Merge pull request #782 from 0xProject/feature/contract-wrappers-v2

@0xproject/contract-wrappers V2 refactor. Part 1

8 files changed, 703 insertions, 1266 deletions

diff --git a/packages/contract-wrappers/src/contract_wrappers/contract_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/contract_wrapper.ts
index 04f69bc3d..a88745485 100644
--- a/packages/contract-wrappers/src/contract_wrappers/contract_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/contract_wrapper.ts
@@ -1,14 +1,7 @@
-import {
-    Artifact,
-    BlockParamLiteral,
-    ContractAbi,
-    FilterObject,
-    LogEntry,
-    LogWithDecodedArgs,
-    RawLog,
-} from '@0xproject/types';
-import { intervalUtils } from '@0xproject/utils';
+import { ContractArtifact } from '@0xproject/sol-compiler';
+import { AbiDecoder, intervalUtils } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { BlockParamLiteral, ContractAbi, FilterObject, LogEntry, LogWithDecodedArgs, RawLog } from 'ethereum-types';
 import { Block, BlockAndLogStreamer } from 'ethereumjs-blockstream';
 import * as _ from 'lodash';
 
@@ -29,9 +22,10 @@ const CONTRACT_NAME_TO_NOT_FOUND_ERROR: {
 } = {
     ZRX: ContractWrappersError.ZRXContractDoesNotExist,
     EtherToken: ContractWrappersError.EtherTokenContractDoesNotExist,
-    Token: ContractWrappersError.TokenContractDoesNotExist,
-    TokenRegistry: ContractWrappersError.TokenRegistryContractDoesNotExist,
-    TokenTransferProxy: ContractWrappersError.TokenTransferProxyContractDoesNotExist,
+    ERC20Token: ContractWrappersError.ERC20TokenContractDoesNotExist,
+    ERC20Proxy: ContractWrappersError.ERC20ProxyContractDoesNotExist,
+    ERC721Token: ContractWrappersError.ERC721TokenContractDoesNotExist,
+    ERC721Proxy: ContractWrappersError.ERC721ProxyContractDoesNotExist,
     Exchange: ContractWrappersError.ExchangeContractDoesNotExist,
 };
 
@@ -107,14 +101,12 @@ export abstract class ContractWrapper {
     protected _tryToDecodeLogOrNoop<ArgsType extends ContractEventArgs>(
         log: LogEntry,
     ): LogWithDecodedArgs<ArgsType> | RawLog {
-        if (_.isUndefined(this._web3Wrapper.abiDecoder)) {
-            throw new Error(InternalContractWrappersError.NoAbiDecoder);
-        }
-        const logWithDecodedArgs = this._web3Wrapper.abiDecoder.tryToDecodeLogOrNoop(log);
+        const abiDecoder = new AbiDecoder([this.abi]);
+        const logWithDecodedArgs = abiDecoder.tryToDecodeLogOrNoop(log);
         return logWithDecodedArgs;
     }
     protected async _getContractAbiAndAddressFromArtifactsAsync(
-        artifact: Artifact,
+        artifact: ContractArtifact,
         addressIfExists?: string,
     ): Promise<[ContractAbi, string]> {
         let contractAddress: string;
@@ -128,12 +120,12 @@ export abstract class ContractWrapper {
         }
         const doesContractExist = await this._web3Wrapper.doesContractExistAtAddressAsync(contractAddress);
         if (!doesContractExist) {
-            throw new Error(CONTRACT_NAME_TO_NOT_FOUND_ERROR[artifact.contract_name]);
+            throw new Error(CONTRACT_NAME_TO_NOT_FOUND_ERROR[artifact.contractName]);
         }
-        const abiAndAddress: [ContractAbi, string] = [artifact.abi, contractAddress];
+        const abiAndAddress: [ContractAbi, string] = [artifact.compilerOutput.abi, contractAddress];
         return abiAndAddress;
     }
-    protected _getContractAddress(artifact: Artifact, addressIfExists?: string): string {
+    protected _getContractAddress(artifact: ContractArtifact, addressIfExists?: string): string {
         if (_.isUndefined(addressIfExists)) {
             const contractAddress = artifact.networks[this._networkId].address;
             if (_.isUndefined(contractAddress)) {
diff --git a/packages/contract-wrappers/src/contract_wrappers/token_transfer_proxy_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc20_proxy_wrapper.ts
index 5194931d7..839248754 100644
--- a/packages/contract-wrappers/src/contract_wrappers/token_transfer_proxy_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/erc20_proxy_wrapper.ts
@@ -1,75 +1,75 @@
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import { ContractAbi } from '@0xproject/types';
+import { ContractAbi } from 'ethereum-types';
 import * as _ from 'lodash';
 
 import { artifacts } from '../artifacts';
 import { assert } from '../utils/assert';
 
 import { ContractWrapper } from './contract_wrapper';
-import { TokenTransferProxyContract } from './generated/token_transfer_proxy';
+import { ERC20ProxyContract } from './generated/erc20_proxy';
 
 /**
- * This class includes the functionality related to interacting with the TokenTransferProxy contract.
+ * This class includes the functionality related to interacting with the ERC20Proxy contract.
  */
-export class TokenTransferProxyWrapper extends ContractWrapper {
-    public abi: ContractAbi = artifacts.TokenTransferProxy.abi;
-    private _tokenTransferProxyContractIfExists?: TokenTransferProxyContract;
+export class ERC20ProxyWrapper extends ContractWrapper {
+    public abi: ContractAbi = artifacts.ERC20Proxy.compilerOutput.abi;
+    private _erc20ProxyContractIfExists?: ERC20ProxyContract;
     private _contractAddressIfExists?: string;
     constructor(web3Wrapper: Web3Wrapper, networkId: number, contractAddressIfExists?: string) {
         super(web3Wrapper, networkId);
         this._contractAddressIfExists = contractAddressIfExists;
     }
     /**
-     * Check if the Exchange contract address is authorized by the TokenTransferProxy contract.
+     * Check if the Exchange contract address is authorized by the ERC20Proxy contract.
      * @param   exchangeContractAddress     The hex encoded address of the Exchange contract to call.
      * @return  Whether the exchangeContractAddress is authorized.
      */
     public async isAuthorizedAsync(exchangeContractAddress: string): Promise<boolean> {
         assert.isETHAddressHex('exchangeContractAddress', exchangeContractAddress);
         const normalizedExchangeContractAddress = exchangeContractAddress.toLowerCase();
-        const tokenTransferProxyContractInstance = await this._getTokenTransferProxyContractAsync();
-        const isAuthorized = await tokenTransferProxyContractInstance.authorized.callAsync(
-            normalizedExchangeContractAddress,
-        );
+        const ERC20ProxyContractInstance = await this._getERC20ProxyContractAsync();
+        const isAuthorized = await ERC20ProxyContractInstance.authorized.callAsync(normalizedExchangeContractAddress);
         return isAuthorized;
     }
     /**
-     * Get the list of all Exchange contract addresses authorized by the TokenTransferProxy contract.
+     * Get the list of all Exchange contract addresses authorized by the ERC20Proxy contract.
      * @return  The list of authorized addresses.
      */
     public async getAuthorizedAddressesAsync(): Promise<string[]> {
-        const tokenTransferProxyContractInstance = await this._getTokenTransferProxyContractAsync();
-        const authorizedAddresses = await tokenTransferProxyContractInstance.getAuthorizedAddresses.callAsync();
+        const ERC20ProxyContractInstance = await this._getERC20ProxyContractAsync();
+        const authorizedAddresses = await ERC20ProxyContractInstance.getAuthorizedAddresses.callAsync();
         return authorizedAddresses;
     }
     /**
-     * Retrieves the Ethereum address of the TokenTransferProxy contract deployed on the network
+     * Retrieves the Ethereum address of the ERC20Proxy contract deployed on the network
      * that the user-passed web3 provider is connected to.
-     * @returns The Ethereum address of the TokenTransferProxy contract being used.
+     * @returns The Ethereum address of the ERC20Proxy contract being used.
      */
     public getContractAddress(): string {
-        const contractAddress = this._getContractAddress(artifacts.TokenTransferProxy, this._contractAddressIfExists);
+        const contractAddress = this._getContractAddress(artifacts.ERC20Proxy, this._contractAddressIfExists);
         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._tokenTransferProxyContractIfExists;
+        delete this._erc20ProxyContractIfExists;
     }
-    private async _getTokenTransferProxyContractAsync(): Promise<TokenTransferProxyContract> {
-        if (!_.isUndefined(this._tokenTransferProxyContractIfExists)) {
-            return this._tokenTransferProxyContractIfExists;
+    private async _getERC20ProxyContractAsync(): Promise<ERC20ProxyContract> {
+        if (!_.isUndefined(this._erc20ProxyContractIfExists)) {
+            return this._erc20ProxyContractIfExists;
         }
         const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.TokenTransferProxy,
+            artifacts.ERC20Proxy,
             this._contractAddressIfExists,
         );
-        const contractInstance = new TokenTransferProxyContract(
+        const contractInstance = new ERC20ProxyContract(
             abi,
             address,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
-        this._tokenTransferProxyContractIfExists = contractInstance;
-        return this._tokenTransferProxyContractIfExists;
+        this._erc20ProxyContractIfExists = contractInstance;
+        return this._erc20ProxyContractIfExists;
     }
 }
diff --git a/packages/contract-wrappers/src/contract_wrappers/token_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts
index d9364715f..f393e4ed1 100644
--- a/packages/contract-wrappers/src/contract_wrappers/token_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts
@@ -1,10 +1,12 @@
 import { schemas } from '@0xproject/json-schemas';
-import { ContractAbi, LogWithDecodedArgs } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { ContractAbi, LogWithDecodedArgs } from 'ethereum-types';
 import * as _ from 'lodash';
 
 import { artifacts } from '../artifacts';
+import { methodOptsSchema } from '../schemas/method_opts_schema';
+import { txOptsSchema } from '../schemas/tx_opts_schema';
 import {
     BlockRange,
     ContractWrappersError,
@@ -17,23 +19,25 @@ import { assert } from '../utils/assert';
 import { constants } from '../utils/constants';
 
 import { ContractWrapper } from './contract_wrapper';
-import { TokenContract, TokenContractEventArgs, TokenEvents } from './generated/token';
-import { TokenTransferProxyWrapper } from './token_transfer_proxy_wrapper';
+import { ERC20ProxyWrapper } from './erc20_proxy_wrapper';
+import { ERC20TokenContract, ERC20TokenEventArgs, ERC20TokenEvents } from './generated/erc20_token';
+
+const removeUndefinedProperties = _.pickBy;
 
 /**
  * This class includes all the functionality related to interacting with ERC20 token contracts.
  * All ERC20 method calls are supported, along with some convenience methods for getting/setting allowances
- * to the 0x Proxy smart contract.
+ * to the 0x ERC20 Proxy smart contract.
  */
-export class TokenWrapper extends ContractWrapper {
-    public abi: ContractAbi = artifacts.Token.abi;
+export class ERC20TokenWrapper extends ContractWrapper {
+    public abi: ContractAbi = artifacts.ERC20Token.compilerOutput.abi;
     public UNLIMITED_ALLOWANCE_IN_BASE_UNITS = constants.UNLIMITED_ALLOWANCE_IN_BASE_UNITS;
-    private _tokenContractsByAddress: { [address: string]: TokenContract };
-    private _tokenTransferProxyWrapper: TokenTransferProxyWrapper;
-    constructor(web3Wrapper: Web3Wrapper, networkId: number, tokenTransferProxyWrapper: TokenTransferProxyWrapper) {
+    private _tokenContractsByAddress: { [address: string]: ERC20TokenContract };
+    private _erc20ProxyWrapper: ERC20ProxyWrapper;
+    constructor(web3Wrapper: Web3Wrapper, networkId: number, erc20ProxyWrapper: ERC20ProxyWrapper) {
         super(web3Wrapper, networkId);
         this._tokenContractsByAddress = {};
-        this._tokenTransferProxyWrapper = tokenTransferProxyWrapper;
+        this._erc20ProxyWrapper = erc20ProxyWrapper;
     }
     /**
      * Retrieves an owner's ERC20 token balance.
@@ -49,6 +53,9 @@ export class TokenWrapper extends ContractWrapper {
     ): Promise<BigNumber> {
         assert.isETHAddressHex('ownerAddress', ownerAddress);
         assert.isETHAddressHex('tokenAddress', tokenAddress);
+        if (!_.isUndefined(methodOpts)) {
+            assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
+        }
         const normalizedTokenAddress = tokenAddress.toLowerCase();
         const normalizedOwnerAddress = ownerAddress.toLowerCase();
 
@@ -81,17 +88,24 @@ export class TokenWrapper extends ContractWrapper {
         assert.isETHAddressHex('spenderAddress', spenderAddress);
         assert.isETHAddressHex('tokenAddress', tokenAddress);
         await assert.isSenderAddressAsync('ownerAddress', ownerAddress, this._web3Wrapper);
+        if (!_.isUndefined(txOpts)) {
+            assert.doesConformToSchema('txOpts', txOpts, txOptsSchema);
+        }
         const normalizedTokenAddress = tokenAddress.toLowerCase();
         const normalizedSpenderAddress = spenderAddress.toLowerCase();
         const normalizedOwnerAddress = ownerAddress.toLowerCase();
         assert.isValidBaseUnitAmount('amountInBaseUnits', amountInBaseUnits);
 
         const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
-        const txHash = await tokenContract.approve.sendTransactionAsync(normalizedSpenderAddress, amountInBaseUnits, {
-            from: normalizedOwnerAddress,
-            gas: txOpts.gasLimit,
-            gasPrice: txOpts.gasPrice,
-        });
+        const txHash = await tokenContract.approve.sendTransactionAsync(
+            normalizedSpenderAddress,
+            amountInBaseUnits,
+            removeUndefinedProperties({
+                from: normalizedOwnerAddress,
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+            }),
+        );
         return txHash;
     }
     /**
@@ -112,16 +126,10 @@ export class TokenWrapper extends ContractWrapper {
         spenderAddress: string,
         txOpts: TransactionOpts = {},
     ): Promise<string> {
-        assert.isETHAddressHex('ownerAddress', ownerAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        assert.isETHAddressHex('spenderAddress', spenderAddress);
-        const normalizedTokenAddress = tokenAddress.toLowerCase();
-        const normalizedOwnerAddress = ownerAddress.toLowerCase();
-        const normalizedSpenderAddress = spenderAddress.toLowerCase();
         const txHash = await this.setAllowanceAsync(
-            normalizedTokenAddress,
-            normalizedOwnerAddress,
-            normalizedSpenderAddress,
+            tokenAddress,
+            ownerAddress,
+            spenderAddress,
             this.UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
             txOpts,
         );
@@ -144,6 +152,9 @@ export class TokenWrapper extends ContractWrapper {
         assert.isETHAddressHex('ownerAddress', ownerAddress);
         assert.isETHAddressHex('tokenAddress', tokenAddress);
         assert.isETHAddressHex('spenderAddress', spenderAddress);
+        if (!_.isUndefined(methodOpts)) {
+            assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
+        }
         const normalizedTokenAddress = tokenAddress.toLowerCase();
         const normalizedOwnerAddress = ownerAddress.toLowerCase();
         const normalizedSpenderAddress = spenderAddress.toLowerCase();
@@ -172,18 +183,8 @@ export class TokenWrapper extends ContractWrapper {
         ownerAddress: string,
         methodOpts?: MethodOpts,
     ): Promise<BigNumber> {
-        assert.isETHAddressHex('ownerAddress', ownerAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        const normalizedTokenAddress = tokenAddress.toLowerCase();
-        const normalizedOwnerAddress = ownerAddress.toLowerCase();
-
-        const proxyAddress = this._tokenTransferProxyWrapper.getContractAddress();
-        const allowanceInBaseUnits = await this.getAllowanceAsync(
-            normalizedTokenAddress,
-            normalizedOwnerAddress,
-            proxyAddress,
-            methodOpts,
-        );
+        const proxyAddress = this._erc20ProxyWrapper.getContractAddress();
+        const allowanceInBaseUnits = await this.getAllowanceAsync(tokenAddress, ownerAddress, proxyAddress, methodOpts);
         return allowanceInBaseUnits;
     }
     /**
@@ -202,16 +203,10 @@ export class TokenWrapper extends ContractWrapper {
         amountInBaseUnits: BigNumber,
         txOpts: TransactionOpts = {},
     ): Promise<string> {
-        assert.isETHAddressHex('ownerAddress', ownerAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        const normalizedTokenAddress = tokenAddress.toLowerCase();
-        const normalizedOwnerAddress = ownerAddress.toLowerCase();
-        assert.isValidBaseUnitAmount('amountInBaseUnits', amountInBaseUnits);
-
-        const proxyAddress = this._tokenTransferProxyWrapper.getContractAddress();
+        const proxyAddress = this._erc20ProxyWrapper.getContractAddress();
         const txHash = await this.setAllowanceAsync(
-            normalizedTokenAddress,
-            normalizedOwnerAddress,
+            tokenAddress,
+            ownerAddress,
             proxyAddress,
             amountInBaseUnits,
             txOpts,
@@ -234,13 +229,9 @@ export class TokenWrapper extends ContractWrapper {
         ownerAddress: string,
         txOpts: TransactionOpts = {},
     ): Promise<string> {
-        assert.isETHAddressHex('ownerAddress', ownerAddress);
-        assert.isETHAddressHex('tokenAddress', tokenAddress);
-        const normalizedTokenAddress = tokenAddress.toLowerCase();
-        const normalizedOwnerAddress = ownerAddress.toLowerCase();
         const txHash = await this.setProxyAllowanceAsync(
-            normalizedTokenAddress,
-            normalizedOwnerAddress,
+            tokenAddress,
+            ownerAddress,
             this.UNLIMITED_ALLOWANCE_IN_BASE_UNITS,
             txOpts,
         );
@@ -265,6 +256,9 @@ export class TokenWrapper extends ContractWrapper {
         assert.isETHAddressHex('tokenAddress', tokenAddress);
         assert.isETHAddressHex('toAddress', toAddress);
         await assert.isSenderAddressAsync('fromAddress', fromAddress, this._web3Wrapper);
+        if (!_.isUndefined(txOpts)) {
+            assert.doesConformToSchema('txOpts', txOpts, txOptsSchema);
+        }
         const normalizedTokenAddress = tokenAddress.toLowerCase();
         const normalizedFromAddress = fromAddress.toLowerCase();
         const normalizedToAddress = toAddress.toLowerCase();
@@ -277,11 +271,15 @@ export class TokenWrapper extends ContractWrapper {
             throw new Error(ContractWrappersError.InsufficientBalanceForTransfer);
         }
 
-        const txHash = await tokenContract.transfer.sendTransactionAsync(normalizedToAddress, amountInBaseUnits, {
-            from: normalizedFromAddress,
-            gas: txOpts.gasLimit,
-            gasPrice: txOpts.gasPrice,
-        });
+        const txHash = await tokenContract.transfer.sendTransactionAsync(
+            normalizedToAddress,
+            amountInBaseUnits,
+            removeUndefinedProperties({
+                from: normalizedFromAddress,
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+            }),
+        );
         return txHash;
     }
     /**
@@ -310,6 +308,9 @@ export class TokenWrapper extends ContractWrapper {
         assert.isETHAddressHex('fromAddress', fromAddress);
         assert.isETHAddressHex('tokenAddress', tokenAddress);
         await assert.isSenderAddressAsync('senderAddress', senderAddress, this._web3Wrapper);
+        if (!_.isUndefined(txOpts)) {
+            assert.doesConformToSchema('txOpts', txOpts, txOptsSchema);
+        }
         const normalizedToAddress = toAddress.toLowerCase();
         const normalizedFromAddress = fromAddress.toLowerCase();
         const normalizedTokenAddress = tokenAddress.toLowerCase();
@@ -336,11 +337,11 @@ export class TokenWrapper extends ContractWrapper {
             normalizedFromAddress,
             normalizedToAddress,
             amountInBaseUnits,
-            {
+            removeUndefinedProperties({
                 from: normalizedSenderAddress,
                 gas: txOpts.gasLimit,
                 gasPrice: txOpts.gasPrice,
-            },
+            }),
         );
         return txHash;
     }
@@ -353,22 +354,22 @@ export class TokenWrapper extends ContractWrapper {
      * @param   callback            Callback that gets called when a log is added/removed
      * @return Subscription token used later to unsubscribe
      */
-    public subscribe<ArgsType extends TokenContractEventArgs>(
+    public subscribe<ArgsType extends ERC20TokenEventArgs>(
         tokenAddress: string,
-        eventName: TokenEvents,
+        eventName: ERC20TokenEvents,
         indexFilterValues: IndexedFilterValues,
         callback: EventCallback<ArgsType>,
     ): string {
         assert.isETHAddressHex('tokenAddress', tokenAddress);
         const normalizedTokenAddress = tokenAddress.toLowerCase();
-        assert.doesBelongToStringEnum('eventName', eventName, TokenEvents);
+        assert.doesBelongToStringEnum('eventName', eventName, ERC20TokenEvents);
         assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
         assert.isFunction('callback', callback);
         const subscriptionToken = this._subscribe<ArgsType>(
             normalizedTokenAddress,
             eventName,
             indexFilterValues,
-            artifacts.Token.abi,
+            artifacts.ERC20Token.compilerOutput.abi,
             callback,
         );
         return subscriptionToken;
@@ -378,6 +379,7 @@ export class TokenWrapper extends ContractWrapper {
      * @param   subscriptionToken Subscription token returned by `subscribe()`
      */
     public unsubscribe(subscriptionToken: string): void {
+        assert.isValidSubscriptionToken('subscriptionToken', subscriptionToken);
         this._unsubscribe(subscriptionToken);
     }
     /**
@@ -395,15 +397,15 @@ export class TokenWrapper extends ContractWrapper {
      *                              the value is the value you are interested in. E.g `{_from: aUserAddressHex}`
      * @return  Array of logs that match the parameters
      */
-    public async getLogsAsync<ArgsType extends TokenContractEventArgs>(
+    public async getLogsAsync<ArgsType extends ERC20TokenEventArgs>(
         tokenAddress: string,
-        eventName: TokenEvents,
+        eventName: ERC20TokenEvents,
         blockRange: BlockRange,
         indexFilterValues: IndexedFilterValues,
     ): Promise<Array<LogWithDecodedArgs<ArgsType>>> {
         assert.isETHAddressHex('tokenAddress', tokenAddress);
         const normalizedTokenAddress = tokenAddress.toLowerCase();
-        assert.doesBelongToStringEnum('eventName', eventName, TokenEvents);
+        assert.doesBelongToStringEnum('eventName', eventName, ERC20TokenEvents);
         assert.doesConformToSchema('blockRange', blockRange, schemas.blockRangeSchema);
         assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
         const logs = await this._getLogsAsync<ArgsType>(
@@ -411,26 +413,28 @@ export class TokenWrapper extends ContractWrapper {
             eventName,
             blockRange,
             indexFilterValues,
-            artifacts.Token.abi,
+            artifacts.ERC20Token.compilerOutput.abi,
         );
         return logs;
     }
+    // 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 _invalidateContractInstances(): void {
         this.unsubscribeAll();
         this._tokenContractsByAddress = {};
     }
-    private async _getTokenContractAsync(tokenAddress: string): Promise<TokenContract> {
+    private async _getTokenContractAsync(tokenAddress: string): Promise<ERC20TokenContract> {
         const normalizedTokenAddress = tokenAddress.toLowerCase();
         let tokenContract = this._tokenContractsByAddress[normalizedTokenAddress];
         if (!_.isUndefined(tokenContract)) {
             return tokenContract;
         }
         const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.Token,
+            artifacts.ERC20Token,
             normalizedTokenAddress,
         );
-        const contractInstance = new TokenContract(
+        const contractInstance = new ERC20TokenContract(
             abi,
             address,
             this._web3Wrapper.getProvider(),
diff --git a/packages/contract-wrappers/src/contract_wrappers/erc721_proxy_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc721_proxy_wrapper.ts
new file mode 100644
index 000000000..fba995395
--- /dev/null
+++ b/packages/contract-wrappers/src/contract_wrappers/erc721_proxy_wrapper.ts
@@ -0,0 +1,75 @@
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { ContractAbi } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { artifacts } from '../artifacts';
+import { assert } from '../utils/assert';
+
+import { ContractWrapper } from './contract_wrapper';
+import { ERC721ProxyContract } from './generated/erc721_proxy';
+
+/**
+ * This class includes the functionality related to interacting with the ERC721Proxy contract.
+ */
+export class ERC721ProxyWrapper extends ContractWrapper {
+    public abi: ContractAbi = artifacts.ERC20Proxy.compilerOutput.abi;
+    private _erc721ProxyContractIfExists?: ERC721ProxyContract;
+    private _contractAddressIfExists?: string;
+    constructor(web3Wrapper: Web3Wrapper, networkId: number, contractAddressIfExists?: string) {
+        super(web3Wrapper, networkId);
+        this._contractAddressIfExists = contractAddressIfExists;
+    }
+    /**
+     * Check if the Exchange contract address is authorized by the ERC721Proxy contract.
+     * @param   exchangeContractAddress     The hex encoded address of the Exchange contract to call.
+     * @return  Whether the exchangeContractAddress is authorized.
+     */
+    public async isAuthorizedAsync(exchangeContractAddress: string): Promise<boolean> {
+        assert.isETHAddressHex('exchangeContractAddress', exchangeContractAddress);
+        const normalizedExchangeContractAddress = exchangeContractAddress.toLowerCase();
+        const ERC721ProxyContractInstance = await this._getERC721ProxyContractAsync();
+        const isAuthorized = await ERC721ProxyContractInstance.authorized.callAsync(normalizedExchangeContractAddress);
+        return isAuthorized;
+    }
+    /**
+     * Get the list of all Exchange contract addresses authorized by the ERC721Proxy contract.
+     * @return  The list of authorized addresses.
+     */
+    public async getAuthorizedAddressesAsync(): Promise<string[]> {
+        const ERC721ProxyContractInstance = await this._getERC721ProxyContractAsync();
+        const authorizedAddresses = await ERC721ProxyContractInstance.getAuthorizedAddresses.callAsync();
+        return authorizedAddresses;
+    }
+    /**
+     * Retrieves the Ethereum address of the ERC721Proxy contract deployed on the network
+     * that the user-passed web3 provider is connected to.
+     * @returns The Ethereum address of the ERC721Proxy contract being used.
+     */
+    public getContractAddress(): string {
+        const contractAddress = this._getContractAddress(artifacts.ERC721Proxy, this._contractAddressIfExists);
+        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._erc721ProxyContractIfExists;
+    }
+    private async _getERC721ProxyContractAsync(): Promise<ERC721ProxyContract> {
+        if (!_.isUndefined(this._erc721ProxyContractIfExists)) {
+            return this._erc721ProxyContractIfExists;
+        }
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
+            artifacts.ERC721Proxy,
+            this._contractAddressIfExists,
+        );
+        const contractInstance = new ERC721ProxyContract(
+            abi,
+            address,
+            this._web3Wrapper.getProvider(),
+            this._web3Wrapper.getContractDefaults(),
+        );
+        this._erc721ProxyContractIfExists = contractInstance;
+        return this._erc721ProxyContractIfExists;
+    }
+}
diff --git a/packages/contract-wrappers/src/contract_wrappers/erc721_token_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc721_token_wrapper.ts
new file mode 100644
index 000000000..415415fd7
--- /dev/null
+++ b/packages/contract-wrappers/src/contract_wrappers/erc721_token_wrapper.ts
@@ -0,0 +1,479 @@
+import { schemas } from '@0xproject/json-schemas';
+import { BigNumber } from '@0xproject/utils';
+import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { ContractAbi, LogWithDecodedArgs } from 'ethereum-types';
+import * as _ from 'lodash';
+
+import { constants } from '../../test/utils/constants';
+import { artifacts } from '../artifacts';
+import { methodOptsSchema } from '../schemas/method_opts_schema';
+import { txOptsSchema } from '../schemas/tx_opts_schema';
+import {
+    BlockRange,
+    ContractWrappersError,
+    EventCallback,
+    IndexedFilterValues,
+    MethodOpts,
+    TransactionOpts,
+} from '../types';
+import { assert } from '../utils/assert';
+
+import { ContractWrapper } from './contract_wrapper';
+import { ERC721ProxyWrapper } from './erc721_proxy_wrapper';
+import { ERC721TokenContract, ERC721TokenEventArgs, ERC721TokenEvents } from './generated/erc721_token';
+
+const removeUndefinedProperties = _.pickBy;
+
+/**
+ * This class includes all the functionality related to interacting with ERC721 token contracts.
+ * All ERC721 method calls are supported, along with some convenience methods for getting/setting allowances
+ * to the 0x ERC721 Proxy smart contract.
+ */
+export class ERC721TokenWrapper extends ContractWrapper {
+    public abi: ContractAbi = artifacts.ERC721Token.compilerOutput.abi;
+    private _tokenContractsByAddress: { [address: string]: ERC721TokenContract };
+    private _erc721ProxyWrapper: ERC721ProxyWrapper;
+    constructor(web3Wrapper: Web3Wrapper, networkId: number, erc721ProxyWrapper: ERC721ProxyWrapper) {
+        super(web3Wrapper, networkId);
+        this._tokenContractsByAddress = {};
+        this._erc721ProxyWrapper = erc721ProxyWrapper;
+    }
+    /**
+     * Count all NFTs assigned to an owner
+     * NFTs assigned to the zero address are considered invalid, and this function throws for queries about the zero address.
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   ownerAddress    The hex encoded user Ethereum address whose balance you would like to check.
+     * @param   methodOpts      Optional arguments this method accepts.
+     * @return  The number of NFTs owned by `ownerAddress`, possibly zero
+     */
+    public async getTokenCountAsync(
+        tokenAddress: string,
+        ownerAddress: string,
+        methodOpts?: MethodOpts,
+    ): Promise<BigNumber> {
+        assert.isETHAddressHex('ownerAddress', ownerAddress);
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        if (!_.isUndefined(methodOpts)) {
+            assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
+        }
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        const normalizedOwnerAddress = ownerAddress.toLowerCase();
+
+        const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
+        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
+        const txData = {};
+        let balance = await tokenContract.balanceOf.callAsync(normalizedOwnerAddress, txData, defaultBlock);
+        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
+        balance = new BigNumber(balance);
+        return balance;
+    }
+    /**
+     * Find the owner of an NFT
+     * NFTs assigned to zero address are considered invalid, and queries about them do throw.
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   tokenId         The identifier for an NFT
+     * @param   methodOpts      Optional arguments this method accepts.
+     * @return  The address of the owner of the NFT
+     */
+    public async getOwnerOfAsync(tokenAddress: string, tokenId: BigNumber, methodOpts?: MethodOpts): Promise<string> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        assert.isBigNumber('tokenId', tokenId);
+        if (!_.isUndefined(methodOpts)) {
+            assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
+        }
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+
+        const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
+        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
+        const txData = {};
+        try {
+            const tokenOwner = await tokenContract.ownerOf.callAsync(tokenId, txData, defaultBlock);
+            return tokenOwner;
+        } catch (err) {
+            throw new Error(ContractWrappersError.ERC721OwnerNotFound);
+        }
+    }
+    /**
+     * Query if an address is an authorized operator for all NFT's of `ownerAddress`
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   ownerAddress    The hex encoded user Ethereum address of the token owner.
+     * @param   operatorAddress The hex encoded user Ethereum address of the operator you'd like to check if approved.
+     * @param   methodOpts      Optional arguments this method accepts.
+     * @return  True if `operatorAddress` is an approved operator for `ownerAddress`, false otherwise
+     */
+    public async isApprovedForAllAsync(
+        tokenAddress: string,
+        ownerAddress: string,
+        operatorAddress: string,
+        methodOpts?: MethodOpts,
+    ): Promise<boolean> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        assert.isETHAddressHex('ownerAddress', ownerAddress);
+        assert.isETHAddressHex('operatorAddress', operatorAddress);
+        if (!_.isUndefined(methodOpts)) {
+            assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
+        }
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        const normalizedOwnerAddress = ownerAddress.toLowerCase();
+        const normalizedOperatorAddress = operatorAddress.toLowerCase();
+
+        const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
+        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
+        const txData = {};
+        const isApprovedForAll = await tokenContract.isApprovedForAll.callAsync(
+            normalizedOwnerAddress,
+            normalizedOperatorAddress,
+            txData,
+            defaultBlock,
+        );
+        return isApprovedForAll;
+    }
+    /**
+     * Query if 0x proxy is an authorized operator for all NFT's of `ownerAddress`
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   ownerAddress    The hex encoded user Ethereum address of the token owner.
+     * @param   methodOpts      Optional arguments this method accepts.
+     * @return  True if `operatorAddress` is an approved operator for `ownerAddress`, false otherwise
+     */
+    public async isProxyApprovedForAllAsync(
+        tokenAddress: string,
+        ownerAddress: string,
+        methodOpts?: MethodOpts,
+    ): Promise<boolean> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        assert.isETHAddressHex('ownerAddress', ownerAddress);
+        if (!_.isUndefined(methodOpts)) {
+            assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
+        }
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        const normalizedOwnerAddress = ownerAddress.toLowerCase();
+        const proxyAddress = this._erc721ProxyWrapper.getContractAddress();
+        const isProxyApprovedForAll = await this.isApprovedForAllAsync(
+            normalizedTokenAddress,
+            normalizedOwnerAddress,
+            proxyAddress,
+            methodOpts,
+        );
+        return isProxyApprovedForAll;
+    }
+    /**
+     * Get the approved address for a single NFT. Returns undefined if no approval was set
+     * Throws if `_tokenId` is not a valid NFT
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   tokenId         The identifier for an NFT
+     * @param   methodOpts      Optional arguments this method accepts.
+     * @return  The approved address for this NFT, or the undefined if there is none
+     */
+    public async getApprovedIfExistsAsync(
+        tokenAddress: string,
+        tokenId: BigNumber,
+        methodOpts?: MethodOpts,
+    ): Promise<string | undefined> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        assert.isBigNumber('tokenId', tokenId);
+        if (!_.isUndefined(methodOpts)) {
+            assert.doesConformToSchema('methodOpts', methodOpts, methodOptsSchema);
+        }
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+
+        const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
+        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
+        const txData = {};
+        const approvedAddress = await tokenContract.getApproved.callAsync(tokenId, txData, defaultBlock);
+        if (approvedAddress === constants.NULL_ADDRESS) {
+            return undefined;
+        }
+        return approvedAddress;
+    }
+    /**
+     * Checks if 0x proxy is approved for a single NFT
+     * Throws if `_tokenId` is not a valid NFT
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   tokenId         The identifier for an NFT
+     * @param   methodOpts      Optional arguments this method accepts.
+     * @return  True if 0x proxy is approved
+     */
+    public async isProxyApprovedAsync(
+        tokenAddress: string,
+        tokenId: BigNumber,
+        methodOpts?: MethodOpts,
+    ): Promise<boolean> {
+        const proxyAddress = this._erc721ProxyWrapper.getContractAddress();
+        const approvedAddress = await this.getApprovedIfExistsAsync(tokenAddress, tokenId, methodOpts);
+        const isProxyApproved = approvedAddress === proxyAddress;
+        return isProxyApproved;
+    }
+    /**
+     * Enable or disable approval for a third party ("operator") to manage all of `ownerAddress`'s assets.
+     * Throws if `_tokenId` is not a valid NFT
+     * Emits the ApprovalForAll event.
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   ownerAddress    The hex encoded user Ethereum address of the token owner.
+     * @param   operatorAddress The hex encoded user Ethereum address of the operator you'd like to set approval for.
+     * @param   isApproved      The boolean variable to set the approval to.
+     * @param   txOpts          Transaction parameters.
+     * @return  Transaction hash.
+     */
+    public async setApprovalForAllAsync(
+        tokenAddress: string,
+        ownerAddress: string,
+        operatorAddress: string,
+        isApproved: boolean,
+        txOpts: TransactionOpts = {},
+    ): Promise<string> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        await assert.isSenderAddressAsync('ownerAddress', ownerAddress, this._web3Wrapper);
+        assert.isETHAddressHex('operatorAddress', operatorAddress);
+        assert.isBoolean('isApproved', isApproved);
+        if (!_.isUndefined(txOpts)) {
+            assert.doesConformToSchema('txOpts', txOpts, txOptsSchema);
+        }
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        const normalizedOwnerAddress = ownerAddress.toLowerCase();
+        const normalizedOperatorAddress = operatorAddress.toLowerCase();
+
+        const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
+        const txHash = await tokenContract.setApprovalForAll.sendTransactionAsync(
+            normalizedOperatorAddress,
+            isApproved,
+            removeUndefinedProperties({
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+                from: normalizedOwnerAddress,
+            }),
+        );
+        return txHash;
+    }
+    /**
+     * Enable or disable approval for a third party ("operator") to manage all of `ownerAddress`'s assets.
+     * Throws if `_tokenId` is not a valid NFT
+     * Emits the ApprovalForAll event.
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   ownerAddress    The hex encoded user Ethereum address of the token owner.
+     * @param   operatorAddress The hex encoded user Ethereum address of the operator you'd like to set approval for.
+     * @param   isApproved      The boolean variable to set the approval to.
+     * @param   txOpts          Transaction parameters.
+     * @return  Transaction hash.
+     */
+    public async setProxyApprovalForAllAsync(
+        tokenAddress: string,
+        ownerAddress: string,
+        isApproved: boolean,
+        txOpts: TransactionOpts = {},
+    ): Promise<string> {
+        const proxyAddress = this._erc721ProxyWrapper.getContractAddress();
+        const txHash = await this.setApprovalForAllAsync(tokenAddress, ownerAddress, proxyAddress, isApproved, txOpts);
+        return txHash;
+    }
+    /**
+     * Set or reaffirm the approved address for an NFT
+     * The zero address indicates there is no approved address. Throws unless `msg.sender` is the current NFT owner,
+     * or an authorized operator of the current owner.
+     * Throws if `_tokenId` is not a valid NFT
+     * Emits the Approval event.
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   approvedAddress The hex encoded user Ethereum address you'd like to set approval for.
+     * @param   tokenId         The identifier for an NFT
+     * @param   txOpts          Transaction parameters.
+     * @return  Transaction hash.
+     */
+    public async setApprovalAsync(
+        tokenAddress: string,
+        approvedAddress: string,
+        tokenId: BigNumber,
+        txOpts: TransactionOpts = {},
+    ): Promise<string> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        assert.isETHAddressHex('approvedAddress', approvedAddress);
+        assert.isBigNumber('tokenId', tokenId);
+        if (!_.isUndefined(txOpts)) {
+            assert.doesConformToSchema('txOpts', txOpts, txOptsSchema);
+        }
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        const normalizedApprovedAddress = approvedAddress.toLowerCase();
+
+        const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
+        const tokenOwnerAddress = await tokenContract.ownerOf.callAsync(tokenId);
+        await assert.isSenderAddressAsync('tokenOwnerAddress', tokenOwnerAddress, this._web3Wrapper);
+        const txHash = await tokenContract.approve.sendTransactionAsync(
+            normalizedApprovedAddress,
+            tokenId,
+            removeUndefinedProperties({
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+                from: tokenOwnerAddress,
+            }),
+        );
+        return txHash;
+    }
+    /**
+     * Set or reaffirm 0x proxy as an approved address for an NFT
+     * Throws unless `msg.sender` is the current NFT owner, or an authorized operator of the current owner.
+     * Throws if `_tokenId` is not a valid NFT
+     * Emits the Approval event.
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   tokenId         The identifier for an NFT
+     * @param   txOpts          Transaction parameters.
+     * @return  Transaction hash.
+     */
+    public async setProxyApprovalAsync(
+        tokenAddress: string,
+        tokenId: BigNumber,
+        txOpts: TransactionOpts = {},
+    ): Promise<string> {
+        const proxyAddress = this._erc721ProxyWrapper.getContractAddress();
+        const txHash = await this.setApprovalAsync(tokenAddress, proxyAddress, tokenId, txOpts);
+        return txHash;
+    }
+    /**
+     * Enable or disable approval for a third party ("operator") to manage all of `ownerAddress`'s assets.
+     * Throws if `_tokenId` is not a valid NFT
+     * Emits the ApprovalForAll event.
+     * @param   tokenAddress    The hex encoded contract Ethereum address where the ERC721 token is deployed.
+     * @param   receiverAddress The hex encoded Ethereum address of the user to send the NFT to.
+     * @param   senderAddress The hex encoded Ethereum address of the user to send the NFT to.
+     * @param   tokenId         The identifier for an NFT
+     * @param   txOpts          Transaction parameters.
+     * @return  Transaction hash.
+     */
+    public async transferFromAsync(
+        tokenAddress: string,
+        receiverAddress: string,
+        senderAddress: string,
+        tokenId: BigNumber,
+        txOpts: TransactionOpts = {},
+    ): Promise<string> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        assert.isETHAddressHex('receiverAddress', receiverAddress);
+        await assert.isSenderAddressAsync('senderAddress', senderAddress, this._web3Wrapper);
+        if (!_.isUndefined(txOpts)) {
+            assert.doesConformToSchema('txOpts', txOpts, txOptsSchema);
+        }
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        const normalizedReceiverAddress = receiverAddress.toLowerCase();
+        const normalizedSenderAddress = senderAddress.toLowerCase();
+        const tokenContract = await this._getTokenContractAsync(normalizedTokenAddress);
+        const ownerAddress = await this.getOwnerOfAsync(tokenAddress, tokenId);
+        const isApprovedForAll = await this.isApprovedForAllAsync(
+            normalizedTokenAddress,
+            ownerAddress,
+            normalizedSenderAddress,
+        );
+        if (!isApprovedForAll) {
+            const approvedAddress = await this.getApprovedIfExistsAsync(normalizedTokenAddress, tokenId);
+            if (approvedAddress !== senderAddress) {
+                throw new Error(ContractWrappersError.ERC721NoApproval);
+            }
+        }
+        const txHash = await tokenContract.transferFrom.sendTransactionAsync(
+            ownerAddress,
+            normalizedReceiverAddress,
+            tokenId,
+            removeUndefinedProperties({
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+                from: normalizedSenderAddress,
+            }),
+        );
+        return txHash;
+    }
+    /**
+     * Subscribe to an event type emitted by the Token contract.
+     * @param   tokenAddress        The hex encoded address where the ERC721 token is deployed.
+     * @param   eventName           The token contract event you would like to subscribe to.
+     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
+     *                              the value is the value you are interested in. E.g `{maker: aUserAddressHex}`
+     * @param   callback            Callback that gets called when a log is added/removed
+     * @return Subscription token used later to unsubscribe
+     */
+    public subscribe<ArgsType extends ERC721TokenEventArgs>(
+        tokenAddress: string,
+        eventName: ERC721TokenEvents,
+        indexFilterValues: IndexedFilterValues,
+        callback: EventCallback<ArgsType>,
+    ): string {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        assert.doesBelongToStringEnum('eventName', eventName, ERC721TokenEvents);
+        assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
+        assert.isFunction('callback', callback);
+        const subscriptionToken = this._subscribe<ArgsType>(
+            normalizedTokenAddress,
+            eventName,
+            indexFilterValues,
+            artifacts.ERC721Token.compilerOutput.abi,
+            callback,
+        );
+        return subscriptionToken;
+    }
+    /**
+     * Cancel a subscription
+     * @param   subscriptionToken Subscription token returned by `subscribe()`
+     */
+    public unsubscribe(subscriptionToken: string): void {
+        assert.isValidSubscriptionToken('subscriptionToken', subscriptionToken);
+        this._unsubscribe(subscriptionToken);
+    }
+    /**
+     * Cancels all existing subscriptions
+     */
+    public unsubscribeAll(): void {
+        super._unsubscribeAll();
+    }
+    /**
+     * Gets historical logs without creating a subscription
+     * @param   tokenAddress        An address of the token that emitted the logs.
+     * @param   eventName           The token contract event you would like to subscribe to.
+     * @param   blockRange          Block range to get logs from.
+     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
+     *                              the value is the value you are interested in. E.g `{_from: aUserAddressHex}`
+     * @return  Array of logs that match the parameters
+     */
+    public async getLogsAsync<ArgsType extends ERC721TokenEventArgs>(
+        tokenAddress: string,
+        eventName: ERC721TokenEvents,
+        blockRange: BlockRange,
+        indexFilterValues: IndexedFilterValues,
+    ): Promise<Array<LogWithDecodedArgs<ArgsType>>> {
+        assert.isETHAddressHex('tokenAddress', tokenAddress);
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        assert.doesBelongToStringEnum('eventName', eventName, ERC721TokenEvents);
+        assert.doesConformToSchema('blockRange', blockRange, schemas.blockRangeSchema);
+        assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
+        const logs = await this._getLogsAsync<ArgsType>(
+            normalizedTokenAddress,
+            eventName,
+            blockRange,
+            indexFilterValues,
+            artifacts.ERC721Token.compilerOutput.abi,
+        );
+        return logs;
+    }
+    // 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 _invalidateContractInstances(): void {
+        this.unsubscribeAll();
+        this._tokenContractsByAddress = {};
+    }
+    private async _getTokenContractAsync(tokenAddress: string): Promise<ERC721TokenContract> {
+        const normalizedTokenAddress = tokenAddress.toLowerCase();
+        let tokenContract = this._tokenContractsByAddress[normalizedTokenAddress];
+        if (!_.isUndefined(tokenContract)) {
+            return tokenContract;
+        }
+        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
+            artifacts.ERC721Token,
+            normalizedTokenAddress,
+        );
+        const contractInstance = new ERC721TokenContract(
+            abi,
+            address,
+            this._web3Wrapper.getProvider(),
+            this._web3Wrapper.getContractDefaults(),
+        );
+        tokenContract = contractInstance;
+        this._tokenContractsByAddress[normalizedTokenAddress] = tokenContract;
+        return tokenContract;
+    }
+}
diff --git a/packages/contract-wrappers/src/contract_wrappers/ether_token_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/ether_token_wrapper.ts
index 36b7a234a..97872c247 100644
--- a/packages/contract-wrappers/src/contract_wrappers/ether_token_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/ether_token_wrapper.ts
@@ -1,7 +1,7 @@
 import { schemas } from '@0xproject/json-schemas';
-import { ContractAbi, LogWithDecodedArgs } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 import { Web3Wrapper } from '@0xproject/web3-wrapper';
+import { ContractAbi, LogWithDecodedArgs } from 'ethereum-types';
 import * as _ from 'lodash';
 
 import { artifacts } from '../artifacts';
@@ -9,22 +9,24 @@ import { BlockRange, ContractWrappersError, EventCallback, IndexedFilterValues,
 import { assert } from '../utils/assert';
 
 import { ContractWrapper } from './contract_wrapper';
-import { EtherTokenContract, EtherTokenContractEventArgs, EtherTokenEvents } from './generated/ether_token';
-import { TokenWrapper } from './token_wrapper';
+import { ERC20TokenWrapper } from './erc20_token_wrapper';
+import { WETH9Contract, WETH9EventArgs, WETH9Events } from './generated/weth9';
+
+const removeUndefinedProperties = _.pickBy;
 
 /**
  * This class includes all the functionality related to interacting with a wrapped Ether ERC20 token contract.
  * The caller can convert ETH into the equivalent number of wrapped ETH ERC20 tokens and back.
  */
 export class EtherTokenWrapper extends ContractWrapper {
-    public abi: ContractAbi = artifacts.EtherToken.abi;
+    public abi: ContractAbi = artifacts.EtherToken.compilerOutput.abi;
     private _etherTokenContractsByAddress: {
-        [address: string]: EtherTokenContract;
+        [address: string]: WETH9Contract;
     } = {};
-    private _tokenWrapper: TokenWrapper;
-    constructor(web3Wrapper: Web3Wrapper, networkId: number, tokenWrapper: TokenWrapper) {
+    private _erc20TokenWrapper: ERC20TokenWrapper;
+    constructor(web3Wrapper: Web3Wrapper, networkId: number, erc20TokenWrapper: ERC20TokenWrapper) {
         super(web3Wrapper, networkId);
-        this._tokenWrapper = tokenWrapper;
+        this._erc20TokenWrapper = erc20TokenWrapper;
     }
     /**
      * Deposit ETH into the Wrapped ETH smart contract and issues the equivalent number of wrapped ETH tokens
@@ -52,12 +54,14 @@ export class EtherTokenWrapper extends ContractWrapper {
         assert.assert(ethBalanceInWei.gte(amountInWei), ContractWrappersError.InsufficientEthBalanceForDeposit);
 
         const wethContract = await this._getEtherTokenContractAsync(normalizedEtherTokenAddress);
-        const txHash = await wethContract.deposit.sendTransactionAsync({
-            from: normalizedDepositorAddress,
-            value: amountInWei,
-            gas: txOpts.gasLimit,
-            gasPrice: txOpts.gasPrice,
-        });
+        const txHash = await wethContract.deposit.sendTransactionAsync(
+            removeUndefinedProperties({
+                from: normalizedDepositorAddress,
+                value: amountInWei,
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+            }),
+        );
         return txHash;
     }
     /**
@@ -81,7 +85,7 @@ export class EtherTokenWrapper extends ContractWrapper {
         const normalizedEtherTokenAddress = etherTokenAddress.toLowerCase();
         const normalizedWithdrawerAddress = withdrawer.toLowerCase();
 
-        const WETHBalanceInBaseUnits = await this._tokenWrapper.getBalanceAsync(
+        const WETHBalanceInBaseUnits = await this._erc20TokenWrapper.getBalanceAsync(
             normalizedEtherTokenAddress,
             normalizedWithdrawerAddress,
         );
@@ -91,11 +95,14 @@ export class EtherTokenWrapper extends ContractWrapper {
         );
 
         const wethContract = await this._getEtherTokenContractAsync(normalizedEtherTokenAddress);
-        const txHash = await wethContract.withdraw.sendTransactionAsync(amountInWei, {
-            from: normalizedWithdrawerAddress,
-            gas: txOpts.gasLimit,
-            gasPrice: txOpts.gasPrice,
-        });
+        const txHash = await wethContract.withdraw.sendTransactionAsync(
+            amountInWei,
+            removeUndefinedProperties({
+                from: normalizedWithdrawerAddress,
+                gas: txOpts.gasLimit,
+                gasPrice: txOpts.gasPrice,
+            }),
+        );
         return txHash;
     }
     /**
@@ -107,15 +114,15 @@ export class EtherTokenWrapper extends ContractWrapper {
      *                              the value is the value you are interested in. E.g `{_owner: aUserAddressHex}`
      * @return  Array of logs that match the parameters
      */
-    public async getLogsAsync<ArgsType extends EtherTokenContractEventArgs>(
+    public async getLogsAsync<ArgsType extends WETH9EventArgs>(
         etherTokenAddress: string,
-        eventName: EtherTokenEvents,
+        eventName: WETH9Events,
         blockRange: BlockRange,
         indexFilterValues: IndexedFilterValues,
     ): Promise<Array<LogWithDecodedArgs<ArgsType>>> {
         assert.isETHAddressHex('etherTokenAddress', etherTokenAddress);
         const normalizedEtherTokenAddress = etherTokenAddress.toLowerCase();
-        assert.doesBelongToStringEnum('eventName', eventName, EtherTokenEvents);
+        assert.doesBelongToStringEnum('eventName', eventName, WETH9Events);
         assert.doesConformToSchema('blockRange', blockRange, schemas.blockRangeSchema);
         assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
         const logs = await this._getLogsAsync<ArgsType>(
@@ -123,7 +130,7 @@ export class EtherTokenWrapper extends ContractWrapper {
             eventName,
             blockRange,
             indexFilterValues,
-            artifacts.EtherToken.abi,
+            artifacts.EtherToken.compilerOutput.abi,
         );
         return logs;
     }
@@ -136,22 +143,22 @@ export class EtherTokenWrapper extends ContractWrapper {
      * @param   callback            Callback that gets called when a log is added/removed
      * @return Subscription token used later to unsubscribe
      */
-    public subscribe<ArgsType extends EtherTokenContractEventArgs>(
+    public subscribe<ArgsType extends WETH9EventArgs>(
         etherTokenAddress: string,
-        eventName: EtherTokenEvents,
+        eventName: WETH9Events,
         indexFilterValues: IndexedFilterValues,
         callback: EventCallback<ArgsType>,
     ): string {
         assert.isETHAddressHex('etherTokenAddress', etherTokenAddress);
         const normalizedEtherTokenAddress = etherTokenAddress.toLowerCase();
-        assert.doesBelongToStringEnum('eventName', eventName, EtherTokenEvents);
+        assert.doesBelongToStringEnum('eventName', eventName, WETH9Events);
         assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
         assert.isFunction('callback', callback);
         const subscriptionToken = this._subscribe<ArgsType>(
             normalizedEtherTokenAddress,
             eventName,
             indexFilterValues,
-            artifacts.EtherToken.abi,
+            artifacts.EtherToken.compilerOutput.abi,
             callback,
         );
         return subscriptionToken;
@@ -161,6 +168,7 @@ export class EtherTokenWrapper extends ContractWrapper {
      * @param   subscriptionToken Subscription token returned by `subscribe()`
      */
     public unsubscribe(subscriptionToken: string): void {
+        assert.isValidSubscriptionToken('subscriptionToken', subscriptionToken);
         this._unsubscribe(subscriptionToken);
     }
     /**
@@ -187,7 +195,7 @@ export class EtherTokenWrapper extends ContractWrapper {
         this.unsubscribeAll();
         this._etherTokenContractsByAddress = {};
     }
-    private async _getEtherTokenContractAsync(etherTokenAddress: string): Promise<EtherTokenContract> {
+    private async _getEtherTokenContractAsync(etherTokenAddress: string): Promise<WETH9Contract> {
         let etherTokenContract = this._etherTokenContractsByAddress[etherTokenAddress];
         if (!_.isUndefined(etherTokenContract)) {
             return etherTokenContract;
@@ -196,7 +204,7 @@ export class EtherTokenWrapper extends ContractWrapper {
             artifacts.EtherToken,
             etherTokenAddress,
         );
-        const contractInstance = new EtherTokenContract(
+        const contractInstance = new WETH9Contract(
             abi,
             address,
             this._web3Wrapper.getProvider(),
diff --git a/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
deleted file mode 100644
index 8548a06b6..000000000
--- a/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
+++ /dev/null
@@ -1,988 +0,0 @@
-import { schemas } from '@0xproject/json-schemas';
-import { formatters, getOrderHashHex, OrderStateUtils } from '@0xproject/order-utils';
-import {
-    BlockParamLiteral,
-    ContractAbi,
-    DecodedLogArgs,
-    ECSignature,
-    ExchangeContractErrs,
-    LogEntry,
-    LogWithDecodedArgs,
-    Order,
-    OrderState,
-    SignedOrder,
-} from '@0xproject/types';
-import { BigNumber } from '@0xproject/utils';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import * as _ from 'lodash';
-
-import { artifacts } from '../artifacts';
-import { SimpleBalanceAndProxyAllowanceFetcher } from '../fetchers/simple_balance_and_proxy_allowance_fetcher';
-import { SimpleOrderFilledCancelledFetcher } from '../fetchers/simple_order_filled_cancelled_fetcher';
-import { BalanceAndProxyAllowanceLazyStore } from '../stores/balance_proxy_allowance_lazy_store';
-import {
-    BlockRange,
-    EventCallback,
-    ExchangeContractErrCodes,
-    IndexedFilterValues,
-    MethodOpts,
-    OrderCancellationRequest,
-    OrderFillRequest,
-    OrderTransactionOpts,
-    ValidateOrderFillableOpts,
-} from '../types';
-import { assert } from '../utils/assert';
-import { decorators } from '../utils/decorators';
-import { ExchangeTransferSimulator } from '../utils/exchange_transfer_simulator';
-import { OrderValidationUtils } from '../utils/order_validation_utils';
-
-import { ContractWrapper } from './contract_wrapper';
-import {
-    ExchangeContract,
-    ExchangeContractEventArgs,
-    ExchangeEvents,
-    LogErrorContractEventArgs,
-} from './generated/exchange';
-import { TokenWrapper } from './token_wrapper';
-const SHOULD_VALIDATE_BY_DEFAULT = true;
-
-interface ExchangeContractErrCodesToMsgs {
-    [exchangeContractErrCodes: number]: string;
-}
-
-/**
- * This class includes all the functionality related to calling methods and subscribing to
- * events of the 0x Exchange smart contract.
- */
-export class ExchangeWrapper extends ContractWrapper {
-    public abi: ContractAbi = artifacts.Exchange.abi;
-    private _exchangeContractIfExists?: ExchangeContract;
-    private _orderValidationUtilsIfExists?: OrderValidationUtils;
-    private _tokenWrapper: TokenWrapper;
-    private _exchangeContractErrCodesToMsg: ExchangeContractErrCodesToMsgs = {
-        [ExchangeContractErrCodes.ERROR_FILL_EXPIRED]: ExchangeContractErrs.OrderFillExpired,
-        [ExchangeContractErrCodes.ERROR_CANCEL_EXPIRED]: ExchangeContractErrs.OrderFillExpired,
-        [ExchangeContractErrCodes.ERROR_FILL_NO_VALUE]: ExchangeContractErrs.OrderRemainingFillAmountZero,
-        [ExchangeContractErrCodes.ERROR_CANCEL_NO_VALUE]: ExchangeContractErrs.OrderRemainingFillAmountZero,
-        [ExchangeContractErrCodes.ERROR_FILL_TRUNCATION]: ExchangeContractErrs.OrderFillRoundingError,
-        [ExchangeContractErrCodes.ERROR_FILL_BALANCE_ALLOWANCE]: ExchangeContractErrs.FillBalanceAllowanceError,
-    };
-    private _contractAddressIfExists?: string;
-    private _zrxContractAddressIfExists?: string;
-    constructor(
-        web3Wrapper: Web3Wrapper,
-        networkId: number,
-        tokenWrapper: TokenWrapper,
-        contractAddressIfExists?: string,
-        zrxContractAddressIfExists?: string,
-    ) {
-        super(web3Wrapper, networkId);
-        this._tokenWrapper = tokenWrapper;
-        this._contractAddressIfExists = contractAddressIfExists;
-        this._zrxContractAddressIfExists = zrxContractAddressIfExists;
-    }
-    /**
-     * Returns the unavailable takerAmount of an order. Unavailable amount is defined as the total
-     * amount that has been filled or cancelled. The remaining takerAmount can be calculated by
-     * subtracting the unavailable amount from the total order takerAmount.
-     * @param   orderHash               The hex encoded orderHash for which you would like to retrieve the
-     *                                  unavailable takerAmount.
-     * @param   methodOpts              Optional arguments this method accepts.
-     * @return  The amount of the order (in taker tokens) that has either been filled or cancelled.
-     */
-    public async getUnavailableTakerAmountAsync(orderHash: string, methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.doesConformToSchema('orderHash', orderHash, schemas.orderHashSchema);
-
-        const exchangeContract = await this._getExchangeContractAsync();
-        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        const txData = {};
-        let unavailableTakerTokenAmount = await exchangeContract.getUnavailableTakerTokenAmount.callAsync(
-            orderHash,
-            txData,
-            defaultBlock,
-        );
-        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
-        unavailableTakerTokenAmount = new BigNumber(unavailableTakerTokenAmount);
-        return unavailableTakerTokenAmount;
-    }
-    /**
-     * Retrieve the takerAmount of an order that has already been filled.
-     * @param   orderHash    The hex encoded orderHash for which you would like to retrieve the filled takerAmount.
-     * @param   methodOpts   Optional arguments this method accepts.
-     * @return  The amount of the order (in taker tokens) that has already been filled.
-     */
-    public async getFilledTakerAmountAsync(orderHash: string, methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.doesConformToSchema('orderHash', orderHash, schemas.orderHashSchema);
-
-        const exchangeContract = await this._getExchangeContractAsync();
-        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        const txData = {};
-        let fillAmountInBaseUnits = await exchangeContract.filled.callAsync(orderHash, txData, defaultBlock);
-        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
-        fillAmountInBaseUnits = new BigNumber(fillAmountInBaseUnits);
-        return fillAmountInBaseUnits;
-    }
-    /**
-     * Retrieve the takerAmount of an order that has been cancelled.
-     * @param   orderHash    The hex encoded orderHash for which you would like to retrieve the
-     *                       cancelled takerAmount.
-     * @param   methodOpts   Optional arguments this method accepts.
-     * @return  The amount of the order (in taker tokens) that has been cancelled.
-     */
-    public async getCancelledTakerAmountAsync(orderHash: string, methodOpts?: MethodOpts): Promise<BigNumber> {
-        assert.doesConformToSchema('orderHash', orderHash, schemas.orderHashSchema);
-
-        const exchangeContract = await this._getExchangeContractAsync();
-        const defaultBlock = _.isUndefined(methodOpts) ? undefined : methodOpts.defaultBlock;
-        const txData = {};
-        let cancelledAmountInBaseUnits = await exchangeContract.cancelled.callAsync(orderHash, txData, defaultBlock);
-        // Wrap BigNumbers returned from web3 with our own (later) version of BigNumber
-        cancelledAmountInBaseUnits = new BigNumber(cancelledAmountInBaseUnits);
-        return cancelledAmountInBaseUnits;
-    }
-    /**
-     * Fills a signed order with an amount denominated in baseUnits of the taker token.
-     * Since the order in which transactions are included in the next block is indeterminate, race-conditions
-     * could arise where a users balance or allowance changes before the fillOrder executes. Because of this,
-     * we allow you to specify `shouldThrowOnInsufficientBalanceOrAllowance`.
-     * If false, the smart contract will not throw if the parties
-     * do not have sufficient balances/allowances, preserving gas costs. Setting it to true forgoes this check
-     * and causes the smart contract to throw (using all the gas supplied) instead.
-     * @param   signedOrder                                 An object that conforms to the SignedOrder interface.
-     * @param   fillTakerTokenAmount                        The amount of the order (in taker tokens baseUnits) that
-     *                                                      you wish to fill.
-     * @param   shouldThrowOnInsufficientBalanceOrAllowance Whether or not you wish for the contract call to throw
-     *                                                      if upon execution the tokens cannot be transferred.
-     * @param   takerAddress                                The user Ethereum address who would like to fill this order.
-     *                                                      Must be available via the supplied Provider
-     *                                                      passed to 0x.js.
-     * @param   orderTransactionOpts                        Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.asyncZeroExErrorHandler
-    public async fillOrderAsync(
-        signedOrder: SignedOrder,
-        fillTakerTokenAmount: BigNumber,
-        shouldThrowOnInsufficientBalanceOrAllowance: boolean,
-        takerAddress: string,
-        orderTransactionOpts: OrderTransactionOpts = {},
-    ): Promise<string> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        assert.isBoolean('shouldThrowOnInsufficientBalanceOrAllowance', shouldThrowOnInsufficientBalanceOrAllowance);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const normalizedTakerAddress = takerAddress.toLowerCase();
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const shouldValidate = _.isUndefined(orderTransactionOpts.shouldValidate)
-            ? SHOULD_VALIDATE_BY_DEFAULT
-            : orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = this.getZRXTokenAddress();
-            const balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
-                this._tokenWrapper,
-                BlockParamLiteral.Latest,
-            );
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(balanceAndProxyAllowanceLazyStore);
-            const orderValidationUtils = await this._getOrderValidationUtilsAsync();
-            await orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
-                exchangeTradeEmulator,
-                signedOrder,
-                fillTakerTokenAmount,
-                normalizedTakerAddress,
-                zrxTokenAddress,
-            );
-        }
-
-        const [orderAddresses, orderValues] = formatters.getOrderAddressesAndValues(signedOrder);
-
-        const txHash: string = await exchangeInstance.fillOrder.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmount,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            signedOrder.ecSignature.v,
-            signedOrder.ecSignature.r,
-            signedOrder.ecSignature.s,
-            {
-                from: normalizedTakerAddress,
-                gas: orderTransactionOpts.gasLimit,
-                gasPrice: orderTransactionOpts.gasPrice,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Sequentially and atomically fills signedOrders up to the specified takerTokenFillAmount.
-     * If the fill amount is reached - it succeeds and does not fill the rest of the orders.
-     * If fill amount is not reached - it fills as much of the fill amount as possible and succeeds.
-     * @param   signedOrders                                The array of signedOrders that you would like to fill until
-     *                                                      takerTokenFillAmount is reached.
-     * @param   fillTakerTokenAmount                        The total amount of the takerTokens you would like to fill.
-     * @param   shouldThrowOnInsufficientBalanceOrAllowance Whether or not you wish for the contract call to throw if
-     *                                                      upon execution any of the tokens cannot be transferred.
-     *                                                      If set to false, the call will continue to fill subsequent
-     *                                                      signedOrders even when some cannot be filled.
-     * @param   takerAddress                                The user Ethereum address who would like to fill these
-     *                                                      orders. Must be available via the supplied Provider
-     *                                                      passed to 0x.js.
-     * @param   orderTransactionOpts                        Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.asyncZeroExErrorHandler
-    public async fillOrdersUpToAsync(
-        signedOrders: SignedOrder[],
-        fillTakerTokenAmount: BigNumber,
-        shouldThrowOnInsufficientBalanceOrAllowance: boolean,
-        takerAddress: string,
-        orderTransactionOpts: OrderTransactionOpts = {},
-    ): Promise<string> {
-        assert.doesConformToSchema('signedOrders', signedOrders, schemas.signedOrdersSchema);
-        const takerTokenAddresses = _.map(signedOrders, signedOrder => signedOrder.takerTokenAddress);
-        assert.hasAtMostOneUniqueValue(
-            takerTokenAddresses,
-            ExchangeContractErrs.MultipleTakerTokensInFillUpToDisallowed,
-        );
-        const exchangeContractAddresses = _.map(signedOrders, signedOrder => signedOrder.exchangeContractAddress);
-        assert.hasAtMostOneUniqueValue(
-            exchangeContractAddresses,
-            ExchangeContractErrs.BatchOrdersMustHaveSameExchangeAddress,
-        );
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        assert.isBoolean('shouldThrowOnInsufficientBalanceOrAllowance', shouldThrowOnInsufficientBalanceOrAllowance);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const normalizedTakerAddress = takerAddress.toLowerCase();
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts.shouldValidate)
-            ? SHOULD_VALIDATE_BY_DEFAULT
-            : orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            let filledTakerTokenAmount = new BigNumber(0);
-            const zrxTokenAddress = this.getZRXTokenAddress();
-            const balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
-                this._tokenWrapper,
-                BlockParamLiteral.Latest,
-            );
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(balanceAndProxyAllowanceLazyStore);
-            const orderValidationUtils = await this._getOrderValidationUtilsAsync();
-            for (const signedOrder of signedOrders) {
-                const singleFilledTakerTokenAmount = await orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
-                    exchangeTradeEmulator,
-                    signedOrder,
-                    fillTakerTokenAmount.minus(filledTakerTokenAmount),
-                    normalizedTakerAddress,
-                    zrxTokenAddress,
-                );
-                filledTakerTokenAmount = filledTakerTokenAmount.plus(singleFilledTakerTokenAmount);
-                if (filledTakerTokenAmount.eq(fillTakerTokenAmount)) {
-                    break;
-                }
-            }
-        }
-
-        if (_.isEmpty(signedOrders)) {
-            throw new Error(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
-        }
-
-        const orderAddressesValuesAndSignatureArray = _.map(signedOrders, signedOrder => {
-            return [
-                ...formatters.getOrderAddressesAndValues(signedOrder),
-                signedOrder.ecSignature.v,
-                signedOrder.ecSignature.r,
-                signedOrder.ecSignature.s,
-            ];
-        });
-        // We use _.unzip<any> because _.unzip doesn't type check if values have different types :'(
-        const [orderAddressesArray, orderValuesArray, vArray, rArray, sArray] = _.unzip<any>(
-            orderAddressesValuesAndSignatureArray,
-        );
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const txHash = await exchangeInstance.fillOrdersUpTo.sendTransactionAsync(
-            orderAddressesArray,
-            orderValuesArray,
-            fillTakerTokenAmount,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            vArray,
-            rArray,
-            sArray,
-            {
-                from: normalizedTakerAddress,
-                gas: orderTransactionOpts.gasLimit,
-                gasPrice: orderTransactionOpts.gasPrice,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Batch version of fillOrderAsync.
-     * Executes multiple fills atomically in a single transaction.
-     * If shouldThrowOnInsufficientBalanceOrAllowance is set to false, it will continue filling subsequent orders even
-     * when earlier ones fail.
-     * When shouldThrowOnInsufficientBalanceOrAllowance is set to true, if any fill fails, the entire batch fails.
-     * @param   orderFillRequests                               An array of objects that conform to the
-     *                                                          OrderFillRequest interface.
-     * @param   shouldThrowOnInsufficientBalanceOrAllowance     Whether or not you wish for the contract call to throw
-     *                                                          if upon execution any of the tokens cannot be
-     *                                                          transferred. If set to false, the call will continue to
-     *                                                          fill subsequent signedOrders even when some
-     *                                                          cannot be filled.
-     * @param   takerAddress                                    The user Ethereum address who would like to fill
-     *                                                          these orders. Must be available via the supplied
-     *                                                          Provider passed to 0x.js.
-     * @param   orderTransactionOpts                            Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.asyncZeroExErrorHandler
-    public async batchFillOrdersAsync(
-        orderFillRequests: OrderFillRequest[],
-        shouldThrowOnInsufficientBalanceOrAllowance: boolean,
-        takerAddress: string,
-        orderTransactionOpts: OrderTransactionOpts = {},
-    ): Promise<string> {
-        assert.doesConformToSchema('orderFillRequests', orderFillRequests, schemas.orderFillRequestsSchema);
-        const exchangeContractAddresses = _.map(
-            orderFillRequests,
-            orderFillRequest => orderFillRequest.signedOrder.exchangeContractAddress,
-        );
-        assert.hasAtMostOneUniqueValue(
-            exchangeContractAddresses,
-            ExchangeContractErrs.BatchOrdersMustHaveSameExchangeAddress,
-        );
-        assert.isBoolean('shouldThrowOnInsufficientBalanceOrAllowance', shouldThrowOnInsufficientBalanceOrAllowance);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const normalizedTakerAddress = takerAddress.toLowerCase();
-        const shouldValidate = _.isUndefined(orderTransactionOpts.shouldValidate)
-            ? SHOULD_VALIDATE_BY_DEFAULT
-            : orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = this.getZRXTokenAddress();
-            const balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
-                this._tokenWrapper,
-                BlockParamLiteral.Latest,
-            );
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(balanceAndProxyAllowanceLazyStore);
-            const orderValidationUtils = await this._getOrderValidationUtilsAsync();
-            for (const orderFillRequest of orderFillRequests) {
-                await orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
-                    exchangeTradeEmulator,
-                    orderFillRequest.signedOrder,
-                    orderFillRequest.takerTokenFillAmount,
-                    normalizedTakerAddress,
-                    zrxTokenAddress,
-                );
-            }
-        }
-        if (_.isEmpty(orderFillRequests)) {
-            throw new Error(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
-        }
-
-        const orderAddressesValuesAmountsAndSignatureArray = _.map(orderFillRequests, orderFillRequest => {
-            return [
-                ...formatters.getOrderAddressesAndValues(orderFillRequest.signedOrder),
-                orderFillRequest.takerTokenFillAmount,
-                orderFillRequest.signedOrder.ecSignature.v,
-                orderFillRequest.signedOrder.ecSignature.r,
-                orderFillRequest.signedOrder.ecSignature.s,
-            ];
-        });
-        // We use _.unzip<any> because _.unzip doesn't type check if values have different types :'(
-        const [orderAddressesArray, orderValuesArray, fillTakerTokenAmounts, vArray, rArray, sArray] = _.unzip<any>(
-            orderAddressesValuesAmountsAndSignatureArray,
-        );
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const txHash = await exchangeInstance.batchFillOrders.sendTransactionAsync(
-            orderAddressesArray,
-            orderValuesArray,
-            fillTakerTokenAmounts,
-            shouldThrowOnInsufficientBalanceOrAllowance,
-            vArray,
-            rArray,
-            sArray,
-            {
-                from: normalizedTakerAddress,
-                gas: orderTransactionOpts.gasLimit,
-                gasPrice: orderTransactionOpts.gasPrice,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Attempts to fill a specific amount of an order. If the entire amount specified cannot be filled,
-     * the fill order is abandoned.
-     * @param   signedOrder             An object that conforms to the SignedOrder interface. The
-     *                                  signedOrder you wish to fill.
-     * @param   fillTakerTokenAmount    The total amount of the takerTokens you would like to fill.
-     * @param   takerAddress            The user Ethereum address who would like to fill this order.
-     *                                  Must be available via the supplied Provider passed to 0x.js.
-     * @param   orderTransactionOpts    Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.asyncZeroExErrorHandler
-    public async fillOrKillOrderAsync(
-        signedOrder: SignedOrder,
-        fillTakerTokenAmount: BigNumber,
-        takerAddress: string,
-        orderTransactionOpts: OrderTransactionOpts = {},
-    ): Promise<string> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const normalizedTakerAddress = takerAddress.toLowerCase();
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts.shouldValidate)
-            ? SHOULD_VALIDATE_BY_DEFAULT
-            : orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = this.getZRXTokenAddress();
-            const balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
-                this._tokenWrapper,
-                BlockParamLiteral.Latest,
-            );
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(balanceAndProxyAllowanceLazyStore);
-            const orderValidationUtils = await this._getOrderValidationUtilsAsync();
-            await orderValidationUtils.validateFillOrKillOrderThrowIfInvalidAsync(
-                exchangeTradeEmulator,
-                signedOrder,
-                fillTakerTokenAmount,
-                normalizedTakerAddress,
-                zrxTokenAddress,
-            );
-        }
-
-        const [orderAddresses, orderValues] = formatters.getOrderAddressesAndValues(signedOrder);
-        const txHash = await exchangeInstance.fillOrKillOrder.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmount,
-            signedOrder.ecSignature.v,
-            signedOrder.ecSignature.r,
-            signedOrder.ecSignature.s,
-            {
-                from: normalizedTakerAddress,
-                gas: orderTransactionOpts.gasLimit,
-                gasPrice: orderTransactionOpts.gasPrice,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Batch version of fillOrKill. Allows a taker to specify a batch of orders that will either be atomically
-     * filled (each to the specified fillAmount) or aborted.
-     * @param   orderFillRequests           An array of objects that conform to the OrderFillRequest interface.
-     * @param   takerAddress                The user Ethereum address who would like to fill there orders.
-     *                                      Must be available via the supplied Provider passed to 0x.js.
-     * @param   orderTransactionOpts        Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.asyncZeroExErrorHandler
-    public async batchFillOrKillAsync(
-        orderFillRequests: OrderFillRequest[],
-        takerAddress: string,
-        orderTransactionOpts: OrderTransactionOpts = {},
-    ): Promise<string> {
-        assert.doesConformToSchema('orderFillRequests', orderFillRequests, schemas.orderFillRequestsSchema);
-        const exchangeContractAddresses = _.map(
-            orderFillRequests,
-            orderFillRequest => orderFillRequest.signedOrder.exchangeContractAddress,
-        );
-        assert.hasAtMostOneUniqueValue(
-            exchangeContractAddresses,
-            ExchangeContractErrs.BatchOrdersMustHaveSameExchangeAddress,
-        );
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const normalizedTakerAddress = takerAddress.toLowerCase();
-        if (_.isEmpty(orderFillRequests)) {
-            throw new Error(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
-        }
-        const exchangeInstance = await this._getExchangeContractAsync();
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts.shouldValidate)
-            ? SHOULD_VALIDATE_BY_DEFAULT
-            : orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const zrxTokenAddress = this.getZRXTokenAddress();
-            const balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
-                this._tokenWrapper,
-                BlockParamLiteral.Latest,
-            );
-            const exchangeTradeEmulator = new ExchangeTransferSimulator(balanceAndProxyAllowanceLazyStore);
-            const orderValidationUtils = await this._getOrderValidationUtilsAsync();
-            for (const orderFillRequest of orderFillRequests) {
-                await orderValidationUtils.validateFillOrKillOrderThrowIfInvalidAsync(
-                    exchangeTradeEmulator,
-                    orderFillRequest.signedOrder,
-                    orderFillRequest.takerTokenFillAmount,
-                    normalizedTakerAddress,
-                    zrxTokenAddress,
-                );
-            }
-        }
-
-        const orderAddressesValuesAndTakerTokenFillAmounts = _.map(orderFillRequests, request => {
-            return [
-                ...formatters.getOrderAddressesAndValues(request.signedOrder),
-                request.takerTokenFillAmount,
-                request.signedOrder.ecSignature.v,
-                request.signedOrder.ecSignature.r,
-                request.signedOrder.ecSignature.s,
-            ];
-        });
-
-        // We use _.unzip<any> because _.unzip doesn't type check if values have different types :'(
-        const [orderAddresses, orderValues, fillTakerTokenAmounts, vParams, rParams, sParams] = _.unzip<any>(
-            orderAddressesValuesAndTakerTokenFillAmounts,
-        );
-        const txHash = await exchangeInstance.batchFillOrKillOrders.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            fillTakerTokenAmounts,
-            vParams,
-            rParams,
-            sParams,
-            {
-                from: normalizedTakerAddress,
-                gas: orderTransactionOpts.gasLimit,
-                gasPrice: orderTransactionOpts.gasPrice,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Cancel a given fill amount of an order. Cancellations are cumulative.
-     * @param   order                   An object that conforms to the Order or SignedOrder interface.
-     *                                  The order you would like to cancel.
-     * @param   cancelTakerTokenAmount  The amount (specified in taker tokens) that you would like to cancel.
-     * @param   transactionOpts         Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.asyncZeroExErrorHandler
-    public async cancelOrderAsync(
-        order: Order | SignedOrder,
-        cancelTakerTokenAmount: BigNumber,
-        orderTransactionOpts: OrderTransactionOpts = {},
-    ): Promise<string> {
-        assert.doesConformToSchema('order', order, schemas.orderSchema);
-        assert.isValidBaseUnitAmount('takerTokenCancelAmount', cancelTakerTokenAmount);
-        await assert.isSenderAddressAsync('order.maker', order.maker, this._web3Wrapper);
-        const normalizedMakerAddress = order.maker.toLowerCase();
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts.shouldValidate)
-            ? SHOULD_VALIDATE_BY_DEFAULT
-            : orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            const orderHash = getOrderHashHex(order);
-            const unavailableTakerTokenAmount = await this.getUnavailableTakerAmountAsync(orderHash);
-            OrderValidationUtils.validateCancelOrderThrowIfInvalid(
-                order,
-                cancelTakerTokenAmount,
-                unavailableTakerTokenAmount,
-            );
-        }
-
-        const [orderAddresses, orderValues] = formatters.getOrderAddressesAndValues(order);
-        const txHash = await exchangeInstance.cancelOrder.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            cancelTakerTokenAmount,
-            {
-                from: normalizedMakerAddress,
-                gas: orderTransactionOpts.gasLimit,
-                gasPrice: orderTransactionOpts.gasPrice,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Batch version of cancelOrderAsync. Atomically cancels multiple orders in a single transaction.
-     * All orders must be from the same maker.
-     * @param   orderCancellationRequests   An array of objects that conform to the OrderCancellationRequest
-     *                                      interface.
-     * @param   transactionOpts             Optional arguments this method accepts.
-     * @return  Transaction hash.
-     */
-    @decorators.asyncZeroExErrorHandler
-    public async batchCancelOrdersAsync(
-        orderCancellationRequests: OrderCancellationRequest[],
-        orderTransactionOpts: OrderTransactionOpts = {},
-    ): Promise<string> {
-        assert.doesConformToSchema(
-            'orderCancellationRequests',
-            orderCancellationRequests,
-            schemas.orderCancellationRequestsSchema,
-        );
-        const exchangeContractAddresses = _.map(
-            orderCancellationRequests,
-            orderCancellationRequest => orderCancellationRequest.order.exchangeContractAddress,
-        );
-        assert.hasAtMostOneUniqueValue(
-            exchangeContractAddresses,
-            ExchangeContractErrs.BatchOrdersMustHaveSameExchangeAddress,
-        );
-        const makers = _.map(orderCancellationRequests, cancellationRequest => cancellationRequest.order.maker);
-        assert.hasAtMostOneUniqueValue(makers, ExchangeContractErrs.MultipleMakersInSingleCancelBatchDisallowed);
-        const maker = makers[0];
-        await assert.isSenderAddressAsync('maker', maker, this._web3Wrapper);
-        const normalizedMakerAddress = maker.toLowerCase();
-
-        const shouldValidate = _.isUndefined(orderTransactionOpts.shouldValidate)
-            ? SHOULD_VALIDATE_BY_DEFAULT
-            : orderTransactionOpts.shouldValidate;
-        if (shouldValidate) {
-            for (const orderCancellationRequest of orderCancellationRequests) {
-                const orderHash = getOrderHashHex(orderCancellationRequest.order);
-                const unavailableTakerTokenAmount = await this.getUnavailableTakerAmountAsync(orderHash);
-                OrderValidationUtils.validateCancelOrderThrowIfInvalid(
-                    orderCancellationRequest.order,
-                    orderCancellationRequest.takerTokenCancelAmount,
-                    unavailableTakerTokenAmount,
-                );
-            }
-        }
-        if (_.isEmpty(orderCancellationRequests)) {
-            throw new Error(ExchangeContractErrs.BatchOrdersMustHaveAtLeastOneItem);
-        }
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const orderAddressesValuesAndTakerTokenCancelAmounts = _.map(orderCancellationRequests, cancellationRequest => {
-            return [
-                ...formatters.getOrderAddressesAndValues(cancellationRequest.order),
-                cancellationRequest.takerTokenCancelAmount,
-            ];
-        });
-        // We use _.unzip<any> because _.unzip doesn't type check if values have different types :'(
-        const [orderAddresses, orderValues, cancelTakerTokenAmounts] = _.unzip<any>(
-            orderAddressesValuesAndTakerTokenCancelAmounts,
-        );
-        const txHash = await exchangeInstance.batchCancelOrders.sendTransactionAsync(
-            orderAddresses,
-            orderValues,
-            cancelTakerTokenAmounts,
-            {
-                from: normalizedMakerAddress,
-                gas: orderTransactionOpts.gasLimit,
-                gasPrice: orderTransactionOpts.gasPrice,
-            },
-        );
-        return txHash;
-    }
-    /**
-     * Subscribe to an event type emitted by the Exchange contract.
-     * @param   eventName           The exchange contract event you would like to subscribe to.
-     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
-     *                              the value is the value you are interested in. E.g `{maker: aUserAddressHex}`
-     * @param   callback            Callback that gets called when a log is added/removed
-     * @return Subscription token used later to unsubscribe
-     */
-    public subscribe<ArgsType extends ExchangeContractEventArgs>(
-        eventName: ExchangeEvents,
-        indexFilterValues: IndexedFilterValues,
-        callback: EventCallback<ArgsType>,
-    ): string {
-        assert.doesBelongToStringEnum('eventName', eventName, ExchangeEvents);
-        assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
-        assert.isFunction('callback', callback);
-        const exchangeContractAddress = this.getContractAddress();
-        const subscriptionToken = this._subscribe<ArgsType>(
-            exchangeContractAddress,
-            eventName,
-            indexFilterValues,
-            artifacts.Exchange.abi,
-            callback,
-        );
-        return subscriptionToken;
-    }
-    /**
-     * Cancel a subscription
-     * @param   subscriptionToken Subscription token returned by `subscribe()`
-     */
-    public unsubscribe(subscriptionToken: string): void {
-        this._unsubscribe(subscriptionToken);
-    }
-    /**
-     * Cancels all existing subscriptions
-     */
-    public unsubscribeAll(): void {
-        super._unsubscribeAll();
-    }
-    /**
-     * Gets historical logs without creating a subscription
-     * @param   eventName           The exchange contract event you would like to subscribe to.
-     * @param   blockRange          Block range to get logs from.
-     * @param   indexFilterValues   An object where the keys are indexed args returned by the event and
-     *                              the value is the value you are interested in. E.g `{_from: aUserAddressHex}`
-     * @return  Array of logs that match the parameters
-     */
-    public async getLogsAsync<ArgsType extends ExchangeContractEventArgs>(
-        eventName: ExchangeEvents,
-        blockRange: BlockRange,
-        indexFilterValues: IndexedFilterValues,
-    ): Promise<Array<LogWithDecodedArgs<ArgsType>>> {
-        assert.doesBelongToStringEnum('eventName', eventName, ExchangeEvents);
-        assert.doesConformToSchema('blockRange', blockRange, schemas.blockRangeSchema);
-        assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
-        const exchangeContractAddress = this.getContractAddress();
-        const logs = await this._getLogsAsync<ArgsType>(
-            exchangeContractAddress,
-            eventName,
-            blockRange,
-            indexFilterValues,
-            artifacts.Exchange.abi,
-        );
-        return logs;
-    }
-    /**
-     * Retrieves the Ethereum address of the Exchange contract deployed on the network
-     * that the user-passed web3 provider is connected to.
-     * @returns The Ethereum address of the Exchange contract being used.
-     */
-    public getContractAddress(): string {
-        const contractAddress = this._getContractAddress(artifacts.Exchange, this._contractAddressIfExists);
-        return contractAddress;
-    }
-    /**
-     * Checks if order is still fillable and throws an error otherwise. Useful for orderbook
-     * pruning where you want to remove stale orders without knowing who the taker will be.
-     * @param   signedOrder     An object that conforms to the SignedOrder interface. The
-     *                          signedOrder you wish to validate.
-     * @param   opts            An object that conforms to the ValidateOrderFillableOpts
-     *                          interface. Allows specifying a specific fillTakerTokenAmount
-     *                          to validate for.
-     */
-    public async validateOrderFillableOrThrowAsync(
-        signedOrder: SignedOrder,
-        opts?: ValidateOrderFillableOpts,
-    ): Promise<void> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        const zrxTokenAddress = this.getZRXTokenAddress();
-        const expectedFillTakerTokenAmount = !_.isUndefined(opts) ? opts.expectedFillTakerTokenAmount : undefined;
-        const balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
-            this._tokenWrapper,
-            BlockParamLiteral.Latest,
-        );
-        const exchangeTradeEmulator = new ExchangeTransferSimulator(balanceAndProxyAllowanceLazyStore);
-        const orderValidationUtils = await this._getOrderValidationUtilsAsync();
-        await orderValidationUtils.validateOrderFillableOrThrowAsync(
-            exchangeTradeEmulator,
-            signedOrder,
-            zrxTokenAddress,
-            expectedFillTakerTokenAmount,
-        );
-    }
-    /**
-     * Checks if order fill will succeed and throws an error otherwise.
-     * @param   signedOrder             An object that conforms to the SignedOrder interface. The
-     *                                  signedOrder you wish to fill.
-     * @param   fillTakerTokenAmount    The total amount of the takerTokens you would like to fill.
-     * @param   takerAddress            The user Ethereum address who would like to fill this order.
-     *                                  Must be available via the supplied Provider passed to 0x.js.
-     */
-    public async validateFillOrderThrowIfInvalidAsync(
-        signedOrder: SignedOrder,
-        fillTakerTokenAmount: BigNumber,
-        takerAddress: string,
-    ): Promise<void> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const normalizedTakerAddress = takerAddress.toLowerCase();
-        const zrxTokenAddress = this.getZRXTokenAddress();
-        const balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
-            this._tokenWrapper,
-            BlockParamLiteral.Latest,
-        );
-        const exchangeTradeEmulator = new ExchangeTransferSimulator(balanceAndProxyAllowanceLazyStore);
-        const orderValidationUtils = await this._getOrderValidationUtilsAsync();
-        await orderValidationUtils.validateFillOrderThrowIfInvalidAsync(
-            exchangeTradeEmulator,
-            signedOrder,
-            fillTakerTokenAmount,
-            normalizedTakerAddress,
-            zrxTokenAddress,
-        );
-    }
-    /**
-     * Checks if cancelling a given order will succeed and throws an informative error if it won't.
-     * @param   order                   An object that conforms to the Order or SignedOrder interface.
-     *                                  The order you would like to cancel.
-     * @param   cancelTakerTokenAmount  The amount (specified in taker tokens) that you would like to cancel.
-     */
-    public async validateCancelOrderThrowIfInvalidAsync(
-        order: Order,
-        cancelTakerTokenAmount: BigNumber,
-    ): Promise<void> {
-        assert.doesConformToSchema('order', order, schemas.orderSchema);
-        assert.isValidBaseUnitAmount('cancelTakerTokenAmount', cancelTakerTokenAmount);
-        const orderHash = getOrderHashHex(order);
-        const unavailableTakerTokenAmount = await this.getUnavailableTakerAmountAsync(orderHash);
-        OrderValidationUtils.validateCancelOrderThrowIfInvalid(
-            order,
-            cancelTakerTokenAmount,
-            unavailableTakerTokenAmount,
-        );
-    }
-    /**
-     * Checks if calling fillOrKill on a given order will succeed and throws an informative error if it won't.
-     * @param   signedOrder             An object that conforms to the SignedOrder interface. The
-     *                                  signedOrder you wish to fill.
-     * @param   fillTakerTokenAmount    The total amount of the takerTokens you would like to fill.
-     * @param   takerAddress            The user Ethereum address who would like to fill this order.
-     *                                  Must be available via the supplied Provider passed to 0x.js.
-     */
-    public async validateFillOrKillOrderThrowIfInvalidAsync(
-        signedOrder: SignedOrder,
-        fillTakerTokenAmount: BigNumber,
-        takerAddress: string,
-    ): Promise<void> {
-        assert.doesConformToSchema('signedOrder', signedOrder, schemas.signedOrderSchema);
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        await assert.isSenderAddressAsync('takerAddress', takerAddress, this._web3Wrapper);
-        const normalizedTakerAddress = takerAddress.toLowerCase();
-        const zrxTokenAddress = this.getZRXTokenAddress();
-        const balanceAndProxyAllowanceLazyStore = new BalanceAndProxyAllowanceLazyStore(
-            this._tokenWrapper,
-            BlockParamLiteral.Latest,
-        );
-        const exchangeTradeEmulator = new ExchangeTransferSimulator(balanceAndProxyAllowanceLazyStore);
-        const orderValidationUtils = await this._getOrderValidationUtilsAsync();
-        await orderValidationUtils.validateFillOrKillOrderThrowIfInvalidAsync(
-            exchangeTradeEmulator,
-            signedOrder,
-            fillTakerTokenAmount,
-            normalizedTakerAddress,
-            zrxTokenAddress,
-        );
-    }
-    /**
-     * Checks if rounding error will be > 0.1% when computing makerTokenAmount by doing:
-     * `(fillTakerTokenAmount * makerTokenAmount) / takerTokenAmount`.
-     * 0x Protocol does not accept any trades that result in large rounding errors. This means that tokens with few or
-     * no decimals can only be filled in quantities and ratios that avoid large rounding errors.
-     * @param   fillTakerTokenAmount   The amount of the order (in taker tokens baseUnits) that you wish to fill.
-     * @param   takerTokenAmount       The order size on the taker side
-     * @param   makerTokenAmount       The order size on the maker side
-     */
-    public async isRoundingErrorAsync(
-        fillTakerTokenAmount: BigNumber,
-        takerTokenAmount: BigNumber,
-        makerTokenAmount: BigNumber,
-    ): Promise<boolean> {
-        assert.isValidBaseUnitAmount('fillTakerTokenAmount', fillTakerTokenAmount);
-        assert.isValidBaseUnitAmount('takerTokenAmount', takerTokenAmount);
-        assert.isValidBaseUnitAmount('makerTokenAmount', makerTokenAmount);
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const isRoundingError = await exchangeInstance.isRoundingError.callAsync(
-            fillTakerTokenAmount,
-            takerTokenAmount,
-            makerTokenAmount,
-        );
-        return isRoundingError;
-    }
-    /**
-     * Checks if logs contain LogError, which is emitted by Exchange contract on transaction failure.
-     * @param   logs   Transaction logs as returned by `zeroEx.awaitTransactionMinedAsync`
-     */
-    public throwLogErrorsAsErrors(logs: Array<LogWithDecodedArgs<DecodedLogArgs> | LogEntry>): void {
-        const errLog = _.find(logs, {
-            event: ExchangeEvents.LogError,
-        });
-        if (!_.isUndefined(errLog)) {
-            const logArgs = (errLog as LogWithDecodedArgs<LogErrorContractEventArgs>).args;
-            const errCode = logArgs.errorId;
-            const errMessage = this._exchangeContractErrCodesToMsg[errCode];
-            throw new Error(errMessage);
-        }
-    }
-    /**
-     * Gets the latest OrderState of a signedOrder
-     * @param   signedOrder   The signedOrder
-     * @param   stateLayer    Optional, desired blockchain state layer (defaults to latest).
-     * @return  OrderState of the signedOrder
-     */
-    public async getOrderStateAsync(
-        signedOrder: SignedOrder,
-        stateLayer: BlockParamLiteral = BlockParamLiteral.Latest,
-    ): Promise<OrderState> {
-        const simpleBalanceAndProxyAllowanceFetcher = new SimpleBalanceAndProxyAllowanceFetcher(
-            this._tokenWrapper,
-            stateLayer,
-        );
-        const simpleOrderFilledCancelledFetcher = new SimpleOrderFilledCancelledFetcher(this, stateLayer);
-        const orderStateUtils = new OrderStateUtils(
-            simpleBalanceAndProxyAllowanceFetcher,
-            simpleOrderFilledCancelledFetcher,
-        );
-        const orderState = orderStateUtils.getOrderStateAsync(signedOrder);
-        return orderState;
-    }
-    /**
-     * Returns the ZRX token address used by the exchange contract.
-     * @return Address of ZRX token
-     */
-    public getZRXTokenAddress(): string {
-        const contractAddress = this._getContractAddress(artifacts.ZRX, this._zrxContractAddressIfExists);
-        return contractAddress;
-    }
-    // tslint:disable:no-unused-variable
-    private _invalidateContractInstances(): void {
-        this.unsubscribeAll();
-        delete this._exchangeContractIfExists;
-    }
-    private async _isValidSignatureUsingContractCallAsync(
-        dataHex: string,
-        ecSignature: ECSignature,
-        signerAddressHex: string,
-    ): Promise<boolean> {
-        assert.isHexString('dataHex', dataHex);
-        assert.doesConformToSchema('ecSignature', ecSignature, schemas.ecSignatureSchema);
-        assert.isETHAddressHex('signerAddressHex', signerAddressHex);
-        const normalizedSignerAddress = signerAddressHex.toLowerCase();
-
-        const exchangeInstance = await this._getExchangeContractAsync();
-
-        const isValidSignature = await exchangeInstance.isValidSignature.callAsync(
-            normalizedSignerAddress,
-            dataHex,
-            ecSignature.v,
-            ecSignature.r,
-            ecSignature.s,
-        );
-        return isValidSignature;
-    }
-    private async _getOrderHashHexUsingContractCallAsync(order: Order | SignedOrder): Promise<string> {
-        const exchangeInstance = await this._getExchangeContractAsync();
-        const [orderAddresses, orderValues] = formatters.getOrderAddressesAndValues(order);
-        const orderHashHex = await exchangeInstance.getOrderHash.callAsync(orderAddresses, orderValues);
-        return orderHashHex;
-    }
-    private async _getOrderValidationUtilsAsync(): Promise<OrderValidationUtils> {
-        if (!_.isUndefined(this._orderValidationUtilsIfExists)) {
-            return this._orderValidationUtilsIfExists;
-        }
-        const exchangeContract = await this._getExchangeContractAsync();
-        this._orderValidationUtilsIfExists = new OrderValidationUtils(exchangeContract);
-        return this._orderValidationUtilsIfExists;
-    }
-    // tslint:enable:no-unused-variable
-    private async _getExchangeContractAsync(): Promise<ExchangeContract> {
-        if (!_.isUndefined(this._exchangeContractIfExists)) {
-            return this._exchangeContractIfExists;
-        }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.Exchange,
-            this._contractAddressIfExists,
-        );
-        const contractInstance = new ExchangeContract(
-            abi,
-            address,
-            this._web3Wrapper.getProvider(),
-            this._web3Wrapper.getContractDefaults(),
-        );
-        this._exchangeContractIfExists = contractInstance;
-        return this._exchangeContractIfExists;
-    }
-} // tslint:disable:max-file-line-count
diff --git a/packages/contract-wrappers/src/contract_wrappers/token_registry_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/token_registry_wrapper.ts
deleted file mode 100644
index 7b558ed69..000000000
--- a/packages/contract-wrappers/src/contract_wrappers/token_registry_wrapper.ts
+++ /dev/null
@@ -1,133 +0,0 @@
-import { ContractAbi, Token } from '@0xproject/types';
-import { Web3Wrapper } from '@0xproject/web3-wrapper';
-import * as _ from 'lodash';
-
-import { artifacts } from '../artifacts';
-import { TokenMetadata } from '../types';
-import { assert } from '../utils/assert';
-import { constants } from '../utils/constants';
-
-import { ContractWrapper } from './contract_wrapper';
-import { TokenRegistryContract } from './generated/token_registry';
-
-/**
- * This class includes all the functionality related to interacting with the 0x Token Registry smart contract.
- */
-export class TokenRegistryWrapper extends ContractWrapper {
-    public abi: ContractAbi = artifacts.TokenRegistry.abi;
-    private _tokenRegistryContractIfExists?: TokenRegistryContract;
-    private _contractAddressIfExists?: string;
-    private static _createTokenFromMetadata(metadata: TokenMetadata): Token | undefined {
-        if (metadata[0] === constants.NULL_ADDRESS) {
-            return undefined;
-        }
-        const token = {
-            address: metadata[0],
-            name: metadata[1],
-            symbol: metadata[2],
-            decimals: metadata[3],
-        };
-        return token;
-    }
-    constructor(web3Wrapper: Web3Wrapper, networkId: number, contractAddressIfExists?: string) {
-        super(web3Wrapper, networkId);
-        this._contractAddressIfExists = contractAddressIfExists;
-    }
-    /**
-     * Retrieves all the tokens currently listed in the Token Registry smart contract
-     * @return  An array of objects that conform to the Token interface.
-     */
-    public async getTokensAsync(): Promise<Token[]> {
-        const addresses = await this.getTokenAddressesAsync();
-        const tokenPromises: Array<Promise<Token | undefined>> = _.map(addresses, async (address: string) =>
-            this.getTokenIfExistsAsync(address),
-        );
-        const tokens = await Promise.all(tokenPromises);
-        return tokens as Token[];
-    }
-    /**
-     * Retrieves all the addresses of the tokens currently listed in the Token Registry smart contract
-     * @return  An array of token addresses.
-     */
-    public async getTokenAddressesAsync(): Promise<string[]> {
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const addresses = await tokenRegistryContract.getTokenAddresses.callAsync();
-        const lowerCaseAddresses = _.map(addresses, address => address.toLowerCase());
-        return lowerCaseAddresses;
-    }
-    /**
-     * Retrieves a token by address currently listed in the Token Registry smart contract
-     * @return  An object that conforms to the Token interface or undefined if token not found.
-     */
-    public async getTokenIfExistsAsync(address: string): Promise<Token | undefined> {
-        assert.isETHAddressHex('address', address);
-        const normalizedAddress = address.toLowerCase();
-
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const metadata = await tokenRegistryContract.getTokenMetaData.callAsync(normalizedAddress);
-        const token = TokenRegistryWrapper._createTokenFromMetadata(metadata);
-        return token;
-    }
-    public async getTokenAddressBySymbolIfExistsAsync(symbol: string): Promise<string | undefined> {
-        assert.isString('symbol', symbol);
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const addressIfExists = await tokenRegistryContract.getTokenAddressBySymbol.callAsync(symbol);
-        if (addressIfExists === constants.NULL_ADDRESS) {
-            return undefined;
-        }
-        return addressIfExists;
-    }
-    public async getTokenAddressByNameIfExistsAsync(name: string): Promise<string | undefined> {
-        assert.isString('name', name);
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const addressIfExists = await tokenRegistryContract.getTokenAddressByName.callAsync(name);
-        if (addressIfExists === constants.NULL_ADDRESS) {
-            return undefined;
-        }
-        return addressIfExists;
-    }
-    public async getTokenBySymbolIfExistsAsync(symbol: string): Promise<Token | undefined> {
-        assert.isString('symbol', symbol);
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const metadata = await tokenRegistryContract.getTokenBySymbol.callAsync(symbol);
-        const token = TokenRegistryWrapper._createTokenFromMetadata(metadata);
-        return token;
-    }
-    public async getTokenByNameIfExistsAsync(name: string): Promise<Token | undefined> {
-        assert.isString('name', name);
-        const tokenRegistryContract = await this._getTokenRegistryContractAsync();
-        const metadata = await tokenRegistryContract.getTokenByName.callAsync(name);
-        const token = TokenRegistryWrapper._createTokenFromMetadata(metadata);
-        return token;
-    }
-    /**
-     * Retrieves the Ethereum address of the TokenRegistry contract deployed on the network
-     * that the user-passed web3 provider is connected to.
-     * @returns The Ethereum address of the TokenRegistry contract being used.
-     */
-    public getContractAddress(): string {
-        const contractAddress = this._getContractAddress(artifacts.TokenRegistry, this._contractAddressIfExists);
-        return contractAddress;
-    }
-    // tslint:disable-next-line:no-unused-variable
-    private _invalidateContractInstance(): void {
-        delete this._tokenRegistryContractIfExists;
-    }
-    private async _getTokenRegistryContractAsync(): Promise<TokenRegistryContract> {
-        if (!_.isUndefined(this._tokenRegistryContractIfExists)) {
-            return this._tokenRegistryContractIfExists;
-        }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.TokenRegistry,
-            this._contractAddressIfExists,
-        );
-        const contractInstance = new TokenRegistryContract(
-            abi,
-            address,
-            this._web3Wrapper.getProvider(),
-            this._web3Wrapper.getContractDefaults(),
-        );
-        this._tokenRegistryContractIfExists = contractInstance;
-        return this._tokenRegistryContractIfExists;
-    }
-}