Remove artifacts from migrations package and update contract-wrappers accordingly

11 files changed, 129 insertions, 318 deletions

diff --git a/packages/contract-wrappers/src/contract_wrappers.ts b/packages/contract-wrappers/src/contract_wrappers.ts
index b272fabda..8e4693da6 100644
--- a/packages/contract-wrappers/src/contract_wrappers.ts
+++ b/packages/contract-wrappers/src/contract_wrappers.ts
@@ -83,46 +83,29 @@ export class ContractWrappers {
         const blockPollingIntervalMs = _.isUndefined(config.blockPollingIntervalMs)
             ? constants.DEFAULT_BLOCK_POLLING_INTERVAL
             : config.blockPollingIntervalMs;
-        this.erc20Proxy = new ERC20ProxyWrapper(this._web3Wrapper, config.networkId, config.erc20ProxyContractAddress);
-        this.erc721Proxy = new ERC721ProxyWrapper(
-            this._web3Wrapper,
-            config.networkId,
-            config.erc721ProxyContractAddress,
-        );
-        this.erc20Token = new ERC20TokenWrapper(
-            this._web3Wrapper,
-            config.networkId,
-            this.erc20Proxy,
-            blockPollingIntervalMs,
-        );
-        this.erc721Token = new ERC721TokenWrapper(
-            this._web3Wrapper,
-            config.networkId,
-            this.erc721Proxy,
-            blockPollingIntervalMs,
-        );
-        this.etherToken = new EtherTokenWrapper(
-            this._web3Wrapper,
-            config.networkId,
-            this.erc20Token,
-            blockPollingIntervalMs,
-        );
+        if (_.isUndefined(config.contractAddresses.erc20Proxy)) {
+            throw new Error('config.contractAddresses.erc20Proxy is required for testing');
+        }
+        this.erc20Proxy = new ERC20ProxyWrapper(this._web3Wrapper, config.contractAddresses.erc20Proxy);
+        this.erc721Proxy = new ERC721ProxyWrapper(this._web3Wrapper, config.contractAddresses.erc721Proxy);
+        this.erc20Token = new ERC20TokenWrapper(this._web3Wrapper, this.erc20Proxy, blockPollingIntervalMs);
+        this.erc721Token = new ERC721TokenWrapper(this._web3Wrapper, this.erc721Proxy, blockPollingIntervalMs);
+        this.etherToken = new EtherTokenWrapper(this._web3Wrapper, this.erc20Token, blockPollingIntervalMs);
         this.exchange = new ExchangeWrapper(
             this._web3Wrapper,
-            config.networkId,
             this.erc20Token,
             this.erc721Token,
-            config.exchangeContractAddress,
-            config.zrxContractAddress,
+            config.contractAddresses.exchange,
+            config.contractAddresses.zrxToken,
             blockPollingIntervalMs,
         );
         this.forwarder = new ForwarderWrapper(
             this._web3Wrapper,
-            config.networkId,
-            config.forwarderContractAddress,
-            config.zrxContractAddress,
+            config.contractAddresses.forwarder,
+            config.contractAddresses.zrxToken,
+            config.contractAddresses.etherToken,
         );
-        this.orderValidator = new OrderValidatorWrapper(this._web3Wrapper, config.networkId);
+        this.orderValidator = new OrderValidatorWrapper(this._web3Wrapper, config.contractAddresses.orderValidator);
     }
     /**
      * Sets a new web3 provider for 0x.js. Updating the provider will stop all
@@ -130,16 +113,17 @@ export class ContractWrappers {
      * @param   provider    The Web3Provider you would like the 0x.js library to use from now on.
      * @param   networkId   The id of the network your provider is connected to
      */
-    public setProvider(provider: Provider, networkId: number): void {
+    public setProvider(provider: Provider): void {
+        // TODO(albrow): Make sure all contract wrappers are called below.
         this._web3Wrapper.setProvider(provider);
         (this.exchange as any)._invalidateContractInstances();
-        (this.exchange as any)._setNetworkId(networkId);
         (this.erc20Token as any)._invalidateContractInstances();
-        (this.erc20Token as any)._setNetworkId(networkId);
         (this.erc20Proxy as any)._invalidateContractInstance();
-        (this.erc20Proxy as any)._setNetworkId(networkId);
+        (this.erc721Token as any)._invalidateContractInstances();
+        (this.erc721Proxy as any)._invalidateContractInstance();
         (this.etherToken as any)._invalidateContractInstance();
-        (this.etherToken as any)._setNetworkId(networkId);
+        (this.forwarder as any)._invalidateContractInstance();
+        (this.orderValidator as any)._invalidateContractInstance();
     }
     /**
      * Get the provider instance currently used by 0x.js
diff --git a/packages/contract-wrappers/src/contract_wrappers/contract_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/contract_wrapper.ts
index f7a89e3be..aed9d44db 100644
--- a/packages/contract-wrappers/src/contract_wrappers/contract_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/contract_wrapper.ts
@@ -3,7 +3,6 @@ import { marshaller, Web3Wrapper } from '@0xproject/web3-wrapper';
 import {
     BlockParamLiteral,
     ContractAbi,
-    ContractArtifact,
     FilterObject,
     LogEntry,
     LogWithDecodedArgs,
@@ -24,22 +23,9 @@ import {
 import { constants } from '../utils/constants';
 import { filterUtils } from '../utils/filter_utils';
 
-const CONTRACT_NAME_TO_NOT_FOUND_ERROR: {
-    [contractName: string]: ContractWrappersError;
-} = {
-    ZRX: ContractWrappersError.ZRXContractDoesNotExist,
-    EtherToken: ContractWrappersError.EtherTokenContractDoesNotExist,
-    ERC20Token: ContractWrappersError.ERC20TokenContractDoesNotExist,
-    ERC20Proxy: ContractWrappersError.ERC20ProxyContractDoesNotExist,
-    ERC721Token: ContractWrappersError.ERC721TokenContractDoesNotExist,
-    ERC721Proxy: ContractWrappersError.ERC721ProxyContractDoesNotExist,
-    Exchange: ContractWrappersError.ExchangeContractDoesNotExist,
-};
-
 export abstract class ContractWrapper {
     public abstract abi: ContractAbi;
     protected _web3Wrapper: Web3Wrapper;
-    protected _networkId: number;
     private _blockAndLogStreamerIfExists: BlockAndLogStreamer<Block, Log> | undefined;
     private _blockPollingIntervalMs: number;
     private _blockAndLogStreamIntervalIfExists?: NodeJS.Timer;
@@ -56,9 +42,8 @@ export abstract class ContractWrapper {
             logUtils.warn(err);
         }
     }
-    constructor(web3Wrapper: Web3Wrapper, networkId: number, blockPollingIntervalMs?: number) {
+    constructor(web3Wrapper: Web3Wrapper, blockPollingIntervalMs?: number) {
         this._web3Wrapper = web3Wrapper;
-        this._networkId = networkId;
         this._blockPollingIntervalMs = _.isUndefined(blockPollingIntervalMs)
             ? constants.DEFAULT_BLOCK_POLLING_INTERVAL
             : blockPollingIntervalMs;
@@ -124,40 +109,6 @@ export abstract class ContractWrapper {
         const logWithDecodedArgs = abiDecoder.tryToDecodeLogOrNoop(log);
         return logWithDecodedArgs;
     }
-    protected async _getContractAbiAndAddressFromArtifactsAsync(
-        artifact: ContractArtifact,
-        addressIfExists?: string,
-    ): Promise<[ContractAbi, string]> {
-        let contractAddress: string;
-        if (_.isUndefined(addressIfExists)) {
-            if (_.isUndefined(artifact.networks[this._networkId])) {
-                throw new Error(ContractWrappersError.ContractNotDeployedOnNetwork);
-            }
-            contractAddress = artifact.networks[this._networkId].address.toLowerCase();
-        } else {
-            contractAddress = addressIfExists;
-        }
-        const doesContractExist = await this._web3Wrapper.doesContractExistAtAddressAsync(contractAddress);
-        if (!doesContractExist) {
-            throw new Error(CONTRACT_NAME_TO_NOT_FOUND_ERROR[artifact.contractName]);
-        }
-        const abiAndAddress: [ContractAbi, string] = [artifact.compilerOutput.abi, contractAddress];
-        return abiAndAddress;
-    }
-    protected _getContractAddress(artifact: ContractArtifact, addressIfExists?: string): string {
-        if (_.isUndefined(addressIfExists)) {
-            if (_.isUndefined(artifact.networks[this._networkId])) {
-                throw new Error(ContractWrappersError.ContractNotDeployedOnNetwork);
-            }
-            const contractAddress = artifact.networks[this._networkId].address;
-            if (_.isUndefined(contractAddress)) {
-                throw new Error(CONTRACT_NAME_TO_NOT_FOUND_ERROR[artifact.contractName]);
-            }
-            return contractAddress;
-        } else {
-            return addressIfExists;
-        }
-    }
     private _onLogStateChanged<ArgsType extends ContractEventArgs>(isRemoved: boolean, rawLog: RawLogEntry): void {
         const log: LogEntry = marshaller.unmarshalLog(rawLog);
         _.forEach(this._filters, (filter: FilterObject, filterToken: string) => {
@@ -222,14 +173,6 @@ export abstract class ContractWrapper {
         });
         return logs as RawLogEntry[];
     }
-    // HACK: This should be a package-scoped method (which doesn't exist in TS)
-    // We don't want this method available in the public interface for all classes
-    // who inherit from ContractWrapper, and it is only used by the internal implementation
-    // of those higher classes.
-    // tslint:disable-next-line:no-unused-variable
-    private _setNetworkId(networkId: number): void {
-        this._networkId = networkId;
-    }
     private _stopBlockAndLogStream(): void {
         if (_.isUndefined(this._blockAndLogStreamerIfExists)) {
             throw new Error(ContractWrappersError.SubscriptionNotFound);
diff --git a/packages/contract-wrappers/src/contract_wrappers/erc20_proxy_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc20_proxy_wrapper.ts
index 5900f0502..31b3b6755 100644
--- a/packages/contract-wrappers/src/contract_wrappers/erc20_proxy_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/erc20_proxy_wrapper.ts
@@ -13,25 +13,25 @@ import { ContractWrapper } from './contract_wrapper';
  */
 export class ERC20ProxyWrapper extends ContractWrapper {
     public abi: ContractAbi = artifacts.ERC20Proxy.compilerOutput.abi;
+    public address: string;
     private _erc20ProxyContractIfExists?: wrappers.ERC20ProxyContract;
-    private _contractAddressIfExists?: string;
     /**
      * Instantiate ERC20ProxyWrapper
      * @param web3Wrapper Web3Wrapper instance to use
-     * @param networkId Desired networkId
-     * @param contractAddressIfExists The contract address to use. This is usually pulled from
-     * the artifacts but needs to be specified when using with your own custom testnet.
+     * @param address The address of the ERC20Proxy contract
      */
-    constructor(web3Wrapper: Web3Wrapper, networkId: number, contractAddressIfExists?: string) {
-        super(web3Wrapper, networkId);
-        this._contractAddressIfExists = contractAddressIfExists;
+    // TODO(albrow): Make address optional and default to looking up the address
+    // based in a hard-coded mapping based on web3Wrapper network id.
+    constructor(web3Wrapper: Web3Wrapper, address: string) {
+        super(web3Wrapper);
+        this.address = address;
     }
     /**
      * Get the 4 bytes ID of this asset proxy
      * @return  Proxy id
      */
     public async getProxyIdAsync(): Promise<AssetProxyId> {
-        const ERC20ProxyContractInstance = await this._getERC20ProxyContractAsync();
+        const ERC20ProxyContractInstance = this._getERC20ProxyContract();
         const proxyId = (await ERC20ProxyContractInstance.getProxyId.callAsync()) as AssetProxyId;
         return proxyId;
     }
@@ -43,7 +43,7 @@ export class ERC20ProxyWrapper extends ContractWrapper {
     public async isAuthorizedAsync(exchangeContractAddress: string): Promise<boolean> {
         assert.isETHAddressHex('exchangeContractAddress', exchangeContractAddress);
         const normalizedExchangeContractAddress = exchangeContractAddress.toLowerCase();
-        const ERC20ProxyContractInstance = await this._getERC20ProxyContractAsync();
+        const ERC20ProxyContractInstance = this._getERC20ProxyContract();
         const isAuthorized = await ERC20ProxyContractInstance.authorized.callAsync(normalizedExchangeContractAddress);
         return isAuthorized;
     }
@@ -52,36 +52,23 @@ export class ERC20ProxyWrapper extends ContractWrapper {
      * @return  The list of authorized addresses.
      */
     public async getAuthorizedAddressesAsync(): Promise<string[]> {
-        const ERC20ProxyContractInstance = await this._getERC20ProxyContractAsync();
+        const ERC20ProxyContractInstance = this._getERC20ProxyContract();
         const authorizedAddresses = await ERC20ProxyContractInstance.getAuthorizedAddresses.callAsync();
         return authorizedAddresses;
     }
-    /**
-     * 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 ERC20Proxy contract being used.
-     */
-    public getContractAddress(): string {
-        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._erc20ProxyContractIfExists;
     }
-    private async _getERC20ProxyContractAsync(): Promise<wrappers.ERC20ProxyContract> {
+    private _getERC20ProxyContract(): wrappers.ERC20ProxyContract {
         if (!_.isUndefined(this._erc20ProxyContractIfExists)) {
             return this._erc20ProxyContractIfExists;
         }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.ERC20Proxy,
-            this._contractAddressIfExists,
-        );
         const contractInstance = new wrappers.ERC20ProxyContract(
-            abi,
-            address,
+            this.abi,
+            this.address,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
diff --git a/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts
index 3be5bcaee..53cda5d08 100644
--- a/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/erc20_token_wrapper.ts
@@ -36,17 +36,11 @@ export class ERC20TokenWrapper extends ContractWrapper {
     /**
      * Instantiate ERC20TokenWrapper
      * @param web3Wrapper Web3Wrapper instance to use
-     * @param networkId Desired networkId
      * @param erc20ProxyWrapper The ERC20ProxyWrapper instance to use
      * @param blockPollingIntervalMs The block polling interval to use for active subscriptions
      */
-    constructor(
-        web3Wrapper: Web3Wrapper,
-        networkId: number,
-        erc20ProxyWrapper: ERC20ProxyWrapper,
-        blockPollingIntervalMs?: number,
-    ) {
-        super(web3Wrapper, networkId, blockPollingIntervalMs);
+    constructor(web3Wrapper: Web3Wrapper, erc20ProxyWrapper: ERC20ProxyWrapper, blockPollingIntervalMs?: number) {
+        super(web3Wrapper, blockPollingIntervalMs);
         this._tokenContractsByAddress = {};
         this._erc20ProxyWrapper = erc20ProxyWrapper;
     }
@@ -188,7 +182,7 @@ export class ERC20TokenWrapper extends ContractWrapper {
         ownerAddress: string,
         methodOpts: MethodOpts = {},
     ): Promise<BigNumber> {
-        const proxyAddress = this._erc20ProxyWrapper.getContractAddress();
+        const proxyAddress = this._erc20ProxyWrapper.address;
         const allowanceInBaseUnits = await this.getAllowanceAsync(tokenAddress, ownerAddress, proxyAddress, methodOpts);
         return allowanceInBaseUnits;
     }
@@ -208,7 +202,7 @@ export class ERC20TokenWrapper extends ContractWrapper {
         amountInBaseUnits: BigNumber,
         txOpts: TransactionOpts = {},
     ): Promise<string> {
-        const proxyAddress = this._erc20ProxyWrapper.getContractAddress();
+        const proxyAddress = this._erc20ProxyWrapper.address;
         const txHash = await this.setAllowanceAsync(
             tokenAddress,
             ownerAddress,
@@ -434,13 +428,15 @@ export class ERC20TokenWrapper extends ContractWrapper {
         if (!_.isUndefined(tokenContract)) {
             return tokenContract;
         }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.ERC20Token,
-            normalizedTokenAddress,
-        );
+        // TODO(albrow): Do we really still need this check? The default error
+        // looks okay to me.
+        const doesContractExist = await this._web3Wrapper.doesContractExistAtAddressAsync(tokenAddress);
+        if (!doesContractExist) {
+            throw new Error(ContractWrappersError.ERC20TokenContractDoesNotExist);
+        }
         const contractInstance = new wrappers.ERC20TokenContract(
-            abi,
-            address,
+            this.abi,
+            normalizedTokenAddress,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
diff --git a/packages/contract-wrappers/src/contract_wrappers/erc721_proxy_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc721_proxy_wrapper.ts
index 6ba162213..2472d512b 100644
--- a/packages/contract-wrappers/src/contract_wrappers/erc721_proxy_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/erc721_proxy_wrapper.ts
@@ -13,25 +13,25 @@ import { ContractWrapper } from './contract_wrapper';
  */
 export class ERC721ProxyWrapper extends ContractWrapper {
     public abi: ContractAbi = artifacts.ERC20Proxy.compilerOutput.abi;
+    public address: string;
     private _erc721ProxyContractIfExists?: wrappers.ERC721ProxyContract;
-    private _contractAddressIfExists?: string;
     /**
      * Instantiate ERC721ProxyWrapper
      * @param web3Wrapper Web3Wrapper instance to use
-     * @param networkId Desired networkId
-     * @param contractAddressIfExists The contract address to use. This is usually pulled from
-     * the artifacts but needs to be specified when using with your own custom testnet.
+     * @param address The address of the ERC721Proxy contract
      */
-    constructor(web3Wrapper: Web3Wrapper, networkId: number, contractAddressIfExists?: string) {
-        super(web3Wrapper, networkId);
-        this._contractAddressIfExists = contractAddressIfExists;
+    // TODO(albrow): Make address optional and default to looking up the address
+    // based in a hard-coded mapping based on web3Wrapper network id.
+    constructor(web3Wrapper: Web3Wrapper, address: string) {
+        super(web3Wrapper);
+        this.address = address;
     }
     /**
      * Get the 4 bytes ID of this asset proxy
      * @return  Proxy id
      */
     public async getProxyIdAsync(): Promise<AssetProxyId> {
-        const ERC721ProxyContractInstance = await this._getERC721ProxyContractAsync();
+        const ERC721ProxyContractInstance = await this._getERC721ProxyContract();
         const proxyId = (await ERC721ProxyContractInstance.getProxyId.callAsync()) as AssetProxyId;
         return proxyId;
     }
@@ -43,7 +43,7 @@ export class ERC721ProxyWrapper extends ContractWrapper {
     public async isAuthorizedAsync(exchangeContractAddress: string): Promise<boolean> {
         assert.isETHAddressHex('exchangeContractAddress', exchangeContractAddress);
         const normalizedExchangeContractAddress = exchangeContractAddress.toLowerCase();
-        const ERC721ProxyContractInstance = await this._getERC721ProxyContractAsync();
+        const ERC721ProxyContractInstance = await this._getERC721ProxyContract();
         const isAuthorized = await ERC721ProxyContractInstance.authorized.callAsync(normalizedExchangeContractAddress);
         return isAuthorized;
     }
@@ -52,36 +52,23 @@ export class ERC721ProxyWrapper extends ContractWrapper {
      * @return  The list of authorized addresses.
      */
     public async getAuthorizedAddressesAsync(): Promise<string[]> {
-        const ERC721ProxyContractInstance = await this._getERC721ProxyContractAsync();
+        const ERC721ProxyContractInstance = await this._getERC721ProxyContract();
         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<wrappers.ERC721ProxyContract> {
+    private _getERC721ProxyContract(): wrappers.ERC721ProxyContract {
         if (!_.isUndefined(this._erc721ProxyContractIfExists)) {
             return this._erc721ProxyContractIfExists;
         }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.ERC721Proxy,
-            this._contractAddressIfExists,
-        );
         const contractInstance = new wrappers.ERC721ProxyContract(
-            abi,
-            address,
+            this.abi,
+            this.address,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
diff --git a/packages/contract-wrappers/src/contract_wrappers/erc721_token_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/erc721_token_wrapper.ts
index 23b335710..7fcd74eaf 100644
--- a/packages/contract-wrappers/src/contract_wrappers/erc721_token_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/erc721_token_wrapper.ts
@@ -35,17 +35,11 @@ export class ERC721TokenWrapper extends ContractWrapper {
     /**
      * Instantiate ERC721TokenWrapper
      * @param web3Wrapper Web3Wrapper instance to use
-     * @param networkId Desired networkId
      * @param erc721ProxyWrapper The ERC721ProxyWrapper instance to use
      * @param blockPollingIntervalMs The block polling interval to use for active subscriptions
      */
-    constructor(
-        web3Wrapper: Web3Wrapper,
-        networkId: number,
-        erc721ProxyWrapper: ERC721ProxyWrapper,
-        blockPollingIntervalMs?: number,
-    ) {
-        super(web3Wrapper, networkId, blockPollingIntervalMs);
+    constructor(web3Wrapper: Web3Wrapper, erc721ProxyWrapper: ERC721ProxyWrapper, blockPollingIntervalMs?: number) {
+        super(web3Wrapper, blockPollingIntervalMs);
         this._tokenContractsByAddress = {};
         this._erc721ProxyWrapper = erc721ProxyWrapper;
     }
@@ -149,7 +143,7 @@ export class ERC721TokenWrapper extends ContractWrapper {
         ownerAddress: string,
         methodOpts: MethodOpts = {},
     ): Promise<boolean> {
-        const proxyAddress = this._erc721ProxyWrapper.getContractAddress();
+        const proxyAddress = this._erc721ProxyWrapper.address;
         const isProxyApprovedForAll = await this.isApprovedForAllAsync(
             tokenAddress,
             ownerAddress,
@@ -198,7 +192,7 @@ export class ERC721TokenWrapper extends ContractWrapper {
         tokenId: BigNumber,
         methodOpts: MethodOpts = {},
     ): Promise<boolean> {
-        const proxyAddress = this._erc721ProxyWrapper.getContractAddress();
+        const proxyAddress = this._erc721ProxyWrapper.address;
         const approvedAddress = await this.getApprovedIfExistsAsync(tokenAddress, tokenId, methodOpts);
         const isProxyApproved = approvedAddress === proxyAddress;
         return isProxyApproved;
@@ -259,7 +253,7 @@ export class ERC721TokenWrapper extends ContractWrapper {
         isApproved: boolean,
         txOpts: TransactionOpts = {},
     ): Promise<string> {
-        const proxyAddress = this._erc721ProxyWrapper.getContractAddress();
+        const proxyAddress = this._erc721ProxyWrapper.address;
         const txHash = await this.setApprovalForAllAsync(tokenAddress, ownerAddress, proxyAddress, isApproved, txOpts);
         return txHash;
     }
@@ -317,7 +311,7 @@ export class ERC721TokenWrapper extends ContractWrapper {
         tokenId: BigNumber,
         txOpts: TransactionOpts = {},
     ): Promise<string> {
-        const proxyAddress = this._erc721ProxyWrapper.getContractAddress();
+        const proxyAddress = this._erc721ProxyWrapper.address;
         const txHash = await this.setApprovalAsync(tokenAddress, proxyAddress, tokenId, txOpts);
         return txHash;
     }
@@ -461,13 +455,15 @@ export class ERC721TokenWrapper extends ContractWrapper {
         if (!_.isUndefined(tokenContract)) {
             return tokenContract;
         }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.ERC721Token,
-            normalizedTokenAddress,
-        );
+        // TODO(albrow): Do we really still need this check? The default error
+        // looks okay to me.
+        const doesContractExist = await this._web3Wrapper.doesContractExistAtAddressAsync(tokenAddress);
+        if (!doesContractExist) {
+            throw new Error(ContractWrappersError.ERC721TokenContractDoesNotExist);
+        }
         const contractInstance = new wrappers.ERC721TokenContract(
-            abi,
-            address,
+            this.abi,
+            normalizedTokenAddress,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
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 30653adf2..526324abd 100644
--- a/packages/contract-wrappers/src/contract_wrappers/ether_token_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/ether_token_wrapper.ts
@@ -30,13 +30,8 @@ export class EtherTokenWrapper extends ContractWrapper {
      * @param erc20TokenWrapper The ERC20TokenWrapper instance to use
      * @param blockPollingIntervalMs The block polling interval to use for active subscriptions
      */
-    constructor(
-        web3Wrapper: Web3Wrapper,
-        networkId: number,
-        erc20TokenWrapper: ERC20TokenWrapper,
-        blockPollingIntervalMs?: number,
-    ) {
-        super(web3Wrapper, networkId, blockPollingIntervalMs);
+    constructor(web3Wrapper: Web3Wrapper, erc20TokenWrapper: ERC20TokenWrapper, blockPollingIntervalMs?: number) {
+        super(web3Wrapper, blockPollingIntervalMs);
         this._erc20TokenWrapper = erc20TokenWrapper;
     }
     /**
@@ -191,19 +186,6 @@ export class EtherTokenWrapper extends ContractWrapper {
     public unsubscribeAll(): void {
         super._unsubscribeAll();
     }
-    /**
-     * Retrieves the Ethereum address of the EtherToken contract deployed on the network
-     * that the user-passed web3 provider is connected to. If it's not Kovan, Ropsten, Rinkeby, Mainnet or TestRPC
-     * (networkId: 50), it will return undefined (e.g a private network).
-     * @returns The Ethereum address of the EtherToken contract or undefined.
-     */
-    public getContractAddressIfExists(): string | undefined {
-        const networkSpecificArtifact = artifacts.WETH9.networks[this._networkId];
-        const contractAddressIfExists = _.isUndefined(networkSpecificArtifact)
-            ? undefined
-            : networkSpecificArtifact.address;
-        return contractAddressIfExists;
-    }
     // tslint:disable-next-line:no-unused-variable
     private _invalidateContractInstance(): void {
         this.unsubscribeAll();
@@ -214,13 +196,16 @@ export class EtherTokenWrapper extends ContractWrapper {
         if (!_.isUndefined(etherTokenContract)) {
             return etherTokenContract;
         }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.WETH9,
-            etherTokenAddress,
-        );
+        // TODO(albrow): Do we really still need this check? The default error
+        // looks okay to me.
+        // TODO(albrow): Should we normalize the token address here?
+        const doesContractExist = await this._web3Wrapper.doesContractExistAtAddressAsync(etherTokenAddress);
+        if (!doesContractExist) {
+            throw new Error(ContractWrappersError.EtherTokenContractDoesNotExist);
+        }
         const contractInstance = new wrappers.WETH9Contract(
-            abi,
-            address,
+            this.abi,
+            etherTokenAddress,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
diff --git a/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
index 613747720..b65baee55 100644
--- a/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/exchange_wrapper.ts
@@ -24,7 +24,6 @@ import {
     IndexedFilterValues,
     MethodOpts,
     OrderInfo,
-    OrderStatus,
     OrderTransactionOpts,
     ValidateOrderFillableOpts,
 } from '../types';
@@ -42,35 +41,34 @@ import { ERC721TokenWrapper } from './erc721_token_wrapper';
  */
 export class ExchangeWrapper extends ContractWrapper {
     public abi: ContractAbi = artifacts.Exchange.compilerOutput.abi;
+    public address: string;
+    public zrxTokenAddress: string;
     private _exchangeContractIfExists?: wrappers.ExchangeContract;
     private _erc721TokenWrapper: ERC721TokenWrapper;
     private _erc20TokenWrapper: ERC20TokenWrapper;
-    private _contractAddressIfExists?: string;
-    private _zrxContractAddressIfExists?: string;
     /**
      * Instantiate ExchangeWrapper
-     * @param web3Wrapper Web3Wrapper instance to use
-     * @param networkId Desired networkId
-     * @param contractAddressIfExists The exchange contract address to use. This is usually pulled from
-     * the artifacts but needs to be specified when using with your own custom testnet.
-     * @param zrxContractAddressIfExists The ZRXToken contract address to use. This is usually pulled from
-     * the artifacts but needs to be specified when using with your own custom testnet.
-     * @param blockPollingIntervalMs The block polling interval to use for active subscriptions
+     * @param web3Wrapper Web3Wrapper instance to use.
+     * @param erc20TokenWrapper ERC20TokenWrapper instance to use.
+     * @param erc721TokenWrapper ERC721TokenWrapper instance to use.
+     * @param address The address of the Exchange contract.
+     * @param zrxTokenAddress The address of the ZRX Token contract.
+     * @param blockPollingIntervalMs The block polling interval to use for active subscriptions.
      */
     constructor(
         web3Wrapper: Web3Wrapper,
-        networkId: number,
         erc20TokenWrapper: ERC20TokenWrapper,
         erc721TokenWrapper: ERC721TokenWrapper,
-        contractAddressIfExists?: string,
-        zrxContractAddressIfExists?: string,
+        // TODO(albrow): Make address optional?
+        address: string,
+        zrxTokenAddress: string,
         blockPollingIntervalMs?: number,
     ) {
-        super(web3Wrapper, networkId, blockPollingIntervalMs);
+        super(web3Wrapper, blockPollingIntervalMs);
         this._erc20TokenWrapper = erc20TokenWrapper;
         this._erc721TokenWrapper = erc721TokenWrapper;
-        this._contractAddressIfExists = contractAddressIfExists;
-        this._zrxContractAddressIfExists = zrxContractAddressIfExists;
+        this.address = address;
+        this.zrxTokenAddress = zrxTokenAddress;
     }
     /**
      * Retrieve the address of an asset proxy by signature.
@@ -1050,9 +1048,8 @@ export class ExchangeWrapper extends ContractWrapper {
         assert.doesBelongToStringEnum('eventName', eventName, wrappers.ExchangeEvents);
         assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
         assert.isFunction('callback', callback);
-        const exchangeContractAddress = this.getContractAddress();
         const subscriptionToken = this._subscribe<ArgsType>(
-            exchangeContractAddress,
+            this.address,
             eventName,
             indexFilterValues,
             artifacts.Exchange.compilerOutput.abi,
@@ -1090,9 +1087,8 @@ export class ExchangeWrapper extends ContractWrapper {
         assert.doesBelongToStringEnum('eventName', eventName, wrappers.ExchangeEvents);
         assert.doesConformToSchema('blockRange', blockRange, schemas.blockRangeSchema);
         assert.doesConformToSchema('indexFilterValues', indexFilterValues, schemas.indexFilterValuesSchema);
-        const exchangeContractAddress = this.getContractAddress();
         const logs = await this._getLogsAsync<ArgsType>(
-            exchangeContractAddress,
+            this.address,
             eventName,
             blockRange,
             indexFilterValues,
@@ -1159,29 +1155,11 @@ export class ExchangeWrapper extends ContractWrapper {
         );
     }
     /**
-     * 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;
-    }
-    /**
-     * Returns the ZRX token address used by the exchange contract.
-     * @return Address of ZRX token
-     */
-    public getZRXTokenAddress(): string {
-        const contractAddress = this._getContractAddress(artifacts.ZRXToken, this._zrxContractAddressIfExists);
-        return contractAddress;
-    }
-    /**
      * Returns the ZRX asset data used by the exchange contract.
      * @return ZRX asset data
      */
     public getZRXAssetData(): string {
-        const zrxTokenAddress = this.getZRXTokenAddress();
-        const zrxAssetData = assetDataUtils.encodeERC20AssetData(zrxTokenAddress);
+        const zrxAssetData = assetDataUtils.encodeERC20AssetData(this.zrxTokenAddress);
         return zrxAssetData;
     }
     /**
@@ -1204,13 +1182,9 @@ export class ExchangeWrapper extends ContractWrapper {
         if (!_.isUndefined(this._exchangeContractIfExists)) {
             return this._exchangeContractIfExists;
         }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.Exchange,
-            this._contractAddressIfExists,
-        );
         const contractInstance = new wrappers.ExchangeContract(
-            abi,
-            address,
+            this.abi,
+            this.address,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
diff --git a/packages/contract-wrappers/src/contract_wrappers/forwarder_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/forwarder_wrapper.ts
index 854a8381b..cd8f9ece9 100644
--- a/packages/contract-wrappers/src/contract_wrappers/forwarder_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/forwarder_wrapper.ts
@@ -22,18 +22,16 @@ import { ContractWrapper } from './contract_wrapper';
  */
 export class ForwarderWrapper extends ContractWrapper {
     public abi: ContractAbi = artifacts.Forwarder.compilerOutput.abi;
+    public address: string;
+    public zrxTokenAddress: string;
+    public etherTokenAddress: string;
     private _forwarderContractIfExists?: wrappers.ForwarderContract;
-    private _contractAddressIfExists?: string;
-    private _zrxContractAddressIfExists?: string;
-    constructor(
-        web3Wrapper: Web3Wrapper,
-        networkId: number,
-        contractAddressIfExists?: string,
-        zrxContractAddressIfExists?: string,
-    ) {
-        super(web3Wrapper, networkId);
-        this._contractAddressIfExists = contractAddressIfExists;
-        this._zrxContractAddressIfExists = zrxContractAddressIfExists;
+    // TODO(albrow): Make addresses optional?
+    constructor(web3Wrapper: Web3Wrapper, address: string, zrxTokenAddress: string, etherTokenAddress: string) {
+        super(web3Wrapper);
+        this.address = address;
+        this.zrxTokenAddress = zrxTokenAddress;
+        this.etherTokenAddress = etherTokenAddress;
     }
     /**
      * Purchases as much of orders' makerAssets as possible by selling up to 95% of transaction's ETH value.
@@ -72,12 +70,8 @@ export class ForwarderWrapper extends ContractWrapper {
         assert.isETHAddressHex('feeRecipientAddress', feeRecipientAddress);
         assert.doesConformToSchema('orderTransactionOpts', orderTransactionOpts, orderTxOptsSchema, [txOptsSchema]);
         // other assertions
-        assert.ordersCanBeUsedForForwarderContract(signedOrders, this.getEtherTokenAddress());
-        assert.feeOrdersCanBeUsedForForwarderContract(
-            signedFeeOrders,
-            this.getZRXTokenAddress(),
-            this.getEtherTokenAddress(),
-        );
+        assert.ordersCanBeUsedForForwarderContract(signedOrders, this.etherTokenAddress);
+        assert.feeOrdersCanBeUsedForForwarderContract(signedFeeOrders, this.zrxTokenAddress, this.etherTokenAddress);
         // format feePercentage
         const formattedFeePercentage = utils.numberPercentageToEtherTokenAmountPercentage(feePercentage);
         // lowercase input addresses
@@ -164,12 +158,8 @@ export class ForwarderWrapper extends ContractWrapper {
         assert.isETHAddressHex('feeRecipientAddress', feeRecipientAddress);
         assert.doesConformToSchema('orderTransactionOpts', orderTransactionOpts, orderTxOptsSchema, [txOptsSchema]);
         // other assertions
-        assert.ordersCanBeUsedForForwarderContract(signedOrders, this.getEtherTokenAddress());
-        assert.feeOrdersCanBeUsedForForwarderContract(
-            signedFeeOrders,
-            this.getZRXTokenAddress(),
-            this.getEtherTokenAddress(),
-        );
+        assert.ordersCanBeUsedForForwarderContract(signedOrders, this.etherTokenAddress);
+        assert.feeOrdersCanBeUsedForForwarderContract(signedFeeOrders, this.zrxTokenAddress, this.etherTokenAddress);
         // format feePercentage
         const formattedFeePercentage = utils.numberPercentageToEtherTokenAmountPercentage(feePercentage);
         // lowercase input addresses
@@ -219,31 +209,6 @@ export class ForwarderWrapper extends ContractWrapper {
         );
         return txHash;
     }
-    /**
-     * Retrieves the Ethereum address of the Forwarder contract deployed on the network
-     * that the user-passed web3 provider is connected to.
-     * @returns The Ethereum address of the Forwarder contract being used.
-     */
-    public getContractAddress(): string {
-        const contractAddress = this._getContractAddress(artifacts.Forwarder, this._contractAddressIfExists);
-        return contractAddress;
-    }
-    /**
-     * Returns the ZRX token address used by the forwarder contract.
-     * @return Address of ZRX token
-     */
-    public getZRXTokenAddress(): string {
-        const contractAddress = this._getContractAddress(artifacts.ZRXToken, this._zrxContractAddressIfExists);
-        return contractAddress;
-    }
-    /**
-     * Returns the Ether token address used by the forwarder contract.
-     * @return Address of Ether token
-     */
-    public getEtherTokenAddress(): string {
-        const contractAddress = this._getContractAddress(artifacts.WETH9);
-        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
@@ -254,13 +219,9 @@ export class ForwarderWrapper extends ContractWrapper {
         if (!_.isUndefined(this._forwarderContractIfExists)) {
             return this._forwarderContractIfExists;
         }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(
-            artifacts.Forwarder,
-            this._contractAddressIfExists,
-        );
         const contractInstance = new wrappers.ForwarderContract(
-            abi,
-            address,
+            this.abi,
+            this.address,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
diff --git a/packages/contract-wrappers/src/contract_wrappers/order_validator_wrapper.ts b/packages/contract-wrappers/src/contract_wrappers/order_validator_wrapper.ts
index 02f9dd4de..23e0d42c1 100644
--- a/packages/contract-wrappers/src/contract_wrappers/order_validator_wrapper.ts
+++ b/packages/contract-wrappers/src/contract_wrappers/order_validator_wrapper.ts
@@ -16,14 +16,17 @@ import { ContractWrapper } from './contract_wrapper';
  */
 export class OrderValidatorWrapper extends ContractWrapper {
     public abi: ContractAbi = artifacts.OrderValidator.compilerOutput.abi;
+    public address: string;
     private _orderValidatorContractIfExists?: wrappers.OrderValidatorContract;
     /**
      * Instantiate OrderValidatorWrapper
-     * @param web3Wrapper Web3Wrapper instance to use
-     * @param networkId Desired networkId
+     * @param web3Wrapper Web3Wrapper instance to use.
+     * @param address The address of the OrderValidator contract.
      */
-    constructor(web3Wrapper: Web3Wrapper, networkId: number) {
-        super(web3Wrapper, networkId);
+    // TODO(albrow): Make address optional?
+    constructor(web3Wrapper: Web3Wrapper, address: string) {
+        super(web3Wrapper);
+        this.address = address;
     }
     /**
      * Get an object conforming to OrderAndTraderInfo containing on-chain information of the provided order and address
@@ -173,10 +176,9 @@ export class OrderValidatorWrapper extends ContractWrapper {
         if (!_.isUndefined(this._orderValidatorContractIfExists)) {
             return this._orderValidatorContractIfExists;
         }
-        const [abi, address] = await this._getContractAbiAndAddressFromArtifactsAsync(artifacts.OrderValidator);
         const contractInstance = new wrappers.OrderValidatorContract(
-            abi,
-            address,
+            this.abi,
+            this.address,
             this._web3Wrapper.getProvider(),
             this._web3Wrapper.getContractDefaults(),
         );
diff --git a/packages/contract-wrappers/src/types.ts b/packages/contract-wrappers/src/types.ts
index 0ac5f05e4..f882cc188 100644
--- a/packages/contract-wrappers/src/types.ts
+++ b/packages/contract-wrappers/src/types.ts
@@ -1,7 +1,7 @@
 import { wrappers } from '@0xproject/contracts';
+import { ContractAddresses, OrderState, SignedOrder } from '@0xproject/types';
 import { BigNumber } from '@0xproject/utils';
 
-import { OrderState, SignedOrder } from '@0xproject/types';
 import { BlockParam, ContractEventArg, DecodedLogArgs, LogEntryEvent, LogWithDecodedArgs } from 'ethereum-types';
 
 export enum ExchangeWrapperError {
@@ -120,11 +120,7 @@ export type SyncMethod = (...args: any[]) => any;
 export interface ContractWrappersConfig {
     networkId: number;
     gasPrice?: BigNumber;
-    exchangeContractAddress?: string;
-    zrxContractAddress?: string;
-    erc20ProxyContractAddress?: string;
-    erc721ProxyContractAddress?: string;
-    forwarderContractAddress?: string;
+    contractAddresses: ContractAddresses;
     blockPollingIntervalMs?: number;
 }