From 2586e69e91e2269f77af58bf470418444d45d9f3 Mon Sep 17 00:00:00 2001
From: Paul Irish <paul.irish@gmail.com>
Date: Sun, 27 Mar 2016 12:17:07 -0700
Subject: [PATCH] Enable device emulation, network throttling, and disable disk
 cache.

---
 helpers/browser/driver.js | 15 ++++++-
 helpers/emulation.js      | 90 +++++++++++++++++++++++++++++++++++++++
 index.js                  |  2 +-
 3 files changed, 105 insertions(+), 2 deletions(-)
 create mode 100644 helpers/emulation.js

diff --git a/helpers/browser/driver.js b/helpers/browser/driver.js
index 778952d80c78..1746788b23d1 100644
--- a/helpers/browser/driver.js
+++ b/helpers/browser/driver.js
@@ -18,6 +18,8 @@
 
 const chromeRemoteInterface = require('chrome-remote-interface');
 const NetworkRecorder = require('../network-recorder');
+const emulation = require('../emulation');
+
 const npmlog = require('npmlog');
 
 const port = process.env.PORT || 9222;
@@ -68,7 +70,9 @@ class ChromeProtocol {
       chromeRemoteInterface({port: port}, chrome => {
         this._chrome = chrome;
         this.beginLogging();
-        resolve(null);
+        this.beginEmulation().then(_ => {
+          resolve(null);
+        });
       }).on('error', e => reject(e));
     });
   }
@@ -226,6 +230,15 @@ class ChromeProtocol {
       });
     });
   }
+
+  beginEmulation() {
+    return new Promise((resolve, reject) => {
+      emulation.enableNexus5X(this);
+      emulation.enableNetworkThrottling(this);
+      emulation.disableCache(this);
+      this.pendingCommandsComplete().then(_ => resolve());
+    });
+  }
 }
 
 function _log(level, prefix, data) {
diff --git a/helpers/emulation.js b/helpers/emulation.js
new file mode 100644
index 000000000000..7ae52e57f5bb
--- /dev/null
+++ b/helpers/emulation.js
@@ -0,0 +1,90 @@
+/**
+ * @license
+ * Copyright 2016 Google Inc. All Rights Reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+'use strict';
+
+// Nexus5X metrics adaparted from emulated_devices/module.json
+const DEVICE_EMULATION_METRICS = {
+  mobile: true,
+  screenWidth: 412,
+  screenHeight: 732,
+  width: 412,
+  height: 732,
+  positionX: 0,
+  positionY: 0,
+  scale: 1,
+  deviceScaleFactor: 2.625,
+  fitWindow: false,
+  screenOrientation: {
+    angle: 0,
+    type: 'portraitPrimary'
+  }
+};
+
+const DEVICE_EMULATION_USERAGENT = {
+  userAgent: 'Mozilla/5.0 (Linux; Android 6.0; Nexus 5 Build/MRA58N) AppleWebKit/537.36' +
+    '(KHTML, like Gecko) Chrome/51.0.2690.0 Mobile Safari/537.36'
+};
+
+const NETWORK_THROTTLING_CONFIG = {
+  latency: 150, // 150ms
+  downloadThroughput: 1.6 * 1024 * 1024 / 8, // 1.6Mbps
+  uploadThroughput: 750 * 1024 / 8, // 750Kbps
+  offline: false
+};
+
+function enableNexus5X(driver) {
+  driver.sendCommand('Emulation.setDeviceMetricsOverride', DEVICE_EMULATION_METRICS);
+  driver.sendCommand('Network.setUserAgentOverride', DEVICE_EMULATION_USERAGENT);
+  driver.sendCommand('Emulation.setTouchEmulationEnabled', {
+    enabled: true,
+    configuration: 'mobile'
+  });
+
+  // from emulation/TouchModel.js
+  /* eslint-disable no-proto */ /* global window, document */
+  const injectedFunction = function() {
+    const touchEvents = ['ontouchstart', 'ontouchend', 'ontouchmove', 'ontouchcancel'];
+    var recepients = [window.__proto__, document.__proto__];
+    for (var i = 0; i < touchEvents.length; ++i) {
+      for (var j = 0; j < recepients.length; ++j) {
+        if (!(touchEvents[i] in recepients[j])) {
+          Object.defineProperty(recepients[j], touchEvents[i], {
+            value: null, writable: true, configurable: true, enumerable: true
+          });
+        }
+      }
+    }
+  };
+  /* eslint-enable */
+  driver.sendCommand('Page.addScriptToEvaluateOnLoad', {
+    scriptSource: '(' + injectedFunction.toString() + ')()'
+  });
+}
+
+function disableCache(driver) {
+  driver.sendCommand('Network.setCacheDisabled', {cacheDisabled: true});
+}
+
+function enableNetworkThrottling(driver) {
+  driver.sendCommand('Network.emulateNetworkConditions', NETWORK_THROTTLING_CONFIG);
+}
+
+module.exports = {
+  enableNexus5X: enableNexus5X,
+  enableNetworkThrottling: enableNetworkThrottling,
+  disableCache: disableCache
+};
diff --git a/index.js b/index.js
index aa1301f46119..9a13149e495e 100644
--- a/index.js
+++ b/index.js
@@ -16,7 +16,7 @@
  */
 'use strict';
 
-const defaultUrl = 'https://voice-memos.appspot.com';
+const defaultUrl = 'https://m.flipkart.com';
 const ChromeProtocol = require('./helpers/browser/driver');
 
 const Auditor = require('./auditor');