Fix some issues in Firefox (closes #2035, closes #2180)

src/browser/provider/built-in/chrome/local-chrome.js

@@ -1,13 +1,9 @@
-import OS from 'os-family';
-import Promise from 'pinkie';
 import browserTools from 'testcafe-browser-tools';
 import killBrowserProcess from '../../utils/kill-browser-process';
-import delay from '../../../../utils/delay';
+import BrowserStarter from '../../utils/browser-starter';
 
 
-const MACOS_PROCESS_THROTTLING = 500;
-
-var throttlingPromise = Promise.resolve();
+const browserStarter = new BrowserStarter();
 
 function buildChromeArgs (config, cdpPort, platformArgs, profileDir) {
     return []
@@ -22,18 +18,12 @@ function buildChromeArgs (config, cdpPort, platformArgs, profileDir) {
 }
 
 export async function start (pageUrl, { browserName, config, cdpPort, tempProfileDir }) {
-    var chromeInfo           = await browserTools.getBrowserInfo(config.path || browserName);
-    var chromeOpenParameters = Object.assign({}, chromeInfo);
+    const chromeInfo           = await browserTools.getBrowserInfo(config.path || browserName);
+    const chromeOpenParameters = Object.assign({}, chromeInfo);
 
     chromeOpenParameters.cmd = buildChromeArgs(config, cdpPort, chromeOpenParameters.cmd, tempProfileDir);
 
-    var currentThrottlingPromise = throttlingPromise;
-
-    if (OS.mac)
-        throttlingPromise = throttlingPromise.then(() => delay(MACOS_PROCESS_THROTTLING));
-
-    await currentThrottlingPromise
-        .then(() => browserTools.open(chromeOpenParameters, pageUrl));
+    await browserStarter.startBrowser(chromeOpenParameters, pageUrl);
 }
 
 export async function stop ({ browserId }) {

src/browser/provider/built-in/firefox/local-firefox.js

@@ -1,8 +1,11 @@
 import OS from 'os-family';
 import browserTools from 'testcafe-browser-tools';
 import killBrowserProcess from '../../utils/kill-browser-process';
+import BrowserStarter from '../../utils/browser-starter';
 
 
+const browserStarter = new BrowserStarter();
+
 function correctOpenParametersForMac (parameters) {
     parameters.macOpenCmdTemplate = parameters.macOpenCmdTemplate
         .replace('open', 'open -n')
@@ -23,16 +26,16 @@ function buildFirefoxArgs (config, platformArgs, profileDir) {
 }
 
 export async function start (pageUrl, runtimeInfo) {
-    var { browserName, config, tempProfileDir } = runtimeInfo;
-    var firefoxInfo                             = await browserTools.getBrowserInfo(config.path || browserName);
-    var firefoxOpenParameters                   = Object.assign({}, firefoxInfo);
+    const { browserName, config, tempProfileDir } = runtimeInfo;
+    const firefoxInfo                             = await browserTools.getBrowserInfo(config.path || browserName);
+    const firefoxOpenParameters                   = Object.assign({}, firefoxInfo);
 
     if (OS.mac && !config.userProfile)
         correctOpenParametersForMac(firefoxOpenParameters);
 
     firefoxOpenParameters.cmd = buildFirefoxArgs(config, firefoxOpenParameters.cmd, tempProfileDir, runtimeInfo.newInstance);
 
-    await browserTools.open(firefoxOpenParameters, pageUrl);
+    await browserStarter.startBrowser(firefoxOpenParameters, pageUrl);
 }
 
 export async function stop ({ browserId }) {

src/browser/provider/built-in/firefox/runtime-info.js

@@ -38,7 +38,8 @@ async function generatePrefs (profileDir, port) {
         'user_pref("extensions.shield-recipe-client.first_run", false);',
         'user_pref("extensions.shield-recipe-client.startupExperimentPrefs.browser.newtabpage.activity-stream.enabled", false);',
         'user_pref("devtools.toolbox.host", "window");',
-        'user_pref("devtools.toolbox.previousHost", "bottom");'
+        'user_pref("devtools.toolbox.previousHost", "bottom");',
+        'user_pref("signon.rememberSignons", false);'
     ];
 
     if (port) {

src/browser/provider/utils/browser-starter.js

@@ -0,0 +1,38 @@
+import Promise from 'pinkie';
+import OS from 'os-family';
+import browserTools from 'testcafe-browser-tools';
+import delay from '../../../utils/delay';
+
+
+const POST_OPERATION_DELAY = 500;
+
+class OperationsQueue {
+    constructor () {
+        this.chainPromise = Promise.resolve();
+    }
+
+    executeOperation (operation) {
+        const operationPromise = this.chainPromise.then(operation);
+
+        this.chainPromise = operationPromise.then(() => delay(POST_OPERATION_DELAY));
+
+        return operationPromise;
+    }
+}
+
+export default class BrowserStarter {
+    constructor () {
+        // NOTE: You can't start multiple instances of the same app at the same time on macOS.
+        // That's why a queue of opening requests is needed.
+        this.macOSBrowserOpeningQueue = new OperationsQueue();
+    }
+
+    async startBrowser (...openArgs) {
+        const openBrowserOperation = () => browserTools.open(...openArgs);
+
+        if (OS.mac)
+            await this.macOSBrowserOpeningQueue.executeOperation(openBrowserOperation);
+        else
+            await openBrowserOperation();
+    }
+}