Merge pull request #522 from 0xProject/feature/contracts/forwarder

Forwarding contract

5 files changed, 1056 insertions, 0 deletions

diff --git a/packages/contracts/test/forwarder/forwarder.ts b/packages/contracts/test/forwarder/forwarder.ts
new file mode 100644
index 000000000..0b6e24451
--- /dev/null
+++ b/packages/contracts/test/forwarder/forwarder.ts
@@ -0,0 +1,818 @@
+import { BlockchainLifecycle } from '@0xproject/dev-utils';
+import { assetProxyUtils } from '@0xproject/order-utils';
+import { AssetProxyId, SignedOrder } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import * as chai from 'chai';
+import { TransactionReceiptWithDecodedLogs } from 'ethereum-types';
+
+import { DummyERC20TokenContract } from '../../generated_contract_wrappers/dummy_e_r_c20_token';
+import { DummyERC721TokenContract } from '../../generated_contract_wrappers/dummy_e_r_c721_token';
+import { ExchangeContract } from '../../generated_contract_wrappers/exchange';
+import { ForwarderContract } from '../../generated_contract_wrappers/forwarder';
+import { WETH9Contract } from '../../generated_contract_wrappers/weth9';
+import { artifacts } from '../utils/artifacts';
+import { expectRevertOrAlwaysFailingTransactionAsync, expectRevertOrOtherErrorAsync } from '../utils/assertions';
+import { chaiSetup } from '../utils/chai_setup';
+import { constants } from '../utils/constants';
+import { ERC20Wrapper } from '../utils/erc20_wrapper';
+import { ERC721Wrapper } from '../utils/erc721_wrapper';
+import { ExchangeWrapper } from '../utils/exchange_wrapper';
+import { formatters } from '../utils/formatters';
+import { ForwarderWrapper } from '../utils/forwarder_wrapper';
+import { OrderFactory } from '../utils/order_factory';
+import { ContractName, ERC20BalancesByOwner } from '../utils/types';
+import { provider, txDefaults, web3Wrapper } from '../utils/web3_wrapper';
+
+chaiSetup.configure();
+const expect = chai.expect;
+const blockchainLifecycle = new BlockchainLifecycle(web3Wrapper);
+const DECIMALS_DEFAULT = 18;
+// Set a gasPrice so when checking balance of msg.sender we can accurately calculate gasPrice*gasUsed
+const DEFAULT_GAS_PRICE = new BigNumber(1);
+
+describe(ContractName.Forwarder, () => {
+    let makerAddress: string;
+    let owner: string;
+    let takerAddress: string;
+    let feeRecipientAddress: string;
+    let otherAddress: string;
+    let defaultMakerAssetAddress: string;
+
+    let weth: DummyERC20TokenContract;
+    let zrxToken: DummyERC20TokenContract;
+    let erc721Token: DummyERC721TokenContract;
+    let forwarderContract: ForwarderContract;
+    let wethContract: WETH9Contract;
+    let forwarderWrapper: ForwarderWrapper;
+    let exchangeWrapper: ExchangeWrapper;
+
+    let signedOrder: SignedOrder;
+    let signedOrders: SignedOrder[];
+    let orderWithFee: SignedOrder;
+    let signedOrdersWithFee: SignedOrder[];
+    let feeOrder: SignedOrder;
+    let feeOrders: SignedOrder[];
+    let orderFactory: OrderFactory;
+    let erc20Wrapper: ERC20Wrapper;
+    let erc20Balances: ERC20BalancesByOwner;
+    let tx: TransactionReceiptWithDecodedLogs;
+
+    let erc721MakerAssetIds: BigNumber[];
+    let feeProportion: number = 0;
+
+    before(async () => {
+        await blockchainLifecycle.startAsync();
+        const accounts = await web3Wrapper.getAvailableAddressesAsync();
+        const usedAddresses = ([owner, makerAddress, takerAddress, feeRecipientAddress, otherAddress] = accounts);
+
+        const erc721Wrapper = new ERC721Wrapper(provider, usedAddresses, owner);
+        erc20Wrapper = new ERC20Wrapper(provider, usedAddresses, owner);
+
+        const numDummyErc20ToDeploy = 3;
+        let erc20TokenA;
+        [erc20TokenA, zrxToken] = await erc20Wrapper.deployDummyTokensAsync(
+            numDummyErc20ToDeploy,
+            constants.DUMMY_TOKEN_DECIMALS,
+        );
+        const erc20Proxy = await erc20Wrapper.deployProxyAsync();
+        await erc20Wrapper.setBalancesAndAllowancesAsync();
+
+        [erc721Token] = await erc721Wrapper.deployDummyTokensAsync();
+        const erc721Proxy = await erc721Wrapper.deployProxyAsync();
+        await erc721Wrapper.setBalancesAndAllowancesAsync();
+        const erc721Balances = await erc721Wrapper.getBalancesAsync();
+        erc721MakerAssetIds = erc721Balances[makerAddress][erc721Token.address];
+
+        wethContract = await WETH9Contract.deployFrom0xArtifactAsync(artifacts.EtherToken, provider, txDefaults);
+        weth = new DummyERC20TokenContract(wethContract.abi, wethContract.address, provider);
+        erc20Wrapper.addDummyTokenContract(weth);
+
+        const wethAssetData = assetProxyUtils.encodeERC20AssetData(wethContract.address);
+        const zrxAssetData = assetProxyUtils.encodeERC20AssetData(zrxToken.address);
+        const exchangeInstance = await ExchangeContract.deployFrom0xArtifactAsync(
+            artifacts.Exchange,
+            provider,
+            txDefaults,
+            zrxAssetData,
+        );
+        const exchangeContract = new ExchangeContract(exchangeInstance.abi, exchangeInstance.address, provider);
+        exchangeWrapper = new ExchangeWrapper(exchangeContract, provider);
+        await exchangeWrapper.registerAssetProxyAsync(erc20Proxy.address, owner);
+        await exchangeWrapper.registerAssetProxyAsync(erc721Proxy.address, owner);
+
+        await erc20Proxy.addAuthorizedAddress.sendTransactionAsync(exchangeInstance.address, {
+            from: owner,
+        });
+        await erc721Proxy.addAuthorizedAddress.sendTransactionAsync(exchangeInstance.address, {
+            from: owner,
+        });
+
+        defaultMakerAssetAddress = erc20TokenA.address;
+        const defaultTakerAssetAddress = wethContract.address;
+        const defaultOrderParams = {
+            exchangeAddress: exchangeInstance.address,
+            makerAddress,
+            feeRecipientAddress,
+            makerAssetData: assetProxyUtils.encodeERC20AssetData(defaultMakerAssetAddress),
+            takerAssetData: assetProxyUtils.encodeERC20AssetData(defaultTakerAssetAddress),
+            makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(200), DECIMALS_DEFAULT),
+            takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), DECIMALS_DEFAULT),
+            makerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+            takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(0), DECIMALS_DEFAULT),
+        };
+        const privateKey = constants.TESTRPC_PRIVATE_KEYS[accounts.indexOf(makerAddress)];
+        orderFactory = new OrderFactory(privateKey, defaultOrderParams);
+
+        const forwarderInstance = await ForwarderContract.deployFrom0xArtifactAsync(
+            artifacts.Forwarder,
+            provider,
+            txDefaults,
+            exchangeInstance.address,
+            wethContract.address,
+            zrxToken.address,
+            AssetProxyId.ERC20,
+            zrxAssetData,
+            wethAssetData,
+        );
+        forwarderContract = new ForwarderContract(forwarderInstance.abi, forwarderInstance.address, provider);
+        forwarderWrapper = new ForwarderWrapper(forwarderContract, provider, zrxToken.address);
+        erc20Wrapper.addTokenOwnerAddress(forwarderInstance.address);
+
+        web3Wrapper.abiDecoder.addABI(forwarderContract.abi);
+        web3Wrapper.abiDecoder.addABI(exchangeInstance.abi);
+    });
+    after(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    beforeEach(async () => {
+        await blockchainLifecycle.startAsync();
+        feeProportion = 0;
+        erc20Balances = await erc20Wrapper.getBalancesAsync();
+        signedOrder = orderFactory.newSignedOrder();
+        signedOrders = [signedOrder];
+        feeOrder = orderFactory.newSignedOrder({
+            makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+            takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+        });
+        feeOrders = [feeOrder];
+        orderWithFee = orderFactory.newSignedOrder({
+            takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+        });
+        signedOrdersWithFee = [orderWithFee];
+    });
+    afterEach(async () => {
+        await blockchainLifecycle.revertAsync();
+    });
+    describe('calculations', () => {
+        it('throws if orders passed in are not enough to satisfy requested amount', async () => {
+            feeOrders = [feeOrder];
+            const makerTokenFillAmount = feeOrder.makerAssetAmount.div(2);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                feeOrders,
+                [],
+                feeProportion,
+                makerTokenFillAmount,
+            );
+            // Fill the feeOrder
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(feeOrders, [], makerTokenFillAmount, {
+                from: takerAddress,
+                value: fillAmountWei,
+            });
+            return expectRevertOrOtherErrorAsync(
+                forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                    feeOrders,
+                    [],
+                    feeProportion,
+                    makerTokenFillAmount,
+                ),
+                'Unable to satisfy makerAssetFillAmount with provided orders',
+            );
+        });
+        it('throws if orders passed are cancelled', async () => {
+            tx = await exchangeWrapper.cancelOrderAsync(feeOrder, makerAddress);
+            // Cancel the feeOrder
+            return expectRevertOrOtherErrorAsync(
+                forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                    feeOrders,
+                    [],
+                    feeProportion,
+                    feeOrder.makerAssetAmount.div(2),
+                ),
+                'Unable to satisfy makerAssetFillAmount with provided orders',
+            );
+        });
+    });
+    describe('marketSellEthForERC20 without extra fees', () => {
+        it('should fill the order', async () => {
+            const fillAmount = signedOrder.takerAssetAmount.div(2);
+            const makerBalanceBefore = erc20Balances[makerAddress][defaultMakerAssetAddress];
+            const takerBalanceBefore = erc20Balances[takerAddress][defaultMakerAssetAddress];
+            feeOrders = [];
+            tx = await forwarderWrapper.marketSellEthForERC20Async(signedOrders, feeOrders, {
+                value: fillAmount,
+                from: takerAddress,
+            });
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const makerBalanceAfter = newBalances[makerAddress][defaultMakerAssetAddress];
+            const takerBalanceAfter = newBalances[takerAddress][defaultMakerAssetAddress];
+            const makerTokenFillAmount = fillAmount
+                .times(signedOrder.makerAssetAmount)
+                .dividedToIntegerBy(signedOrder.takerAssetAmount);
+
+            expect(makerBalanceAfter).to.be.bignumber.equal(makerBalanceBefore.minus(makerTokenFillAmount));
+            expect(takerBalanceAfter).to.be.bignumber.equal(takerBalanceBefore.plus(makerTokenFillAmount));
+            expect(newBalances[forwarderContract.address][weth.address]).to.be.bignumber.equal(new BigNumber(0));
+        });
+        it('should fill the order and perform fee abstraction', async () => {
+            const fillAmount = signedOrder.takerAssetAmount.div(4);
+            const takerBalanceBefore = erc20Balances[takerAddress][defaultMakerAssetAddress];
+            tx = await forwarderWrapper.marketSellEthForERC20Async(signedOrdersWithFee, feeOrders, {
+                value: fillAmount,
+                from: takerAddress,
+            });
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const takerBalanceAfter = newBalances[takerAddress][defaultMakerAssetAddress];
+
+            const acceptPercentage = 98;
+            const acceptableThreshold = takerBalanceBefore.plus(fillAmount.times(acceptPercentage).dividedBy(100));
+            const isWithinThreshold = takerBalanceAfter.greaterThanOrEqualTo(acceptableThreshold);
+            expect(isWithinThreshold).to.be.true();
+            expect(newBalances[forwarderContract.address][weth.address]).to.be.bignumber.equal(new BigNumber(0));
+        });
+        it('should fill the order when token is ZRX with fees', async () => {
+            orderWithFee = orderFactory.newSignedOrder({
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+            });
+            signedOrdersWithFee = [orderWithFee];
+            feeOrders = [];
+            const fillAmount = signedOrder.takerAssetAmount.div(4);
+            const takerBalanceBefore = erc20Balances[takerAddress][zrxToken.address];
+            tx = await forwarderWrapper.marketSellEthForERC20Async(signedOrdersWithFee, feeOrders, {
+                value: fillAmount,
+                from: takerAddress,
+            });
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const takerBalanceAfter = newBalances[takerAddress][zrxToken.address];
+
+            const acceptPercentage = 98;
+            const acceptableThreshold = takerBalanceBefore.plus(fillAmount.times(acceptPercentage).dividedBy(100));
+            const isWithinThreshold = takerBalanceAfter.greaterThanOrEqualTo(acceptableThreshold);
+            expect(isWithinThreshold).to.be.true();
+            expect(newBalances[forwarderContract.address][weth.address]).to.be.bignumber.equal(new BigNumber(0));
+        });
+        it('should fail if sent an ETH amount too high', async () => {
+            signedOrder = orderFactory.newSignedOrder({
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+            });
+            const fillAmount = signedOrder.takerAssetAmount.times(2);
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketSellEthForERC20Async(signedOrdersWithFee, feeOrders, {
+                    value: fillAmount,
+                    from: takerAddress,
+                }),
+            );
+        });
+        it('should fail if fee abstraction amount is too high', async () => {
+            orderWithFee = orderFactory.newSignedOrder({
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(50), DECIMALS_DEFAULT),
+            });
+            signedOrdersWithFee = [orderWithFee];
+            feeOrder = orderFactory.newSignedOrder({
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+            });
+            feeOrders = [feeOrder];
+            const fillAmount = signedOrder.takerAssetAmount.div(4);
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketSellEthForERC20Async(signedOrdersWithFee, feeOrders, {
+                    value: fillAmount,
+                    from: takerAddress,
+                }),
+            );
+        });
+        it('throws when mixed ERC721 and ERC20 assets with ERC20 first', async () => {
+            const makerAssetId = erc721MakerAssetIds[0];
+            const erc721SignedOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: new BigNumber(1),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
+            });
+            const erc20SignedOrder = orderFactory.newSignedOrder();
+            signedOrders = [erc20SignedOrder, erc721SignedOrder];
+            const fillAmountWei = erc20SignedOrder.takerAssetAmount.plus(erc721SignedOrder.takerAssetAmount);
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketSellEthForERC20Async(signedOrders, feeOrders, {
+                    from: takerAddress,
+                    value: fillAmountWei,
+                }),
+            );
+        });
+    });
+    describe('marketSellEthForERC20 with extra fees', () => {
+        it('should fill the order and send fee to fee recipient', async () => {
+            const initEthBalance = await web3Wrapper.getBalanceInWeiAsync(feeRecipientAddress);
+            const fillAmount = signedOrder.takerAssetAmount.div(2);
+            feeProportion = 150; // 1.5%
+            feeOrders = [];
+            tx = await forwarderWrapper.marketSellEthForERC20Async(
+                signedOrders,
+                feeOrders,
+                {
+                    from: takerAddress,
+                    value: fillAmount,
+                    gasPrice: DEFAULT_GAS_PRICE,
+                },
+                {
+                    feeProportion,
+                    feeRecipient: feeRecipientAddress,
+                },
+            );
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const makerBalanceBefore = erc20Balances[makerAddress][defaultMakerAssetAddress];
+            const makerBalanceAfter = newBalances[makerAddress][defaultMakerAssetAddress];
+            const takerBalanceAfter = newBalances[takerAddress][defaultMakerAssetAddress];
+            const afterEthBalance = await web3Wrapper.getBalanceInWeiAsync(feeRecipientAddress);
+            const takerBoughtAmount = takerBalanceAfter.minus(erc20Balances[takerAddress][defaultMakerAssetAddress]);
+
+            expect(makerBalanceAfter).to.be.bignumber.equal(makerBalanceBefore.minus(takerBoughtAmount));
+            expect(afterEthBalance).to.be.bignumber.equal(
+                initEthBalance.plus(fillAmount.times(feeProportion).dividedBy(10000)),
+            );
+            expect(newBalances[forwarderContract.address][weth.address]).to.be.bignumber.equal(new BigNumber(0));
+        });
+        it('should fail if the fee is set too high', async () => {
+            const initEthBalance = await web3Wrapper.getBalanceInWeiAsync(feeRecipientAddress);
+            const fillAmount = signedOrder.takerAssetAmount.div(2);
+            feeProportion = 1500; // 15.0%
+            feeOrders = [];
+            expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketSellEthForERC20Async(
+                    signedOrders,
+                    feeOrders,
+                    {
+                        from: takerAddress,
+                        value: fillAmount,
+                        gasPrice: DEFAULT_GAS_PRICE,
+                    },
+                    {
+                        feeProportion,
+                        feeRecipient: feeRecipientAddress,
+                    },
+                ),
+            );
+            const afterEthBalance = await web3Wrapper.getBalanceInWeiAsync(feeRecipientAddress);
+            expect(afterEthBalance).to.be.bignumber.equal(initEthBalance);
+        });
+    });
+    describe('marketBuyTokensWithEth', () => {
+        it('should buy the exact amount of assets', async () => {
+            const makerAssetAmount = signedOrder.makerAssetAmount.div(2);
+            const initEthBalance = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const balancesBefore = await erc20Wrapper.getBalancesAsync();
+            const rate = signedOrder.makerAssetAmount.dividedBy(signedOrder.takerAssetAmount);
+            const fillAmountWei = makerAssetAmount.dividedToIntegerBy(rate);
+            feeOrders = [];
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: fillAmountWei,
+                gasPrice: DEFAULT_GAS_PRICE,
+            });
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const takerBalanceBefore = balancesBefore[takerAddress][defaultMakerAssetAddress];
+            const takerBalanceAfter = newBalances[takerAddress][defaultMakerAssetAddress];
+            const afterEthBalance = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const expectedEthBalanceAfterGasCosts = initEthBalance.minus(fillAmountWei).minus(tx.gasUsed);
+            expect(takerBalanceAfter).to.be.bignumber.eq(takerBalanceBefore.plus(makerAssetAmount));
+            expect(afterEthBalance).to.be.bignumber.eq(expectedEthBalanceAfterGasCosts);
+        });
+        it('should buy the exact amount of assets and return excess ETH', async () => {
+            const makerAssetAmount = signedOrder.makerAssetAmount.div(2);
+            const initEthBalance = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const balancesBefore = await erc20Wrapper.getBalancesAsync();
+            const rate = signedOrder.makerAssetAmount.dividedBy(signedOrder.takerAssetAmount);
+            const fillAmount = makerAssetAmount.dividedToIntegerBy(rate);
+            const excessFillAmount = fillAmount.times(2);
+            feeOrders = [];
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: excessFillAmount,
+                gasPrice: DEFAULT_GAS_PRICE,
+            });
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const takerBalanceBefore = balancesBefore[takerAddress][defaultMakerAssetAddress];
+            const takerBalanceAfter = newBalances[takerAddress][defaultMakerAssetAddress];
+            const afterEthBalance = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const expectedEthBalanceAfterGasCosts = initEthBalance.minus(fillAmount).minus(tx.gasUsed);
+            expect(takerBalanceAfter).to.be.bignumber.eq(takerBalanceBefore.plus(makerAssetAmount));
+            expect(afterEthBalance).to.be.bignumber.eq(expectedEthBalanceAfterGasCosts);
+        });
+        it('should buy the exact amount of assets with fee abstraction', async () => {
+            const makerAssetAmount = signedOrder.makerAssetAmount.div(2);
+            const balancesBefore = await erc20Wrapper.getBalancesAsync();
+            const rate = signedOrder.makerAssetAmount.dividedBy(signedOrder.takerAssetAmount);
+            const fillAmount = makerAssetAmount.dividedToIntegerBy(rate);
+            const excessFillAmount = fillAmount.times(2);
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrdersWithFee, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: excessFillAmount,
+            });
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const takerBalanceBefore = balancesBefore[takerAddress][defaultMakerAssetAddress];
+            const takerBalanceAfter = newBalances[takerAddress][defaultMakerAssetAddress];
+            expect(takerBalanceAfter).to.be.bignumber.eq(takerBalanceBefore.plus(makerAssetAmount));
+        });
+        it('should buy the exact amount of assets when buying zrx with fee abstraction', async () => {
+            signedOrder = orderFactory.newSignedOrder({
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+            });
+            signedOrdersWithFee = [signedOrder];
+            feeOrders = [];
+            const makerAssetAmount = signedOrder.makerAssetAmount.div(2);
+            const takerWeiBalanceBefore = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const balancesBefore = await erc20Wrapper.getBalancesAsync();
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrdersWithFee,
+                feeOrders,
+                feeProportion,
+                makerAssetAmount,
+            );
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrdersWithFee, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: fillAmountWei,
+                gasPrice: DEFAULT_GAS_PRICE,
+            });
+            const newBalances = await erc20Wrapper.getBalancesAsync();
+            const takerTokenBalanceBefore = balancesBefore[takerAddress][zrxToken.address];
+            const takerTokenBalanceAfter = newBalances[takerAddress][zrxToken.address];
+            const takerWeiBalanceAfter = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const expectedCostAfterGas = fillAmountWei.plus(tx.gasUsed);
+            expect(takerTokenBalanceAfter).to.be.bignumber.greaterThan(takerTokenBalanceBefore.plus(makerAssetAmount));
+            expect(takerWeiBalanceAfter).to.be.bignumber.equal(takerWeiBalanceBefore.minus(expectedCostAfterGas));
+        });
+        it('throws if fees are higher than 5% when buying zrx', async () => {
+            const highFeeZRXOrder = orderFactory.newSignedOrder({
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                makerAssetAmount: signedOrder.makerAssetAmount,
+                takerFee: signedOrder.makerAssetAmount.times(0.06),
+            });
+            signedOrdersWithFee = [highFeeZRXOrder];
+            feeOrders = [];
+            const makerAssetAmount = signedOrder.makerAssetAmount.div(2);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrdersWithFee,
+                feeOrders,
+                feeProportion,
+                makerAssetAmount,
+            );
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketBuyTokensWithEthAsync(signedOrdersWithFee, feeOrders, makerAssetAmount, {
+                    from: takerAddress,
+                    value: fillAmountWei,
+                }),
+            );
+        });
+        it('throws if fees are higher than 5% when buying erc20', async () => {
+            const highFeeERC20Order = orderFactory.newSignedOrder({
+                takerFee: signedOrder.makerAssetAmount.times(0.06),
+            });
+            signedOrdersWithFee = [highFeeERC20Order];
+            feeOrders = [feeOrder];
+            const makerAssetAmount = signedOrder.makerAssetAmount.div(2);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrdersWithFee,
+                feeOrders,
+                feeProportion,
+                makerAssetAmount,
+            );
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketBuyTokensWithEthAsync(signedOrdersWithFee, feeOrders, makerAssetAmount, {
+                    from: takerAddress,
+                    value: fillAmountWei,
+                }),
+            );
+        });
+        it('throws if makerAssetAmount is 0', async () => {
+            const makerAssetAmount = new BigNumber(0);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrdersWithFee,
+                feeOrders,
+                feeProportion,
+                makerAssetAmount,
+            );
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketBuyTokensWithEthAsync(signedOrdersWithFee, feeOrders, makerAssetAmount, {
+                    from: takerAddress,
+                    value: fillAmountWei,
+                }),
+            );
+        });
+        it('throws if the amount of ETH sent in is less than the takerAssetFilledAmount', async () => {
+            const makerAssetAmount = signedOrder.makerAssetAmount;
+            const fillAmount = signedOrder.takerAssetAmount.div(2);
+            const zero = new BigNumber(0);
+            // Deposit enough taker balance to fill the order
+            const wethDepositTxHash = await wethContract.deposit.sendTransactionAsync({
+                from: takerAddress,
+                value: signedOrder.takerAssetAmount,
+            });
+            await web3Wrapper.awaitTransactionSuccessAsync(wethDepositTxHash);
+            // Transfer all of this WETH to the forwarding contract
+            const wethTransferTxHash = await wethContract.transfer.sendTransactionAsync(
+                forwarderContract.address,
+                signedOrder.takerAssetAmount,
+                { from: takerAddress },
+            );
+            await web3Wrapper.awaitTransactionSuccessAsync(wethTransferTxHash);
+            // We use the contract directly to get around wrapper validations and calculations
+            const formattedOrders = formatters.createMarketSellOrders(signedOrders, zero);
+            const formattedFeeOrders = formatters.createMarketSellOrders(feeOrders, zero);
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderContract.marketBuyTokensWithEth.sendTransactionAsync(
+                    formattedOrders.orders,
+                    formattedOrders.signatures,
+                    formattedFeeOrders.orders,
+                    formattedFeeOrders.signatures,
+                    makerAssetAmount,
+                    zero,
+                    constants.NULL_ADDRESS,
+                    { value: fillAmount, from: takerAddress },
+                ),
+            );
+        });
+    });
+    describe('marketBuyTokensWithEth - ERC721', async () => {
+        it('buys ERC721 assets', async () => {
+            const makerAssetId = erc721MakerAssetIds[0];
+            signedOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: new BigNumber(1),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
+            });
+            feeOrders = [];
+            signedOrders = [signedOrder];
+            const makerAssetAmount = new BigNumber(signedOrders.length);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrders,
+                feeOrders,
+                feeProportion,
+                makerAssetAmount,
+            );
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: fillAmountWei,
+            });
+            const newOwnerTakerAsset = await erc721Token.ownerOf.callAsync(makerAssetId);
+            expect(newOwnerTakerAsset).to.be.bignumber.equal(takerAddress);
+        });
+        it('buys ERC721 assets with fee abstraction', async () => {
+            const makerAssetId = erc721MakerAssetIds[0];
+            signedOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: new BigNumber(1),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
+            });
+            signedOrders = [signedOrder];
+            const makerAssetAmount = new BigNumber(signedOrders.length);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrders,
+                feeOrders,
+                feeProportion,
+                makerAssetAmount,
+            );
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: fillAmountWei,
+            });
+            const newOwnerTakerAsset = await erc721Token.ownerOf.callAsync(makerAssetId);
+            expect(newOwnerTakerAsset).to.be.bignumber.equal(takerAddress);
+        });
+        it('buys ERC721 assets with fee abstraction and pays fee to fee recipient', async () => {
+            const makerAssetId = erc721MakerAssetIds[0];
+            signedOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: new BigNumber(1),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(1), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
+            });
+            signedOrders = [signedOrder];
+            feeProportion = 100;
+            const initTakerBalanceWei = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const initFeeRecipientBalanceWei = await web3Wrapper.getBalanceInWeiAsync(feeRecipientAddress);
+            const makerAssetAmount = new BigNumber(signedOrders.length);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrders,
+                feeOrders,
+                feeProportion,
+                makerAssetAmount,
+            );
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(
+                signedOrders,
+                feeOrders,
+                makerAssetAmount,
+                {
+                    from: takerAddress,
+                    value: fillAmountWei,
+                    gasPrice: DEFAULT_GAS_PRICE,
+                },
+                {
+                    feeProportion,
+                    feeRecipient: feeRecipientAddress,
+                },
+            );
+            const afterFeeRecipientEthBalance = await web3Wrapper.getBalanceInWeiAsync(feeRecipientAddress);
+            const afterTakerBalanceWei = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const takerFilledAmount = initTakerBalanceWei.minus(afterTakerBalanceWei).plus(tx.gasUsed);
+            const newOwnerTakerAsset = await erc721Token.ownerOf.callAsync(makerAssetId);
+            expect(newOwnerTakerAsset).to.be.bignumber.equal(takerAddress);
+            const balanceDiff = afterFeeRecipientEthBalance.minus(initFeeRecipientBalanceWei);
+            expect(takerFilledAmount.dividedToIntegerBy(balanceDiff)).to.be.bignumber.equal(101);
+            expect(takerFilledAmount.minus(balanceDiff).dividedToIntegerBy(balanceDiff)).to.be.bignumber.equal(100);
+        });
+        it('buys multiple ERC721 assets with fee abstraction and pays fee to fee recipient', async () => {
+            const makerAssetId1 = erc721MakerAssetIds[0];
+            const makerAssetId2 = erc721MakerAssetIds[1];
+            const signedOrder1 = orderFactory.newSignedOrder({
+                makerAssetAmount: new BigNumber(1),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(3), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId1),
+            });
+            const signedOrder2 = orderFactory.newSignedOrder({
+                makerAssetAmount: new BigNumber(1),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(4), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId2),
+            });
+            signedOrders = [signedOrder1, signedOrder2];
+            feeProportion = 10;
+            const makerAssetAmount = new BigNumber(signedOrders.length);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrders,
+                feeOrders,
+                feeProportion,
+                makerAssetAmount,
+            );
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: fillAmountWei,
+            });
+            const newOwnerTakerAsset1 = await erc721Token.ownerOf.callAsync(makerAssetId1);
+            expect(newOwnerTakerAsset1).to.be.bignumber.equal(takerAddress);
+            const newOwnerTakerAsset2 = await erc721Token.ownerOf.callAsync(makerAssetId2);
+            expect(newOwnerTakerAsset2).to.be.bignumber.equal(takerAddress);
+        });
+        it('buys ERC721 assets with fee abstraction and handles fee orders filled and excess eth', async () => {
+            const makerAssetId = erc721MakerAssetIds[0];
+            feeProportion = 0;
+            // In this scenario a total of 6 ZRX fees need to be paid.
+            // There are two fee orders, but the first fee order is partially filled while
+            // the Forwarding contract tx is in the mempool.
+            const erc721MakerAssetAmount = new BigNumber(1);
+            signedOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: erc721MakerAssetAmount,
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), DECIMALS_DEFAULT),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(6), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
+            });
+            signedOrders = [signedOrder];
+            const firstFeeOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(8), DECIMALS_DEFAULT),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(0.1), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(0), DECIMALS_DEFAULT),
+            });
+            const secondFeeOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(8), DECIMALS_DEFAULT),
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(0.12), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(0), DECIMALS_DEFAULT),
+            });
+            feeOrders = [firstFeeOrder, secondFeeOrder];
+            const makerAssetAmount = new BigNumber(signedOrders.length);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrders,
+                feeOrders,
+                feeProportion,
+                erc721MakerAssetAmount,
+            );
+            // Simulate another otherAddress user partially filling firstFeeOrder
+            const firstFeeOrderFillAmount = firstFeeOrder.makerAssetAmount.div(2);
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync([firstFeeOrder], [], firstFeeOrderFillAmount, {
+                from: otherAddress,
+                value: fillAmountWei,
+            });
+            // For tests we calculate how much this should've cost given that firstFeeOrder was filled
+            const expectedFillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrders,
+                feeOrders,
+                feeProportion,
+                erc721MakerAssetAmount,
+            );
+            // With 4 ZRX remaining in firstFeeOrder, the secondFeeOrder will need to be filled to make up
+            // the total amount of fees required (6)
+            // Since the fee orders can be filled while the transaction is pending the user safely sends in
+            // extra ether to cover any slippage
+            const initEthBalance = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const slippageFillAmountWei = fillAmountWei.times(2);
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: slippageFillAmountWei,
+                gasPrice: DEFAULT_GAS_PRICE,
+            });
+            const afterEthBalance = await web3Wrapper.getBalanceInWeiAsync(takerAddress);
+            const expectedEthBalanceAfterGasCosts = initEthBalance.minus(expectedFillAmountWei).minus(tx.gasUsed);
+            const newOwnerTakerAsset = await erc721Token.ownerOf.callAsync(makerAssetId);
+            expect(newOwnerTakerAsset).to.be.bignumber.equal(takerAddress);
+            expect(afterEthBalance).to.be.bignumber.equal(expectedEthBalanceAfterGasCosts);
+        });
+        it('buys ERC721 assets with fee abstraction and handles fee orders filled', async () => {
+            const makerAssetId = erc721MakerAssetIds[0];
+            feeProportion = 0;
+            // In this scenario a total of 6 ZRX fees need to be paid.
+            // There are two fee orders, but the first fee order is partially filled while
+            // the Forwarding contract tx is in the mempool.
+            const erc721MakerAssetAmount = new BigNumber(1);
+            signedOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: erc721MakerAssetAmount,
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(10), DECIMALS_DEFAULT),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(6), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
+            });
+            const zrxMakerAssetAmount = Web3Wrapper.toBaseUnitAmount(new BigNumber(8), DECIMALS_DEFAULT);
+            signedOrders = [signedOrder];
+            const firstFeeOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: zrxMakerAssetAmount,
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(0.1), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(0), DECIMALS_DEFAULT),
+            });
+            const secondFeeOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: zrxMakerAssetAmount,
+                takerAssetAmount: Web3Wrapper.toBaseUnitAmount(new BigNumber(0.12), DECIMALS_DEFAULT),
+                makerAssetData: assetProxyUtils.encodeERC20AssetData(zrxToken.address),
+                takerFee: Web3Wrapper.toBaseUnitAmount(new BigNumber(0), DECIMALS_DEFAULT),
+            });
+            feeOrders = [firstFeeOrder, secondFeeOrder];
+            const makerAssetAmount = new BigNumber(signedOrders.length);
+            const fillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrders,
+                feeOrders,
+                feeProportion,
+                erc721MakerAssetAmount,
+            );
+            // Simulate another otherAddress user partially filling firstFeeOrder
+            const firstFeeOrderFillAmount = firstFeeOrder.makerAssetAmount.div(2);
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync([firstFeeOrder], [], firstFeeOrderFillAmount, {
+                from: otherAddress,
+                value: fillAmountWei,
+            });
+            const expectedFillAmountWei = await forwarderWrapper.calculateMarketBuyFillAmountWeiAsync(
+                signedOrders,
+                feeOrders,
+                feeProportion,
+                erc721MakerAssetAmount,
+            );
+            tx = await forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                from: takerAddress,
+                value: expectedFillAmountWei,
+            });
+            const newOwnerTakerAsset = await erc721Token.ownerOf.callAsync(makerAssetId);
+            expect(newOwnerTakerAsset).to.be.bignumber.equal(takerAddress);
+        });
+        it('throws when mixed ERC721 and ERC20 assets', async () => {
+            const makerAssetId = erc721MakerAssetIds[0];
+            const erc721SignedOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: new BigNumber(1),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
+            });
+            const erc20SignedOrder = orderFactory.newSignedOrder();
+            signedOrders = [erc721SignedOrder, erc20SignedOrder];
+            const makerAssetAmount = new BigNumber(signedOrders.length);
+            const fillAmountWei = erc20SignedOrder.takerAssetAmount.plus(erc721SignedOrder.takerAssetAmount);
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                    from: takerAddress,
+                    value: fillAmountWei,
+                }),
+            );
+        });
+        it('throws when mixed ERC721 and ERC20 assets with ERC20 first', async () => {
+            const makerAssetId = erc721MakerAssetIds[0];
+            const erc721SignedOrder = orderFactory.newSignedOrder({
+                makerAssetAmount: new BigNumber(1),
+                makerAssetData: assetProxyUtils.encodeERC721AssetData(erc721Token.address, makerAssetId),
+            });
+            const erc20SignedOrder = orderFactory.newSignedOrder();
+            signedOrders = [erc20SignedOrder, erc721SignedOrder];
+            const makerAssetAmount = new BigNumber(signedOrders.length);
+            const fillAmountWei = erc20SignedOrder.takerAssetAmount.plus(erc721SignedOrder.takerAssetAmount);
+            return expectRevertOrAlwaysFailingTransactionAsync(
+                forwarderWrapper.marketBuyTokensWithEthAsync(signedOrders, feeOrders, makerAssetAmount, {
+                    from: takerAddress,
+                    value: fillAmountWei,
+                }),
+            );
+        });
+    });
+});
+// tslint:disable:max-file-line-count
+// tslint:enable:no-unnecessary-type-assertion
diff --git a/packages/contracts/test/utils/artifacts.ts b/packages/contracts/test/utils/artifacts.ts
index 23e93c085..d3f808218 100644
--- a/packages/contracts/test/utils/artifacts.ts
+++ b/packages/contracts/test/utils/artifacts.ts
@@ -8,6 +8,7 @@ import * as ERC20Proxy from '../../artifacts/ERC20Proxy.json';
 import * as ERC721Proxy from '../../artifacts/ERC721Proxy.json';
 import * as Exchange from '../../artifacts/Exchange.json';
 import * as ExchangeWrapper from '../../artifacts/ExchangeWrapper.json';
+import * as Forwarder from '../../artifacts/Forwarder.json';
 import * as IAssetProxy from '../../artifacts/IAssetProxy.json';
 import * as MixinAuthorizable from '../../artifacts/MixinAuthorizable.json';
 import * as MultiSigWallet from '../../artifacts/MultiSigWallet.json';
@@ -34,6 +35,7 @@ export const artifacts = {
     Exchange: (Exchange as any) as ContractArtifact,
     ExchangeWrapper: (ExchangeWrapper as any) as ContractArtifact,
     EtherToken: (EtherToken as any) as ContractArtifact,
+    Forwarder: (Forwarder as any) as ContractArtifact,
     IAssetProxy: (IAssetProxy as any) as ContractArtifact,
     MixinAuthorizable: (MixinAuthorizable as any) as ContractArtifact,
     MultiSigWallet: (MultiSigWallet as any) as ContractArtifact,
diff --git a/packages/contracts/test/utils/erc20_wrapper.ts b/packages/contracts/test/utils/erc20_wrapper.ts
index 53e9791bc..9351b1e3d 100644
--- a/packages/contracts/test/utils/erc20_wrapper.ts
+++ b/packages/contracts/test/utils/erc20_wrapper.ts
@@ -138,6 +138,14 @@ export class ERC20Wrapper {
         });
         return balancesByOwner;
     }
+    public addDummyTokenContract(dummy: DummyERC20TokenContract): void {
+        if (!_.isUndefined(this._dummyTokenContracts)) {
+            this._dummyTokenContracts.push(dummy);
+        }
+    }
+    public addTokenOwnerAddress(address: string): void {
+        this._tokenOwnerAddresses.push(address);
+    }
     public getTokenOwnerAddresses(): string[] {
         return this._tokenOwnerAddresses;
     }
diff --git a/packages/contracts/test/utils/forwarder_wrapper.ts b/packages/contracts/test/utils/forwarder_wrapper.ts
new file mode 100644
index 000000000..d227420ee
--- /dev/null
+++ b/packages/contracts/test/utils/forwarder_wrapper.ts
@@ -0,0 +1,220 @@
+import { assetProxyUtils } from '@0xproject/order-utils';
+import { AssetProxyId, SignedOrder } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { Provider, TransactionReceiptWithDecodedLogs, TxDataPayable } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { ForwarderContract } from '../../generated_contract_wrappers/forwarder';
+
+import { constants } from './constants';
+import { formatters } from './formatters';
+import { LogDecoder } from './log_decoder';
+import { MarketSellOrders } from './types';
+
+const DEFAULT_FEE_PROPORTION = 0;
+const PERCENTAGE_DENOMINATOR = 10000;
+const ZERO_AMOUNT = new BigNumber(0);
+const INSUFFICENT_ORDERS_FOR_MAKER_AMOUNT = 'Unable to satisfy makerAssetFillAmount with provided orders';
+
+export class ForwarderWrapper {
+    private _web3Wrapper: Web3Wrapper;
+    private _forwarderContract: ForwarderContract;
+    private _logDecoder: LogDecoder;
+    private _zrxAddress: string;
+    private static _createOptimizedSellOrders(signedOrders: SignedOrder[]): MarketSellOrders {
+        const marketSellOrders = formatters.createMarketSellOrders(signedOrders, ZERO_AMOUNT);
+        const assetDataId = assetProxyUtils.decodeAssetDataId(signedOrders[0].makerAssetData);
+        // Contract will fill this in for us as all of the assetData is assumed to be the same
+        for (let i = 0; i < signedOrders.length; i++) {
+            if (i !== 0 && assetDataId === AssetProxyId.ERC20) {
+                // Forwarding contract will fill this in from the first order
+                marketSellOrders.orders[i].makerAssetData = constants.NULL_BYTES;
+            }
+            marketSellOrders.orders[i].takerAssetData = constants.NULL_BYTES;
+        }
+        return marketSellOrders;
+    }
+    private static _createOptimizedZRXSellOrders(signedOrders: SignedOrder[]): MarketSellOrders {
+        const marketSellOrders = formatters.createMarketSellOrders(signedOrders, ZERO_AMOUNT);
+        // Contract will fill this in for us as all of the assetData is assumed to be the same
+        for (let i = 0; i < signedOrders.length; i++) {
+            marketSellOrders.orders[i].makerAssetData = constants.NULL_BYTES;
+            marketSellOrders.orders[i].takerAssetData = constants.NULL_BYTES;
+        }
+        return marketSellOrders;
+    }
+    private static _calculateAdditionalFeeProportionAmount(feeProportion: number, fillAmountWei: BigNumber): BigNumber {
+        if (feeProportion > 0) {
+            // Add to the total ETH transaction to ensure all NFTs can be filled after fees
+            // 150 = 1.5% = 0.015
+            const denominator = new BigNumber(1).minus(new BigNumber(feeProportion).dividedBy(PERCENTAGE_DENOMINATOR));
+            return fillAmountWei.dividedBy(denominator).round(0, BigNumber.ROUND_FLOOR);
+        }
+        return fillAmountWei;
+    }
+    constructor(contractInstance: ForwarderContract, provider: Provider, zrxAddress: string) {
+        this._forwarderContract = contractInstance;
+        this._web3Wrapper = new Web3Wrapper(provider);
+        this._logDecoder = new LogDecoder(this._web3Wrapper, this._forwarderContract.address);
+        // this._web3Wrapper.abiDecoder.addABI(contractInstance.abi);
+        this._zrxAddress = zrxAddress;
+    }
+    public async marketBuyTokensWithEthAsync(
+        orders: SignedOrder[],
+        feeOrders: SignedOrder[],
+        makerTokenBuyAmount: BigNumber,
+        txData: TxDataPayable,
+        opts: { feeProportion?: number; feeRecipient?: string } = {},
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const params = ForwarderWrapper._createOptimizedSellOrders(orders);
+        const feeParams = ForwarderWrapper._createOptimizedZRXSellOrders(feeOrders);
+        const feeProportion = _.isUndefined(opts.feeProportion) ? DEFAULT_FEE_PROPORTION : opts.feeProportion;
+        const feeRecipient = _.isUndefined(opts.feeRecipient) ? constants.NULL_ADDRESS : opts.feeRecipient;
+        const txHash: string = await this._forwarderContract.marketBuyTokensWithEth.sendTransactionAsync(
+            params.orders,
+            params.signatures,
+            feeParams.orders,
+            feeParams.signatures,
+            makerTokenBuyAmount,
+            feeProportion,
+            feeRecipient,
+            txData,
+        );
+        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
+        return tx;
+    }
+    public async marketSellEthForERC20Async(
+        orders: SignedOrder[],
+        feeOrders: SignedOrder[],
+        txData: TxDataPayable,
+        opts: { feeProportion?: number; feeRecipient?: string } = {},
+    ): Promise<TransactionReceiptWithDecodedLogs> {
+        const assetDataId = assetProxyUtils.decodeAssetDataId(orders[0].makerAssetData);
+        if (assetDataId !== AssetProxyId.ERC20) {
+            throw new Error('Asset type not supported by marketSellEthForERC20');
+        }
+        const params = ForwarderWrapper._createOptimizedSellOrders(orders);
+        const feeParams = ForwarderWrapper._createOptimizedZRXSellOrders(feeOrders);
+        const feeProportion = _.isUndefined(opts.feeProportion) ? DEFAULT_FEE_PROPORTION : opts.feeProportion;
+        const feeRecipient = _.isUndefined(opts.feeRecipient) ? constants.NULL_ADDRESS : opts.feeRecipient;
+        const txHash: string = await this._forwarderContract.marketSellEthForERC20.sendTransactionAsync(
+            params.orders,
+            params.signatures,
+            feeParams.orders,
+            feeParams.signatures,
+            feeProportion,
+            feeRecipient,
+            txData,
+        );
+        const tx = await this._logDecoder.getTxWithDecodedLogsAsync(txHash);
+        return tx;
+    }
+    public async calculateMarketBuyFillAmountWeiAsync(
+        orders: SignedOrder[],
+        feeOrders: SignedOrder[],
+        feeProportion: number,
+        makerAssetFillAmount: BigNumber,
+    ): Promise<BigNumber> {
+        const assetProxyId = assetProxyUtils.decodeAssetDataId(orders[0].makerAssetData);
+        switch (assetProxyId) {
+            case AssetProxyId.ERC20: {
+                const fillAmountWei = this._calculateMarketBuyERC20FillAmountAsync(
+                    orders,
+                    feeOrders,
+                    feeProportion,
+                    makerAssetFillAmount,
+                );
+                return fillAmountWei;
+            }
+            case AssetProxyId.ERC721: {
+                const fillAmountWei = await this._calculateMarketBuyERC721FillAmountAsync(
+                    orders,
+                    feeOrders,
+                    feeProportion,
+                );
+                return fillAmountWei;
+            }
+            default:
+                throw new Error(`Invalid Asset Proxy Id: ${assetProxyId}`);
+        }
+    }
+    private async _calculateMarketBuyERC20FillAmountAsync(
+        orders: SignedOrder[],
+        feeOrders: SignedOrder[],
+        feeProportion: number,
+        makerAssetFillAmount: BigNumber,
+    ): Promise<BigNumber> {
+        const makerAssetData = assetProxyUtils.decodeAssetData(orders[0].makerAssetData);
+        const makerAssetToken = makerAssetData.tokenAddress;
+        const params = formatters.createMarketBuyOrders(orders, makerAssetFillAmount);
+
+        let fillAmountWei;
+        if (makerAssetToken === this._zrxAddress) {
+            // If buying ZRX we buy the tokens and fees from the ZRX order in one step
+            const expectedBuyFeeTokensFillResults = await this._forwarderContract.calculateMarketBuyZrxResults.callAsync(
+                params.orders,
+                makerAssetFillAmount,
+            );
+            if (expectedBuyFeeTokensFillResults.makerAssetFilledAmount.lessThan(makerAssetFillAmount)) {
+                throw new Error(INSUFFICENT_ORDERS_FOR_MAKER_AMOUNT);
+            }
+            fillAmountWei = expectedBuyFeeTokensFillResults.takerAssetFilledAmount;
+        } else {
+            const expectedMarketBuyFillResults = await this._forwarderContract.calculateMarketBuyResults.callAsync(
+                params.orders,
+                makerAssetFillAmount,
+            );
+            if (expectedMarketBuyFillResults.makerAssetFilledAmount.lessThan(makerAssetFillAmount)) {
+                throw new Error(INSUFFICENT_ORDERS_FOR_MAKER_AMOUNT);
+            }
+            fillAmountWei = expectedMarketBuyFillResults.takerAssetFilledAmount;
+            const expectedFeeAmount = expectedMarketBuyFillResults.takerFeePaid;
+            if (expectedFeeAmount.greaterThan(ZERO_AMOUNT)) {
+                const expectedFeeFillFillAmountWei = await this._calculateMarketBuyERC20FillAmountAsync(
+                    feeOrders,
+                    [],
+                    DEFAULT_FEE_PROPORTION,
+                    expectedFeeAmount,
+                );
+                fillAmountWei = fillAmountWei.plus(expectedFeeFillFillAmountWei);
+            }
+        }
+        fillAmountWei = ForwarderWrapper._calculateAdditionalFeeProportionAmount(feeProportion, fillAmountWei);
+        return fillAmountWei;
+    }
+    private async _calculateMarketBuyERC721FillAmountAsync(
+        orders: SignedOrder[],
+        feeOrders: SignedOrder[],
+        feeProportion: number,
+    ): Promise<BigNumber> {
+        // Total cost when buying ERC721 is the total cost of all ERC721 orders + any fee abstraction
+        let fillAmountWei = _.reduce(
+            orders,
+            (totalAmount: BigNumber, order: SignedOrder) => {
+                return totalAmount.plus(order.takerAssetAmount);
+            },
+            ZERO_AMOUNT,
+        );
+        const totalFees = _.reduce(
+            orders,
+            (totalAmount: BigNumber, order: SignedOrder) => {
+                return totalAmount.plus(order.takerFee);
+            },
+            ZERO_AMOUNT,
+        );
+        if (totalFees.greaterThan(ZERO_AMOUNT)) {
+            // Calculate the ZRX fee abstraction cost
+            const emptyFeeOrders: SignedOrder[] = [];
+            const expectedFeeAmountWei = await this._calculateMarketBuyERC20FillAmountAsync(
+                feeOrders,
+                emptyFeeOrders,
+                DEFAULT_FEE_PROPORTION,
+                totalFees,
+            );
+            fillAmountWei = fillAmountWei.plus(expectedFeeAmountWei);
+        }
+        fillAmountWei = ForwarderWrapper._calculateAdditionalFeeProportionAmount(feeProportion, fillAmountWei);
+        return fillAmountWei;
+    }
+}
diff --git a/packages/contracts/test/utils/types.ts b/packages/contracts/test/utils/types.ts
index b792bb90a..67313b647 100644
--- a/packages/contracts/test/utils/types.ts
+++ b/packages/contracts/test/utils/types.ts
@@ -102,6 +102,7 @@ export enum ContractName {
     TestWallet = 'TestWallet',
     Authorizable = 'Authorizable',
     Whitelist = 'Whitelist',
+    Forwarder = 'Forwarder',
 }
 
 export interface SignedTransaction {
@@ -227,3 +228,10 @@ export interface FillScenario {
     makerStateScenario: TraderStateScenario;
     takerStateScenario: TraderStateScenario;
 }
+
+export interface FillResults {
+    makerAssetFilledAmount: BigNumber;
+    takerAssetFilledAmount: BigNumber;
+    makerFeePaid: BigNumber;
+    takerFeePaid: BigNumber;
+}