bytes'],
+            ]));
+
+        describe('copies backward with one byte overlap', () =>
+            test([
+                [0, 0, 1, 'one byte'],
+                [0, 10, 11, 'eleven bytes'],
+                [0, 30, 31, 'thirty-one bytes'],
+                [0, 31, 32, 'one word'],
+                [0, 32, 33, 'one word and one byte'],
+                [0, 71, 72, 'two words and eight bytes'],
+                [0, 99, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies backward with thirty-one bytes overlap', () =>
+            test([
+                [0, 0, 31, 'thirty-one bytes'],
+                [0, 1, 32, 'one word'],
+                [0, 2, 33, 'one word and one byte'],
+                [0, 41, 72, 'two words and eight bytes'],
+                [0, 69, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies backward with one word overlap', () =>
+            test([
+                [0, 0, 32, 'one word'],
+                [0, 1, 33, 'one word and one byte'],
+                [0, 41, 72, 'two words and eight bytes'],
+                [0, 69, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies backward with one word and one byte overlap', () =>
+            test([
+                [0, 0, 33, 'one word and one byte'],
+                [0, 40, 72, 'two words and eight bytes'],
+                [0, 68, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies backward with two words overlap', () =>
+            test([
+                [0, 0, 64, 'two words'],
+                [0, 8, 72, 'two words and eight bytes'],
+                [0, 36, 100, 'three words and four bytes'],
+            ]));
+
+        describe('copies forward within one word and one byte overlap', () =>
+            test([[0, 0, 1, 'one byte'], [0, 10, 11, 'eleven bytes'], [0, 15, 16, 'sixteen bytes']]));
+    });
 });
 // tslint:disable:max-file-line-count
diff --git a/packages/contracts/test/libraries/lib_mem.ts b/packages/contracts/test/libraries/lib_mem.ts
deleted file mode 100644
index 8cf5cf3a7..000000000
--- a/packages/contracts/test/libraries/lib_mem.ts
+++ /dev/null
@@ -1,190 +0,0 @@
-import { BigNumber } from '@0xproject/utils';
-import * as chai from 'chai';
-
-import { TestLibMemContract } from '../../src/generated_contract_wrappers/test_lib_mem';
-import { artifacts } from '../../src/utils/artifacts';
-import { chaiSetup } from '../../src/utils/chai_setup';
-import { provider, txDefaults } from '../../src/utils/web3_wrapper';
-
-chaiSetup.configure();
-const expect = chai.expect;
-
-// BUG: Ideally we would use Buffer.from(memory).toString('hex')
-// https://github.com/Microsoft/TypeScript/issues/23155
-const toHex = (buf: Uint8Array): string => buf.reduce((a, v) => a + ('00' + v.toString(16)).slice(-2), '0x');
-
-const fromHex = (str: string): Uint8Array => Uint8Array.from(Buffer.from(str.slice(2), 'hex'));
-
-describe('LibMem', () => {
-    let testLibMem: TestLibMemContract;
-
-    before(async () => {
-        // Deploy TestLibMem
-        testLibMem = await TestLibMemContract.deployFrom0xArtifactAsync(artifacts.TestLibMem, provider, txDefaults);
-    });
-
-    describe('memCopy', () => {
-        // Create memory 0x000102...FF
-        const memSize = 256;
-        const memory = new Uint8Array(memSize).map((_, i) => i);
-        const memHex = toHex(memory);
-
-        // Reference implementation to test against
-        const refMemcpy = (mem: Uint8Array, dest: number, source: number, length: number): Uint8Array =>
-            Uint8Array.from(mem).copyWithin(dest, source, source + length);
-
-        // Test vectors: destination, source, length, job description
-        type Tests = Array<[number, number, number, string]>;
-
-        const test = (tests: Tests) =>
-            tests.forEach(([dest, source, length, job]) =>
-                it(job, async () => {
-                    const expected = refMemcpy(memory, dest, source, length);
-                    const resultStr = await testLibMem.testMemcpy.callAsync(
-                        memHex,
-                        new BigNumber(dest),
-                        new BigNumber(source),
-                        new BigNumber(length),
-                    );
-                    const result = fromHex(resultStr);
-                    expect(result).to.deep.equal(expected);
-                }),
-            );
-
-        test([[0, 0, 0, 'copies zero bytes with overlap']]);
-
-        describe('copies forward', () =>
-            test([
-                [128, 0, 0, 'zero bytes'],
-                [128, 0, 1, 'one byte'],
-                [128, 0, 11, 'eleven bytes'],
-                [128, 0, 31, 'thirty-one bytes'],
-                [128, 0, 32, 'one word'],
-                [128, 0, 64, 'two words'],
-                [128, 0, 96, 'three words'],
-                [128, 0, 33, 'one word and one byte'],
-                [128, 0, 72, 'two words and eight bytes'],
-                [128, 0, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies forward within one word', () =>
-            test([
-                [16, 0, 0, 'zero bytes'],
-                [16, 0, 1, 'one byte'],
-                [16, 0, 11, 'eleven bytes'],
-                [16, 0, 16, 'sixteen bytes'],
-            ]));
-
-        describe('copies forward with one byte overlap', () =>
-            test([
-                [0, 0, 1, 'one byte'],
-                [10, 0, 11, 'eleven bytes'],
-                [30, 0, 31, 'thirty-one bytes'],
-                [31, 0, 32, 'one word'],
-                [32, 0, 33, 'one word and one byte'],
-                [71, 0, 72, 'two words and eight bytes'],
-                [99, 0, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies forward with thirty-one bytes overlap', () =>
-            test([
-                [0, 0, 31, 'thirty-one bytes'],
-                [1, 0, 32, 'one word'],
-                [2, 0, 33, 'one word and one byte'],
-                [41, 0, 72, 'two words and eight bytes'],
-                [69, 0, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies forward with one word overlap', () =>
-            test([
-                [0, 0, 32, 'one word'],
-                [1, 0, 33, 'one word and one byte'],
-                [41, 0, 72, 'two words and eight bytes'],
-                [69, 0, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies forward with one word and one byte overlap', () =>
-            test([
-                [0, 0, 33, 'one word and one byte'],
-                [40, 0, 72, 'two words and eight bytes'],
-                [68, 0, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies forward with two words overlap', () =>
-            test([
-                [0, 0, 64, 'two words'],
-                [8, 0, 72, 'two words and eight bytes'],
-                [36, 0, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies forward within one word and one byte overlap', () =>
-            test([[0, 0, 1, 'one byte'], [10, 0, 11, 'eleven bytes'], [15, 0, 16, 'sixteen bytes']]));
-
-        describe('copies backward', () =>
-            test([
-                [0, 128, 0, 'zero bytes'],
-                [0, 128, 1, 'one byte'],
-                [0, 128, 11, 'eleven bytes'],
-                [0, 128, 31, 'thirty-one bytes'],
-                [0, 128, 32, 'one word'],
-                [0, 128, 64, 'two words'],
-                [0, 128, 96, 'three words'],
-                [0, 128, 33, 'one word and one byte'],
-                [0, 128, 72, 'two words and eight bytes'],
-                [0, 128, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies backward within one word', () =>
-            test([
-                [0, 16, 0, 'zero bytes'],
-                [0, 16, 1, 'one byte'],
-                [0, 16, 11, 'eleven bytes'],
-                [0, 16, 16, 'sixteen bytes'],
-            ]));
-
-        describe('copies backward with one byte overlap', () =>
-            test([
-                [0, 0, 1, 'one byte'],
-                [0, 10, 11, 'eleven bytes'],
-                [0, 30, 31, 'thirty-one bytes'],
-                [0, 31, 32, 'one word'],
-                [0, 32, 33, 'one word and one byte'],
-                [0, 71, 72, 'two words and eight bytes'],
-                [0, 99, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies backward with thirty-one bytes overlap', () =>
-            test([
-                [0, 0, 31, 'thirty-one bytes'],
-                [0, 1, 32, 'one word'],
-                [0, 2, 33, 'one word and one byte'],
-                [0, 41, 72, 'two words and eight bytes'],
-                [0, 69, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies backward with one word overlap', () =>
-            test([
-                [0, 0, 32, 'one word'],
-                [0, 1, 33, 'one word and one byte'],
-                [0, 41, 72, 'two words and eight bytes'],
-                [0, 69, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies backward with one word and one byte overlap', () =>
-            test([
-                [0, 0, 33, 'one word and one byte'],
-                [0, 40, 72, 'two words and eight bytes'],
-                [0, 68, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies backward with two words overlap', () =>
-            test([
-                [0, 0, 64, 'two words'],
-                [0, 8, 72, 'two words and eight bytes'],
-                [0, 36, 100, 'three words and four bytes'],
-            ]));
-
-        describe('copies forward within one word and one byte overlap', () =>
-            test([[0, 0, 1, 'one byte'], [0, 10, 11, 'eleven bytes'], [0, 15, 16, 'sixteen bytes']]));
-    });
-});