Merge branch 'development' into feature/order-watcher/dockerize

* development: (898 commits)
  Fixed merge conflict from development
  Ran prettier
  Doc generation working for changes by dutch auction wrapper
  added changelog entry for monorepo-scripts
  Hide dutch auction wrapper from docs -- hopefully this will prevent the "must export Web3Wrapper" error from doc generation
  relaxed version on contract-extension dependencies
  Added NetworkID 50 address for dutch auction wrapper
  removed manual updte of package.json version
  export dutch auction wrapper types from 0x.js
  Export dutch auction wrapper in 0x.js
  ran prettier
  Minor documentation updates to dutch auction wrapper
  `afterAuctionDetails` -> `auctionDetails`
  Added @todo for including dutch auction addresses once deployed
  Ran prettier & linter
  Removed redundant assignment
  removed needless newline on contract-wrappers changelog
  removed timestamp from changelog for abi-gen-wrappers
  added dutch auction address for testnets
  removed .only
  ...

38 files changed, 2377 insertions, 161 deletions

diff --git a/contracts/extensions/CHANGELOG.json b/contracts/extensions/CHANGELOG.json
index da4d9c2ba..40e25565e 100644
--- a/contracts/extensions/CHANGELOG.json
+++ b/contracts/extensions/CHANGELOG.json
@@ -1,10 +1,27 @@
 [
     {
+        "version": "1.2.0",
+        "changes": [
+            {
+                "note": "Added Dutch Auction Wrapper",
+                "pr": 1465
+            }
+        ]
+    },
+    {
         "version": "1.1.0",
         "changes": [
             {
                 "note": "Added Balance Threshold Filter",
                 "pr": 1383
+            },
+            {
+                "note": "Add OrderMatcher",
+                "pr": 1117
+            },
+            {
+                "note": "Add OrderValidator",
+                "pr": 1464
             }
         ]
     },
diff --git a/contracts/extensions/compiler.json b/contracts/extensions/compiler.json
index e6ed0c215..2bb468724 100644
--- a/contracts/extensions/compiler.json
+++ b/contracts/extensions/compiler.json
@@ -18,5 +18,5 @@
             }
         }
     },
-    "contracts": ["BalanceThresholdFilter", "DutchAuction", "Forwarder"]
+    "contracts": ["BalanceThresholdFilter", "DutchAuction", "Forwarder", "OrderMatcher", "OrderValidator"]
 }
diff --git a/contracts/extensions/contracts/BalanceThresholdFilter/MixinBalanceThresholdFilterCore.sol b/contracts/extensions/contracts/BalanceThresholdFilter/MixinBalanceThresholdFilterCore.sol
index df830f36e..da050bf72 100644
--- a/contracts/extensions/contracts/BalanceThresholdFilter/MixinBalanceThresholdFilterCore.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/MixinBalanceThresholdFilterCore.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 import "@0x/contracts-libs/contracts/libs/LibExchangeSelectors.sol";
 import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
diff --git a/contracts/extensions/contracts/BalanceThresholdFilter/MixinExchangeCalldata.sol b/contracts/extensions/contracts/BalanceThresholdFilter/MixinExchangeCalldata.sol
index bd26a468f..a15e95a9d 100644
--- a/contracts/extensions/contracts/BalanceThresholdFilter/MixinExchangeCalldata.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/MixinExchangeCalldata.sol
@@ -17,7 +17,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 import "./mixins/MExchangeCalldata.sol";
 import "@0x/contracts-libs/contracts/libs/LibAddressArray.sol";
diff --git a/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IBalanceThresholdFilterCore.sol b/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IBalanceThresholdFilterCore.sol
index 3d8e2bbd1..4a1bf1fb2 100644
--- a/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IBalanceThresholdFilterCore.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IBalanceThresholdFilterCore.sol
@@ -17,7 +17,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 
 contract IBalanceThresholdFilterCore {
diff --git a/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IThresholdAsset.sol b/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IThresholdAsset.sol
index 3e424b9f4..f78f9c2de 100644
--- a/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IThresholdAsset.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/interfaces/IThresholdAsset.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 
 contract IThresholdAsset {
diff --git a/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MBalanceThresholdFilterCore.sol b/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MBalanceThresholdFilterCore.sol
index b8b67e6ee..074686e8d 100644
--- a/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MBalanceThresholdFilterCore.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MBalanceThresholdFilterCore.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
 import "../interfaces/IThresholdAsset.sol";
diff --git a/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MExchangeCalldata.sol b/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MExchangeCalldata.sol
index bf2940fe1..40536d820 100644
--- a/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MExchangeCalldata.sol
+++ b/contracts/extensions/contracts/BalanceThresholdFilter/mixins/MExchangeCalldata.sol
@@ -17,7 +17,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 
 contract MExchangeCalldata {
diff --git a/contracts/extensions/contracts/Forwarder/MixinAssets.sol b/contracts/extensions/contracts/Forwarder/MixinAssets.sol
index 3ebf75161..116cdf267 100644
--- a/contracts/extensions/contracts/Forwarder/MixinAssets.sol
+++ b/contracts/extensions/contracts/Forwarder/MixinAssets.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
 import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";
diff --git a/contracts/extensions/contracts/Forwarder/MixinExchangeWrapper.sol b/contracts/extensions/contracts/Forwarder/MixinExchangeWrapper.sol
index 210eb14c2..cab26741d 100644
--- a/contracts/extensions/contracts/Forwarder/MixinExchangeWrapper.sol
+++ b/contracts/extensions/contracts/Forwarder/MixinExchangeWrapper.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./libs/LibConstants.sol";
diff --git a/contracts/extensions/contracts/Forwarder/MixinForwarderCore.sol b/contracts/extensions/contracts/Forwarder/MixinForwarderCore.sol
index bab78d79b..11c0147a5 100644
--- a/contracts/extensions/contracts/Forwarder/MixinForwarderCore.sol
+++ b/contracts/extensions/contracts/Forwarder/MixinForwarderCore.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./libs/LibConstants.sol";
diff --git a/contracts/extensions/contracts/Forwarder/MixinWeth.sol b/contracts/extensions/contracts/Forwarder/MixinWeth.sol
index 2a281f3ae..25a35f47b 100644
--- a/contracts/extensions/contracts/Forwarder/MixinWeth.sol
+++ b/contracts/extensions/contracts/Forwarder/MixinWeth.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 import "@0x/contracts-libs/contracts/libs/LibMath.sol";
 import "./libs/LibConstants.sol";
diff --git a/contracts/extensions/contracts/Forwarder/interfaces/IAssets.sol b/contracts/extensions/contracts/Forwarder/interfaces/IAssets.sol
index 1e034c003..cebfd3706 100644
--- a/contracts/extensions/contracts/Forwarder/interfaces/IAssets.sol
+++ b/contracts/extensions/contracts/Forwarder/interfaces/IAssets.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 
 contract IAssets {
diff --git a/contracts/extensions/contracts/Forwarder/interfaces/IForwarder.sol b/contracts/extensions/contracts/Forwarder/interfaces/IForwarder.sol
index f5a26e2ba..6ce8a1d31 100644
--- a/contracts/extensions/contracts/Forwarder/interfaces/IForwarder.sol
+++ b/contracts/extensions/contracts/Forwarder/interfaces/IForwarder.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "./IForwarderCore.sol";
diff --git a/contracts/extensions/contracts/Forwarder/interfaces/IForwarderCore.sol b/contracts/extensions/contracts/Forwarder/interfaces/IForwarderCore.sol
index eede20bb8..7f62722e7 100644
--- a/contracts/extensions/contracts/Forwarder/interfaces/IForwarderCore.sol
+++ b/contracts/extensions/contracts/Forwarder/interfaces/IForwarderCore.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
diff --git a/contracts/extensions/contracts/Forwarder/libs/LibConstants.sol b/contracts/extensions/contracts/Forwarder/libs/LibConstants.sol
index 4a81abf76..0d2f6e36d 100644
--- a/contracts/extensions/contracts/Forwarder/libs/LibConstants.sol
+++ b/contracts/extensions/contracts/Forwarder/libs/LibConstants.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
 import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
diff --git a/contracts/extensions/contracts/Forwarder/libs/LibForwarderErrors.sol b/contracts/extensions/contracts/Forwarder/libs/LibForwarderErrors.sol
index fb3ade1db..7a95b78a0 100644
--- a/contracts/extensions/contracts/Forwarder/libs/LibForwarderErrors.sol
+++ b/contracts/extensions/contracts/Forwarder/libs/LibForwarderErrors.sol
@@ -17,7 +17,7 @@
 */
 
 // solhint-disable
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 
 /// This contract is intended to serve as a reference, but is not actually used for efficiency reasons.
diff --git a/contracts/extensions/contracts/Forwarder/mixins/MAssets.sol b/contracts/extensions/contracts/Forwarder/mixins/MAssets.sol
index 9e7f80d97..1757b37fb 100644
--- a/contracts/extensions/contracts/Forwarder/mixins/MAssets.sol
+++ b/contracts/extensions/contracts/Forwarder/mixins/MAssets.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 import "../interfaces/IAssets.sol";
 
diff --git a/contracts/extensions/contracts/Forwarder/mixins/MExchangeWrapper.sol b/contracts/extensions/contracts/Forwarder/mixins/MExchangeWrapper.sol
index d9e71786a..143f888b1 100644
--- a/contracts/extensions/contracts/Forwarder/mixins/MExchangeWrapper.sol
+++ b/contracts/extensions/contracts/Forwarder/mixins/MExchangeWrapper.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 pragma experimental ABIEncoderV2;
 
 import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
diff --git a/contracts/extensions/contracts/Forwarder/mixins/MWeth.sol b/contracts/extensions/contracts/Forwarder/mixins/MWeth.sol
index 88e77be4e..15d66942f 100644
--- a/contracts/extensions/contracts/Forwarder/mixins/MWeth.sol
+++ b/contracts/extensions/contracts/Forwarder/mixins/MWeth.sol
@@ -16,7 +16,7 @@
 
 */
 
-pragma solidity 0.4.24;
+pragma solidity ^0.4.24;
 
 
 contract MWeth {
diff --git a/contracts/extensions/contracts/OrderMatcher/MixinAssets.sol b/contracts/extensions/contracts/OrderMatcher/MixinAssets.sol
new file mode 100644
index 000000000..f0f91cfc0
--- /dev/null
+++ b/contracts/extensions/contracts/OrderMatcher/MixinAssets.sol
@@ -0,0 +1,195 @@
+/*
+
+  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 "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
+import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC20Token/IERC20Token.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC721Token/IERC721Token.sol";
+import "./mixins/MAssets.sol";
+import "./libs/LibConstants.sol";
+
+
+contract MixinAssets is
+    MAssets,
+    Ownable,
+    LibConstants
+{
+    using LibBytes for bytes;
+
+    /// @dev Withdraws assets from this contract. The contract requires a ZRX balance in order to 
+    ///      function optimally, and this function allows the ZRX to be withdrawn by owner. It may also be
+    ///      used to withdraw assets that were accidentally sent to this contract.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to withdraw.
+    function withdrawAsset(
+        bytes assetData,
+        uint256 amount
+    )
+        external
+        onlyOwner
+    {
+        transferAssetToSender(assetData, amount);
+    }
+
+    /// @dev Approves or disapproves an AssetProxy to spend asset.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveAssetProxy(
+        bytes assetData,
+        uint256 amount
+    )
+        external
+        onlyOwner
+    {
+        bytes4 proxyId = assetData.readBytes4(0);
+
+        if (proxyId == ERC20_DATA_ID) {
+            approveERC20Token(assetData, amount);
+        } else if (proxyId == ERC721_DATA_ID) {
+            approveERC721Token(assetData, amount);
+        } else {
+            revert("UNSUPPORTED_ASSET_PROXY");
+        }
+    }
+
+    /// @dev Transfers given amount of asset to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferAssetToSender(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        bytes4 proxyId = assetData.readBytes4(0);
+
+        if (proxyId == ERC20_DATA_ID) {
+            transferERC20Token(assetData, amount);
+        } else if (proxyId == ERC721_DATA_ID) {
+            transferERC721Token(assetData, amount);
+        } else {
+            revert("UNSUPPORTED_ASSET_PROXY");
+        }
+    }
+
+    /// @dev Decodes ERC20 assetData and transfers given amount to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferERC20Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        // 4 byte id + 12 0 bytes before ABI encoded token address.
+        address token = assetData.readAddress(16);
+
+        // Transfer tokens.
+        // We do a raw call so we can check the success separate
+        // from the return data.
+        bool success = token.call(abi.encodeWithSelector(
+            ERC20_TRANSFER_SELECTOR,
+            msg.sender,
+            amount
+        ));
+        require(
+            success,
+            "TRANSFER_FAILED"
+        );
+        
+        // Check return data.
+        // If there is no return data, we assume the token incorrectly
+        // does not return a bool. In this case we expect it to revert
+        // on failure, which was handled above.
+        // If the token does return data, we require that it is a single
+        // value that evaluates to true.
+        assembly {
+            if returndatasize {
+                success := 0
+                if eq(returndatasize, 32) {
+                    // First 64 bytes of memory are reserved scratch space
+                    returndatacopy(0, 0, 32)
+                    success := mload(0)
+                }
+            }
+        }
+        require(
+            success,
+            "TRANSFER_FAILED"
+        );
+    }
+
+    /// @dev Decodes ERC721 assetData and transfers given amount to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferERC721Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        require(
+            amount == 1,
+            "INVALID_AMOUNT"
+        );
+        // Decode asset data.
+        // 4 byte id + 12 0 bytes before ABI encoded token address.
+        address token = assetData.readAddress(16);
+        // 4 byte id + 32 byte ABI encoded token address before token id.
+        uint256 tokenId = assetData.readUint256(36);
+
+        // Perform transfer.
+        IERC721Token(token).transferFrom(
+            address(this),
+            msg.sender,
+            tokenId
+        );
+    }
+
+    /// @dev Sets approval for ERC20 AssetProxy.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveERC20Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        address token = assetData.readAddress(16);
+        require(
+            IERC20Token(token).approve(ERC20_PROXY_ADDRESS, amount),
+            "APPROVAL_FAILED"
+        );
+    }
+
+    /// @dev Sets approval for ERC721 AssetProxy.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveERC721Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal
+    {
+        address token = assetData.readAddress(16);
+        bool approval = amount >= 1;
+        IERC721Token(token).setApprovalForAll(ERC721_PROXY_ADDRESS, approval);
+    }
+}
diff --git a/contracts/extensions/contracts/OrderMatcher/MixinMatchOrders.sol b/contracts/extensions/contracts/OrderMatcher/MixinMatchOrders.sol
new file mode 100644
index 000000000..1787deb59
--- /dev/null
+++ b/contracts/extensions/contracts/OrderMatcher/MixinMatchOrders.sol
@@ -0,0 +1,86 @@
+/*
+
+  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;
+pragma experimental ABIEncoderV2;
+
+import "./libs/LibConstants.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-libs/contracts/libs/LibFillResults.sol";
+import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";
+
+
+contract MixinMatchOrders is
+    Ownable,
+    LibConstants
+{
+    /// @dev Match two complementary orders that have a profitable spread.
+    ///      Each order is filled at their respective price point. However, the calculations are
+    ///      carried out as though the orders are both being filled at the right order's price point.
+    ///      The profit made by the left order is then used to fill the right order as much as possible.
+    ///      This results in a spread being taken in terms of both assets. The spread is held within this contract.
+    /// @param leftOrder First order to match.
+    /// @param rightOrder Second order to match.
+    /// @param leftSignature Proof that order was created by the left maker.
+    /// @param rightSignature Proof that order was created by the right maker.
+    function matchOrders(
+        LibOrder.Order memory leftOrder,
+        LibOrder.Order memory rightOrder,
+        bytes memory leftSignature,
+        bytes memory rightSignature
+    )
+        public
+        onlyOwner
+    {
+        // Match orders, maximally filling `leftOrder`
+        LibFillResults.MatchedFillResults memory matchedFillResults = EXCHANGE.matchOrders(
+            leftOrder,
+            rightOrder,
+            leftSignature,
+            rightSignature
+        );
+
+        uint256 leftMakerAssetSpreadAmount = matchedFillResults.leftMakerAssetSpreadAmount;
+        uint256 rightOrderTakerAssetAmount = rightOrder.takerAssetAmount;
+
+        // Do not attempt to call `fillOrder` if no spread was taken or `rightOrder` has been completely filled
+        if (leftMakerAssetSpreadAmount == 0 || matchedFillResults.right.takerAssetFilledAmount == rightOrderTakerAssetAmount) {
+            return;
+        }
+
+        // The `assetData` fields of the `rightOrder` could have been null for the `matchOrders` call. We reassign them before calling `fillOrder`.
+        rightOrder.makerAssetData = leftOrder.takerAssetData;
+        rightOrder.takerAssetData = leftOrder.makerAssetData;
+
+        // Query `rightOrder` info to check if it has been completely filled
+        // We need to make this check in case the `rightOrder` was partially filled before the `matchOrders` call
+        LibOrder.OrderInfo memory orderInfo = EXCHANGE.getOrderInfo(rightOrder);
+
+        // Do not attempt to call `fillOrder` if order has been completely filled
+        if (orderInfo.orderTakerAssetFilledAmount == rightOrderTakerAssetAmount) {
+            return;
+        }
+
+        // We do not need to pass in a signature since it was already validated in the `matchOrders` call
+        EXCHANGE.fillOrder(
+            rightOrder,
+            leftMakerAssetSpreadAmount,
+            ""
+        );
+    }
+}
diff --git a/contracts/extensions/contracts/OrderMatcher/OrderMatcher.sol b/contracts/extensions/contracts/OrderMatcher/OrderMatcher.sol
new file mode 100644
index 000000000..4879b7bca
--- /dev/null
+++ b/contracts/extensions/contracts/OrderMatcher/OrderMatcher.sol
@@ -0,0 +1,38 @@
+/*
+
+  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;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-utils/contracts/utils/Ownable/Ownable.sol";
+import "./libs/LibConstants.sol";
+import "./MixinMatchOrders.sol";
+import "./MixinAssets.sol";
+
+
+// solhint-disable no-empty-blocks
+contract OrderMatcher is
+    MixinMatchOrders,
+    MixinAssets
+{
+    constructor (address _exchange)
+        public
+        LibConstants(_exchange)
+        Ownable()
+    {}
+}
diff --git a/contracts/extensions/contracts/OrderMatcher/interfaces/IAssets.sol b/contracts/extensions/contracts/OrderMatcher/interfaces/IAssets.sol
new file mode 100644
index 000000000..9fcc0023a
--- /dev/null
+++ b/contracts/extensions/contracts/OrderMatcher/interfaces/IAssets.sol
@@ -0,0 +1,43 @@
+/*
+
+  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 IAssets {
+
+    /// @dev Withdraws assets from this contract. The contract requires a ZRX balance in order to 
+    ///      function optimally, and this function allows the ZRX to be withdrawn by owner. It may also be
+    ///      used to withdraw assets that were accidentally sent to this contract.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to withdraw.
+    function withdrawAsset(
+        bytes assetData,
+        uint256 amount
+    )
+        external;
+
+    /// @dev Approves or disapproves an AssetProxy to spend asset.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveAssetProxy(
+        bytes assetData,
+        uint256 amount
+    )
+        external;
+}
diff --git a/contracts/extensions/contracts/OrderMatcher/interfaces/IMatchOrders.sol b/contracts/extensions/contracts/OrderMatcher/interfaces/IMatchOrders.sol
new file mode 100644
index 000000000..1443c73b9
--- /dev/null
+++ b/contracts/extensions/contracts/OrderMatcher/interfaces/IMatchOrders.sol
@@ -0,0 +1,43 @@
+/*
+
+  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;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+
+
+contract IMatchOrders {
+
+    /// @dev Match two complementary orders that have a profitable spread.
+    ///      Each order is filled at their respective price point. However, the calculations are
+    ///      carried out as though the orders are both being filled at the right order's price point.
+    ///      The profit made by the left order is then used to fill the right order as much as possible.
+    ///      This results in a spread being taken in terms of both assets. The spread is held within this contract.
+    /// @param leftOrder First order to match.
+    /// @param rightOrder Second order to match.
+    /// @param leftSignature Proof that order was created by the left maker.
+    /// @param rightSignature Proof that order was created by the right maker.
+    function matchOrders(
+        LibOrder.Order memory leftOrder,
+        LibOrder.Order memory rightOrder,
+        bytes memory leftSignature,
+        bytes memory rightSignature
+    )
+        public;
+}
diff --git a/contracts/extensions/contracts/OrderMatcher/interfaces/IOrderMatcher.sol b/contracts/extensions/contracts/OrderMatcher/interfaces/IOrderMatcher.sol
new file mode 100644
index 000000000..75f26dca6
--- /dev/null
+++ b/contracts/extensions/contracts/OrderMatcher/interfaces/IOrderMatcher.sol
@@ -0,0 +1,31 @@
+/*
+
+  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 "@0x/contract-utils/contracts/utils/Ownable/IOwnable.sol";
+import "./IMatchOrders.sol";
+import "./IAssets.sol";
+
+
+// solhint-disable no-empty-blocks
+contract IOrderMatcher is
+    IOwnable,
+    IMatchOrders,
+    IAssets
+{}
diff --git a/contracts/extensions/contracts/OrderMatcher/libs/LibConstants.sol b/contracts/extensions/contracts/OrderMatcher/libs/LibConstants.sol
new file mode 100644
index 000000000..c1a86a9c7
--- /dev/null
+++ b/contracts/extensions/contracts/OrderMatcher/libs/LibConstants.sol
@@ -0,0 +1,56 @@
+/*
+
+  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 "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+
+
+contract LibConstants {
+
+    // bytes4(keccak256("transfer(address,uint256)"))
+    bytes4 constant internal ERC20_TRANSFER_SELECTOR = 0xa9059cbb;
+    // bytes4(keccak256("ERC20Token(address)"))
+    bytes4 constant internal ERC20_DATA_ID = 0xf47261b0;
+    // bytes4(keccak256("ERC721Token(address,uint256)"))
+    bytes4 constant internal ERC721_DATA_ID = 0x02571792;
+ 
+     // solhint-disable var-name-mixedcase
+    IExchange internal EXCHANGE;
+    address internal ERC20_PROXY_ADDRESS;
+    address internal ERC721_PROXY_ADDRESS;
+    // solhint-enable var-name-mixedcase
+
+    constructor (address _exchange)
+        public
+    {
+        EXCHANGE = IExchange(_exchange);
+
+        ERC20_PROXY_ADDRESS = EXCHANGE.getAssetProxy(ERC20_DATA_ID);
+        require(
+            ERC20_PROXY_ADDRESS != address(0),
+            "UNREGISTERED_ASSET_PROXY"
+        );
+
+        ERC721_PROXY_ADDRESS = EXCHANGE.getAssetProxy(ERC721_DATA_ID);
+        require(
+            ERC721_PROXY_ADDRESS != address(0),
+            "UNREGISTERED_ASSET_PROXY"
+        );
+    }
+}
diff --git a/contracts/extensions/contracts/OrderMatcher/mixins/MAssets.sol b/contracts/extensions/contracts/OrderMatcher/mixins/MAssets.sol
new file mode 100644
index 000000000..6ea7a3290
--- /dev/null
+++ b/contracts/extensions/contracts/OrderMatcher/mixins/MAssets.sol
@@ -0,0 +1,71 @@
+/*
+
+  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 "../interfaces/IAssets.sol";
+
+
+contract MAssets is
+    IAssets
+{
+    /// @dev Transfers given amount of asset to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferAssetToSender(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+
+    /// @dev Decodes ERC20 assetData and transfers given amount to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferERC20Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+
+    /// @dev Decodes ERC721 assetData and transfers given amount to sender.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to transfer to sender.
+    function transferERC721Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+
+    /// @dev Sets approval for ERC20 AssetProxy.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveERC20Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+
+    /// @dev Sets approval for ERC721 AssetProxy.
+    /// @param assetData Byte array encoded for the respective asset proxy.
+    /// @param amount Amount of asset to approve for respective proxy.
+    function approveERC721Token(
+        bytes memory assetData,
+        uint256 amount
+    )
+        internal;
+}
diff --git a/contracts/extensions/contracts/OrderValidator/OrderValidator.sol b/contracts/extensions/contracts/OrderValidator/OrderValidator.sol
new file mode 100644
index 000000000..33dd1326c
--- /dev/null
+++ b/contracts/extensions/contracts/OrderValidator/OrderValidator.sol
@@ -0,0 +1,218 @@
+/*
+
+  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;
+pragma experimental ABIEncoderV2;
+
+import "@0x/contracts-interfaces/contracts/protocol/Exchange/IExchange.sol";
+import "@0x/contracts-libs/contracts/libs/LibOrder.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC20Token/IERC20Token.sol";
+import "@0x/contracts-tokens/contracts/tokens/ERC721Token/IERC721Token.sol";
+import "@0x/contracts-utils/contracts/utils/LibBytes/LibBytes.sol";
+
+
+contract OrderValidator {
+
+    using LibBytes for bytes;
+
+    bytes4 constant internal ERC20_DATA_ID = bytes4(keccak256("ERC20Token(address)"));
+    bytes4 constant internal ERC721_DATA_ID = bytes4(keccak256("ERC721Token(address,uint256)"));
+
+    struct TraderInfo {
+        uint256 makerBalance;       // Maker's balance of makerAsset
+        uint256 makerAllowance;     // Maker's allowance to corresponding AssetProxy
+        uint256 takerBalance;       // Taker's balance of takerAsset
+        uint256 takerAllowance;     // Taker's allowance to corresponding AssetProxy
+        uint256 makerZrxBalance;    // Maker's balance of ZRX
+        uint256 makerZrxAllowance;  // Maker's allowance of ZRX to ERC20Proxy
+        uint256 takerZrxBalance;    // Taker's balance of ZRX
+        uint256 takerZrxAllowance;  // Taker's allowance of ZRX to ERC20Proxy
+    }
+
+    // solhint-disable var-name-mixedcase
+    IExchange internal EXCHANGE;
+    bytes internal ZRX_ASSET_DATA;
+    // solhint-enable var-name-mixedcase
+
+    constructor (address _exchange, bytes memory _zrxAssetData)
+        public
+    {
+        EXCHANGE = IExchange(_exchange);
+        ZRX_ASSET_DATA = _zrxAssetData;
+    }
+
+    /// @dev Fetches information for order and maker/taker of order.
+    /// @param order The order structure.
+    /// @param takerAddress Address that will be filling the order.
+    /// @return OrderInfo and TraderInfo instances for given order.
+    function getOrderAndTraderInfo(LibOrder.Order memory order, address takerAddress)
+        public
+        view
+        returns (LibOrder.OrderInfo memory orderInfo, TraderInfo memory traderInfo)
+    {
+        orderInfo = EXCHANGE.getOrderInfo(order);
+        traderInfo = getTraderInfo(order, takerAddress);
+        return (orderInfo, traderInfo);
+    }
+
+    /// @dev Fetches information for all passed in orders and the makers/takers of each order.
+    /// @param orders Array of order specifications.
+    /// @param takerAddresses Array of taker addresses corresponding to each order.
+    /// @return Arrays of OrderInfo and TraderInfo instances that correspond to each order.
+    function getOrdersAndTradersInfo(LibOrder.Order[] memory orders, address[] memory takerAddresses)
+        public
+        view
+        returns (LibOrder.OrderInfo[] memory ordersInfo, TraderInfo[] memory tradersInfo)
+    {
+        ordersInfo = EXCHANGE.getOrdersInfo(orders);
+        tradersInfo = getTradersInfo(orders, takerAddresses);
+        return (ordersInfo, tradersInfo);
+    }
+
+    /// @dev Fetches balance and allowances for maker and taker of order.
+    /// @param order The order structure.
+    /// @param takerAddress Address that will be filling the order.
+    /// @return Balances and allowances of maker and taker of order.
+    function getTraderInfo(LibOrder.Order memory order, address takerAddress)
+        public
+        view
+        returns (TraderInfo memory traderInfo)
+    {
+        (traderInfo.makerBalance, traderInfo.makerAllowance) = getBalanceAndAllowance(order.makerAddress, order.makerAssetData);
+        (traderInfo.takerBalance, traderInfo.takerAllowance) = getBalanceAndAllowance(takerAddress, order.takerAssetData);
+        bytes memory zrxAssetData = ZRX_ASSET_DATA;
+        (traderInfo.makerZrxBalance, traderInfo.makerZrxAllowance) = getBalanceAndAllowance(order.makerAddress, zrxAssetData);
+        (traderInfo.takerZrxBalance, traderInfo.takerZrxAllowance) = getBalanceAndAllowance(takerAddress, zrxAssetData);
+        return traderInfo;
+    }
+
+    /// @dev Fetches balances and allowances of maker and taker for each provided order.
+    /// @param orders Array of order specifications.
+    /// @param takerAddresses Array of taker addresses corresponding to each order.
+    /// @return Array of balances and allowances for maker and taker of each order.
+    function getTradersInfo(LibOrder.Order[] memory orders, address[] memory takerAddresses)
+        public
+        view
+        returns (TraderInfo[] memory)
+    {
+        uint256 ordersLength = orders.length;
+        TraderInfo[] memory tradersInfo = new TraderInfo[](ordersLength);
+        for (uint256 i = 0; i != ordersLength; i++) {
+            tradersInfo[i] = getTraderInfo(orders[i], takerAddresses[i]);
+        }
+        return tradersInfo;
+    }
+
+    /// @dev Fetches token balances and allowances of an address to given assetProxy. Supports ERC20 and ERC721.
+    /// @param target Address to fetch balances and allowances of.
+    /// @param assetData Encoded data that can be decoded by a specified proxy contract when transferring asset.
+    /// @return Balance of asset and allowance set to given proxy of asset.
+    ///         For ERC721 tokens, these values will always be 1 or 0.
+    function getBalanceAndAllowance(address target, bytes memory assetData)
+        public
+        view
+        returns (uint256 balance, uint256 allowance)
+    {
+        bytes4 assetProxyId = assetData.readBytes4(0);
+        address token = assetData.readAddress(16);
+        address assetProxy = EXCHANGE.getAssetProxy(assetProxyId);
+
+        if (assetProxyId == ERC20_DATA_ID) {
+            // Query balance
+            balance = IERC20Token(token).balanceOf(target);
+
+            // Query allowance
+            allowance = IERC20Token(token).allowance(target, assetProxy);
+        } else if (assetProxyId == ERC721_DATA_ID) {
+            uint256 tokenId = assetData.readUint256(36);
+
+            // Query owner of tokenId
+            address owner = getERC721TokenOwner(token, tokenId);
+
+            // Set balance to 1 if tokenId is owned by target
+            balance = target == owner ? 1 : 0;
+
+            // Check if ERC721Proxy is approved to spend tokenId
+            bool isApproved = IERC721Token(token).isApprovedForAll(target, assetProxy);
+            
+            // Set alowance to 1 if ERC721Proxy is approved to spend tokenId
+            allowance = isApproved ? 1 : 0;
+        } else {
+            revert("UNSUPPORTED_ASSET_PROXY");
+        }
+        return (balance, allowance);
+    }
+
+    /// @dev Fetches token balances and allowances of an address for each given assetProxy. Supports ERC20 and ERC721.
+    /// @param target Address to fetch balances and allowances of.
+    /// @param assetData Array of encoded byte arrays that can be decoded by a specified proxy contract when transferring asset.
+    /// @return Balances and allowances of assets.
+    ///         For ERC721 tokens, these values will always be 1 or 0.
+    function getBalancesAndAllowances(address target, bytes[] memory assetData)
+        public
+        view
+        returns (uint256[] memory, uint256[] memory)
+    {
+        uint256 length = assetData.length;
+        uint256[] memory balances = new uint256[](length);
+        uint256[] memory allowances = new uint256[](length);
+        for (uint256 i = 0; i != length; i++) {
+            (balances[i], allowances[i]) = getBalanceAndAllowance(target, assetData[i]);
+        }
+        return (balances, allowances);
+    }
+
+    /// @dev Calls `token.ownerOf(tokenId)`, but returns a null owner instead of reverting on an unowned token.
+    /// @param token Address of ERC721 token.
+    /// @param tokenId The identifier for the specific NFT.
+    /// @return Owner of tokenId or null address if unowned.
+    function getERC721TokenOwner(address token, uint256 tokenId)
+        public
+        view
+        returns (address owner)
+    {
+        assembly {
+            // load free memory pointer
+            let cdStart := mload(64)
+
+            // bytes4(keccak256(ownerOf(uint256))) = 0x6352211e
+            mstore(cdStart, 0x6352211e00000000000000000000000000000000000000000000000000000000)
+            mstore(add(cdStart, 4), tokenId)
+
+            // staticcall `ownerOf(tokenId)`
+            // `ownerOf` will revert if tokenId is not owned
+            let success := staticcall(
+                gas,      // forward all gas
+                token,    // call token contract
+                cdStart,  // start of calldata
+                36,       // length of input is 36 bytes
+                cdStart,  // write output over input
+                32        // size of output is 32 bytes
+            )
+
+            // Success implies that tokenId is owned
+            // Copy owner from return data if successful
+            if success {
+                owner := mload(cdStart)
+            }    
+        }
+
+        // Owner initialized to address(0), no need to modify if call is unsuccessful
+        return owner;
+    }
+}
diff --git a/contracts/extensions/package.json b/contracts/extensions/package.json
index 2d9ed4dcd..aee995645 100644
--- a/contracts/extensions/package.json
+++ b/contracts/extensions/package.json
@@ -19,7 +19,8 @@
         "test:profiler": "SOLIDITY_PROFILER=true run-s build run_mocha profiler:report:html",
         "test:trace": "SOLIDITY_REVERT_TRACE=true run-s build run_mocha",
         "run_mocha": "mocha --require source-map-support/register --require make-promises-safe 'lib/test/**/*.js' --timeout 100000 --bail --exit",
-        "compile": "sol-compiler --contracts-dir contracts",
+        "compile": "sol-compiler",
+        "watch": "sol-compiler -w",
         "clean": "shx rm -rf lib generated-artifacts generated-wrappers",
         "generate_contract_wrappers": "abi-gen --abis  ${npm_package_config_abis} --template ../../node_modules/@0x/abi-gen-templates/contract.handlebars --partials '../../node_modules/@0x/abi-gen-templates/partials/**/*.handlebars' --output generated-wrappers --backend ethers",
         "lint": "tslint --format stylish --project . --exclude ./generated-wrappers/**/* --exclude ./generated-artifacts/**/* --exclude **/lib/**/* && yarn lint-contracts",
@@ -31,7 +32,7 @@
         "lint-contracts": "solhint -c ../.solhint.json contracts/**/**/**/**/*.sol"
     },
     "config": {
-        "abis": "generated-artifacts/@(BalanceThresholdFilter|DutchAuction|Forwarder).json"
+        "abis": "generated-artifacts/@(BalanceThresholdFilter|DutchAuction|Forwarder|OrderMatcher|OrderValidator).json"
     },
     "repository": {
         "type": "git",
@@ -44,6 +45,7 @@
     "homepage": "https://github.com/0xProject/0x-monorepo/contracts/extensions/README.md",
     "devDependencies": {
         "@0x/abi-gen": "^1.0.19",
+        "@0x/contract-wrappers": "^4.1.3",
         "@0x/contracts-test-utils": "^1.0.2",
         "@0x/dev-utils": "^1.0.21",
         "@0x/sol-compiler": "^1.1.16",
diff --git a/contracts/extensions/src/artifacts/index.ts b/contracts/extensions/src/artifacts/index.ts
index ebf0b8050..329d0f3f3 100644
--- a/contracts/extensions/src/artifacts/index.ts
+++ b/contracts/extensions/src/artifacts/index.ts
@@ -3,9 +3,13 @@ import { ContractArtifact } from 'ethereum-types';
 import * as BalanceThresholdFilter from '../../generated-artifacts/BalanceThresholdFilter.json';
 import * as DutchAuction from '../../generated-artifacts/DutchAuction.json';
 import * as Forwarder from '../../generated-artifacts/Forwarder.json';
+import * as OrderMatcher from '../../generated-artifacts/OrderMatcher.json';
+import * as OrderValidator from '../../generated-artifacts/OrderValidator.json';
 
 export const artifacts = {
     BalanceThresholdFilter: BalanceThresholdFilter as ContractArtifact,
     DutchAuction: DutchAuction as ContractArtifact,
     Forwarder: Forwarder as ContractArtifact,
+    OrderMatcher: OrderMatcher as ContractArtifact,
+    OrderValidator: OrderValidator as ContractArtifact,
 };
diff --git a/contracts/extensions/src/wrappers/index.ts b/contracts/extensions/src/wrappers/index.ts
index 8a8122caa..65aec3ccd 100644
--- a/contracts/extensions/src/wrappers/index.ts
+++ b/contracts/extensions/src/wrappers/index.ts
@@ -1,3 +1,5 @@
 export * from '../../generated-wrappers/balance_threshold_filter';
 export * from '../../generated-wrappers/dutch_auction';
 export * from '../../generated-wrappers/forwarder';
+export * from '../../generated-wrappers/order_matcher';
+export * from '../../generated-wrappers/order_validator';
diff --git a/contracts/extensions/test/extensions/dutch_auction.ts b/contracts/extensions/test/extensions/dutch_auction.ts
index 6c3b2f0f3..22b3caa16 100644
--- a/contracts/extensions/test/extensions/dutch_auction.ts
+++ b/contracts/extensions/test/extensions/dutch_auction.ts
@@ -1,3 +1,4 @@
+import { DutchAuctionWrapper } from '@0x/contract-wrappers';
 import {
     artifacts as protocolArtifacts,
     ERC20Wrapper,
@@ -29,12 +30,11 @@ import { RevertReason, SignedOrder } from '@0x/types';
 import { BigNumber } from '@0x/utils';
 import { Web3Wrapper } from '@0x/web3-wrapper';
 import * as chai from 'chai';
-import ethAbi = require('ethereumjs-abi');
-import * as ethUtil from 'ethereumjs-util';
 import * as _ from 'lodash';
 
 import { DutchAuctionContract } from '../../generated-wrappers/dutch_auction';
 import { artifacts } from '../../src/artifacts';
+import { DutchAuctionTestWrapper } from '../utils/dutch_auction_test_wrapper';
 
 chaiSetup.configure();
 const expect = chai.expect;
@@ -68,19 +68,8 @@ describe(ContractName.DutchAuction, () => {
     let erc721MakerAssetIds: BigNumber[];
     const tenMinutesInSeconds = 10 * 60;
 
-    function extendMakerAssetData(makerAssetData: string, beginTimeSeconds: BigNumber, beginAmount: BigNumber): string {
-        return ethUtil.bufferToHex(
-            Buffer.concat([
-                ethUtil.toBuffer(makerAssetData),
-                ethUtil.toBuffer(
-                    (ethAbi as any).rawEncode(
-                        ['uint256', 'uint256'],
-                        [beginTimeSeconds.toString(), beginAmount.toString()],
-                    ),
-                ),
-            ]),
-        );
-    }
+    let dutchAuctionTestWrapper: DutchAuctionTestWrapper;
+    let defaultERC20MakerAssetData: string;
 
     before(async () => {
         await blockchainLifecycle.startAsync();
@@ -136,6 +125,7 @@ describe(ContractName.DutchAuction, () => {
             dutchAuctionInstance.address,
             provider,
         );
+        dutchAuctionTestWrapper = new DutchAuctionTestWrapper(dutchAuctionInstance, provider);
 
         defaultMakerAssetAddress = erc20TokenA.address;
         const defaultTakerAssetAddress = wethContract.address;
@@ -174,7 +164,7 @@ describe(ContractName.DutchAuction, () => {
             feeRecipientAddress,
             // taker address or sender address should be set to the ducth auction contract
             takerAddress: dutchAuctionContract.address,
-            makerAssetData: extendMakerAssetData(
+            makerAssetData: DutchAuctionWrapper.encodeDutchAuctionAssetData(
                 assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
                 auctionBeginTimeSeconds,
                 auctionBeginAmount,
@@ -199,6 +189,7 @@ describe(ContractName.DutchAuction, () => {
         const takerPrivateKey = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(takerAddress)];
         sellerOrderFactory = new OrderFactory(makerPrivateKey, sellerDefaultOrderParams);
         buyerOrderFactory = new OrderFactory(takerPrivateKey, buyerDefaultOrderParams);
+        defaultERC20MakerAssetData = assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress);
     });
     after(async () => {
         await blockchainLifecycle.revertAsync();
@@ -215,49 +206,41 @@ describe(ContractName.DutchAuction, () => {
     describe('matchOrders', () => {
         it('should be worth the begin price at the begining of the auction', async () => {
             auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp + 2);
-            sellOrder = await sellerOrderFactory.newSignedOrderAsync({
-                makerAssetData: extendMakerAssetData(
-                    assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
-                    auctionBeginTimeSeconds,
-                    auctionBeginAmount,
-                ),
-            });
-            const auctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                defaultERC20MakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
+            sellOrder = await sellerOrderFactory.newSignedOrderAsync({ makerAssetData });
+            const auctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+            expect(auctionDetails.currentTimeSeconds).to.be.bignumber.lte(auctionBeginTimeSeconds);
             expect(auctionDetails.currentAmount).to.be.bignumber.equal(auctionBeginAmount);
             expect(auctionDetails.beginAmount).to.be.bignumber.equal(auctionBeginAmount);
         });
         it('should be be worth the end price at the end of the auction', async () => {
             auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds * 2);
             auctionEndTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds);
+            const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                defaultERC20MakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
             sellOrder = await sellerOrderFactory.newSignedOrderAsync({
-                makerAssetData: extendMakerAssetData(
-                    assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
-                    auctionBeginTimeSeconds,
-                    auctionBeginAmount,
-                ),
+                makerAssetData,
                 expirationTimeSeconds: auctionEndTimeSeconds,
             });
-            const auctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            const auctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
+            expect(auctionDetails.currentTimeSeconds).to.be.bignumber.gte(auctionEndTimeSeconds);
             expect(auctionDetails.currentAmount).to.be.bignumber.equal(auctionEndAmount);
             expect(auctionDetails.beginAmount).to.be.bignumber.equal(auctionBeginAmount);
         });
         it('should match orders at current amount and send excess to buyer', async () => {
-            const beforeAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            const beforeAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
             buyOrder = await buyerOrderFactory.newSignedOrderAsync({
                 makerAssetAmount: beforeAuctionDetails.currentAmount.times(2),
             });
-            await web3Wrapper.awaitTransactionSuccessAsync(
-                await dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
-            );
-            const afterAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            await dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+            const afterAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
             const newBalances = await erc20Wrapper.getBalancesAsync();
             expect(newBalances[dutchAuctionContract.address][wethContract.address]).to.be.bignumber.equal(
                 constants.ZERO_AMOUNT,
@@ -276,17 +259,8 @@ describe(ContractName.DutchAuction, () => {
             sellOrder = await sellerOrderFactory.newSignedOrderAsync({
                 makerFee: new BigNumber(1),
             });
-            const txHash = await dutchAuctionContract.matchOrders.sendTransactionAsync(
-                buyOrder,
-                sellOrder,
-                buyOrder.signature,
-                sellOrder.signature,
-                {
-                    from: takerAddress,
-                },
-            );
-            await web3Wrapper.awaitTransactionSuccessAsync(txHash);
-            const afterAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            await dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+            const afterAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
             const newBalances = await erc20Wrapper.getBalancesAsync();
             expect(newBalances[makerAddress][wethContract.address]).to.be.bignumber.gte(
                 erc20Balances[makerAddress][wethContract.address].plus(afterAuctionDetails.currentAmount),
@@ -299,18 +273,9 @@ describe(ContractName.DutchAuction, () => {
             buyOrder = await buyerOrderFactory.newSignedOrderAsync({
                 makerFee: new BigNumber(1),
             });
-            const txHash = await dutchAuctionContract.matchOrders.sendTransactionAsync(
-                buyOrder,
-                sellOrder,
-                buyOrder.signature,
-                sellOrder.signature,
-                {
-                    from: takerAddress,
-                },
-            );
-            await web3Wrapper.awaitTransactionSuccessAsync(txHash);
+            await dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
             const newBalances = await erc20Wrapper.getBalancesAsync();
-            const afterAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+            const afterAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
             expect(newBalances[makerAddress][wethContract.address]).to.be.bignumber.gte(
                 erc20Balances[makerAddress][wethContract.address].plus(afterAuctionDetails.currentAmount),
             );
@@ -321,24 +286,17 @@ describe(ContractName.DutchAuction, () => {
         it('should revert when auction expires', async () => {
             auctionBeginTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds * 2);
             auctionEndTimeSeconds = new BigNumber(currentBlockTimestamp - tenMinutesInSeconds);
+            const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                defaultERC20MakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
             sellOrder = await sellerOrderFactory.newSignedOrderAsync({
                 expirationTimeSeconds: auctionEndTimeSeconds,
-                makerAssetData: extendMakerAssetData(
-                    assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
-                    auctionBeginTimeSeconds,
-                    auctionBeginAmount,
-                ),
+                makerAssetData,
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.AuctionExpired,
             );
         });
@@ -347,15 +305,7 @@ describe(ContractName.DutchAuction, () => {
                 makerAssetAmount: sellOrder.takerAssetAmount,
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.AuctionInvalidAmount,
             );
         });
@@ -364,38 +314,23 @@ describe(ContractName.DutchAuction, () => {
                 takerAssetAmount: auctionBeginAmount.plus(1),
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.AuctionInvalidAmount,
             );
         });
         it('begin time is less than end time', async () => {
             auctionBeginTimeSeconds = new BigNumber(auctionEndTimeSeconds).plus(tenMinutesInSeconds);
+            const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                defaultERC20MakerAssetData,
+                auctionBeginTimeSeconds,
+                auctionBeginAmount,
+            );
             sellOrder = await sellerOrderFactory.newSignedOrderAsync({
                 expirationTimeSeconds: auctionEndTimeSeconds,
-                makerAssetData: extendMakerAssetData(
-                    assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
-                    auctionBeginTimeSeconds,
-                    auctionBeginAmount,
-                ),
+                makerAssetData,
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.AuctionInvalidBeginTime,
             );
         });
@@ -404,45 +339,30 @@ describe(ContractName.DutchAuction, () => {
                 makerAssetData: assetDataUtils.encodeERC20AssetData(defaultMakerAssetAddress),
             });
             return expectTransactionFailedAsync(
-                dutchAuctionContract.matchOrders.sendTransactionAsync(
-                    buyOrder,
-                    sellOrder,
-                    buyOrder.signature,
-                    sellOrder.signature,
-                    {
-                        from: takerAddress,
-                    },
-                ),
+                dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress),
                 RevertReason.InvalidAssetData,
             );
         });
+
         describe('ERC721', () => {
             it('should match orders when ERC721', async () => {
                 const makerAssetId = erc721MakerAssetIds[0];
+                const erc721MakerAssetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, makerAssetId);
+                const makerAssetData = DutchAuctionWrapper.encodeDutchAuctionAssetData(
+                    erc721MakerAssetData,
+                    auctionBeginTimeSeconds,
+                    auctionBeginAmount,
+                );
                 sellOrder = await sellerOrderFactory.newSignedOrderAsync({
                     makerAssetAmount: new BigNumber(1),
-                    makerAssetData: extendMakerAssetData(
-                        assetDataUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
-                        auctionBeginTimeSeconds,
-                        auctionBeginAmount,
-                    ),
+                    makerAssetData,
                 });
                 buyOrder = await buyerOrderFactory.newSignedOrderAsync({
                     takerAssetAmount: new BigNumber(1),
                     takerAssetData: sellOrder.makerAssetData,
                 });
-                await web3Wrapper.awaitTransactionSuccessAsync(
-                    await dutchAuctionContract.matchOrders.sendTransactionAsync(
-                        buyOrder,
-                        sellOrder,
-                        buyOrder.signature,
-                        sellOrder.signature,
-                        {
-                            from: takerAddress,
-                        },
-                    ),
-                );
-                const afterAuctionDetails = await dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+                await dutchAuctionTestWrapper.matchOrdersAsync(buyOrder, sellOrder, takerAddress);
+                const afterAuctionDetails = await dutchAuctionTestWrapper.getAuctionDetailsAsync(sellOrder);
                 const newBalances = await erc20Wrapper.getBalancesAsync();
                 // HACK gte used here due to a bug in ganache where the timestamp can change
                 // between multiple calls to the same block. Which can move the amount in our case
diff --git a/contracts/extensions/test/extensions/forwarder.ts b/contracts/extensions/test/extensions/forwarder.ts
index 4027f493d..69939ed04 100644
--- a/contracts/extensions/test/extensions/forwarder.ts
+++ b/contracts/extensions/test/extensions/forwarder.ts
@@ -48,7 +48,6 @@ describe(ContractName.Forwarder, () => {
     let owner: string;
     let takerAddress: string;
     let feeRecipientAddress: string;
-    let otherAddress: string;
     let defaultMakerAssetAddress: string;
     let zrxAssetData: string;
     let wethAssetData: string;
@@ -78,7 +77,7 @@ describe(ContractName.Forwarder, () => {
     before(async () => {
         await blockchainLifecycle.startAsync();
         const accounts = await web3Wrapper.getAvailableAddressesAsync();
-        const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress, otherAddress] = accounts);
+        const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress] = accounts);
 
         const txHash = await web3Wrapper.sendTransactionAsync({ from: accounts[0], to: accounts[0], value: 0 });
         const transaction = await web3Wrapper.getTransactionByHashAsync(txHash);
diff --git a/contracts/extensions/test/extensions/order_matcher.ts b/contracts/extensions/test/extensions/order_matcher.ts
new file mode 100644
index 000000000..acb46ced4
--- /dev/null
+++ b/contracts/extensions/test/extensions/order_matcher.ts
@@ -0,0 +1,818 @@
+import {
+    artifacts as protocolArtifacts,
+    ERC20ProxyContract,
+    ERC20Wrapper,
+    ERC721ProxyContract,
+    ExchangeContract,
+    ExchangeFillEventArgs,
+    ExchangeWrapper,
+} from '@0x/contracts-protocol';
+import {
+    chaiSetup,
+    constants,
+    ERC20BalancesByOwner,
+    expectContractCreationFailedAsync,
+    expectTransactionFailedAsync,
+    LogDecoder,
+    OrderFactory,
+    provider,
+    sendTransactionResult,
+    txDefaults,
+    web3Wrapper,
+} from '@0x/contracts-test-utils';
+import { artifacts as tokenArtifacts, DummyERC20TokenContract, DummyERC721TokenContract } from '@0x/contracts-tokens';
+import { BlockchainLifecycle } from '@0x/dev-utils';
+import { assetDataUtils } from '@0x/order-utils';
+import { RevertReason } from '@0x/types';
+import { BigNumber } from '@0x/utils';
+import { Web3Wrapper } from '@0x/web3-wrapper';
+import * as chai from 'chai';
+import { LogWithDecodedArgs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { OrderMatcherContract } from '../../generated-wrappers/order_matcher';
+import { artifacts } from '../../src/artifacts';
+
+const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
+chaiSetup.configure();
+const expect = chai.expect;
+// tslint:disable:no-unnecessary-type-assertion
+describe('OrderMatcher', () => {
+    let makerAddressLeft: string;
+    let makerAddressRight: string;
+    let owner: string;
+    let takerAddress: string;
+    let feeRecipientAddressLeft: string;
+    let feeRecipientAddressRight: string;
+
+    let erc20TokenA: DummyERC20TokenContract;
+    let erc20TokenB: DummyERC20TokenContract;
+    let zrxToken: DummyERC20TokenContract;
+    let exchange: ExchangeContract;
+    let erc20Proxy: ERC20ProxyContract;
+    let erc721Proxy: ERC721ProxyContract;
+    let orderMatcher: OrderMatcherContract;
+
+    let erc20BalancesByOwner: ERC20BalancesByOwner;
+    let exchangeWrapper: ExchangeWrapper;
+    let erc20Wrapper: ERC20Wrapper;
+    let orderFactoryLeft: OrderFactory;
+    let orderFactoryRight: OrderFactory;
+
+    let leftMakerAssetData: string;
+    let leftTakerAssetData: string;
+    let defaultERC20MakerAssetAddress: string;
+    let defaultERC20TakerAssetAddress: string;
+
+    before(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    after(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    before(async () => {
+        // Create accounts
+        const accounts = await web3Wrapper.getAvailableAddressesAsync();
+        // Hack(albrow): Both Prettier and TSLint insert a trailing comma below
+        // but that is invalid syntax as of TypeScript version >= 2.8. We don't
+        // have the right fine-grained configuration options in TSLint,
+        // Prettier, or TypeScript, to reconcile this, so we will just have to
+        // wait for them to sort it out. We disable TSLint and Prettier for
+        // this part of the code for now. This occurs several times in this
+        // file. See https://github.com/prettier/prettier/issues/4624.
+        // prettier-ignore
+        const usedAddresses = ([
+            owner,
+            makerAddressLeft,
+            makerAddressRight,
+            takerAddress,
+            feeRecipientAddressLeft,
+            // tslint:disable-next-line:trailing-comma
+            feeRecipientAddressRight
+        ] = _.slice(accounts, 0, 6));
+        // Create wrappers
+        erc20Wrapper = new ERC20Wrapper(provider, usedAddresses, owner);
+        // Deploy ERC20 token & ERC20 proxy
+        const numDummyErc20ToDeploy = 3;
+        [erc20TokenA, erc20TokenB, zrxToken] = await erc20Wrapper.deployDummyTokensAsync(
+            numDummyErc20ToDeploy,
+            constants.DUMMY_TOKEN_DECIMALS,
+        );
+        erc20Proxy = await erc20Wrapper.deployProxyAsync();
+        await erc20Wrapper.setBalancesAndAllowancesAsync();
+        // Deploy ERC721 proxy
+        erc721Proxy = await ERC721ProxyContract.deployFrom0xArtifactAsync(
+            protocolArtifacts.ERC721Proxy,
+            provider,
+            txDefaults,
+        );
+        // Depoy exchange
+        exchange = await ExchangeContract.deployFrom0xArtifactAsync(
+            protocolArtifacts.Exchange,
+            provider,
+            txDefaults,
+            assetDataUtils.encodeERC20AssetData(zrxToken.address),
+        );
+        exchangeWrapper = new ExchangeWrapper(exchange, provider);
+        await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
+        await exchangeWrapper.registerAssetProxyAsync(erc721Proxy.address, owner);
+        // Authorize ERC20 trades by exchange
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await erc20Proxy.addAuthorizedAddress.sendTransactionAsync(exchange.address, {
+                from: owner,
+            }),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        // Deploy OrderMatcher
+        orderMatcher = await OrderMatcherContract.deployFrom0xArtifactAsync(
+            artifacts.OrderMatcher,
+            provider,
+            txDefaults,
+            exchange.address,
+        );
+        // Set default addresses
+        defaultERC20MakerAssetAddress = erc20TokenA.address;
+        defaultERC20TakerAssetAddress = erc20TokenB.address;
+        leftMakerAssetData = assetDataUtils.encodeERC20AssetData(defaultERC20MakerAssetAddress);
+        leftTakerAssetData = assetDataUtils.encodeERC20AssetData(defaultERC20TakerAssetAddress);
+        // Set OrderMatcher balances and allowances
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await erc20TokenA.setBalance.sendTransactionAsync(orderMatcher.address, constants.INITIAL_ERC20_BALANCE, {
+                from: owner,
+            }),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await erc20TokenB.setBalance.sendTransactionAsync(orderMatcher.address, constants.INITIAL_ERC20_BALANCE, {
+                from: owner,
+            }),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await orderMatcher.approveAssetProxy.sendTransactionAsync(
+                leftMakerAssetData,
+                constants.INITIAL_ERC20_ALLOWANCE,
+            ),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        await web3Wrapper.awaitTransactionSuccessAsync(
+            await orderMatcher.approveAssetProxy.sendTransactionAsync(
+                leftTakerAssetData,
+                constants.INITIAL_ERC20_ALLOWANCE,
+            ),
+            constants.AWAIT_TRANSACTION_MINED_MS,
+        );
+        // Create default order parameters
+        const defaultOrderParamsLeft = {
+            ...constants.STATIC_ORDER_PARAMS,
+            makerAddress: makerAddressLeft,
+            exchangeAddress: exchange.address,
+            makerAssetData: leftMakerAssetData,
+            takerAssetData: leftTakerAssetData,
+            feeRecipientAddress: feeRecipientAddressLeft,
+            makerFee: constants.ZERO_AMOUNT,
+            takerFee: constants.ZERO_AMOUNT,
+        };
+        const defaultOrderParamsRight = {
+            ...constants.STATIC_ORDER_PARAMS,
+            makerAddress: makerAddressRight,
+            exchangeAddress: exchange.address,
+            makerAssetData: leftTakerAssetData,
+            takerAssetData: leftMakerAssetData,
+            feeRecipientAddress: feeRecipientAddressRight,
+            makerFee: constants.ZERO_AMOUNT,
+            takerFee: constants.ZERO_AMOUNT,
+        };
+        const privateKeyLeft = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(makerAddressLeft)];
+        orderFactoryLeft = new OrderFactory(privateKeyLeft, defaultOrderParamsLeft);
+        const privateKeyRight = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(makerAddressRight)];
+        orderFactoryRight = new OrderFactory(privateKeyRight, defaultOrderParamsRight);
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('constructor', () => {
+        it('should revert if assetProxy is unregistered', async () => {
+            const exchangeInstance = await ExchangeContract.deployFrom0xArtifactAsync(
+                protocolArtifacts.Exchange,
+                provider,
+                txDefaults,
+                constants.NULL_BYTES,
+            );
+            return expectContractCreationFailedAsync(
+                (OrderMatcherContract.deployFrom0xArtifactAsync(
+                    artifacts.OrderMatcher,
+                    provider,
+                    txDefaults,
+                    exchangeInstance.address,
+                ) as any) as sendTransactionResult,
+                RevertReason.UnregisteredAssetProxy,
+            );
+        });
+    });
+    describe('matchOrders', () => {
+        beforeEach(async () => {
+            erc20BalancesByOwner = await erc20Wrapper.getBalancesAsync();
+        });
+        it('should revert if not called by owner', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(2), 18),
+            });
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await expectTransactionFailedAsync(
+                web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: takerAddress,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                RevertReason.OnlyContractOwner,
+            );
+        });
+        it('should transfer the correct amounts when orders completely fill each other', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(2), 18),
+            });
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderRight.makerAssetAmount,
+                amountBoughtByRightMaker: signedOrderRight.takerAssetAmount,
+                // Taker
+                leftMakerAssetSpreadAmount: signedOrderLeft.makerAssetAmount.minus(signedOrderRight.takerAssetAmount),
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftMakerAssetTakerBalance.plus(expectedTransferAmounts.leftMakerAssetSpreadAmount),
+            );
+        });
+        it('should transfer the correct amounts when orders completely fill each other and taker doesnt take a profit', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+            });
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderRight.makerAssetAmount,
+                amountBoughtByRightMaker: signedOrderRight.takerAssetAmount,
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(initialLeftMakerAssetTakerBalance);
+        });
+        it('should transfer the correct amounts when left order is completely filled and right order would be partially filled', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(20), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(4), 18),
+            });
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderRight.makerAssetAmount,
+                amountBoughtByRightMaker: signedOrderRight.takerAssetAmount,
+                // Taker
+                leftMakerAssetSpreadAmount: signedOrderLeft.makerAssetAmount.minus(signedOrderRight.takerAssetAmount),
+                leftTakerAssetSpreadAmount: signedOrderRight.makerAssetAmount.minus(signedOrderLeft.takerAssetAmount),
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const initialLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            // Match signedOrderLeft with signedOrderRight
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftMakerAssetTakerBalance.plus(expectedTransferAmounts.leftMakerAssetSpreadAmount),
+            );
+            expect(newLeftTakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftTakerAssetTakerBalance.plus(expectedTransferAmounts.leftTakerAssetSpreadAmount),
+            );
+        });
+        it('should not call fillOrder when rightOrder is completely filled after matchOrders call and orders were never partially filled', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(2), 18),
+            });
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            const logDecoder = new LogDecoder(web3Wrapper, { ...artifacts, ...tokenArtifacts, ...protocolArtifacts });
+            const txReceipt = await logDecoder.getTxWithDecodedLogsAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+            );
+            const fillLogs = _.filter(
+                txReceipt.logs,
+                log => (log as LogWithDecodedArgs<ExchangeFillEventArgs>).event === 'Fill',
+            );
+            // Only 2 Fill logs should exist for `matchOrders` call. `fillOrder` should not have been called and should not have emitted a Fill event.
+            expect(fillLogs.length).to.be.equal(2);
+        });
+        it('should not call fillOrder when rightOrder is completely filled after matchOrders call and orders were initially partially filled', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(2), 18),
+            });
+            await exchangeWrapper.fillOrderAsync(signedOrderLeft, takerAddress, {
+                takerAssetFillAmount: signedOrderLeft.takerAssetAmount.dividedToIntegerBy(5),
+            });
+            await exchangeWrapper.fillOrderAsync(signedOrderRight, takerAddress, {
+                takerAssetFillAmount: signedOrderRight.takerAssetAmount.dividedToIntegerBy(5),
+            });
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            const logDecoder = new LogDecoder(web3Wrapper, { ...artifacts, ...tokenArtifacts, ...protocolArtifacts });
+            const txReceipt = await logDecoder.getTxWithDecodedLogsAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+            );
+            const fillLogs = _.filter(
+                txReceipt.logs,
+                log => (log as LogWithDecodedArgs<ExchangeFillEventArgs>).event === 'Fill',
+            );
+            // Only 2 Fill logs should exist for `matchOrders` call. `fillOrder` should not have been called and should not have emitted a Fill event.
+            expect(fillLogs.length).to.be.equal(2);
+        });
+        it('should only take a spread in rightMakerAsset if entire leftMakerAssetSpread amount can be used to fill rightOrder after matchOrders call', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(0.9), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(100), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(990), 18),
+            });
+            const initialLeftMakerAssetSpreadAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(1.09), 18);
+            const leftTakerAssetSpreadAmount = initialLeftMakerAssetSpreadAmount
+                .times(signedOrderRight.makerAssetAmount)
+                .dividedToIntegerBy(signedOrderRight.takerAssetAmount);
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderLeft.takerAssetAmount.plus(leftTakerAssetSpreadAmount),
+                amountBoughtByRightMaker: signedOrderLeft.makerAssetAmount,
+                // Taker
+                leftMakerAssetSpreadAmount: constants.ZERO_AMOUNT,
+                leftTakerAssetSpreadAmount,
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const initialLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            // Match signedOrderLeft with signedOrderRight
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftMakerAssetTakerBalance.plus(expectedTransferAmounts.leftMakerAssetSpreadAmount),
+            );
+            expect(newLeftTakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftTakerAssetTakerBalance.plus(expectedTransferAmounts.leftTakerAssetSpreadAmount),
+            );
+        });
+        it("should succeed if rightOrder's makerAssetData and takerAssetData are not provided", async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(20), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(4), 18),
+            });
+            // Match signedOrderLeft with signedOrderRight
+            const expectedTransferAmounts = {
+                // Left Maker
+                amountSoldByLeftMaker: signedOrderLeft.makerAssetAmount,
+                amountBoughtByLeftMaker: signedOrderLeft.takerAssetAmount,
+                // Right Maker
+                amountSoldByRightMaker: signedOrderRight.makerAssetAmount,
+                amountBoughtByRightMaker: signedOrderRight.takerAssetAmount,
+                // Taker
+                leftMakerAssetSpreadAmount: signedOrderLeft.makerAssetAmount.minus(signedOrderRight.takerAssetAmount),
+                leftTakerAssetSpreadAmount: signedOrderRight.makerAssetAmount.minus(signedOrderLeft.takerAssetAmount),
+            };
+            const initialLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const initialLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            // Match signedOrderLeft with signedOrderRight
+            signedOrderRight.makerAssetData = constants.NULL_BYTES;
+            signedOrderRight.takerAssetData = constants.NULL_BYTES;
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newLeftMakerAssetTakerBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            const newLeftTakerAssetTakerBalance = await erc20TokenB.balanceOf.callAsync(orderMatcher.address);
+            const newErc20Balances = await erc20Wrapper.getBalancesAsync();
+            expect(newErc20Balances[makerAddressLeft][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20MakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20TakerAssetAddress].minus(
+                    expectedTransferAmounts.amountSoldByRightMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressLeft][defaultERC20TakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressLeft][defaultERC20TakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByLeftMaker,
+                ),
+            );
+            expect(newErc20Balances[makerAddressRight][defaultERC20MakerAssetAddress]).to.be.bignumber.equal(
+                erc20BalancesByOwner[makerAddressRight][defaultERC20MakerAssetAddress].plus(
+                    expectedTransferAmounts.amountBoughtByRightMaker,
+                ),
+            );
+            expect(newLeftMakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftMakerAssetTakerBalance.plus(expectedTransferAmounts.leftMakerAssetSpreadAmount),
+            );
+            expect(newLeftTakerAssetTakerBalance).to.be.bignumber.equal(
+                initialLeftTakerAssetTakerBalance.plus(expectedTransferAmounts.leftTakerAssetSpreadAmount),
+            );
+        });
+        it('should revert with the correct reason if matchOrders call reverts', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+            });
+            signedOrderRight.signature = `0xff${signedOrderRight.signature.slice(4)}`;
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await expectTransactionFailedAsync(
+                web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                RevertReason.InvalidOrderSignature,
+            );
+        });
+        it('should revert with the correct reason if fillOrder call reverts', async () => {
+            // Create orders to match
+            const signedOrderLeft = await orderFactoryLeft.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(5), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), 18),
+            });
+            const signedOrderRight = await orderFactoryRight.newSignedOrderAsync({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(20), 18),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(4), 18),
+            });
+            // Matcher will not have enough allowance to fill rightOrder
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.approveAssetProxy.sendTransactionAsync(leftMakerAssetData, constants.ZERO_AMOUNT, {
+                    from: owner,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const data = exchange.matchOrders.getABIEncodedTransactionData(
+                signedOrderLeft,
+                signedOrderRight,
+                signedOrderLeft.signature,
+                signedOrderRight.signature,
+            );
+            await expectTransactionFailedAsync(
+                web3Wrapper.sendTransactionAsync({
+                    data,
+                    to: orderMatcher.address,
+                    from: owner,
+                    gas: constants.MAX_MATCH_ORDERS_GAS,
+                }),
+                RevertReason.TransferFailed,
+            );
+        });
+    });
+    describe('withdrawAsset', () => {
+        it('should allow owner to withdraw ERC20 tokens', async () => {
+            const erc20AWithdrawAmount = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            expect(erc20AWithdrawAmount).to.be.bignumber.gt(constants.ZERO_AMOUNT);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.withdrawAsset.sendTransactionAsync(leftMakerAssetData, erc20AWithdrawAmount, {
+                    from: owner,
+                }),
+            );
+            const newBalance = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            expect(newBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+        });
+        it('should allow owner to withdraw ERC721 tokens', async () => {
+            const erc721Token = await DummyERC721TokenContract.deployFrom0xArtifactAsync(
+                tokenArtifacts.DummyERC721Token,
+                provider,
+                txDefaults,
+                constants.DUMMY_TOKEN_NAME,
+                constants.DUMMY_TOKEN_SYMBOL,
+            );
+            const tokenId = new BigNumber(1);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.mint.sendTransactionAsync(orderMatcher.address, tokenId, { from: owner }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const assetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, tokenId);
+            const withdrawAmount = new BigNumber(1);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.withdrawAsset.sendTransactionAsync(assetData, withdrawAmount, { from: owner }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const erc721Owner = await erc721Token.ownerOf.callAsync(tokenId);
+            expect(erc721Owner).to.be.equal(owner);
+        });
+        it('should revert if not called by owner', async () => {
+            const erc20AWithdrawAmount = await erc20TokenA.balanceOf.callAsync(orderMatcher.address);
+            expect(erc20AWithdrawAmount).to.be.bignumber.gt(constants.ZERO_AMOUNT);
+            await expectTransactionFailedAsync(
+                orderMatcher.withdrawAsset.sendTransactionAsync(leftMakerAssetData, erc20AWithdrawAmount, {
+                    from: takerAddress,
+                }),
+                RevertReason.OnlyContractOwner,
+            );
+        });
+    });
+    describe('approveAssetProxy', () => {
+        it('should be able to set an allowance for ERC20 tokens', async () => {
+            const allowance = new BigNumber(55465465426546);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.approveAssetProxy.sendTransactionAsync(leftMakerAssetData, allowance, {
+                    from: owner,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const newAllowance = await erc20TokenA.allowance.callAsync(orderMatcher.address, erc20Proxy.address);
+            expect(newAllowance).to.be.bignumber.equal(allowance);
+        });
+        it('should be able to approve an ERC721 token by passing in allowance = 1', async () => {
+            const erc721Token = await DummyERC721TokenContract.deployFrom0xArtifactAsync(
+                tokenArtifacts.DummyERC721Token,
+                provider,
+                txDefaults,
+                constants.DUMMY_TOKEN_NAME,
+                constants.DUMMY_TOKEN_SYMBOL,
+            );
+            const assetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, constants.ZERO_AMOUNT);
+            const allowance = new BigNumber(1);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.approveAssetProxy.sendTransactionAsync(assetData, allowance, { from: owner }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = await erc721Token.isApprovedForAll.callAsync(orderMatcher.address, erc721Proxy.address);
+            expect(isApproved).to.be.equal(true);
+        });
+        it('should be able to approve an ERC721 token by passing in allowance > 1', async () => {
+            const erc721Token = await DummyERC721TokenContract.deployFrom0xArtifactAsync(
+                tokenArtifacts.DummyERC721Token,
+                provider,
+                txDefaults,
+                constants.DUMMY_TOKEN_NAME,
+                constants.DUMMY_TOKEN_SYMBOL,
+            );
+            const assetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, constants.ZERO_AMOUNT);
+            const allowance = new BigNumber(2);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await orderMatcher.approveAssetProxy.sendTransactionAsync(assetData, allowance, { from: owner }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = await erc721Token.isApprovedForAll.callAsync(orderMatcher.address, erc721Proxy.address);
+            expect(isApproved).to.be.equal(true);
+        });
+        it('should revert if not called by owner', async () => {
+            const approval = new BigNumber(1);
+            await expectTransactionFailedAsync(
+                orderMatcher.approveAssetProxy.sendTransactionAsync(leftMakerAssetData, approval, {
+                    from: takerAddress,
+                }),
+                RevertReason.OnlyContractOwner,
+            );
+        });
+    });
+});
+// tslint:disable:max-file-line-count
+// tslint:enable:no-unnecessary-type-assertion
diff --git a/contracts/extensions/test/extensions/order_validator.ts b/contracts/extensions/test/extensions/order_validator.ts
new file mode 100644
index 000000000..82a6b937f
--- /dev/null
+++ b/contracts/extensions/test/extensions/order_validator.ts
@@ -0,0 +1,609 @@
+import {
+    artifacts as protocolArtifacts,
+    ERC20ProxyContract,
+    ERC20Wrapper,
+    ERC721ProxyContract,
+    ERC721Wrapper,
+    ExchangeContract,
+    ExchangeWrapper,
+} from '@0x/contracts-protocol';
+import {
+    chaiSetup,
+    constants,
+    OrderFactory,
+    OrderStatus,
+    provider,
+    txDefaults,
+    web3Wrapper,
+} from '@0x/contracts-test-utils';
+import { DummyERC20TokenContract, DummyERC721TokenContract } from '@0x/contracts-tokens';
+import { BlockchainLifecycle } from '@0x/dev-utils';
+import { assetDataUtils, orderHashUtils } from '@0x/order-utils';
+import { SignedOrder } from '@0x/types';
+import { BigNumber } from '@0x/utils';
+import * as chai from 'chai';
+import * as _ from 'lodash';
+
+import { OrderValidatorContract } from '../../generated-wrappers/order_validator';
+import { artifacts } from '../../src/artifacts/index';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
+
+describe('OrderValidator', () => {
+    let makerAddress: string;
+    let owner: string;
+    let takerAddress: string;
+    let erc20AssetData: string;
+    let erc721AssetData: string;
+
+    let erc20Token: DummyERC20TokenContract;
+    let zrxToken: DummyERC20TokenContract;
+    let erc721Token: DummyERC721TokenContract;
+    let exchange: ExchangeContract;
+    let orderValidator: OrderValidatorContract;
+    let erc20Proxy: ERC20ProxyContract;
+    let erc721Proxy: ERC721ProxyContract;
+
+    let signedOrder: SignedOrder;
+    let signedOrder2: SignedOrder;
+    let orderFactory: OrderFactory;
+
+    const tokenId = new BigNumber(123456789);
+    const tokenId2 = new BigNumber(987654321);
+    const ERC721_BALANCE = new BigNumber(1);
+    const ERC721_ALLOWANCE = new BigNumber(1);
+
+    before(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    after(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+
+    before(async () => {
+        const accounts = await web3Wrapper.getAvailableAddressesAsync();
+        const usedAddresses = ([owner, makerAddress, takerAddress] = _.slice(accounts, 0, 3));
+
+        const erc20Wrapper = new ERC20Wrapper(provider, usedAddresses, owner);
+        const erc721Wrapper = new ERC721Wrapper(provider, usedAddresses, owner);
+
+        const numDummyErc20ToDeploy = 2;
+        [erc20Token, zrxToken] = await erc20Wrapper.deployDummyTokensAsync(
+            numDummyErc20ToDeploy,
+            constants.DUMMY_TOKEN_DECIMALS,
+        );
+        erc20Proxy = await erc20Wrapper.deployProxyAsync();
+
+        [erc721Token] = await erc721Wrapper.deployDummyTokensAsync();
+        erc721Proxy = await erc721Wrapper.deployProxyAsync();
+
+        const zrxAssetData = assetDataUtils.encodeERC20AssetData(zrxToken.address);
+        exchange = await ExchangeContract.deployFrom0xArtifactAsync(
+            protocolArtifacts.Exchange,
+            provider,
+            txDefaults,
+            zrxAssetData,
+        );
+        const exchangeWrapper = new ExchangeWrapper(exchange, provider);
+        await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
+        await exchangeWrapper.registerAssetProxyAsync(erc721Proxy.address, owner);
+
+        orderValidator = await OrderValidatorContract.deployFrom0xArtifactAsync(
+            artifacts.OrderValidator,
+            provider,
+            txDefaults,
+            exchange.address,
+            zrxAssetData,
+        );
+
+        erc20AssetData = assetDataUtils.encodeERC20AssetData(erc20Token.address);
+        erc721AssetData = assetDataUtils.encodeERC721AssetData(erc721Token.address, tokenId);
+        const defaultOrderParams = {
+            ...constants.STATIC_ORDER_PARAMS,
+            exchangeAddress: exchange.address,
+            makerAddress,
+            feeRecipientAddress: constants.NULL_ADDRESS,
+            makerAssetData: erc20AssetData,
+            takerAssetData: erc721AssetData,
+        };
+        const privateKey = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(makerAddress)];
+        orderFactory = new OrderFactory(privateKey, defaultOrderParams);
+    });
+
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+
+    describe('getBalanceAndAllowance', () => {
+        describe('getERC721TokenOwner', async () => {
+            it('should return the null address when tokenId is not owned', async () => {
+                const tokenOwner = await orderValidator.getERC721TokenOwner.callAsync(makerAddress, tokenId);
+                expect(tokenOwner).to.be.equal(constants.NULL_ADDRESS);
+            });
+            it('should return the owner address when tokenId is owned', async () => {
+                await web3Wrapper.awaitTransactionSuccessAsync(
+                    await erc721Token.mint.sendTransactionAsync(makerAddress, tokenId),
+                    constants.AWAIT_TRANSACTION_MINED_MS,
+                );
+                const tokenOwner = await orderValidator.getERC721TokenOwner.callAsync(erc721Token.address, tokenId);
+                expect(tokenOwner).to.be.equal(makerAddress);
+            });
+        });
+        describe('ERC20 assetData', () => {
+            it('should return the correct balances and allowances when both values are 0', async () => {
+                const [newBalance, newAllowance] = await orderValidator.getBalanceAndAllowance.callAsync(
+                    makerAddress,
+                    erc20AssetData,
+                );
+                expect(constants.ZERO_AMOUNT).to.be.bignumber.equal(newBalance);
+                expect(constants.ZERO_AMOUNT).to.be.bignumber.equal(newAllowance);
+            });
+            it('should return the correct balance and allowance when both values are non-zero', async () => {
+                const balance = new BigNumber(123);
+                const allowance = new BigNumber(456);
+                await web3Wrapper.awaitTransactionSuccessAsync(
+                    await erc20Token.setBalance.sendTransactionAsync(makerAddress, balance),
+                    constants.AWAIT_TRANSACTION_MINED_MS,
+                );
+                await web3Wrapper.awaitTransactionSuccessAsync(
+                    await erc20Token.approve.sendTransactionAsync(erc20Proxy.address, allowance, {
+                        from: makerAddress,
+                    }),
+                    constants.AWAIT_TRANSACTION_MINED_MS,
+                );
+                const [newBalance, newAllowance] = await orderValidator.getBalanceAndAllowance.callAsync(
+                    makerAddress,
+                    erc20AssetData,
+                );
+                expect(balance).to.be.bignumber.equal(newBalance);
+                expect(allowance).to.be.bignumber.equal(newAllowance);
+            });
+        });
+        describe('ERC721 assetData', () => {
+            it('should return a balance of 0 when the tokenId is not owned by target', async () => {
+                const [newBalance] = await orderValidator.getBalanceAndAllowance.callAsync(
+                    makerAddress,
+                    erc721AssetData,
+                );
+                expect(newBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            });
+            it('should return an allowance of 0 when no approval is set', async () => {
+                const [, newAllowance] = await orderValidator.getBalanceAndAllowance.callAsync(
+                    makerAddress,
+                    erc721AssetData,
+                );
+                expect(newAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            });
+            it('should return a balance of 1 when the tokenId is owned by target', async () => {
+                await web3Wrapper.awaitTransactionSuccessAsync(
+                    await erc721Token.mint.sendTransactionAsync(makerAddress, tokenId),
+                    constants.AWAIT_TRANSACTION_MINED_MS,
+                );
+                const [newBalance] = await orderValidator.getBalanceAndAllowance.callAsync(
+                    makerAddress,
+                    erc721AssetData,
+                );
+                expect(newBalance).to.be.bignumber.equal(ERC721_BALANCE);
+            });
+            it('should return an allowance of 1 when ERC721Proxy is approved for all', async () => {
+                const isApproved = true;
+                await web3Wrapper.awaitTransactionSuccessAsync(
+                    await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
+                        from: makerAddress,
+                    }),
+                    constants.AWAIT_TRANSACTION_MINED_MS,
+                );
+                const [, newAllowance] = await orderValidator.getBalanceAndAllowance.callAsync(
+                    makerAddress,
+                    erc721AssetData,
+                );
+                expect(newAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+            });
+            it('should return an allowance of 0 when ERC721Proxy is approved for specific tokenId', async () => {
+                await web3Wrapper.awaitTransactionSuccessAsync(
+                    await erc721Token.mint.sendTransactionAsync(makerAddress, tokenId),
+                    constants.AWAIT_TRANSACTION_MINED_MS,
+                );
+                await web3Wrapper.awaitTransactionSuccessAsync(
+                    await erc721Token.approve.sendTransactionAsync(erc721Proxy.address, tokenId, {
+                        from: makerAddress,
+                    }),
+                    constants.AWAIT_TRANSACTION_MINED_MS,
+                );
+                const [, newAllowance] = await orderValidator.getBalanceAndAllowance.callAsync(
+                    makerAddress,
+                    erc721AssetData,
+                );
+                expect(newAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            });
+        });
+    });
+    describe('getBalancesAndAllowances', () => {
+        it('should return the correct balances and allowances when all values are 0', async () => {
+            const [
+                [erc20Balance, erc721Balance],
+                [erc20Allowance, erc721Allowance],
+            ] = await orderValidator.getBalancesAndAllowances.callAsync(makerAddress, [
+                erc20AssetData,
+                erc721AssetData,
+            ]);
+            expect(erc20Balance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(erc721Balance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(erc20Allowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(erc721Allowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+        });
+        it('should return the correct balances and allowances when balances and allowances are non-zero', async () => {
+            const balance = new BigNumber(123);
+            const allowance = new BigNumber(456);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.setBalance.sendTransactionAsync(makerAddress, balance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.approve.sendTransactionAsync(erc20Proxy.address, allowance, {
+                    from: makerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.mint.sendTransactionAsync(makerAddress, tokenId),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = true;
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
+                    from: makerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const [
+                [erc20Balance, erc721Balance],
+                [erc20Allowance, erc721Allowance],
+            ] = await orderValidator.getBalancesAndAllowances.callAsync(makerAddress, [
+                erc20AssetData,
+                erc721AssetData,
+            ]);
+            expect(erc20Balance).to.be.bignumber.equal(balance);
+            expect(erc721Balance).to.be.bignumber.equal(ERC721_BALANCE);
+            expect(erc20Allowance).to.be.bignumber.equal(allowance);
+            expect(erc721Allowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+        });
+    });
+    describe('getTraderInfo', () => {
+        beforeEach(async () => {
+            signedOrder = await orderFactory.newSignedOrderAsync();
+        });
+        it('should return the correct info when no balances or allowances are set', async () => {
+            const traderInfo = await orderValidator.getTraderInfo.callAsync(signedOrder, takerAddress);
+            expect(traderInfo.makerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.makerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.makerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+        });
+        it('should return the correct info when balances and allowances are set', async () => {
+            const makerBalance = new BigNumber(123);
+            const makerAllowance = new BigNumber(456);
+            const makerZrxBalance = new BigNumber(789);
+            const takerZrxAllowance = new BigNumber(987);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.setBalance.sendTransactionAsync(makerAddress, makerBalance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.approve.sendTransactionAsync(erc20Proxy.address, makerAllowance, {
+                    from: makerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await zrxToken.setBalance.sendTransactionAsync(makerAddress, makerZrxBalance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await zrxToken.approve.sendTransactionAsync(erc20Proxy.address, takerZrxAllowance, {
+                    from: takerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.mint.sendTransactionAsync(takerAddress, tokenId),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = true;
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
+                    from: takerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const traderInfo = await orderValidator.getTraderInfo.callAsync(signedOrder, takerAddress);
+            expect(traderInfo.makerBalance).to.be.bignumber.equal(makerBalance);
+            expect(traderInfo.makerAllowance).to.be.bignumber.equal(makerAllowance);
+            expect(traderInfo.takerBalance).to.be.bignumber.equal(ERC721_BALANCE);
+            expect(traderInfo.takerAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+            expect(traderInfo.makerZrxBalance).to.be.bignumber.equal(makerZrxBalance);
+            expect(traderInfo.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerZrxAllowance).to.be.bignumber.equal(takerZrxAllowance);
+        });
+    });
+    describe('getTradersInfo', () => {
+        beforeEach(async () => {
+            signedOrder = await orderFactory.newSignedOrderAsync();
+            signedOrder2 = await orderFactory.newSignedOrderAsync({
+                takerAssetData: assetDataUtils.encodeERC721AssetData(erc721Token.address, tokenId2),
+            });
+        });
+        it('should return the correct info when no balances or allowances have been set', async () => {
+            const orders = [signedOrder, signedOrder2];
+            const takers = [takerAddress, takerAddress];
+            const [traderInfo1, traderInfo2] = await orderValidator.getTradersInfo.callAsync(orders, takers);
+            expect(traderInfo1.makerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.makerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.makerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.makerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.makerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.makerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+        });
+        it('should return the correct info when balances and allowances are set', async () => {
+            const makerBalance = new BigNumber(123);
+            const makerAllowance = new BigNumber(456);
+            const makerZrxBalance = new BigNumber(789);
+            const takerZrxAllowance = new BigNumber(987);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.setBalance.sendTransactionAsync(makerAddress, makerBalance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.approve.sendTransactionAsync(erc20Proxy.address, makerAllowance, {
+                    from: makerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await zrxToken.setBalance.sendTransactionAsync(makerAddress, makerZrxBalance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await zrxToken.approve.sendTransactionAsync(erc20Proxy.address, takerZrxAllowance, {
+                    from: takerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = true;
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
+                    from: takerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.mint.sendTransactionAsync(takerAddress, tokenId2),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const orders = [signedOrder, signedOrder2];
+            const takers = [takerAddress, takerAddress];
+            const [traderInfo1, traderInfo2] = await orderValidator.getTradersInfo.callAsync(orders, takers);
+
+            expect(traderInfo1.makerBalance).to.be.bignumber.equal(makerBalance);
+            expect(traderInfo1.makerAllowance).to.be.bignumber.equal(makerAllowance);
+            expect(traderInfo1.takerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+            expect(traderInfo1.makerZrxBalance).to.be.bignumber.equal(makerZrxBalance);
+            expect(traderInfo1.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerZrxAllowance).to.be.bignumber.equal(takerZrxAllowance);
+            expect(traderInfo2.makerBalance).to.be.bignumber.equal(makerBalance);
+            expect(traderInfo2.makerAllowance).to.be.bignumber.equal(makerAllowance);
+            expect(traderInfo2.takerBalance).to.be.bignumber.equal(ERC721_BALANCE);
+            expect(traderInfo2.takerAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+            expect(traderInfo2.makerZrxBalance).to.be.bignumber.equal(makerZrxBalance);
+            expect(traderInfo2.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerZrxAllowance).to.be.bignumber.equal(takerZrxAllowance);
+        });
+    });
+    describe('getOrderAndTraderInfo', () => {
+        beforeEach(async () => {
+            signedOrder = await orderFactory.newSignedOrderAsync();
+        });
+        it('should return the correct info when no balances or allowances are set', async () => {
+            const [orderInfo, traderInfo] = await orderValidator.getOrderAndTraderInfo.callAsync(
+                signedOrder,
+                takerAddress,
+            );
+            const expectedOrderHash = orderHashUtils.getOrderHashHex(signedOrder);
+            expect(orderInfo.orderStatus).to.be.equal(OrderStatus.FILLABLE);
+            expect(orderInfo.orderHash).to.be.equal(expectedOrderHash);
+            expect(orderInfo.orderTakerAssetFilledAmount).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.makerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.makerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.makerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+        });
+        it('should return the correct info when balances and allowances are set', async () => {
+            const makerBalance = new BigNumber(123);
+            const makerAllowance = new BigNumber(456);
+            const makerZrxBalance = new BigNumber(789);
+            const takerZrxAllowance = new BigNumber(987);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.setBalance.sendTransactionAsync(makerAddress, makerBalance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.approve.sendTransactionAsync(erc20Proxy.address, makerAllowance, {
+                    from: makerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await zrxToken.setBalance.sendTransactionAsync(makerAddress, makerZrxBalance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await zrxToken.approve.sendTransactionAsync(erc20Proxy.address, takerZrxAllowance, {
+                    from: takerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.mint.sendTransactionAsync(takerAddress, tokenId),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = true;
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
+                    from: takerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const [orderInfo, traderInfo] = await orderValidator.getOrderAndTraderInfo.callAsync(
+                signedOrder,
+                takerAddress,
+            );
+            const expectedOrderHash = orderHashUtils.getOrderHashHex(signedOrder);
+            expect(orderInfo.orderStatus).to.be.equal(OrderStatus.FILLABLE);
+            expect(orderInfo.orderHash).to.be.equal(expectedOrderHash);
+            expect(orderInfo.orderTakerAssetFilledAmount).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.makerBalance).to.be.bignumber.equal(makerBalance);
+            expect(traderInfo.makerAllowance).to.be.bignumber.equal(makerAllowance);
+            expect(traderInfo.takerBalance).to.be.bignumber.equal(ERC721_BALANCE);
+            expect(traderInfo.takerAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+            expect(traderInfo.makerZrxBalance).to.be.bignumber.equal(makerZrxBalance);
+            expect(traderInfo.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo.takerZrxAllowance).to.be.bignumber.equal(takerZrxAllowance);
+        });
+    });
+    describe('getOrdersAndTradersInfo', () => {
+        beforeEach(async () => {
+            signedOrder = await orderFactory.newSignedOrderAsync();
+            signedOrder2 = await orderFactory.newSignedOrderAsync({
+                takerAssetData: assetDataUtils.encodeERC721AssetData(erc721Token.address, tokenId2),
+            });
+        });
+        it('should return the correct info when no balances or allowances have been set', async () => {
+            const orders = [signedOrder, signedOrder2];
+            const takers = [takerAddress, takerAddress];
+            const [
+                [orderInfo1, orderInfo2],
+                [traderInfo1, traderInfo2],
+            ] = await orderValidator.getOrdersAndTradersInfo.callAsync(orders, takers);
+            const expectedOrderHash1 = orderHashUtils.getOrderHashHex(signedOrder);
+            const expectedOrderHash2 = orderHashUtils.getOrderHashHex(signedOrder2);
+            expect(orderInfo1.orderStatus).to.be.equal(OrderStatus.FILLABLE);
+            expect(orderInfo1.orderHash).to.be.equal(expectedOrderHash1);
+            expect(orderInfo1.orderTakerAssetFilledAmount).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(orderInfo2.orderStatus).to.be.equal(OrderStatus.FILLABLE);
+            expect(orderInfo2.orderHash).to.be.equal(expectedOrderHash2);
+            expect(orderInfo2.orderTakerAssetFilledAmount).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.makerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.makerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.makerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.makerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.makerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.makerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+        });
+        it('should return the correct info when balances and allowances are set', async () => {
+            const makerBalance = new BigNumber(123);
+            const makerAllowance = new BigNumber(456);
+            const makerZrxBalance = new BigNumber(789);
+            const takerZrxAllowance = new BigNumber(987);
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.setBalance.sendTransactionAsync(makerAddress, makerBalance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc20Token.approve.sendTransactionAsync(erc20Proxy.address, makerAllowance, {
+                    from: makerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await zrxToken.setBalance.sendTransactionAsync(makerAddress, makerZrxBalance),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await zrxToken.approve.sendTransactionAsync(erc20Proxy.address, takerZrxAllowance, {
+                    from: takerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const isApproved = true;
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.setApprovalForAll.sendTransactionAsync(erc721Proxy.address, isApproved, {
+                    from: takerAddress,
+                }),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(
+                await erc721Token.mint.sendTransactionAsync(takerAddress, tokenId2),
+                constants.AWAIT_TRANSACTION_MINED_MS,
+            );
+            const orders = [signedOrder, signedOrder2];
+            const takers = [takerAddress, takerAddress];
+            const [
+                [orderInfo1, orderInfo2],
+                [traderInfo1, traderInfo2],
+            ] = await orderValidator.getOrdersAndTradersInfo.callAsync(orders, takers);
+            const expectedOrderHash1 = orderHashUtils.getOrderHashHex(signedOrder);
+            const expectedOrderHash2 = orderHashUtils.getOrderHashHex(signedOrder2);
+            expect(orderInfo1.orderStatus).to.be.equal(OrderStatus.FILLABLE);
+            expect(orderInfo1.orderHash).to.be.equal(expectedOrderHash1);
+            expect(orderInfo1.orderTakerAssetFilledAmount).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(orderInfo2.orderStatus).to.be.equal(OrderStatus.FILLABLE);
+            expect(orderInfo2.orderHash).to.be.equal(expectedOrderHash2);
+            expect(orderInfo2.orderTakerAssetFilledAmount).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.makerBalance).to.be.bignumber.equal(makerBalance);
+            expect(traderInfo1.makerAllowance).to.be.bignumber.equal(makerAllowance);
+            expect(traderInfo1.takerBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+            expect(traderInfo1.makerZrxBalance).to.be.bignumber.equal(makerZrxBalance);
+            expect(traderInfo1.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo1.takerZrxAllowance).to.be.bignumber.equal(takerZrxAllowance);
+            expect(traderInfo2.makerBalance).to.be.bignumber.equal(makerBalance);
+            expect(traderInfo2.makerAllowance).to.be.bignumber.equal(makerAllowance);
+            expect(traderInfo2.takerBalance).to.be.bignumber.equal(ERC721_BALANCE);
+            expect(traderInfo2.takerAllowance).to.be.bignumber.equal(ERC721_ALLOWANCE);
+            expect(traderInfo2.makerZrxBalance).to.be.bignumber.equal(makerZrxBalance);
+            expect(traderInfo2.makerZrxAllowance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerZrxBalance).to.be.bignumber.equal(constants.ZERO_AMOUNT);
+            expect(traderInfo2.takerZrxAllowance).to.be.bignumber.equal(takerZrxAllowance);
+        });
+    });
+});
+// tslint:disable:max-file-line-count
diff --git a/contracts/extensions/test/utils/dutch_auction_test_wrapper.ts b/contracts/extensions/test/utils/dutch_auction_test_wrapper.ts
new file mode 100644
index 000000000..c1e2f2070
--- /dev/null
+++ b/contracts/extensions/test/utils/dutch_auction_test_wrapper.ts
@@ -0,0 +1,62 @@
+import { artifacts as protocolArtifacts } from '@0x/contracts-protocol';
+import { LogDecoder } from '@0x/contracts-test-utils';
+import { artifacts as tokensArtifacts } from '@0x/contracts-tokens';
+import { DutchAuctionDetails, SignedOrder } from '@0x/types';
+import { Web3Wrapper } from '@0x/web3-wrapper';
+import { Provider, TransactionReceiptWithDecodedLogs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { DutchAuctionContract } from '../../generated-wrappers/dutch_auction';
+import { artifacts } from '../../src/artifacts';
+
+export class DutchAuctionTestWrapper {
+    private readonly _dutchAuctionContract: DutchAuctionContract;
+    private readonly _web3Wrapper: Web3Wrapper;
+    private readonly _logDecoder: LogDecoder;
+
+    constructor(contractInstance: DutchAuctionContract, provider: Provider) {
+        this._dutchAuctionContract = contractInstance;
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._logDecoder = new LogDecoder(this._web3Wrapper, {
+            ...artifacts,
+            ...tokensArtifacts,
+            ...protocolArtifacts,
+        });
+    }
+    /**
+     * Matches the buy and sell orders at an amount given the following: the current block time, the auction
+     * start time and the auction begin amount. The sell order is a an order at the lowest amount
+     * at the end of the auction. Excess from the match is transferred to the seller.
+     * Over time the price moves from beginAmount to endAmount given the current block.timestamp.
+     * @param buyOrder The Buyer's order. This order is for the current expected price of the auction.
+     * @param sellOrder The Seller's order. This order is for the lowest amount (at the end of the auction).
+     * @param from Address the transaction is being sent from.
+     * @return Transaction receipt with decoded logs.
+     */
+    public async matchOrdersAsync(
+        buyOrder: SignedOrder,
+        sellOrder: SignedOrder,
+        from: string,
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const txHash = await this._dutchAuctionContract.matchOrders.sendTransactionAsync(
+            buyOrder,
+            sellOrder,
+            buyOrder.signature,
+            sellOrder.signature,
+            {
+                from,
+            },
+        );
+        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
+        return tx;
+    }
+    /**
+     * Calculates the Auction Details for the given order
+     * @param sellOrder The Seller's order. This order is for the lowest amount (at the end of the auction).
+     * @return The dutch auction details.
+     */
+    public async getAuctionDetailsAsync(sellOrder: SignedOrder): Promise<DutchAuctionDetails> {
+        const auctionDetails = await this._dutchAuctionContract.getAuctionDetails.callAsync(sellOrder);
+        return auctionDetails;
+    }
+}
diff --git a/contracts/extensions/tsconfig.json b/contracts/extensions/tsconfig.json
index a303e3f5c..ed9b4fbe1 100644
--- a/contracts/extensions/tsconfig.json
+++ b/contracts/extensions/tsconfig.json
@@ -9,7 +9,9 @@
     "files": [
         "./generated-artifacts/BalanceThresholdFilter.json",
         "./generated-artifacts/DutchAuction.json",
-        "./generated-artifacts/Forwarder.json"
+        "./generated-artifacts/Forwarder.json",
+        "./generated-artifacts/OrderMatcher.json",
+        "./generated-artifacts/OrderValidator.json"
     ],
     "exclude": ["./deploy/solc/solc_bin"]
 }