2 files changed, 10 insertions, 17 deletions
diff --git a/packages/0x.js/src/0x.ts b/packages/0x.js/src/0x.ts
index 85c2b7724..1f4af9fea 100644
--- a/packages/0x.js/src/0x.ts
+++ b/packages/0x.js/src/0x.ts
@@ -169,17 +169,14 @@ export class ZeroEx {
      * @param   config      The configuration object. Look up the type for the description.
      * @return  An instance of the 0x.js ZeroEx class.
      */
-    constructor(provider: Web3Provider, config?: ZeroExConfig) {
+    constructor(provider: Web3Provider, config: ZeroExConfig) {
         assert.isWeb3Provider('provider', provider);
-        if (!_.isUndefined(config)) {
-            assert.doesConformToSchema('config', config, zeroExConfigSchema);
-        }
+        assert.doesConformToSchema('config', config, zeroExConfigSchema);
         const artifactJSONs = _.values(artifacts);
         const abiArrays = _.map(artifactJSONs, artifact => artifact.abi);
         this._abiDecoder = new AbiDecoder(abiArrays);
-        const gasPrice = _.isUndefined(config) ? undefined : config.gasPrice;
         const defaults = {
-            gasPrice,
+            gasPrice: config.gasPrice,
         };
         this._web3Wrapper = new Web3Wrapper(provider, defaults);
         this.token = new TokenWrapper(
@@ -187,26 +184,20 @@ export class ZeroEx {
             this._abiDecoder,
             this._getTokenTransferProxyAddressAsync.bind(this),
         );
-        const exchageContractAddressIfExists = _.isUndefined(config) ? undefined : config.exchangeContractAddress;
         this.exchange = new ExchangeWrapper(
             this._web3Wrapper,
             this._abiDecoder,
             this.token,
-            exchageContractAddressIfExists,
+            config.exchangeContractAddress,
         );
         this.proxy = new TokenTransferProxyWrapper(
             this._web3Wrapper,
             this._getTokenTransferProxyAddressAsync.bind(this),
         );
-        const tokenRegistryContractAddressIfExists = _.isUndefined(config) ?
-                                                     undefined :
-                                                     config.tokenRegistryContractAddress;
-        this.tokenRegistry = new TokenRegistryWrapper(this._web3Wrapper, tokenRegistryContractAddressIfExists);
-        const etherTokenContractAddressIfExists = _.isUndefined(config) ? undefined : config.etherTokenContractAddress;
-        this.etherToken = new EtherTokenWrapper(this._web3Wrapper, this.token, etherTokenContractAddressIfExists);
-        const orderWatcherConfig = _.isUndefined(config) ? undefined : config.orderWatcherConfig;
+        this.tokenRegistry = new TokenRegistryWrapper(this._web3Wrapper, config.tokenRegistryContractAddress);
+        this.etherToken = new EtherTokenWrapper(this._web3Wrapper, this.token, config.etherTokenContractAddress);
         this.orderStateWatcher = new OrderStateWatcher(
-            this._web3Wrapper, this._abiDecoder, this.token, this.exchange, orderWatcherConfig,
+            this._web3Wrapper, this._abiDecoder, this.token, this.exchange, config.orderWatcherConfig,
         );
     }
     /**
diff --git a/packages/0x.js/src/types.ts b/packages/0x.js/src/types.ts
index ac4106d0b..d34bb02b6 100644
--- a/packages/0x.js/src/types.ts
+++ b/packages/0x.js/src/types.ts
@@ -407,6 +407,7 @@ export interface OrderStateWatcherConfig {
 }
 
 /*
+ * networkId: The id of the underlying ethereum network the provider is connected to. (1-mainnet, 42-kovan, 50-testrpc)
  * gasPrice: Gas price to use with every transaction
  * exchangeContractAddress: The address of an exchange contract to use
  * tokenRegistryContractAddress: The address of a token registry contract to use
@@ -414,7 +415,8 @@ export interface OrderStateWatcherConfig {
  * orderWatcherConfig: All the configs related to the orderWatcher
  */
 export interface ZeroExConfig {
-    gasPrice?: BigNumber; // Gas price to use with every transaction
+    networkId: number;
+    gasPrice?: BigNumber;
     exchangeContractAddress?: string;
     tokenRegistryContractAddress?: string;
     etherTokenContractAddress?: string;