6 files changed, 111 insertions, 0 deletions
diff --git a/packages/dev-utils/src/constants.ts b/packages/dev-utils/src/constants.ts
new file mode 100644
index 000000000..14cb5b937
--- /dev/null
+++ b/packages/dev-utils/src/constants.ts
@@ -0,0 +1,4 @@
+export const constants = {
+    RPC_URL: 'http://localhost:8545',
+    GAS_ESTIMATE: 500000,
+};
diff --git a/packages/dev-utils/src/globals.d.ts b/packages/dev-utils/src/globals.d.ts
new file mode 100644
index 000000000..7b132ee28
--- /dev/null
+++ b/packages/dev-utils/src/globals.d.ts
@@ -0,0 +1,2 @@
+declare module 'web3-provider-engine';
+declare module 'web3-provider-engine/subproviders/rpc';
diff --git a/packages/dev-utils/src/index.ts b/packages/dev-utils/src/index.ts
index 9ba0cb5cf..e899ac206 100644
--- a/packages/dev-utils/src/index.ts
+++ b/packages/dev-utils/src/index.ts
@@ -1,2 +1,4 @@
 export { RPC } from './rpc';
 export { BlockchainLifecycle } from './blockchain_lifecycle';
+export { web3Factory } from './web3_factory';
+export { constants as devConstants } from './constants';
diff --git a/packages/dev-utils/src/subproviders/empty_wallet_subprovider.ts b/packages/dev-utils/src/subproviders/empty_wallet_subprovider.ts
new file mode 100644
index 000000000..8c1fdfdb2
--- /dev/null
+++ b/packages/dev-utils/src/subproviders/empty_wallet_subprovider.ts
@@ -0,0 +1,27 @@
+import { JSONRPCPayload } from '@0xproject/types';
+
+/*
+ * This class implements the web3-provider-engine subprovider interface and returns
+ * that the provider has no addresses when queried.
+ * Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+ */
+export class EmptyWalletSubprovider {
+    // This method needs to be here to satisfy the interface but linter wants it to be static.
+    // tslint:disable-next-line:prefer-function-over-method
+    public handleRequest(payload: JSONRPCPayload, next: () => void, end: (err: Error | null, result: any) => void) {
+        switch (payload.method) {
+            case 'eth_accounts':
+                end(null, []);
+                return;
+
+            default:
+                next();
+                return;
+        }
+    }
+    // Required to implement this method despite not needing it for this subprovider
+    // tslint:disable-next-line:prefer-function-over-method
+    public setEngine(engine: any) {
+        // noop
+    }
+}
diff --git a/packages/dev-utils/src/subproviders/fake_gas_estimate_subprovider.ts b/packages/dev-utils/src/subproviders/fake_gas_estimate_subprovider.ts
new file mode 100644
index 000000000..b455a0ed7
--- /dev/null
+++ b/packages/dev-utils/src/subproviders/fake_gas_estimate_subprovider.ts
@@ -0,0 +1,34 @@
+import { JSONRPCPayload } from '@0xproject/types';
+
+/*
+ * This class implements the web3-provider-engine subprovider interface and returns
+ * the constant gas estimate when queried.
+ * HACK: We need this so that our tests don't use testrpc gas estimation which sometimes kills the node.
+ * Source: https://github.com/trufflesuite/ganache-cli/issues/417
+ * Source: https://github.com/trufflesuite/ganache-cli/issues/437
+ * Source: https://github.com/MetaMask/provider-engine/blob/master/subproviders/subprovider.js
+ */
+export class FakeGasEstimateSubprovider {
+    private _constantGasAmount: number;
+    constructor(constantGasAmount: number) {
+        this._constantGasAmount = constantGasAmount;
+    }
+    // This method needs to be here to satisfy the interface but linter wants it to be static.
+    // tslint:disable-next-line:prefer-function-over-method
+    public handleRequest(payload: JSONRPCPayload, next: () => void, end: (err: Error | null, result: any) => void) {
+        switch (payload.method) {
+            case 'eth_estimateGas':
+                end(null, this._constantGasAmount);
+                return;
+
+            default:
+                next();
+                return;
+        }
+    }
+    // Required to implement this method despite not needing it for this subprovider
+    // tslint:disable-next-line:prefer-function-over-method
+    public setEngine(engine: any) {
+        // noop
+    }
+}
diff --git a/packages/dev-utils/src/web3_factory.ts b/packages/dev-utils/src/web3_factory.ts
new file mode 100644
index 000000000..26c26e03d
--- /dev/null
+++ b/packages/dev-utils/src/web3_factory.ts
@@ -0,0 +1,42 @@
+// HACK: web3 injects XMLHttpRequest into the global scope and ProviderEngine checks XMLHttpRequest
+// to know whether it is running in a browser or node environment. We need it to be undefined since
+// we are not running in a browser env.
+// Filed issue: https://github.com/ethereum/web3.js/issues/844
+(global as any).XMLHttpRequest = undefined;
+import ProviderEngine = require('web3-provider-engine');
+import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
+
+import { EmptyWalletSubprovider } from './subproviders/empty_wallet_subprovider';
+import { FakeGasEstimateSubprovider } from './subproviders/fake_gas_estimate_subprovider';
+
+import { constants } from './constants';
+
+// HACK: web3 leaks XMLHttpRequest into the global scope and causes requests to hang
+// because they are using the wrong XHR package.
+// importing web3 after subproviders fixes this issue
+// Filed issue: https://github.com/ethereum/web3.js/issues/844
+// tslint:disable-next-line:ordered-imports
+import * as Web3 from 'web3';
+
+export const web3Factory = {
+    create(hasAddresses: boolean = true): Web3 {
+        const provider = this.getRpcProvider(hasAddresses);
+        const web3 = new Web3();
+        web3.setProvider(provider);
+        return web3;
+    },
+    getRpcProvider(hasAddresses: boolean = true): Web3.Provider {
+        const provider = new ProviderEngine();
+        if (!hasAddresses) {
+            provider.addProvider(new EmptyWalletSubprovider());
+        }
+        provider.addProvider(new FakeGasEstimateSubprovider(constants.GAS_ESTIMATE));
+        provider.addProvider(
+            new RpcSubprovider({
+                rpcUrl: constants.RPC_URL,
+            }),
+        );
+        provider.start();
+        return provider;
+    },
+};