From 4b6716efefbede10c3816613d9d32d84c2a07844 Mon Sep 17 00:00:00 2001
From: sa <sixsecondfiesta@gmail.com>
Date: Sat, 19 Mar 2016 21:14:41 -0400
Subject: [PATCH] Infer user agent from Electron's online version list

---
 src/infer/inferUserAgent.js | 52 +++++++++++++++++++++++++++++++++++++
 src/options/optionsMain.js  | 40 ++++++++++++++--------------
 2 files changed, 72 insertions(+), 20 deletions(-)
 create mode 100644 src/infer/inferUserAgent.js

diff --git a/src/infer/inferUserAgent.js b/src/infer/inferUserAgent.js
new file mode 100644
index 0000000..161b728
--- /dev/null
+++ b/src/infer/inferUserAgent.js
@@ -0,0 +1,52 @@
+import request from 'request';
+import _ from 'lodash';
+
+const ELECTRON_VERSIONS_URL = 'https://atom.io/download/atom-shell/index.json';
+
+function getChromeVersionForElectronVersion(electronVersion, url = ELECTRON_VERSIONS_URL) {
+    return new Promise((resolve, reject) => {
+        request(url, (error, response, body) => {
+            if (error) {
+                reject(error);
+                return;
+            }
+            if (response.statusCode === 200) {
+                const data = JSON.parse(body);
+                const electronVersionToChromeVersion = _.zipObject(data.map(d => d.version), data.map(d => d.chrome));
+                if (!(electronVersion in electronVersionToChromeVersion)) {
+                    reject(`Electron version '${ electronVersion }' not found in retrieved version list!`);
+                    return;
+                }
+                resolve(electronVersionToChromeVersion[electronVersion]);
+                return;
+            }
+            reject('Bad request: ' + response.statusCode);
+            return;
+        });
+    });
+}
+
+export function getUserAgentString(chromeVersion, platform) {
+    let userAgent;
+    switch (platform) {
+        case 'darwin':
+            userAgent = `Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/${ chromeVersion } Safari/537.36`;
+            break;
+        case 'win32':
+            userAgent = `Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/${ chromeVersion } Safari/537.36`;
+            break;
+        case 'linux':
+            userAgent = `Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/${ chromeVersion } Safari/537.36`;
+            break;
+        default:
+            break;
+    }
+    return userAgent;
+}
+
+export function inferUserAgent(electronVersion, platform) {
+    return getChromeVersionForElectronVersion(electronVersion)
+        .then(chromeVersion => {
+            return getUserAgentString(chromeVersion, platform);
+        });
+}
diff --git a/src/options/optionsMain.js b/src/options/optionsMain.js
index 554fe73..dc126bb 100644
--- a/src/options/optionsMain.js
+++ b/src/options/optionsMain.js
@@ -1,4 +1,3 @@
-import os from 'os';
 import path from 'path';
 import _ from 'lodash';
 import async from 'async';
@@ -7,6 +6,7 @@ import sanitizeFilenameLib from 'sanitize-filename';
 import inferIcon from './../infer/inferIcon';
 import inferTitle from './../infer/inferTitle';
 import inferOs from './../infer/inferOs';
+import {inferUserAgent, getUserAgentString} from './../infer/inferUserAgent';
 import normalizeUrl from './normalizeUrl';
 import packageJson from './../../package.json';
 
@@ -14,6 +14,8 @@ const {inferPlatform, inferArch} = inferOs;
 
 const PLACEHOLDER_APP_DIR = path.join(__dirname, '../../', 'app');
 const ELECTRON_VERSION = '0.36.4';
+const CHROME_VERSION = '47.0.2526.73';
+
 const DEFAULT_APP_NAME = 'APP';
 
 /**
@@ -45,7 +47,7 @@ function optionsFactory(inpOptions, callback) {
         width: inpOptions.width || 1280,
         height: inpOptions.height || 800,
         showMenuBar: inpOptions.showMenuBar || false,
-        userAgent: inpOptions.userAgent || getFakeUserAgent(),
+        userAgent: inpOptions.userAgent,
         ignoreCertificate: inpOptions.ignoreCertificate || false,
         insecure: inpOptions.insecure || false,
         flashPluginDir: inpOptions.flash || null,
@@ -66,6 +68,22 @@ function optionsFactory(inpOptions, callback) {
     }
 
     async.waterfall([
+        callback => {
+            if (options.userAgent) {
+                callback();
+                return;
+            }
+            inferUserAgent(options.version, options.platform)
+                .then(userAgent => {
+                    options.userAgent = userAgent;
+                    callback();
+                })
+                .catch(error => {
+                    console.warn('Cannot get user agent:', error);
+                    options.userAgent = getUserAgentString(CHROME_VERSION, options.platform);
+                    callback();
+                });
+        },
         callback => {
             if (options.icon) {
                 callback();
@@ -118,22 +136,4 @@ function sanitizeOptions(options) {
     return options;
 }
 
-function getFakeUserAgent() {
-    let userAgent;
-    switch (os.platform()) {
-        case 'darwin':
-            userAgent = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10_10_1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.1 Safari/537.36';
-            break;
-        case 'win32':
-            userAgent = 'Mozilla/5.0 (Windows NT 6.1) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2228.0 Safari/537.36';
-            break;
-        case 'linux':
-            userAgent = 'Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2227.0 Safari/537.36';
-            break;
-        default:
-            break;
-    }
-    return userAgent;
-}
-
 export default optionsFactory;