merge v2-prototype

25 files changed, 170 insertions, 79 deletions

diff --git a/packages/subproviders/CHANGELOG.json b/packages/subproviders/CHANGELOG.json
index 7a3f29fe0..6942aa5db 100644
--- a/packages/subproviders/CHANGELOG.json
+++ b/packages/subproviders/CHANGELOG.json
@@ -5,8 +5,16 @@
             {
                 "note": "Add `EthLightwalletSubprovider`"
             }
-        ],
-        "timestamp": 1531149657
+        ]
+    },
+    {
+        "timestamp": 1531919263,
+        "version": "0.10.6",
+        "changes": [
+            {
+                "note": "Dependencies updated"
+            }
+        ]
     },
     {
         "timestamp": 1529397769,
diff --git a/packages/subproviders/CHANGELOG.md b/packages/subproviders/CHANGELOG.md
index 6fab0a4c4..c433721eb 100644
--- a/packages/subproviders/CHANGELOG.md
+++ b/packages/subproviders/CHANGELOG.md
@@ -5,6 +5,10 @@ Edit the package's CHANGELOG.json file only.
 
 CHANGELOG
 
+## v0.10.6 - _July 18, 2018_
+
+    * Dependencies updated
+
 ## v0.10.5 - _July 9, 2018_
 
     * Update web3-provider-engine to v14.0.6 including the leaked global.XMLHttpRequest bug fix
diff --git a/packages/subproviders/package.json b/packages/subproviders/package.json
index bdc846e6b..620a46384 100644
--- a/packages/subproviders/package.json
+++ b/packages/subproviders/package.json
@@ -1,6 +1,6 @@
 {
     "name": "@0xproject/subproviders",
-    "version": "0.10.5",
+    "version": "0.10.6",
     "engines": {
         "node": ">=6.12"
     },
@@ -42,9 +42,9 @@
     "dependencies": {
         "@0xproject/assert": "^0.3.0",
         "@0xproject/types": "^1.0.0",
-        "@0xproject/web3-wrapper": "^0.7.2",
-        "@0xproject/typescript-typings": "^0.4.2",
-        "@0xproject/utils": "^0.7.2",
+        "@0xproject/web3-wrapper": "^0.7.3",
+        "@0xproject/typescript-typings": "^0.4.3",
+        "@0xproject/utils": "^0.7.3",
         "@ledgerhq/hw-app-eth": "^4.3.0",
         "@ledgerhq/hw-transport-u2f": "^4.3.0",
         "ethereum-types": "^0.0.2",
@@ -55,6 +55,7 @@
         "ethereumjs-util": "^5.1.1",
         "ganache-core": "0xProject/ganache-core",
         "hdkey": "^0.7.1",
+        "json-rpc-error": "2.0.0",
         "lodash": "^4.17.4",
         "semaphore-async-await": "^1.5.1",
         "web3-provider-engine": "14.0.6"
@@ -62,7 +63,7 @@
     "devDependencies": {
         "@0xproject/monorepo-scripts": "^0.2.2",
         "@0xproject/tslint-config": "^0.4.21",
-        "@0xproject/utils": "^0.7.2",
+        "@0xproject/utils": "^0.7.3",
         "@types/bip39": "^2.4.0",
         "@types/bn.js": "^4.11.0",
         "@types/hdkey": "^0.7.0",
@@ -81,7 +82,7 @@
         "nyc": "^11.0.1",
         "shx": "^0.2.2",
         "sinon": "^4.0.0",
-        "tslint": "5.8.0",
+        "tslint": "5.11.0",
         "typedoc": "0xProject/typedoc",
         "typescript": "2.7.1",
         "webpack": "^3.1.0"
diff --git a/packages/subproviders/src/index.ts b/packages/subproviders/src/index.ts
index 71d643f14..9d4480e59 100644
--- a/packages/subproviders/src/index.ts
+++ b/packages/subproviders/src/index.ts
@@ -1,5 +1,6 @@
 import Eth from '@ledgerhq/hw-app-eth';
 import TransportU2F from '@ledgerhq/hw-transport-u2f';
+export import Web3ProviderEngine = require('web3-provider-engine');
 export { ECSignature } from '@0xproject/types';
 
 import { LedgerEthereumClient } from './types';
@@ -10,6 +11,7 @@ export { FakeGasEstimateSubprovider } from './subproviders/fake_gas_estimate_sub
 export { SignerSubprovider } from './subproviders/signer';
 export { RedundantSubprovider } from './subproviders/redundant_subprovider';
 export { LedgerSubprovider } from './subproviders/ledger';
+export { RPCSubprovider } from './subproviders/rpc_subprovider';
 export { GanacheSubprovider } from './subproviders/ganache';
 export { Subprovider } from './subproviders/subprovider';
 export { NonceTrackerSubprovider } from './subproviders/nonce_tracker';
diff --git a/packages/subproviders/src/subproviders/eth_lightwallet_subprovider.ts b/packages/subproviders/src/subproviders/eth_lightwallet_subprovider.ts
index a9ebbb790..454dae58e 100644
--- a/packages/subproviders/src/subproviders/eth_lightwallet_subprovider.ts
+++ b/packages/subproviders/src/subproviders/eth_lightwallet_subprovider.ts
@@ -12,8 +12,8 @@ import { PrivateKeyWalletSubprovider } from './private_key_wallet';
  * Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
  */
 export class EthLightwalletSubprovider extends BaseWalletSubprovider {
-    private _keystore: lightwallet.keystore;
-    private _pwDerivedKey: Uint8Array;
+    private readonly _keystore: lightwallet.keystore;
+    private readonly _pwDerivedKey: Uint8Array;
     constructor(keystore: lightwallet.keystore, pwDerivedKey: Uint8Array) {
         super();
         this._keystore = keystore;
diff --git a/packages/subproviders/src/subproviders/fake_gas_estimate_subprovider.ts b/packages/subproviders/src/subproviders/fake_gas_estimate_subprovider.ts
index d750505e7..bc1b34aba 100644
--- a/packages/subproviders/src/subproviders/fake_gas_estimate_subprovider.ts
+++ b/packages/subproviders/src/subproviders/fake_gas_estimate_subprovider.ts
@@ -14,7 +14,7 @@ import { Subprovider } from './subprovider';
  * It intercepts the `eth_estimateGas` JSON RPC call and always returns a constant gas amount when queried.
  */
 export class FakeGasEstimateSubprovider extends Subprovider {
-    private _constantGasAmount: number;
+    private readonly _constantGasAmount: number;
     /**
      * Instantiates an instance of the FakeGasEstimateSubprovider
      * @param constantGasAmount The constant gas amount you want returned
diff --git a/packages/subproviders/src/subproviders/ganache.ts b/packages/subproviders/src/subproviders/ganache.ts
index 79c43bc68..986094dba 100644
--- a/packages/subproviders/src/subproviders/ganache.ts
+++ b/packages/subproviders/src/subproviders/ganache.ts
@@ -10,7 +10,7 @@ import { Subprovider } from './subprovider';
  * It intercepts all JSON RPC requests and relays them to an in-process ganache instance.
  */
 export class GanacheSubprovider extends Subprovider {
-    private _ganacheProvider: Provider;
+    private readonly _ganacheProvider: Provider;
     /**
      * Instantiates a GanacheSubprovider
      * @param opts The desired opts with which to instantiate the Ganache provider
diff --git a/packages/subproviders/src/subproviders/ledger.ts b/packages/subproviders/src/subproviders/ledger.ts
index 8345be33c..6ad5de2e2 100644
--- a/packages/subproviders/src/subproviders/ledger.ts
+++ b/packages/subproviders/src/subproviders/ledger.ts
@@ -32,14 +32,14 @@ const DEFAULT_ADDRESS_SEARCH_LIMIT = 1000;
  */
 export class LedgerSubprovider extends BaseWalletSubprovider {
     // tslint:disable-next-line:no-unused-variable
-    private _nonceLock = new Lock();
-    private _connectionLock = new Lock();
-    private _networkId: number;
+    private readonly _nonceLock = new Lock();
+    private readonly _connectionLock = new Lock();
+    private readonly _networkId: number;
     private _baseDerivationPath: string;
-    private _ledgerEthereumClientFactoryAsync: LedgerEthereumClientFactoryAsync;
+    private readonly _ledgerEthereumClientFactoryAsync: LedgerEthereumClientFactoryAsync;
     private _ledgerClientIfExists?: LedgerEthereumClient;
-    private _shouldAlwaysAskForConfirmation: boolean;
-    private _addressSearchLimit: number;
+    private readonly _shouldAlwaysAskForConfirmation: boolean;
+    private readonly _addressSearchLimit: number;
     /**
      * Instantiates a LedgerSubprovider. Defaults to derivationPath set to `44'/60'/0'`.
      * TestRPC/Ganache defaults to `m/44'/60'/0'/0`, so set this in the configs if desired.
diff --git a/packages/subproviders/src/subproviders/mnemonic_wallet.ts b/packages/subproviders/src/subproviders/mnemonic_wallet.ts
index 596300425..1495112b6 100644
--- a/packages/subproviders/src/subproviders/mnemonic_wallet.ts
+++ b/packages/subproviders/src/subproviders/mnemonic_wallet.ts
@@ -20,10 +20,10 @@ const DEFAULT_ADDRESS_SEARCH_LIMIT = 1000;
  * all requests with accounts derived from the supplied mnemonic.
  */
 export class MnemonicWalletSubprovider extends BaseWalletSubprovider {
-    private _addressSearchLimit: number;
+    private readonly _addressSearchLimit: number;
     private _baseDerivationPath: string;
     private _derivedKeyInfo: DerivedHDKeyInfo;
-    private _mnemonic: string;
+    private readonly _mnemonic: string;
 
     /**
      * Instantiates a MnemonicWalletSubprovider. Defaults to baseDerivationPath set to `44'/60'/0'/0`.
diff --git a/packages/subproviders/src/subproviders/nonce_tracker.ts b/packages/subproviders/src/subproviders/nonce_tracker.ts
index dcc421574..eea722aee 100644
--- a/packages/subproviders/src/subproviders/nonce_tracker.ts
+++ b/packages/subproviders/src/subproviders/nonce_tracker.ts
@@ -17,7 +17,7 @@ const NONCE_TOO_LOW_ERROR_MESSAGE = 'Transaction nonce is too low';
  * We added the additional feature of clearing the cached nonce value when a `nonce value too low` error occurs.
  */
 export class NonceTrackerSubprovider extends Subprovider {
-    private _nonceCache: { [address: string]: string } = {};
+    private readonly _nonceCache: { [address: string]: string } = {};
     private static _reconstructTransaction(payload: JSONRPCRequestPayload): EthereumTx {
         const raw = payload.params[0];
         if (_.isUndefined(raw)) {
diff --git a/packages/subproviders/src/subproviders/private_key_wallet.ts b/packages/subproviders/src/subproviders/private_key_wallet.ts
index b3f48fd90..9d6fc487e 100644
--- a/packages/subproviders/src/subproviders/private_key_wallet.ts
+++ b/packages/subproviders/src/subproviders/private_key_wallet.ts
@@ -13,8 +13,8 @@ import { BaseWalletSubprovider } from './base_wallet_subprovider';
  * all requests with the supplied Ethereum private key.
  */
 export class PrivateKeyWalletSubprovider extends BaseWalletSubprovider {
-    private _address: string;
-    private _privateKeyBuffer: Buffer;
+    private readonly _address: string;
+    private readonly _privateKeyBuffer: Buffer;
     /**
      * Instantiates a PrivateKeyWalletSubprovider.
      * @param privateKey The corresponding private key to an Ethereum address
diff --git a/packages/subproviders/src/subproviders/redundant_subprovider.ts b/packages/subproviders/src/subproviders/redundant_subprovider.ts
index a60d6706e..7aa6226d5 100644
--- a/packages/subproviders/src/subproviders/redundant_subprovider.ts
+++ b/packages/subproviders/src/subproviders/redundant_subprovider.ts
@@ -12,7 +12,7 @@ import { Subprovider } from './subprovider';
  * set of JSON RPC endpoints.
  */
 export class RedundantSubprovider extends Subprovider {
-    private _subproviders: Subprovider[];
+    private readonly _subproviders: Subprovider[];
     private static async _firstSuccessAsync(
         subproviders: Subprovider[],
         payload: JSONRPCRequestPayload,
diff --git a/packages/subproviders/src/subproviders/rpc_subprovider.ts b/packages/subproviders/src/subproviders/rpc_subprovider.ts
new file mode 100644
index 000000000..d874c6f05
--- /dev/null
+++ b/packages/subproviders/src/subproviders/rpc_subprovider.ts
@@ -0,0 +1,90 @@
+import { assert } from '@0xproject/assert';
+import { StatusCodes } from '@0xproject/types';
+import { fetchAsync } from '@0xproject/utils';
+import { JSONRPCRequestPayload } from 'ethereum-types';
+import JsonRpcError = require('json-rpc-error');
+
+import { Callback, ErrorCallback } from '../types';
+
+import { Subprovider } from './subprovider';
+
+/**
+ * This class implements the [web3-provider-engine](https://github.com/MetaMask/provider-engine) subprovider interface.
+ * It forwards on JSON RPC requests to the supplied `rpcUrl` endpoint
+ */
+export class RPCSubprovider extends Subprovider {
+    private readonly _rpcUrl: string;
+    private readonly _requestTimeoutMs: number;
+    constructor(rpcUrl: string, requestTimeoutMs: number = 20000) {
+        super();
+        assert.isString('rpcUrl', rpcUrl);
+        assert.isNumber('requestTimeoutMs', requestTimeoutMs);
+        this._rpcUrl = rpcUrl;
+        this._requestTimeoutMs = requestTimeoutMs;
+    }
+    /**
+     * This method conforms to the web3-provider-engine interface.
+     * It is called internally by the ProviderEngine when it is this subproviders
+     * turn to handle a JSON RPC request.
+     * @param payload JSON RPC payload
+     * @param next Callback to call if this subprovider decides not to handle the request
+     * @param end Callback to call if subprovider handled the request and wants to pass back the request.
+     */
+    // tslint:disable-next-line:prefer-function-over-method async-suffix
+    public async handleRequest(payload: JSONRPCRequestPayload, _next: Callback, end: ErrorCallback): Promise<void> {
+        const finalPayload = Subprovider._createFinalPayload(payload);
+        const headers = new Headers({
+            Accept: 'application/json',
+            'Content-Type': 'application/json',
+        });
+
+        let response;
+        try {
+            response = await fetchAsync(
+                this._rpcUrl,
+                {
+                    method: 'POST',
+                    headers,
+                    body: JSON.stringify(finalPayload),
+                },
+                this._requestTimeoutMs,
+            );
+        } catch (err) {
+            end(new JsonRpcError.InternalError(err));
+            return;
+        }
+
+        const text = await response.text();
+        if (!response.ok) {
+            const statusCode = response.status;
+            switch (statusCode) {
+                case StatusCodes.MethodNotAllowed:
+                    end(new JsonRpcError.MethodNotFound());
+                    return;
+                case StatusCodes.GatewayTimeout:
+                    const errMsg =
+                        'Gateway timeout. The request took too long to process. This can happen when querying logs over too wide a block range.';
+                    const err = new Error(errMsg);
+                    end(new JsonRpcError.InternalError(err));
+                    return;
+                default:
+                    end(new JsonRpcError.InternalError(text));
+                    return;
+            }
+        }
+
+        let data;
+        try {
+            data = JSON.parse(text);
+        } catch (err) {
+            end(new JsonRpcError.InternalError(err));
+            return;
+        }
+
+        if (data.error) {
+            end(data.error);
+            return;
+        }
+        end(null, data.result);
+    }
+}
diff --git a/packages/subproviders/src/subproviders/signer.ts b/packages/subproviders/src/subproviders/signer.ts
index f7329e00c..d5fd86897 100644
--- a/packages/subproviders/src/subproviders/signer.ts
+++ b/packages/subproviders/src/subproviders/signer.ts
@@ -12,7 +12,7 @@ import { Subprovider } from './subprovider';
  * are passed onwards for subsequent subproviders to handle.
  */
 export class SignerSubprovider extends Subprovider {
-    private _web3Wrapper: Web3Wrapper;
+    private readonly _web3Wrapper: Web3Wrapper;
     /**
      * Instantiates a new SignerSubprovider
      * @param provider Web3 provider that should handle  all user account related requests
diff --git a/packages/subproviders/src/subproviders/subprovider.ts b/packages/subproviders/src/subproviders/subprovider.ts
index ff8378c4e..5dc273569 100644
--- a/packages/subproviders/src/subproviders/subprovider.ts
+++ b/packages/subproviders/src/subproviders/subprovider.ts
@@ -9,18 +9,7 @@ import { Callback, ErrorCallback, JSONRPCRequestPayloadWithMethod } from '../typ
 export abstract class Subprovider {
     // tslint:disable-next-line:underscore-private-and-protected
     private engine!: Provider;
-    // Ported from: https://github.com/MetaMask/provider-engine/blob/master/util/random-id.js
-    private static _getRandomId(): number {
-        const extraDigits = 3;
-        const baseTen = 10;
-        // 13 time digits
-        const datePart = new Date().getTime() * Math.pow(baseTen, extraDigits);
-        // 3 random digits
-        const extraPart = Math.floor(Math.random() * Math.pow(baseTen, extraDigits));
-        // 16 digits
-        return datePart + extraPart;
-    }
-    private static _createFinalPayload(
+    protected static _createFinalPayload(
         payload: Partial<JSONRPCRequestPayloadWithMethod>,
     ): Partial<JSONRPCRequestPayloadWithMethod> {
         const finalPayload = {
@@ -32,6 +21,17 @@ export abstract class Subprovider {
         };
         return finalPayload;
     }
+    // Ported from: https://github.com/MetaMask/provider-engine/blob/master/util/random-id.js
+    private static _getRandomId(): number {
+        const extraDigits = 3;
+        const baseTen = 10;
+        // 13 time digits
+        const datePart = new Date().getTime() * Math.pow(baseTen, extraDigits);
+        // 3 random digits
+        const extraPart = Math.floor(Math.random() * Math.pow(baseTen, extraDigits));
+        // 16 digits
+        return datePart + extraPart;
+    }
     // tslint:disable-next-line:async-suffix
     public abstract async handleRequest(
         payload: JSONRPCRequestPayload,
diff --git a/packages/subproviders/src/utils/subprovider_utils.ts b/packages/subproviders/src/utils/subprovider_utils.ts
index 24ebedd06..beda408ab 100644
--- a/packages/subproviders/src/utils/subprovider_utils.ts
+++ b/packages/subproviders/src/utils/subprovider_utils.ts
@@ -1,4 +1,4 @@
-import ProviderEngine = require('web3-provider-engine');
+import Web3ProviderEngine = require('web3-provider-engine');
 
 import { Subprovider } from '../subproviders/subprovider';
 
@@ -7,7 +7,7 @@ import { Subprovider } from '../subproviders/subprovider';
  * @param provider    Given provider
  * @param subprovider Subprovider to prepend
  */
-export function prependSubprovider(provider: ProviderEngine, subprovider: Subprovider): void {
+export function prependSubprovider(provider: Web3ProviderEngine, subprovider: Subprovider): void {
     subprovider.setEngine(provider);
     // HACK: We use implementation details of provider engine here
     // https://github.com/MetaMask/provider-engine/blob/master/index.js#L68
diff --git a/packages/subproviders/src/utils/wallet_utils.ts b/packages/subproviders/src/utils/wallet_utils.ts
index 3748077ef..4c233645b 100644
--- a/packages/subproviders/src/utils/wallet_utils.ts
+++ b/packages/subproviders/src/utils/wallet_utils.ts
@@ -6,8 +6,8 @@ import { DerivedHDKeyInfo } from '../types';
 const DEFAULT_ADDRESS_SEARCH_LIMIT = 1000;
 
 class DerivedHDKeyInfoIterator implements IterableIterator<DerivedHDKeyInfo> {
-    private _parentDerivedKeyInfo: DerivedHDKeyInfo;
-    private _searchLimit: number;
+    private readonly _parentDerivedKeyInfo: DerivedHDKeyInfo;
+    private readonly _searchLimit: number;
     private _index: number;
 
     constructor(initialDerivedKey: DerivedHDKeyInfo, searchLimit: number = DEFAULT_ADDRESS_SEARCH_LIMIT) {
diff --git a/packages/subproviders/test/integration/ledger_subprovider_test.ts b/packages/subproviders/test/integration/ledger_subprovider_test.ts
index 196cecf32..527ee5b22 100644
--- a/packages/subproviders/test/integration/ledger_subprovider_test.ts
+++ b/packages/subproviders/test/integration/ledger_subprovider_test.ts
@@ -7,10 +7,8 @@ import TransportNodeHid from '@ledgerhq/hw-transport-node-hid';
 import * as chai from 'chai';
 import { JSONRPCResponsePayload } from 'ethereum-types';
 import * as ethUtils from 'ethereumjs-util';
-import Web3ProviderEngine = require('web3-provider-engine');
-import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
 
-import { LedgerSubprovider } from '../../src';
+import { LedgerSubprovider, RPCSubprovider, Web3ProviderEngine } from '../../src';
 import { LedgerEthereumClient } from '../../src/types';
 import { chaiSetup } from '../chai_setup';
 import { fixtureData } from '../utils/fixture_data';
@@ -86,9 +84,7 @@ describe('LedgerSubprovider', () => {
         before(() => {
             ledgerProvider = new Web3ProviderEngine();
             ledgerProvider.addProvider(ledgerSubprovider);
-            const httpProvider = new RpcSubprovider({
-                rpcUrl: 'http://localhost:8545',
-            });
+            const httpProvider = new RPCSubprovider('http://localhost:8545');
             ledgerProvider.addProvider(httpProvider);
             ledgerProvider.start();
 
@@ -180,7 +176,7 @@ describe('LedgerSubprovider', () => {
                     params: [tx],
                     id: 1,
                 };
-                await promisify(defaultProvider.sendAsync, defaultProvider)(payload);
+                await promisify(defaultProvider.sendAsync.bind(defaultProvider))(payload);
 
                 // Send transaction from Ledger
                 tx = {
diff --git a/packages/subproviders/test/unit/eth_lightwallet_subprovider_test.ts b/packages/subproviders/test/unit/eth_lightwallet_subprovider_test.ts
index f17c21f02..063817a95 100644
--- a/packages/subproviders/test/unit/eth_lightwallet_subprovider_test.ts
+++ b/packages/subproviders/test/unit/eth_lightwallet_subprovider_test.ts
@@ -2,9 +2,8 @@ import * as chai from 'chai';
 import * as lightwallet from 'eth-lightwallet';
 import { JSONRPCResponsePayload } from 'ethereum-types';
 import * as ethUtils from 'ethereumjs-util';
-import Web3ProviderEngine = require('web3-provider-engine');
 
-import { EthLightwalletSubprovider } from '../../src';
+import { EthLightwalletSubprovider, Web3ProviderEngine } from '../../src';
 import { DoneCallback } from '../../src/types';
 import { chaiSetup } from '../chai_setup';
 import { fixtureData } from '../utils/fixture_data';
diff --git a/packages/subproviders/test/unit/ledger_subprovider_test.ts b/packages/subproviders/test/unit/ledger_subprovider_test.ts
index 3b57e125b..a1d146dbc 100644
--- a/packages/subproviders/test/unit/ledger_subprovider_test.ts
+++ b/packages/subproviders/test/unit/ledger_subprovider_test.ts
@@ -2,9 +2,8 @@ import * as chai from 'chai';
 import { JSONRPCResponsePayload } from 'ethereum-types';
 import * as ethUtils from 'ethereumjs-util';
 import * as _ from 'lodash';
-import Web3ProviderEngine = require('web3-provider-engine');
 
-import { LedgerSubprovider } from '../../src';
+import { LedgerSubprovider, Web3ProviderEngine } from '../../src';
 import {
     DoneCallback,
     LedgerCommunicationClient,
@@ -56,7 +55,7 @@ describe('LedgerSubprovider', () => {
                     return ecSignature;
                 },
                 transport: {
-                    close: _.noop,
+                    close: _.noop.bind(_),
                 } as LedgerCommunicationClient,
             };
             // tslint:enable:no-object-literal-type-assertion
diff --git a/packages/subproviders/test/unit/mnemonic_wallet_subprovider_test.ts b/packages/subproviders/test/unit/mnemonic_wallet_subprovider_test.ts
index 51ba7094c..f2bdda3cd 100644
--- a/packages/subproviders/test/unit/mnemonic_wallet_subprovider_test.ts
+++ b/packages/subproviders/test/unit/mnemonic_wallet_subprovider_test.ts
@@ -1,9 +1,8 @@
 import * as chai from 'chai';
 import { JSONRPCResponsePayload } from 'ethereum-types';
 import * as ethUtils from 'ethereumjs-util';
-import Web3ProviderEngine = require('web3-provider-engine');
 
-import { GanacheSubprovider, MnemonicWalletSubprovider } from '../../src/';
+import { GanacheSubprovider, MnemonicWalletSubprovider, Web3ProviderEngine } from '../../src/';
 import { DoneCallback, WalletSubproviderErrors } from '../../src/types';
 import { chaiSetup } from '../chai_setup';
 import { fixtureData } from '../utils/fixture_data';
diff --git a/packages/subproviders/test/unit/nonce_tracker_subprovider_test.ts b/packages/subproviders/test/unit/nonce_tracker_subprovider_test.ts
index fa33cd50a..05f213cf5 100644
--- a/packages/subproviders/test/unit/nonce_tracker_subprovider_test.ts
+++ b/packages/subproviders/test/unit/nonce_tracker_subprovider_test.ts
@@ -1,11 +1,10 @@
 import * as chai from 'chai';
-import Web3ProviderEngine = require('web3-provider-engine');
 import FixtureSubprovider = require('web3-provider-engine/subproviders/fixture');
 
 import { promisify } from '@0xproject/utils';
 import EthereumTx = require('ethereumjs-tx');
 
-import { NonceTrackerSubprovider } from '../../src';
+import { NonceTrackerSubprovider, Web3ProviderEngine } from '../../src';
 import { chaiSetup } from '../chai_setup';
 
 const expect = chai.expect;
@@ -61,9 +60,9 @@ describe('NonceTrackerSubprovider', () => {
 
         const payload = { ...getTransactionCountPayload, params: ['0x0', 'pending'] };
 
-        const response = await promisify<any>(provider.sendAsync, provider)(payload);
+        const response = await promisify<any>(provider.sendAsync.bind(provider))(payload);
         expect(response.result).to.be.eq('0x00');
-        const secondResponse = await promisify<any>(provider.sendAsync, provider)(payload);
+        const secondResponse = await promisify<any>(provider.sendAsync.bind(provider))(payload);
         expect(secondResponse.result).to.be.eq('0x00');
     });
     it('does not cache the result for latest transaction count', async () => {
@@ -75,9 +74,9 @@ describe('NonceTrackerSubprovider', () => {
 
         const payload = { ...getTransactionCountPayload, params: ['0x0', 'latest'] };
 
-        const response = await promisify<any>(provider.sendAsync, provider)(payload);
+        const response = await promisify<any>(provider.sendAsync.bind(provider))(payload);
         expect(response.result).to.be.eq('0x00');
-        const secondResponse = await promisify<any>(provider.sendAsync, provider)(payload);
+        const secondResponse = await promisify<any>(provider.sendAsync.bind(provider))(payload);
         expect(secondResponse.result).to.be.eq('0x99');
     });
     it('clears the cache on a Nonce Too Low Error', async () => {
@@ -104,14 +103,14 @@ describe('NonceTrackerSubprovider', () => {
             params: [transaction.serialize()],
         };
 
-        const response = await promisify<any>(provider.sendAsync, provider)(noncePayload);
+        const response = await promisify<any>(provider.sendAsync.bind(provider))(noncePayload);
         expect(response.result).to.be.eq('0x00');
-        const secondResponse = await promisify<any>(provider.sendAsync, provider)(noncePayload);
+        const secondResponse = await promisify<any>(provider.sendAsync.bind(provider))(noncePayload);
         expect(secondResponse.result).to.be.eq('0x00');
         try {
-            await promisify(provider.sendAsync, provider)(txPayload);
+            await promisify(provider.sendAsync.bind(provider))(txPayload);
         } catch (err) {
-            const thirdResponse = await promisify<any>(provider.sendAsync, provider)(noncePayload);
+            const thirdResponse = await promisify<any>(provider.sendAsync.bind(provider))(noncePayload);
             expect(thirdResponse.result).to.be.eq('0x99');
         }
     });
@@ -139,12 +138,12 @@ describe('NonceTrackerSubprovider', () => {
             params: [transaction.serialize()],
         };
 
-        const response = await promisify<any>(provider.sendAsync, provider)(noncePayload);
+        const response = await promisify<any>(provider.sendAsync.bind(provider))(noncePayload);
         expect(response.result).to.be.eq('0x00');
-        const secondResponse = await promisify<any>(provider.sendAsync, provider)(noncePayload);
+        const secondResponse = await promisify<any>(provider.sendAsync.bind(provider))(noncePayload);
         expect(secondResponse.result).to.be.eq('0x00');
-        await promisify(provider.sendAsync, provider)(txPayload);
-        const thirdResponse = await promisify<any>(provider.sendAsync, provider)(noncePayload);
+        await promisify(provider.sendAsync.bind(provider))(txPayload);
+        const thirdResponse = await promisify<any>(provider.sendAsync.bind(provider))(noncePayload);
         expect(thirdResponse.result).to.be.eq('0x01');
     });
 });
diff --git a/packages/subproviders/test/unit/private_key_wallet_subprovider_test.ts b/packages/subproviders/test/unit/private_key_wallet_subprovider_test.ts
index ab321bcff..95773145f 100644
--- a/packages/subproviders/test/unit/private_key_wallet_subprovider_test.ts
+++ b/packages/subproviders/test/unit/private_key_wallet_subprovider_test.ts
@@ -1,9 +1,8 @@
 import * as chai from 'chai';
 import { JSONRPCResponsePayload } from 'ethereum-types';
 import * as ethUtils from 'ethereumjs-util';
-import Web3ProviderEngine = require('web3-provider-engine');
 
-import { GanacheSubprovider, PrivateKeyWalletSubprovider } from '../../src/';
+import { GanacheSubprovider, PrivateKeyWalletSubprovider, Web3ProviderEngine } from '../../src/';
 import { DoneCallback, WalletSubproviderErrors } from '../../src/types';
 import { chaiSetup } from '../chai_setup';
 import { fixtureData } from '../utils/fixture_data';
diff --git a/packages/subproviders/test/unit/redundant_rpc_subprovider_test.ts b/packages/subproviders/test/unit/redundant_rpc_subprovider_test.ts
index 810fb8f45..e30d2f74e 100644
--- a/packages/subproviders/test/unit/redundant_rpc_subprovider_test.ts
+++ b/packages/subproviders/test/unit/redundant_rpc_subprovider_test.ts
@@ -2,10 +2,8 @@ import { DoneCallback } from '@0xproject/types';
 import * as chai from 'chai';
 import { JSONRPCResponsePayload } from 'ethereum-types';
 import * as Sinon from 'sinon';
-import Web3ProviderEngine = require('web3-provider-engine');
-import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
 
-import { RedundantSubprovider } from '../../src';
+import { RedundantSubprovider, RPCSubprovider, Web3ProviderEngine } from '../../src';
 import { Subprovider } from '../../src/subproviders/subprovider';
 import { chaiSetup } from '../chai_setup';
 import { ganacheSubprovider } from '../utils/ganache_subprovider';
@@ -39,9 +37,7 @@ describe('RedundantSubprovider', () => {
     });
     it('succeeds when supplied at least one healthy endpoint', (done: DoneCallback) => {
         provider = new Web3ProviderEngine();
-        const nonExistentSubprovider = new RpcSubprovider({
-            rpcUrl: 'http://does-not-exist:3000',
-        });
+        const nonExistentSubprovider = new RPCSubprovider('http://does-not-exist:3000');
         const handleRequestStub = Sinon.stub(nonExistentSubprovider, 'handleRequest').throws(
             new Error('REQUEST_FAILED'),
         );
diff --git a/packages/subproviders/tsconfig.json b/packages/subproviders/tsconfig.json
index 72dfee80b..e35816553 100644
--- a/packages/subproviders/tsconfig.json
+++ b/packages/subproviders/tsconfig.json
@@ -1,8 +1,7 @@
 {
     "extends": "../../tsconfig",
     "compilerOptions": {
-        "outDir": "lib",
-        "downlevelIteration": true
+        "outDir": "lib"
     },
     "include": ["./src/**/*", "./test/**/*"]
 }