Merge development

13 files changed, 374 insertions, 19 deletions

diff --git a/packages/contract-wrappers/src/artifacts.ts b/packages/contract-wrappers/src/artifacts.ts
index 742d0e1b2..2481b311a 100644
--- a/packages/contract-wrappers/src/artifacts.ts
+++ b/packages/contract-wrappers/src/artifacts.ts
@@ -7,6 +7,7 @@ import * as ERC20Token from './artifacts/ERC20Token.json';
 import * as ERC721Proxy from './artifacts/ERC721Proxy.json';
 import * as ERC721Token from './artifacts/ERC721Token.json';
 import * as Exchange from './artifacts/Exchange.json';
+import * as Forwarder from './artifacts/Forwarder.json';
 import * as EtherToken from './artifacts/WETH9.json';
 import * as ZRXToken from './artifacts/ZRXToken.json';
 
@@ -20,4 +21,5 @@ export const artifacts = {
     EtherToken: (EtherToken as any) as ContractArtifact,
     ERC20Proxy: (ERC20Proxy as any) as ContractArtifact,
     ERC721Proxy: (ERC721Proxy as any) as ContractArtifact,
+    Forwarder: (Forwarder as any) as ContractArtifact,
 };
diff --git a/packages/contract-wrappers/src/contract_wrappers.ts b/packages/contract-wrappers/src/contract_wrappers.ts
index 8010242c5..4277a0746 100644
--- a/packages/contract-wrappers/src/contract_wrappers.ts
+++ b/packages/contract-wrappers/src/contract_wrappers.ts
@@ -11,6 +11,7 @@ import { ERC721ProxyWrapper } from './contract_wrappers/erc721_proxy_wrapper';
 import { ERC721TokenWrapper } from './contract_wrappers/erc721_token_wrapper';
 import { EtherTokenWrapper } from './contract_wrappers/ether_token_wrapper';
 import { ExchangeWrapper } from './contract_wrappers/exchange_wrapper';
+import { ForwarderWrapper } from './contract_wrappers/forwarder_wrapper';
 import { ContractWrappersConfigSchema } from './schemas/contract_wrappers_config_schema';
 import { contractWrappersPrivateNetworkConfigSchema } from './schemas/contract_wrappers_private_network_config_schema';
 import { contractWrappersPublicNetworkConfigSchema } from './schemas/contract_wrappers_public_network_config_schema';
@@ -47,6 +48,11 @@ export class ContractWrappers {
      * erc721Proxy smart contract.
      */
     public erc721Proxy: ERC721ProxyWrapper;
+    /**
+     * An instance of the ForwarderWrapper class containing methods for interacting with any Forwarder smart contract.
+     */
+    public forwarder: ForwarderWrapper;
+
     private _web3Wrapper: Web3Wrapper;
     /**
      * Instantiates a new ContractWrappers instance.
@@ -104,6 +110,12 @@ export class ContractWrappers {
             config.zrxContractAddress,
             blockPollingIntervalMs,
         );
+        this.forwarder = new ForwarderWrapper(
+            this._web3Wrapper,
+            config.networkId,
+            config.forwarderContractAddress,
+            config.zrxContractAddress,
+        );
     }
     /**
      * Sets a new web3 provider for 0x.js. Updating the provider will stop all
diff --git a/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
index 5beb35a27..0febd154f 100644
--- a/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
@@ -882,16 +882,36 @@ export class ExchangeWrapper extends ContractWrapper {
      */
     @decorators.asyncZeroExErrorHandler
     public async getOrderInfoAsync(order: Order | SignedOrder, methodOpts: MethodOpts = {}): Promise<OrderInfo> {
+        assert.doesConformToSchema('order', order, schemas.orderSchema);
         if (!_.isUndefined(methodOpts)) {
             assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
         }
         const exchangeInstance = await this._getExchangeContractAsync();
-
         const txData = {};
         const orderInfo = await exchangeInstance.getOrderInfo.callAsync(order, txData, methodOpts.defaultBlock);
         return orderInfo;
     }
     /**
+     * Get order info for multiple orders
+     * @param orders         Orders
+     * @param methodOpts    Optional arguments this method accepts.
+     * @returns Array of Order infos
+     */
+    @decorators.asyncZeroExErrorHandler
+    public async getOrdersInfoAsync(
+        orders: Array<Order | SignedOrder>,
+        methodOpts: MethodOpts = {},
+    ): Promise<OrderInfo[]> {
+        assert.doesConformToSchema('orders', orders, schemas.ordersSchema);
+        if (!_.isUndefined(methodOpts)) {
+            assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
+        }
+        const exchangeInstance = await this._getExchangeContractAsync();
+        const txData = {};
+        const ordersInfo = await exchangeInstance.getOrdersInfo.callAsync(orders, txData, methodOpts.defaultBlock);
+        return ordersInfo;
+    }
+    /**
      * Cancel a given order.
      * @param   order           An object that conforms to the Order or SignedOrder interface. The order you would like to cancel.
      * @param   orderTransactionOpts Optional arguments this method accepts.
diff --git a/packages/contract-wrappers/src/contract_wrappers/forwarder_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/forwarder_wrapper.ts
new file mode 100644
index 000000000..13ef0fe01
--- /dev/null
+++ b/packages/contract-wrappers/src/contract_wrappers/forwarder_wrapper.ts
@@ -0,0 +1,220 @@
+import { schemas } from '@0xproject/json-schemas';
+import { AssetProxyId, SignedOrder } from '@0xproject/types';
+import { BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { ContractAbi } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { artifacts } from '../artifacts';
+import { orderTxOptsSchema } from '../schemas/order_tx_opts_schema';
+import { txOptsSchema } from '../schemas/tx_opts_schema';
+import { TransactionOpts } from '../types';
+import { assert } from '../utils/assert';
+import { calldataOptimizationUtils } from '../utils/calldata_optimization_utils';
+import { constants } from '../utils/constants';
+
+import { ContractWrapper } from './contract_wrapper';
+import { ForwarderContract } from './generated/forwarder';
+
+/**
+ * This class includes the functionality related to interacting with the Forwarder contract.
+ */
+export class ForwarderWrapper extends ContractWrapper {
+    public abi: ContractAbi = artifacts.Forwarder.compilerOutput.abi;
+    private _forwarderContractIfExists?: ForwarderContract;
+    private _contractAddressIfExists?: string;
+    private _zrxContractAddressIfExists?: string;
+    constructor(
+        web3Wrapper: Web3Wrapper,
+        networkId: number,
+        contractAddressIfExists?: string,
+        zrxContractAddressIfExists?: string,
+    ) {
+        super(web3Wrapper, networkId);
+        this._contractAddressIfExists = contractAddressIfExists;
+        this._zrxContractAddressIfExists = zrxContractAddressIfExists;
+    }
+    /**
+     * Purchases as much of orders' makerAssets as possible by selling up to 95% of transaction's ETH value.
+     * Any ZRX required to pay fees for primary orders will automatically be purchased by this contract.
+     * 5% of ETH value is reserved for paying fees to order feeRecipients (in ZRX) and forwarding contract feeRecipient (in ETH).
+     * Any ETH not spent will be refunded to sender.
+     * @param   signedOrders         An array of objects that conform to the SignedOrder interface. All orders must specify the same makerAsset.
+     *                               All orders must specify WETH as the takerAsset
+     * @param   takerAddress         The user Ethereum address who would like to fill this order. Must be available via the supplied
+     *                               Provider provided at instantiation.
+     * @param   ethAmount            The amount of eth to send with the transaction (in wei).
+     * @param   signedFeeOrders      An array of objects that conform to the SignedOrder interface. All orders must specify ZRX as makerAsset and WETH as takerAsset.
+     *                               Used to purchase ZRX for primary order fees.
+     * @param   feePercentage        The percentage of WETH sold that will payed as fee to forwarding contract feeRecipient.
+     *                               Defaults to 0.
+     * @param   feeRecipientAddress  The address that will receive ETH when signedFeeOrders are filled.
+     * @param   txOpts               Transaction parameters.
+     * @return  Transaction hash.
+     */
+    public async marketSellOrdersWithEthAsync(
+        signedOrders: SignedOrder[],
+        takerAddress: string,
+        ethAmount: BigNumber,
+        signedFeeOrders: SignedOrder[] = [],
+        feePercentage: BigNumber = constants.ZERO_AMOUNT,
+        feeRecipientAddress: string = constants.NULL_ADDRESS,
+        txOpts: TransactionOpts = {},
+    ): Promise<string> {
+        // type assertions
+        assert.doesConformToSchema('signedOrders', signedOrders, schemas.signedOrdersSchema);
+        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
+        assert.isBigNumber('ethAmount', ethAmount);
+        assert.doesConformToSchema('signedFeeOrders', signedFeeOrders, schemas.signedOrdersSchema);
+        assert.isBigNumber('feePercentage', feePercentage);
+        assert.isETHAddressHex('feeRecipientAddress', feeRecipientAddress);
+        assert.doesConformToSchema('txOpts', txOpts, txOptsSchema);
+        // other assertions
+        assert.ordersCanBeUsedForForwarderContract(signedOrders, this.getEtherTokenAddress());
+        assert.feeOrdersCanBeUsedForForwarderContract(
+            signedFeeOrders,
+            this.getZRXTokenAddress(),
+            this.getEtherTokenAddress(),
+        );
+        // lowercase input addresses
+        const normalizedTakerAddress = takerAddress.toLowerCase();
+        const normalizedFeeRecipientAddress = feeRecipientAddress.toLowerCase();
+        // optimize orders
+        const optimizedMarketOrders = calldataOptimizationUtils.optimizeForwarderOrders(signedOrders);
+        const optimizedFeeOrders = calldataOptimizationUtils.optimizeForwarderFeeOrders(signedFeeOrders);
+        // send transaction
+        const forwarderContractInstance = await this._getForwarderContractAsync();
+        const txHash = await forwarderContractInstance.marketSellOrdersWithEth.sendTransactionAsync(
+            optimizedMarketOrders,
+            _.map(optimizedMarketOrders, order => order.signature),
+            optimizedFeeOrders,
+            _.map(optimizedFeeOrders, order => order.signature),
+            feePercentage,
+            feeRecipientAddress,
+            {
+                value: ethAmount,
+                from: normalizedTakerAddress,
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+            },
+        );
+        return txHash;
+    }
+    /**
+     * Attempt to purchase makerAssetFillAmount of makerAsset by selling ethAmount provided with transaction.
+     * Any ZRX required to pay fees for primary orders will automatically be purchased by the contract.
+     * Any ETH not spent will be refunded to sender.
+     * @param   signedOrders         An array of objects that conform to the SignedOrder interface. All orders must specify the same makerAsset.
+     *                               All orders must specify WETH as the takerAsset
+     * @param   makerAssetFillAmount The amount of the order (in taker asset baseUnits) that you wish to fill.
+     * @param   takerAddress         The user Ethereum address who would like to fill this order. Must be available via the supplied
+     *                               Provider provided at instantiation.
+     * @param   ethAmount            The amount of eth to send with the transaction (in wei).
+     * @param   signedFeeOrders      An array of objects that conform to the SignedOrder interface. All orders must specify ZRX as makerAsset and WETH as takerAsset.
+     *                               Used to purchase ZRX for primary order fees.
+     * @param   feePercentage        The percentage of WETH sold that will payed as fee to forwarding contract feeRecipient.
+     *                               Defaults to 0.
+     * @param   feeRecipientAddress  The address that will receive ETH when signedFeeOrders are filled.
+     * @param   txOpts               Transaction parameters.
+     * @return  Transaction hash.
+     */
+    public async marketBuyOrdersWithEthAsync(
+        signedOrders: SignedOrder[],
+        makerAssetFillAmount: BigNumber,
+        takerAddress: string,
+        ethAmount: BigNumber,
+        signedFeeOrders: SignedOrder[] = [],
+        feePercentage: BigNumber = constants.ZERO_AMOUNT,
+        feeRecipientAddress: string = constants.NULL_ADDRESS,
+        txOpts: TransactionOpts = {},
+    ): Promise<string> {
+        // type assertions
+        assert.doesConformToSchema('signedOrders', signedOrders, schemas.signedOrdersSchema);
+        assert.isBigNumber('makerAssetFillAmount', makerAssetFillAmount);
+        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
+        assert.isBigNumber('ethAmount', ethAmount);
+        assert.doesConformToSchema('signedFeeOrders', signedFeeOrders, schemas.signedOrdersSchema);
+        assert.isBigNumber('feePercentage', feePercentage);
+        assert.isETHAddressHex('feeRecipientAddress', feeRecipientAddress);
+        assert.doesConformToSchema('txOpts', txOpts, txOptsSchema);
+        // other assertions
+        assert.ordersCanBeUsedForForwarderContract(signedOrders, this.getEtherTokenAddress());
+        assert.feeOrdersCanBeUsedForForwarderContract(
+            signedFeeOrders,
+            this.getZRXTokenAddress(),
+            this.getEtherTokenAddress(),
+        );
+        // lowercase input addresses
+        const normalizedTakerAddress = takerAddress.toLowerCase();
+        const normalizedFeeRecipientAddress = feeRecipientAddress.toLowerCase();
+        // optimize orders
+        const optimizedMarketOrders = calldataOptimizationUtils.optimizeForwarderOrders(signedOrders);
+        const optimizedFeeOrders = calldataOptimizationUtils.optimizeForwarderFeeOrders(signedFeeOrders);
+        // send transaction
+        const forwarderContractInstance = await this._getForwarderContractAsync();
+        const txHash = await forwarderContractInstance.marketBuyOrdersWithEth.sendTransactionAsync(
+            optimizedMarketOrders,
+            makerAssetFillAmount,
+            _.map(optimizedMarketOrders, order => order.signature),
+            optimizedFeeOrders,
+            _.map(optimizedFeeOrders, order => order.signature),
+            feePercentage,
+            feeRecipientAddress,
+            {
+                value: ethAmount,
+                from: normalizedTakerAddress,
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+            },
+        );
+        return txHash;
+    }
+    /**
+     * Retrieves the Ethereum address of the Forwarder contract deployed on the network
+     * that the user-passed web3 provider is connected to.
+     * @returns The Ethereum address of the Forwarder contract being used.
+     */
+    public getContractAddress(): string {
+        const contractAddress = this._getContractAddress(artifacts.Forwarder, this._contractAddressIfExists);
+        return contractAddress;
+    }
+    /**
+     * Returns the ZRX token address used by the forwarder contract.
+     * @return Address of ZRX token
+     */
+    public getZRXTokenAddress(): string {
+        const contractAddress = this._getContractAddress(artifacts.ZRXToken, this._zrxContractAddressIfExists);
+        return contractAddress;
+    }
+    /**
+     * Returns the Ether token address used by the forwarder contract.
+     * @return Address of Ether token
+     */
+    public getEtherTokenAddress(): string {
+        const contractAddress = this._getContractAddress(artifacts.EtherToken);
+        return contractAddress;
+    }
+    // HACK: We don't want this method to be visible to the other units within that package but not to the end user.
+    // TS doesn't give that possibility and therefore we make it private and access it over an any cast. Because of that tslint sees it as unused.
+    // tslint:disable-next-line:no-unused-variable
+    private _invalidateContractInstance(): void {
+        delete this._forwarderContractIfExists;
+    }
+    private async _getForwarderContractAsync(): Promise<ForwarderContract> {
+        if (!_.isUndefined(this._forwarderContractIfExists)) {
+            return this._forwarderContractIfExists;
+        }
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
+            artifacts.Forwarder,
+            this._contractAddressIfExists,
+        );
+        const contractInstance = new ForwarderContract(
+            abi,
+            address,
+            this._web3Wrapper.getProvider(),
+            this._web3Wrapper.getContractDefaults(),
+        );
+        this._forwarderContractIfExists = contractInstance;
+        return this._forwarderContractIfExists;
+    }
+}
diff --git a/packages/contract-wrappers/src/index.ts b/packages/contract-wrappers/src/index.ts
index da9453640..41d60f05a 100644
--- a/packages/contract-wrappers/src/index.ts
+++ b/packages/contract-wrappers/src/index.ts
@@ -5,6 +5,7 @@ export { EtherTokenWrapper } from './contract_wrappers/ether_token_wrapper';
 export { ExchangeWrapper } from './contract_wrappers/exchange_wrapper';
 export { ERC20ProxyWrapper } from './contract_wrappers/erc20_proxy_wrapper';
 export { ERC721ProxyWrapper } from './contract_wrappers/erc721_proxy_wrapper';
+export { ForwarderWrapper } from './contract_wrappers/forwarder_wrapper';
 
 export {
     ContractWrappersError,
diff --git a/packages/contract-wrappers/src/schemas/contract_wrappers_private_network_config_schema.ts b/packages/contract-wrappers/src/schemas/contract_wrappers_private_network_config_schema.ts
index 7e2eca61c..904690ae7 100644
--- a/packages/contract-wrappers/src/schemas/contract_wrappers_private_network_config_schema.ts
+++ b/packages/contract-wrappers/src/schemas/contract_wrappers_private_network_config_schema.ts
@@ -5,11 +5,11 @@ export const contractWrappersPrivateNetworkConfigSchema = {
             type: 'number',
             minimum: 1,
         },
-        gasPrice: { $ref: '/Number' },
-        zrxContractAddress: { $ref: '/Address' },
-        exchangeContractAddress: { $ref: '/Address' },
-        erc20ProxyContractAddress: { $ref: '/Address' },
-        erc721ProxyContractAddress: { $ref: '/Address' },
+        gasPrice: { $ref: '/numberSchema' },
+        zrxContractAddress: { $ref: '/addressSchema' },
+        exchangeContractAddress: { $ref: '/addressSchema' },
+        erc20ProxyContractAddress: { $ref: '/addressSchema' },
+        erc721ProxyContractAddress: { $ref: '/addressSchema' },
         blockPollingIntervalMs: { type: 'number' },
         orderWatcherConfig: {
             type: 'object',
diff --git a/packages/contract-wrappers/src/schemas/contract_wrappers_public_network_config_schema.ts b/packages/contract-wrappers/src/schemas/contract_wrappers_public_network_config_schema.ts
index b80e04310..5cd008ae0 100644
--- a/packages/contract-wrappers/src/schemas/contract_wrappers_public_network_config_schema.ts
+++ b/packages/contract-wrappers/src/schemas/contract_wrappers_public_network_config_schema.ts
@@ -19,11 +19,11 @@ export const contractWrappersPublicNetworkConfigSchema = {
                 networkNameToId.ganache,
             ],
         },
-        gasPrice: { $ref: '/Number' },
-        zrxContractAddress: { $ref: '/Address' },
-        exchangeContractAddress: { $ref: '/Address' },
-        erc20ProxyContractAddress: { $ref: '/Address' },
-        erc721ProxyContractAddress: { $ref: '/Address' },
+        gasPrice: { $ref: '/numberSchema' },
+        zrxContractAddress: { $ref: '/addressSchema' },
+        exchangeContractAddress: { $ref: '/addressSchema' },
+        erc20ProxyContractAddress: { $ref: '/addressSchema' },
+        erc721ProxyContractAddress: { $ref: '/addressSchema' },
         blockPollingIntervalMs: { type: 'number' },
         orderWatcherConfig: {
             type: 'object',
diff --git a/packages/contract-wrappers/src/schemas/method_opts_schema.ts b/packages/contract-wrappers/src/schemas/method_opts_schema.ts
index ef434070a..83003f818 100644
--- a/packages/contract-wrappers/src/schemas/method_opts_schema.ts
+++ b/packages/contract-wrappers/src/schemas/method_opts_schema.ts
@@ -1,7 +1,7 @@
 export const methodOptsSchema = {
     id: '/MethodOpts',
     properties: {
-        defaultBlock: { $ref: '/BlockParam' },
+        defaultBlock: { $ref: '/blockParamSchema' },
     },
     type: 'object',
 };
diff --git a/packages/contract-wrappers/src/schemas/tx_opts_schema.ts b/packages/contract-wrappers/src/schemas/tx_opts_schema.ts
index bddc33b6c..83c819be2 100644
--- a/packages/contract-wrappers/src/schemas/tx_opts_schema.ts
+++ b/packages/contract-wrappers/src/schemas/tx_opts_schema.ts
@@ -1,7 +1,7 @@
 export const txOptsSchema = {
     id: '/TxOpts',
     properties: {
-        gasPrice: { $ref: '/Number' },
+        gasPrice: { $ref: '/numberSchema' },
         gasLimit: { type: 'number' },
     },
     type: 'object',
diff --git a/packages/contract-wrappers/src/types.ts b/packages/contract-wrappers/src/types.ts
index f9d7a6b9f..2b3cdc591 100644
--- a/packages/contract-wrappers/src/types.ts
+++ b/packages/contract-wrappers/src/types.ts
@@ -109,6 +109,7 @@ export type SyncMethod = (...args: any[]) => any;
  * zrxContractAddress: The address of the ZRX contract to use
  * erc20ProxyContractAddress: The address of the erc20 token transfer proxy contract to use
  * erc721ProxyContractAddress: The address of the erc721 token transfer proxy contract to use
+ * forwarderContractAddress: The address of the forwarder contract to use
  * orderWatcherConfig: All the configs related to the orderWatcher
  * blockPollingIntervalMs: The interval to use for block polling in event watching methods (defaults to 1000)
  */
@@ -119,6 +120,7 @@ export interface ContractWrappersConfig {
     zrxContractAddress?: string;
     erc20ProxyContractAddress?: string;
     erc721ProxyContractAddress?: string;
+    forwarderContractAddress?: string;
     blockPollingIntervalMs?: number;
 }
 
@@ -172,13 +174,13 @@ export enum TransferType {
 export type OnOrderStateChangeCallback = (err: Error | null, orderState?: OrderState) => void;
 
 export interface OrderInfo {
-    orderStatus: number;
+    orderStatus: OrderStatus;
     orderHash: string;
     orderTakerAssetFilledAmount: BigNumber;
 }
 
 export enum OrderStatus {
-    INVALID,
+    INVALID = 0,
     INVALID_MAKER_ASSET_AMOUNT,
     INVALID_TAKER_ASSET_AMOUNT,
     FILLABLE,
diff --git a/packages/contract-wrappers/src/utils/assert.ts b/packages/contract-wrappers/src/utils/assert.ts
index 652e5bec3..bed833b8f 100644
--- a/packages/contract-wrappers/src/utils/assert.ts
+++ b/packages/contract-wrappers/src/utils/assert.ts
@@ -1,11 +1,14 @@
 import { assert as sharedAssert } from '@0xproject/assert';
 // HACK: We need those two unused imports because they're actually used by sharedAssert which gets injected here
 import { Schema } from '@0xproject/json-schemas'; // tslint:disable-line:no-unused-variable
-import { signatureUtils } from '@0xproject/order-utils';
-import { ECSignature } from '@0xproject/types'; // tslint:disable-line:no-unused-variable
+import { signatureUtils, assetDataUtils } from '@0xproject/order-utils';
+import { Order } from '@0xproject/types'; // tslint:disable-line:no-unused-variable
 import { BigNumber } from '@0xproject/utils'; // tslint:disable-line:no-unused-variable
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
 import { Provider } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { constants } from './constants';
 
 export const assert = {
     ...sharedAssert,
@@ -16,12 +19,12 @@ export const assert = {
         signerAddress: string,
     ): Promise<void> {
         const isValid = await signatureUtils.isValidSignatureAsync(provider, orderHash, signature, signerAddress);
-        this.assert(isValid, `Expected order with hash '${orderHash}' to have a valid signature`);
+        sharedAssert.assert(isValid, `Expected order with hash '${orderHash}' to have a valid signature`);
     },
     isValidSubscriptionToken(variableName: string, subscriptionToken: string): void {
         const uuidRegex = new RegExp('^[a-fA-F0-9]{8}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{4}-[a-fA-F0-9]{12}$');
         const isValid = uuidRegex.test(subscriptionToken);
-        this.assert(isValid, `Expected ${variableName} to be a valid subscription token`);
+        sharedAssert.assert(isValid, `Expected ${variableName} to be a valid subscription token`);
     },
     async isSenderAddressAsync(
         variableName: string,
@@ -35,4 +38,53 @@ export const assert = {
             `Specified ${variableName} ${senderAddressHex} isn't available through the supplied web3 provider`,
         );
     },
+    ordersCanBeUsedForForwarderContract(orders: Order[], etherTokenAddress: string): void {
+        sharedAssert.assert(!_.isEmpty(orders), 'Expected at least 1 signed order. Found no orders');
+        assert.ordersHaveAtMostOneUniqueValueForProperty(orders, 'makerAssetData');
+        assert.allTakerAssetDatasAreErc20Token(orders, etherTokenAddress);
+        assert.allTakerAddressesAreNull(orders);
+    },
+    feeOrdersCanBeUsedForForwarderContract(orders: Order[], zrxTokenAddress: string, etherTokenAddress: string): void {
+        if (!_.isEmpty(orders)) {
+            assert.allMakerAssetDatasAreErc20Token(orders, zrxTokenAddress);
+            assert.allTakerAssetDatasAreErc20Token(orders, etherTokenAddress);
+        }
+    },
+    allTakerAddressesAreNull(orders: Order[]): void {
+        assert.ordersHaveAtMostOneUniqueValueForProperty(orders, 'takerAddress', constants.NULL_ADDRESS);
+    },
+    allMakerAssetDatasAreErc20Token(orders: Order[], tokenAddress: string): void {
+        assert.ordersHaveAtMostOneUniqueValueForProperty(
+            orders,
+            'makerAssetData',
+            assetDataUtils.encodeERC20AssetData(tokenAddress),
+        );
+    },
+    allTakerAssetDatasAreErc20Token(orders: Order[], tokenAddress: string): void {
+        assert.ordersHaveAtMostOneUniqueValueForProperty(
+            orders,
+            'takerAssetData',
+            assetDataUtils.encodeERC20AssetData(tokenAddress),
+        );
+    },
+    /*
+     * Asserts that all the orders have the same value for the provided propertyName
+     * If the value parameter is provided, this asserts that all orders have the prope
+    */
+    ordersHaveAtMostOneUniqueValueForProperty(orders: Order[], propertyName: string, value?: any): void {
+        const allValues = _.map(orders, order => _.get(order, propertyName));
+        sharedAssert.hasAtMostOneUniqueValue(
+            allValues,
+            `Expected all orders to have the same ${propertyName} field. Found the following ${propertyName} values: ${JSON.stringify(
+                allValues,
+            )}`,
+        );
+        if (!_.isUndefined(value)) {
+            const firstValue = _.head(allValues);
+            sharedAssert.assert(
+                firstValue === value,
+                `Expected all orders to have a ${propertyName} field with value: ${value}. Found: ${firstValue}`,
+            );
+        }
+    },
 };
diff --git a/packages/contract-wrappers/src/utils/calldata_optimization_utils.ts b/packages/contract-wrappers/src/utils/calldata_optimization_utils.ts
new file mode 100644
index 000000000..3172cf531
--- /dev/null
+++ b/packages/contract-wrappers/src/utils/calldata_optimization_utils.ts
@@ -0,0 +1,44 @@
+import { SignedOrder } from '@0xproject/types';
+import * as _ from 'lodash';
+
+import { constants } from './constants';
+
+export const calldataOptimizationUtils = {
+    /**
+     * Takes an array of orders and outputs an array of equivalent orders where all takerAssetData are '0x' and
+     * all makerAssetData are '0x' except for that of the first order, which retains its original value
+     * @param   orders         An array of SignedOrder objects
+     * @returns optimized orders
+     */
+    optimizeForwarderOrders(orders: SignedOrder[]): SignedOrder[] {
+        const optimizedOrders = _.map(orders, (order, index) =>
+            transformOrder(order, {
+                makerAssetData: index === 0 ? order.makerAssetData : constants.NULL_BYTES,
+                takerAssetData: constants.NULL_BYTES,
+            }),
+        );
+        return optimizedOrders;
+    },
+    /**
+     * Takes an array of orders and outputs an array of equivalent orders where all takerAssetData are '0x' and
+     * all makerAssetData are '0x'
+     * @param   orders         An array of SignedOrder objects
+     * @returns optimized orders
+     */
+    optimizeForwarderFeeOrders(orders: SignedOrder[]): SignedOrder[] {
+        const optimizedOrders = _.map(orders, (order, index) =>
+            transformOrder(order, {
+                makerAssetData: constants.NULL_BYTES,
+                takerAssetData: constants.NULL_BYTES,
+            }),
+        );
+        return optimizedOrders;
+    },
+};
+
+const transformOrder = (order: SignedOrder, partialOrder: Partial<SignedOrder>) => {
+    return {
+        ...order,
+        ...partialOrder,
+    };
+};
diff --git a/packages/contract-wrappers/src/utils/constants.ts b/packages/contract-wrappers/src/utils/constants.ts
index 039475b7f..2df11538c 100644
--- a/packages/contract-wrappers/src/utils/constants.ts
+++ b/packages/contract-wrappers/src/utils/constants.ts
@@ -2,6 +2,7 @@ import { BigNumber } from '@0xproject/utils';
 
 export const constants = {
     NULL_ADDRESS: '0x0000000000000000000000000000000000000000',
+    NULL_BYTES: '0x',
     TESTRPC_NETWORK_ID: 50,
     INVALID_JUMP_PATTERN: 'invalid JUMP at',
     REVERT: 'revert',
@@ -10,4 +11,5 @@ export const constants = {
     // tslint:disable-next-line:custom-no-magic-numbers
     UNLIMITED_ALLOWANCE_IN_BASE_UNITS: new BigNumber(2).pow(256).minus(1),
     DEFAULT_BLOCK_POLLING_INTERVAL: 1000,
+    ZERO_AMOUNT: new BigNumber(0),
 };