2 files changed, 37 insertions, 27 deletions

diff --git a/packages/dev-utils/src/blockchain_lifecycle.ts b/packages/dev-utils/src/blockchain_lifecycle.ts
index 9bd65ee5d..a48cb0856 100644
--- a/packages/dev-utils/src/blockchain_lifecycle.ts
+++ b/packages/dev-utils/src/blockchain_lifecycle.ts
@@ -10,8 +10,8 @@ import * as _ from 'lodash';
 const MINIMUM_BLOCKS = 3;
 
 export class BlockchainLifecycle {
-    private _web3Wrapper: Web3Wrapper;
-    private _snapshotIdsStack: number[];
+    private readonly _web3Wrapper: Web3Wrapper;
+    private readonly _snapshotIdsStack: number[];
     private _addresses: string[] = [];
     private _nodeType: NodeType | undefined;
     constructor(web3Wrapper: Web3Wrapper) {
@@ -34,6 +34,12 @@ export class BlockchainLifecycle {
                     blockNumber = await this._web3Wrapper.getBlockNumberAsync();
                 }
                 this._snapshotIdsStack.push(blockNumber);
+                // HACK(albrow) It's possible that we applied a time offset but
+                // the transaction we mined to put that time offset into the
+                // blockchain was reverted. As a workaround, we mine a new dummy
+                // block so that the latest block timestamp accounts for any
+                // possible time offsets.
+                await this._mineDummyBlockAsync();
                 break;
             default:
                 throw new Error(`Unknown node type: ${nodeType}`);
@@ -59,22 +65,9 @@ export class BlockchainLifecycle {
     }
     private async _mineMinimumBlocksAsync(): Promise<void> {
         logUtils.warn('WARNING: minimum block number for tests not met. Mining additional blocks...');
-        if (this._addresses.length === 0) {
-            this._addresses = await this._web3Wrapper.getAvailableAddressesAsync();
-            if (this._addresses.length === 0) {
-                throw new Error('No accounts found');
-            }
-        }
         while ((await this._web3Wrapper.getBlockNumberAsync()) < MINIMUM_BLOCKS) {
             logUtils.warn('Mining block...');
-            await this._web3Wrapper.awaitTransactionMinedAsync(
-                await this._web3Wrapper.sendTransactionAsync({
-                    from: this._addresses[0],
-                    to: this._addresses[0],
-                    value: '0',
-                }),
-                0,
-            );
+            await this._mineDummyBlockAsync();
         }
         logUtils.warn('Done mining the minimum number of blocks.');
     }
@@ -84,4 +77,22 @@ export class BlockchainLifecycle {
         }
         return this._nodeType;
     }
+    // Sends a transaction that has no real effect on the state and waits for it
+    // to be mined.
+    private async _mineDummyBlockAsync(): Promise<void> {
+        if (this._addresses.length === 0) {
+            this._addresses = await this._web3Wrapper.getAvailableAddressesAsync();
+            if (this._addresses.length === 0) {
+                throw new Error('No accounts found');
+            }
+        }
+        await this._web3Wrapper.awaitTransactionMinedAsync(
+            await this._web3Wrapper.sendTransactionAsync({
+                from: this._addresses[0],
+                to: this._addresses[0],
+                value: '0',
+            }),
+            0,
+        );
+    }
 }
diff --git a/packages/dev-utils/src/web3_factory.ts b/packages/dev-utils/src/web3_factory.ts
index 362a6c3c6..8e713fa68 100644
--- a/packages/dev-utils/src/web3_factory.ts
+++ b/packages/dev-utils/src/web3_factory.ts
@@ -1,7 +1,10 @@
-import ProviderEngine = require('web3-provider-engine');
-import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
-
-import { EmptyWalletSubprovider, FakeGasEstimateSubprovider, GanacheSubprovider } from '@0xproject/subproviders';
+import {
+    EmptyWalletSubprovider,
+    FakeGasEstimateSubprovider,
+    GanacheSubprovider,
+    RPCSubprovider,
+    Web3ProviderEngine,
+} from '@0xproject/subproviders';
 import * as fs from 'fs';
 import * as _ from 'lodash';
 
@@ -16,8 +19,8 @@ export interface Web3Config {
 }
 
 export const web3Factory = {
-    getRpcProvider(config: Web3Config = {}): ProviderEngine {
-        const provider = new ProviderEngine();
+    getRpcProvider(config: Web3Config = {}): Web3ProviderEngine {
+        const provider = new Web3ProviderEngine();
         const hasAddresses = _.isUndefined(config.hasAddresses) || config.hasAddresses;
         config.shouldUseFakeGasEstimate =
             _.isUndefined(config.shouldUseFakeGasEstimate) || config.shouldUseFakeGasEstimate;
@@ -49,11 +52,7 @@ export const web3Factory = {
                 }),
             );
         } else {
-            provider.addProvider(
-                new RpcSubprovider({
-                    rpcUrl: config.rpcUrl || constants.RPC_URL,
-                }),
-            );
+            provider.addProvider(new RPCSubprovider(config.rpcUrl || constants.RPC_URL));
         }
         provider.start();
         return provider;