Merge pull request #352 from 0xProject/feature/testnet-faucets/order-dispenser

Add order signing and dispensing ability to faucet

9 files changed, 182 insertions, 79 deletions

diff --git a/packages/testnet-faucets/README.md b/packages/testnet-faucets/README.md
index a52d16a00..2f6ae347f 100644
--- a/packages/testnet-faucets/README.md
+++ b/packages/testnet-faucets/README.md
@@ -86,17 +86,23 @@ Returns a JSON payload describing the state of the queues for each network. For
 }
 ```
 
-`GET /ether/:recipient`
+`GET /ether/:recipient?networkId=:networkId`
 
-Where recipient is a hex encoded Ethereum address prefixed with `0x`.
+Schedules a transaction that sends 0.1 ETH to the `recipient` on the network specified by `networkId` where `recipient` is a hex encoded Ethereum address prefixed with `0x`. If no `networkId` is provided via query parameters the faucet will default to network 42 (Kovan).
 
-`GET /zrx/:recipient`
+`GET /zrx/:recipient?networkId=:networkId`
 
-Where recipient is a hex encoded Ethereum address prefixed with `0x`.
+Schedules a transaction that sends 0.1 ZRX to the `recipient` on the network specified by `networkId` where `recipient` is a hex encoded Ethereum address prefixed with `0x`. If no `networkId` is provided via query parameters the faucet will default to network 42 (Kovan).
 
-#### Parameters
+`GET /order/weth/:recipient?networkId=:networkId`
 
-The endpoints `/ether` and `/zrx` take a query parameter named `networkId` to specify the desired network where you would like to receive the ETH or ZRX. For example:
+Returns a JSON payload describing an order for 0.1 WETH in exchange for 0.1 ZRX signed by the dispenser address on the network specified by `networkId`. The taker is specified by `recipient` where `recipient` is a hex encoded Ethereum address prefixed with `0x`. If no `networkId` is provided via query parameters the faucet will default to network 42 (Kovan).
+
+`GET /order/zrx/:recipient?networkId=:networkId`
+
+Returns a JSON payload describing an order for 0.1 ZRX in exchange for 0.1 WETH signed by the dispenser address on the network specified by `networkId`. The taker is specified by `recipient` where `recipient` is a hex encoded Ethereum address prefixed with `0x`. If no `networkId` is provided via query parameters the faucet will default to network 42 (Kovan).
+
+#### Example request
 
 ```bash
 curl -i http://localhost:3000/ether/0x14e2F1F157E7DD4057D02817436D628A37120FD1\?networkId=3
@@ -104,8 +110,6 @@ curl -i http://localhost:3000/ether/0x14e2F1F157E7DD4057D02817436D628A37120FD1\?
 
 This command will request the local server to initiate a transfer of 0.1 ETH from the dispensing address to `0x14e2F1F157E7DD4057D02817436D628A37120FD1` on the Ropsten testnet.
 
-If no `networkId` is provided via query parameters the faucet will default to network 42 (Kovan)
-
 ### Docker configs
 
 ```
diff --git a/packages/testnet-faucets/package.json b/packages/testnet-faucets/package.json
index 7c61d123f..3f052d91f 100644
--- a/packages/testnet-faucets/package.json
+++ b/packages/testnet-faucets/package.json
@@ -17,9 +17,10 @@
     "dependencies": {
         "0x.js": "^0.32.0",
         "@0xproject/utils": "^0.3.0",
-        "@0xproject/subproviders": "^0.3.5",
+        "@0xproject/subproviders": "^0.3.6",
         "body-parser": "^1.17.1",
         "ethereumjs-tx": "^1.3.3",
+        "ethereumjs-util": "^5.1.1",
         "express": "^4.15.2",
         "lodash": "^4.17.4",
         "rollbar": "^0.6.5",
@@ -37,6 +38,8 @@
         "shx": "^0.2.2",
         "source-map-loader": "^0.1.6",
         "tslint": "5.8.0",
+        "types-bn": "^0.0.1",
+        "types-ethereumjs-util": "0xProject/types-ethereumjs-util",
         "typescript": "2.7.1",
         "web3-typescript-typings": "^0.9.9",
         "webpack": "^3.1.0",
diff --git a/packages/testnet-faucets/src/ts/handler.ts b/packages/testnet-faucets/src/ts/handler.ts
index 121112fd3..d96b90802 100644
--- a/packages/testnet-faucets/src/ts/handler.ts
+++ b/packages/testnet-faucets/src/ts/handler.ts
@@ -1,11 +1,20 @@
+import { Order, SignedOrder, ZeroEx } from '0x.js';
 import { NonceTrackerSubprovider } from '@0xproject/subproviders';
-import { addressUtils } from '@0xproject/utils';
+import { BigNumber } from '@0xproject/utils';
 import * as express from 'express';
 import * as _ from 'lodash';
+import * as Web3 from 'web3';
+
+// 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 HookedWalletSubprovider = require('web3-provider-engine/subproviders/hooked-wallet');
 import RpcSubprovider = require('web3-provider-engine/subproviders/rpc');
 
+import { configs } from './configs';
 import { EtherRequestQueue } from './ether_request_queue';
 import { idManagement } from './id_management';
 import { RequestQueue } from './request_queue';
@@ -13,38 +22,71 @@ import { rpcUrls } from './rpc_urls';
 import { utils } from './utils';
 import { ZRXRequestQueue } from './zrx_request_queue';
 
-// HACK: web3 leaks XMLHttpRequest into the global scope and causes requests to hang
-// because they are using the wrong XHR package.
-// Filed issue: https://github.com/ethereum/web3.js/issues/844
-// tslint:disable-next-line:ordered-imports
-import * as Web3 from 'web3';
-
-interface RequestQueueByNetworkId {
-    [networkId: string]: RequestQueue;
+interface ItemByNetworkId<T> {
+    [networkId: string]: T;
 }
 
-enum QueueType {
+enum RequestedAssetType {
     ETH = 'ETH',
+    WETH = 'WETH',
     ZRX = 'ZRX',
 }
 
-const DEFAULT_NETWORK_ID = 42; // kovan
+const FIVE_DAYS_IN_MS = 4.32e8; // TODO: make this configurable
 
 export class Handler {
-    private _etherRequestQueueByNetworkId: RequestQueueByNetworkId = {};
-    private _zrxRequestQueueByNetworkId: RequestQueueByNetworkId = {};
+    private _zeroExByNetworkId: ItemByNetworkId<ZeroEx> = {};
+    private _etherRequestQueueByNetworkId: ItemByNetworkId<RequestQueue> = {};
+    private _zrxRequestQueueByNetworkId: ItemByNetworkId<RequestQueue> = {};
+    private static _dispenseAsset(
+        req: express.Request,
+        res: express.Response,
+        requestQueueByNetworkId: ItemByNetworkId<RequestQueue>,
+        requestedAssetType: RequestedAssetType,
+    ) {
+        const requestQueue = _.get(requestQueueByNetworkId, req.params.networkId);
+        if (_.isUndefined(requestQueue)) {
+            res.status(400).send('UNSUPPORTED_NETWORK_ID');
+            return;
+        }
+        const didAddToQueue = requestQueue.add(req.params.recipient);
+        if (!didAddToQueue) {
+            res.status(503).send('QUEUE_IS_FULL');
+            return;
+        }
+        utils.consoleLog(
+            `Added ${req.params.recipient} to queue: ${requestedAssetType} networkId: ${req.params.networkId}`,
+        );
+        res.status(200).end();
+    }
+    private static _createProviderEngine(rpcUrl: string) {
+        const engine = new ProviderEngine();
+        engine.addProvider(new NonceTrackerSubprovider());
+        engine.addProvider(new HookedWalletSubprovider(idManagement));
+        engine.addProvider(
+            new RpcSubprovider({
+                rpcUrl,
+            }),
+        );
+        engine.start();
+        return engine;
+    }
     constructor() {
         _.forIn(rpcUrls, (rpcUrl: string, networkId: string) => {
-            const providerObj = this._createProviderEngine(rpcUrl);
+            const providerObj = Handler._createProviderEngine(rpcUrl);
             const web3 = new Web3(providerObj);
+            const zeroExConfig = {
+                networkId: +networkId,
+            };
+            const zeroEx = new ZeroEx(web3.currentProvider, zeroExConfig);
+            this._zeroExByNetworkId[networkId] = zeroEx;
             this._etherRequestQueueByNetworkId[networkId] = new EtherRequestQueue(web3);
-            this._zrxRequestQueueByNetworkId[networkId] = new ZRXRequestQueue(web3, +networkId);
+            this._zrxRequestQueueByNetworkId[networkId] = new ZRXRequestQueue(web3, zeroEx);
         });
     }
     public getQueueInfo(req: express.Request, res: express.Response) {
         res.setHeader('Content-Type', 'application/json');
         const queueInfo = _.mapValues(rpcUrls, (rpcUrl: string, networkId: string) => {
-            utils.consoleLog(networkId);
             const etherRequestQueue = this._etherRequestQueueByNetworkId[networkId];
             const zrxRequestQueue = this._zrxRequestQueueByNetworkId[networkId];
             return {
@@ -62,53 +104,59 @@ export class Handler {
         res.status(200).send(payload);
     }
     public dispenseEther(req: express.Request, res: express.Response) {
-        this._dispense(req, res, this._etherRequestQueueByNetworkId, QueueType.ETH);
+        Handler._dispenseAsset(req, res, this._etherRequestQueueByNetworkId, RequestedAssetType.ETH);
     }
     public dispenseZRX(req: express.Request, res: express.Response) {
-        this._dispense(req, res, this._zrxRequestQueueByNetworkId, QueueType.ZRX);
+        Handler._dispenseAsset(req, res, this._zrxRequestQueueByNetworkId, RequestedAssetType.ZRX);
     }
-    private _dispense(
-        req: express.Request,
-        res: express.Response,
-        requestQueueByNetworkId: RequestQueueByNetworkId,
-        queueType: QueueType,
-    ) {
-        const recipientAddress = req.params.recipient;
-        if (_.isUndefined(recipientAddress) || !this._isValidEthereumAddress(recipientAddress)) {
-            res.status(400).send('INVALID_RECIPIENT_ADDRESS');
+    public async dispenseWETHOrder(req: express.Request, res: express.Response) {
+        await this._dispenseOrder(req, res, RequestedAssetType.WETH);
+    }
+    public async dispenseZRXOrder(req: express.Request, res: express.Response, next: express.NextFunction) {
+        await this._dispenseOrder(req, res, RequestedAssetType.ZRX);
+    }
+    private async _dispenseOrder(req: express.Request, res: express.Response, requestedAssetType: RequestedAssetType) {
+        const zeroEx = _.get(this._zeroExByNetworkId, req.params.networkId);
+        if (_.isUndefined(zeroEx)) {
+            res.status(400).send('UNSUPPORTED_NETWORK_ID');
             return;
         }
-        const networkId = _.get(req.query, 'networkId', DEFAULT_NETWORK_ID);
-        const requestQueue = _.get(requestQueueByNetworkId, networkId);
-        if (_.isUndefined(requestQueue)) {
-            res.status(400).send('INVALID_NETWORK_ID');
-            return;
+        res.setHeader('Content-Type', 'application/json');
+        const makerTokenAddress = await zeroEx.tokenRegistry.getTokenAddressBySymbolIfExistsAsync(requestedAssetType);
+        if (_.isUndefined(makerTokenAddress)) {
+            throw new Error(`Unsupported asset type: ${requestedAssetType}`);
         }
-        const lowerCaseRecipientAddress = recipientAddress.toLowerCase();
-        const didAddToQueue = requestQueue.add(lowerCaseRecipientAddress);
-        if (!didAddToQueue) {
-            res.status(503).send('QUEUE_IS_FULL');
-            return;
+        const takerTokenSymbol =
+            requestedAssetType === RequestedAssetType.WETH ? RequestedAssetType.ZRX : RequestedAssetType.WETH;
+        const takerTokenAddress = await zeroEx.tokenRegistry.getTokenAddressBySymbolIfExistsAsync(takerTokenSymbol);
+        if (_.isUndefined(takerTokenAddress)) {
+            throw new Error(`Unsupported asset type: ${requestedAssetType}`);
         }
-        utils.consoleLog(`Added ${lowerCaseRecipientAddress} to queue: ${queueType} networkId: ${networkId}`);
-        res.status(200).end();
-    }
-    // tslint:disable-next-line:prefer-function-over-method
-    private _createProviderEngine(rpcUrl: string) {
-        const engine = new ProviderEngine();
-        engine.addProvider(new NonceTrackerSubprovider());
-        engine.addProvider(new HookedWalletSubprovider(idManagement));
-        engine.addProvider(
-            new RpcSubprovider({
-                rpcUrl,
-            }),
-        );
-        engine.start();
-        return engine;
-    }
-    // tslint:disable-next-line:prefer-function-over-method
-    private _isValidEthereumAddress(address: string): boolean {
-        const lowercaseAddress = address.toLowerCase();
-        return addressUtils.isAddress(lowercaseAddress);
+        const makerTokenAmount = new BigNumber(0.1);
+        const takerTokenAmount = new BigNumber(0.1);
+        const order: Order = {
+            maker: configs.DISPENSER_ADDRESS,
+            taker: req.params.recipient,
+            makerFee: new BigNumber(0),
+            takerFee: new BigNumber(0),
+            makerTokenAmount,
+            takerTokenAmount,
+            makerTokenAddress,
+            takerTokenAddress,
+            salt: ZeroEx.generatePseudoRandomSalt(),
+            exchangeContractAddress: zeroEx.exchange.getContractAddress(),
+            feeRecipient: ZeroEx.NULL_ADDRESS,
+            expirationUnixTimestampSec: new BigNumber(Date.now() + FIVE_DAYS_IN_MS),
+        };
+        const orderHash = ZeroEx.getOrderHashHex(order);
+        const signature = await zeroEx.signOrderHashAsync(orderHash, configs.DISPENSER_ADDRESS, false);
+        const signedOrder = {
+            ...order,
+            signature,
+        };
+        const signedOrderHash = ZeroEx.getOrderHashHex(signedOrder);
+        const payload = JSON.stringify(signedOrder);
+        utils.consoleLog(`Dispensed signed order: ${payload}`);
+        res.status(200).send(payload);
     }
 }
diff --git a/packages/testnet-faucets/src/ts/id_management.ts b/packages/testnet-faucets/src/ts/id_management.ts
index db9b610a3..7c598f91c 100644
--- a/packages/testnet-faucets/src/ts/id_management.ts
+++ b/packages/testnet-faucets/src/ts/id_management.ts
@@ -1,8 +1,10 @@
 import EthereumTx = require('ethereumjs-tx');
+import * as ethUtil from 'ethereumjs-util';
+import * as _ from 'lodash';
 
 import { configs } from './configs';
 
-type Callback = (err: Error | null, accounts: any) => void;
+type Callback = (err: Error | null, result: any) => void;
 
 export const idManagement = {
     getAccounts(callback: Callback) {
@@ -18,4 +20,16 @@ export const idManagement = {
         const rawTx = `0x${tx.serialize().toString('hex')}`;
         callback(null, rawTx);
     },
+    signMessage(message: object, callback: Callback) {
+        const dataIfExists = _.get(message, 'data');
+        if (_.isUndefined(dataIfExists)) {
+            callback(new Error('NO_DATA_TO_SIGN'), null);
+        }
+        const privateKeyBuffer = new Buffer(configs.DISPENSER_PRIVATE_KEY as string, 'hex');
+        const dataBuff = ethUtil.toBuffer(dataIfExists);
+        const msgHashBuff = ethUtil.hashPersonalMessage(dataBuff);
+        const sig = ethUtil.ecsign(msgHashBuff, privateKeyBuffer);
+        const rpcSig = ethUtil.toRpcSig(sig.v, sig.r, sig.s);
+        callback(null, rpcSig);
+    },
 };
diff --git a/packages/testnet-faucets/src/ts/parameter_transformer.ts b/packages/testnet-faucets/src/ts/parameter_transformer.ts
new file mode 100644
index 000000000..c5711d462
--- /dev/null
+++ b/packages/testnet-faucets/src/ts/parameter_transformer.ts
@@ -0,0 +1,29 @@
+import { addressUtils } from '@0xproject/utils';
+import { NextFunction, Request, Response } from 'express';
+import * as _ from 'lodash';
+
+import { configs } from './configs';
+import { rpcUrls } from './rpc_urls';
+import { utils } from './utils';
+
+const DEFAULT_NETWORK_ID = 42; // kovan
+
+export const parameterTransformer = {
+    transform(req: Request, res: Response, next: NextFunction) {
+        const recipientAddress = req.params.recipient;
+        if (_.isUndefined(recipientAddress) || !addressUtils.isAddress(recipientAddress)) {
+            res.status(400).send('INVALID_RECIPIENT_ADDRESS');
+            return;
+        }
+        const lowerCaseRecipientAddress = recipientAddress.toLowerCase();
+        req.params.recipient = lowerCaseRecipientAddress;
+        const networkId = _.get(req.query, 'networkId', DEFAULT_NETWORK_ID);
+        const rpcUrlIfExists = _.get(rpcUrls, networkId);
+        if (_.isUndefined(rpcUrlIfExists)) {
+            res.status(400).send('UNSUPPORTED_NETWORK_ID');
+            return;
+        }
+        req.params.networkId = networkId;
+        next();
+    },
+};
diff --git a/packages/testnet-faucets/src/ts/request_queue.ts b/packages/testnet-faucets/src/ts/request_queue.ts
index 7d685522a..718f8be0c 100644
--- a/packages/testnet-faucets/src/ts/request_queue.ts
+++ b/packages/testnet-faucets/src/ts/request_queue.ts
@@ -13,14 +13,12 @@ const DEFAULT_QUEUE_INTERVAL_MS = 1000;
 export class RequestQueue {
     protected _queueIntervalMs: number;
     protected _queue: string[];
-    protected _queueIntervalId: NodeJS.Timer;
+    protected _queueIntervalId?: NodeJS.Timer;
     protected _web3: Web3;
     constructor(web3: any) {
         this._queueIntervalMs = DEFAULT_QUEUE_INTERVAL_MS;
         this._queue = [];
-
         this._web3 = web3;
-
         this._start();
     }
     public add(recipientAddress: string): boolean {
@@ -47,7 +45,9 @@ export class RequestQueue {
         }, this._queueIntervalMs);
     }
     protected _stop() {
-        clearInterval(this._queueIntervalId);
+        if (!_.isUndefined(this._queueIntervalId)) {
+            clearInterval(this._queueIntervalId);
+        }
     }
     // tslint:disable-next-line:prefer-function-over-method
     protected async _processNextRequestFireAndForgetAsync(recipientAddress: string) {
diff --git a/packages/testnet-faucets/src/ts/server.ts b/packages/testnet-faucets/src/ts/server.ts
index 26edfff5a..be1077756 100644
--- a/packages/testnet-faucets/src/ts/server.ts
+++ b/packages/testnet-faucets/src/ts/server.ts
@@ -3,6 +3,7 @@ import * as express from 'express';
 
 import { errorReporter } from './error_reporter';
 import { Handler } from './handler';
+import { parameterTransformer } from './parameter_transformer';
 
 // Setup the errorReporter to catch uncaught exceptions and unhandled rejections
 errorReporter.setup();
@@ -20,8 +21,10 @@ app.get('/ping', (req: express.Request, res: express.Response) => {
     res.status(200).send('pong');
 });
 app.get('/info', handler.getQueueInfo.bind(handler));
-app.get('/ether/:recipient', handler.dispenseEther.bind(handler));
-app.get('/zrx/:recipient', handler.dispenseZRX.bind(handler));
+app.get('/ether/:recipient', parameterTransformer.transform, handler.dispenseEther.bind(handler));
+app.get('/zrx/:recipient', parameterTransformer.transform, handler.dispenseZRX.bind(handler));
+app.get('/order/weth/:recipient', parameterTransformer.transform, handler.dispenseWETHOrder.bind(handler));
+app.get('/order/zrx/:recipient', parameterTransformer.transform, handler.dispenseZRXOrder.bind(handler));
 
 // Log to rollbar any errors unhandled by handlers
 app.use(errorReporter.errorHandler());
diff --git a/packages/testnet-faucets/src/ts/zrx_request_queue.ts b/packages/testnet-faucets/src/ts/zrx_request_queue.ts
index db1b619a8..3659f4856 100644
--- a/packages/testnet-faucets/src/ts/zrx_request_queue.ts
+++ b/packages/testnet-faucets/src/ts/zrx_request_queue.ts
@@ -18,13 +18,10 @@ const QUEUE_INTERVAL_MS = 5000;
 
 export class ZRXRequestQueue extends RequestQueue {
     private _zeroEx: ZeroEx;
-    constructor(web3: Web3, networkId: number) {
+    constructor(web3: Web3, zeroEx: ZeroEx) {
         super(web3);
         this._queueIntervalMs = QUEUE_INTERVAL_MS;
-        const zeroExConfig = {
-            networkId,
-        };
-        this._zeroEx = new ZeroEx(web3.currentProvider, zeroExConfig);
+        this._zeroEx = zeroEx;
     }
     protected async _processNextRequestFireAndForgetAsync(recipientAddress: string) {
         utils.consoleLog(`Processing ZRX ${recipientAddress}`);
diff --git a/packages/testnet-faucets/tsconfig.json b/packages/testnet-faucets/tsconfig.json
index 7f0c084ff..79f9e2413 100644
--- a/packages/testnet-faucets/tsconfig.json
+++ b/packages/testnet-faucets/tsconfig.json
@@ -3,5 +3,10 @@
     "compilerOptions": {
         "outDir": "lib"
     },
-    "include": ["./src/ts/**/*", "../../node_modules/web3-typescript-typings/index.d.ts"]
+    "include": [
+        "./src/ts/**/*",
+        "../../node_modules/types-bn/index.d.ts",
+        "../../node_modules/types-ethereumjs-util/index.d.ts",
+        "../../node_modules/web3-typescript-typings/index.d.ts"
+    ]
 }