Refactor RedundantRpcSubprovider into RedundantSubprovider

5 files changed, 49 insertions, 30 deletions

diff --git a/packages/subproviders/CHANGELOG.json b/packages/subproviders/CHANGELOG.json
index 54eb32378..ca3889202 100644
--- a/packages/subproviders/CHANGELOG.json
+++ b/packages/subproviders/CHANGELOG.json
@@ -1,5 +1,15 @@
 [
     {
+        "version": "0.9.0",
+        "changes": [
+            {
+                "note":
+                    "Refactor RedundantRPCSubprovider into RedundantSubprovider where it now accepts an array of subproviders rather then an array of RPC endpoints",
+                "pr": 500
+            }
+        ]
+    },
+    {
         "timestamp": 1522673609,
         "version": "0.8.4",
         "changes": [
diff --git a/packages/subproviders/src/index.ts b/packages/subproviders/src/index.ts
index 9786347e6..1711387f1 100644
--- a/packages/subproviders/src/index.ts
+++ b/packages/subproviders/src/index.ts
@@ -7,7 +7,7 @@ import { LedgerEthereumClient } from './types';
 export { EmptyWalletSubprovider } from './subproviders/empty_wallet_subprovider';
 export { FakeGasEstimateSubprovider } from './subproviders/fake_gas_estimate_subprovider';
 export { InjectedWeb3Subprovider } from './subproviders/injected_web3';
-export { RedundantRPCSubprovider } from './subproviders/redundant_rpc';
+export { RedundantSubprovider } from './subproviders/redundant_subprovider';
 export { LedgerSubprovider } from './subproviders/ledger';
 export { GanacheSubprovider } from './subproviders/ganache';
 export { Subprovider } from './subproviders/subprovider';
diff --git a/packages/subproviders/src/subproviders/redundant_rpc.ts b/packages/subproviders/src/subproviders/redundant_subprovider.ts
index f8ff0915d..37c8bba5a 100644
--- a/packages/subproviders/src/subproviders/redundant_rpc.ts
+++ b/packages/subproviders/src/subproviders/redundant_subprovider.ts
@@ -1,7 +1,6 @@
 import { JSONRPCRequestPayload } from '@0xproject/types';
 import { promisify } from '@0xproject/utils';
 import * as _ from 'lodash';
-import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
 
 import { Callback } from '../types';
 
@@ -12,17 +11,17 @@ import { Subprovider } from './subprovider';
  * It attempts to handle each JSON RPC request by sequentially attempting to receive a valid response from one of a
  * set of JSON RPC endpoints.
  */
-export class RedundantRPCSubprovider extends Subprovider {
-    private _rpcs: RpcSubprovider[];
+export class RedundantSubprovider extends Subprovider {
+    private _subproviders: Subprovider[];
     private static async _firstSuccessAsync(
-        rpcs: RpcSubprovider[],
+        subproviders: Subprovider[],
         payload: JSONRPCRequestPayload,
         next: Callback,
     ): Promise<any> {
         let lastErr: Error | undefined;
-        for (const rpc of rpcs) {
+        for (const subprovider of subproviders) {
             try {
-                const data = await promisify(rpc.handleRequest.bind(rpc))(payload, next);
+                const data = await promisify(subprovider.handleRequest.bind(subprovider))(payload, next);
                 return data;
             } catch (err) {
                 lastErr = err;
@@ -34,16 +33,12 @@ export class RedundantRPCSubprovider extends Subprovider {
         }
     }
     /**
-     * Instantiates a new RedundantRPCSubprovider
+     * Instantiates a new RedundantSubprovider
      * @param endpoints JSON RPC endpoints to attempt. Attempts are made in the order of the endpoints.
      */
-    constructor(endpoints: string[]) {
+    constructor(subproviders: Subprovider[]) {
         super();
-        this._rpcs = _.map(endpoints, endpoint => {
-            return new RpcSubprovider({
-                rpcUrl: endpoint,
-            });
-        });
+        this._subproviders = subproviders;
     }
     /**
      * This method conforms to the web3-provider-engine interface.
@@ -59,9 +54,9 @@ export class RedundantRPCSubprovider extends Subprovider {
         next: Callback,
         end: (err: Error | null, data?: any) => void,
     ): Promise<void> {
-        const rpcsCopy = this._rpcs.slice();
+        const subprovidersCopy = this._subproviders.slice();
         try {
-            const data = await RedundantRPCSubprovider._firstSuccessAsync(rpcsCopy, payload, next);
+            const data = await RedundantSubprovider._firstSuccessAsync(subprovidersCopy, payload, next);
             end(null, data);
         } catch (err) {
             end(err);
diff --git a/packages/subproviders/test/unit/redundant_rpc_subprovider_test.ts b/packages/subproviders/test/unit/redundant_rpc_subprovider_test.ts
index e7ca6d496..e25cb7eb7 100644
--- a/packages/subproviders/test/unit/redundant_rpc_subprovider_test.ts
+++ b/packages/subproviders/test/unit/redundant_rpc_subprovider_test.ts
@@ -5,7 +5,8 @@ import Web3 = require('web3');
 import Web3ProviderEngine = require('web3-provider-engine');
 import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
 
-import { RedundantRPCSubprovider } from '../../src';
+import { RedundantSubprovider } from '../../src';
+import { Subprovider } from '../../src/subproviders/subprovider';
 import { DoneCallback } from '../../src/types';
 import { chaiSetup } from '../chai_setup';
 import { ganacheSubprovider } from '../utils/ganache_subprovider';
@@ -14,14 +15,12 @@ import { reportCallbackErrors } from '../utils/report_callback_errors';
 const expect = chai.expect;
 chaiSetup.configure();
 
-describe('RedundantRpcSubprovider', () => {
+describe('RedundantSubprovider', () => {
     let provider: Web3ProviderEngine;
     it('succeeds when supplied a healthy endpoint', (done: DoneCallback) => {
         provider = new Web3ProviderEngine();
-        const endpoints = ['http://localhost:8545'];
-        const redundantSubprovider = new RedundantRPCSubprovider(endpoints);
-        // Hack: Hot-swap rpc with ganacheSubprovider
-        (redundantSubprovider as any)._rpcs = [ganacheSubprovider];
+        const subproviders = [ganacheSubprovider];
+        const redundantSubprovider = new RedundantSubprovider(subproviders);
         provider.addProvider(redundantSubprovider);
         provider.start();
 
@@ -40,13 +39,11 @@ describe('RedundantRpcSubprovider', () => {
     });
     it('succeeds when supplied at least one healthy endpoint', (done: DoneCallback) => {
         provider = new Web3ProviderEngine();
-        const endpoints = ['http://does-not-exist:3000', 'http://localhost:8545'];
-        const redundantSubprovider = new RedundantRPCSubprovider(endpoints);
-        // Hack: Hot-swap rpcs with [nonExistentSubprovider, ganacheSubprovider]
         const nonExistentSubprovider = new RpcSubprovider({
             rpcUrl: 'http://does-not-exist:3000',
         });
-        (redundantSubprovider as any)._rpcs = [nonExistentSubprovider, ganacheSubprovider];
+        const subproviders = [nonExistentSubprovider as Subprovider, ganacheSubprovider];
+        const redundantSubprovider = new RedundantSubprovider(subproviders);
         provider.addProvider(redundantSubprovider);
         provider.start();
 
diff --git a/packages/website/ts/blockchain.ts b/packages/website/ts/blockchain.ts
index fd34ab82d..7d79542a3 100644
--- a/packages/website/ts/blockchain.ts
+++ b/packages/website/ts/blockchain.ts
@@ -21,7 +21,8 @@ import {
     ledgerEthereumBrowserClientFactoryAsync,
     LedgerSubprovider,
     LedgerWalletSubprovider,
-    RedundantRPCSubprovider,
+    RedundantSubprovider,
+    Subprovider,
 } from '@0xproject/subproviders';
 import { Provider } from '@0xproject/types';
 import { BigNumber, intervalUtils, logUtils, promisify } from '@0xproject/utils';
@@ -54,6 +55,7 @@ import { utils } from 'ts/utils/utils';
 import Web3 = require('web3');
 import ProviderEngine = require('web3-provider-engine');
 import FilterSubprovider = require('web3-provider-engine/subproviders/filters');
+import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
 
 import * as MintableArtifacts from '../contracts/Mintable.json';
 
@@ -98,7 +100,12 @@ export class Blockchain {
             provider = new ProviderEngine();
             provider.addProvider(new InjectedWeb3Subprovider(injectedWeb3.currentProvider));
             provider.addProvider(new FilterSubprovider());
-            provider.addProvider(new RedundantRPCSubprovider(publicNodeUrlsIfExistsForNetworkId));
+            const rpcSubproviders = _.map(publicNodeUrlsIfExistsForNetworkId, publicNodeUrl => {
+                return new RpcSubprovider({
+                    rpcUrl: publicNodeUrl,
+                });
+            });
+            provider.addProvider(new RedundantSubprovider(rpcSubproviders as Subprovider[]));
             provider.start();
         } else if (doesInjectedWeb3Exist) {
             // Since no public node for this network, all requests go to injectedWeb3 instance
@@ -110,7 +117,12 @@ export class Blockchain {
             provider = new ProviderEngine();
             provider.addProvider(new FilterSubprovider());
             const networkId = configs.IS_MAINNET_ENABLED ? constants.NETWORK_ID_MAINNET : constants.NETWORK_ID_KOVAN;
-            provider.addProvider(new RedundantRPCSubprovider(configs.PUBLIC_NODE_URLS_BY_NETWORK_ID[networkId]));
+            const rpcSubproviders = _.map(configs.PUBLIC_NODE_URLS_BY_NETWORK_ID[networkId], publicNodeUrl => {
+                return new RpcSubprovider({
+                    rpcUrl: publicNodeUrl,
+                });
+            });
+            provider.addProvider(new RedundantSubprovider(rpcSubproviders as Subprovider[]));
             provider.start();
         }
 
@@ -201,7 +213,12 @@ export class Blockchain {
         this._ledgerSubprovider = new LedgerSubprovider(ledgerWalletConfigs);
         provider.addProvider(this._ledgerSubprovider);
         provider.addProvider(new FilterSubprovider());
-        provider.addProvider(new RedundantRPCSubprovider(configs.PUBLIC_NODE_URLS_BY_NETWORK_ID[networkId]));
+        const rpcSubproviders = _.map(configs.PUBLIC_NODE_URLS_BY_NETWORK_ID[networkId], publicNodeUrl => {
+            return new RpcSubprovider({
+                rpcUrl: publicNodeUrl,
+            });
+        });
+        provider.addProvider(new RedundantSubprovider(rpcSubproviders as Subprovider[]));
         provider.start();
         this.networkId = networkId;
         this._dispatcher.updateNetworkId(this.networkId);