Feature request: enable flags/prefs in BrowserStack launcher

[kangyizhang]

Currently BowserStack launcher in karma customLaunchers can not set browser flags/prefs like other launchers whose base is 'Chrome' or 'Firefox'. Example of flags: https://github.com/karma-runner/karma-chrome-launcher#configuration

[luwes]

would be great to have this feature

[Finesse]

I need this too to start browsers in incognito/private mode. This is what I've found so far. I've succeeded to make a Python code that starts incognito Chrome on Browserstack:

Python code

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
from selenium.webdriver.common.by import By
from selenium.webdriver.common.desired_capabilities import DesiredCapabilities
from time import sleep
from datetime import datetime
import os

desired_cap = {
    "browser": "Chrome",
    "goog:chromeOptions": {
        "args": ["incognito", ],
        "w3c": False
    },
}

driver = webdriver.Remote(
    # The environment variable value must be 'http://your-username:your-password@hub-cloud.browserstack.com/wd/hub'
    command_executor=os.environ.get('BROWSERSTACK_HUB_URL'),
    desired_capabilities=desired_cap
)

print("Session: https://automate.browserstack.com/dashboard/v2/sessions/" + driver.session_id)
print("protocol w3c:" + str(driver.w3c))

driver.get("https://google.com/")
driver.quit()

I've tried to use the same capabilities in custom launchers in a Karma configuration. The capabilities have got to BrowserStack sessions (I can see them in "Input Capabilities"), but BrowserStack ignores them for some reason.

Karma configuration

// Karma configuration
// Generated on Wed Oct 07 2015 12:43:21 GMT+0530 (IST)

module.exports = function(config) {
  config.set({

    // base path that will be used to resolve all patterns (eg. files, exclude)
    basePath: '',

    // hostname for local
    hostname: 'bs-local.com',

    // frameworks to use
    // available frameworks: https://npmjs.org/browse/keyword/karma-adapter
    frameworks: ['qunit'],

    //plugins
    plugins: ['karma-qunit', 'karma-browserstack-launcher'],


    // list of files / patterns to load in the browser
    files: [
      'src/*.js',
      'tests/*.js'
    ],


    // list of files to exclude
    exclude: [
    ],


    // preprocess matching files before serving them to the browser
    // available preprocessors: https://npmjs.org/browse/keyword/karma-preprocessor
    preprocessors: {
    },


    // test results reporter to use
    // possible values: 'dots', 'progress'
    // available reporters: https://npmjs.org/browse/keyword/karma-reporter
    reporters: ['progress', 'BrowserStack'],


    // web server host and port
    port: 9876,


    // enable / disable colors in the output (reporters and logs)
    colors: true,


    // level of logging
    // possible values: config.LOG_DISABLE || config.LOG_ERROR || config.LOG_WARN || config.LOG_INFO || config.LOG_DEBUG
    logLevel: config.LOG_INFO,


    // enable / disable watching file and executing tests whenever any file changes
    autoWatch: false,

    browserStack: {
      username: process.env.BROWSERSTACK_USERNAME,
      accessKey: process.env.BROWSERSTACK_ACCESS_KEY,
      apiClientEndpoint: 'https://api.browserstack.com',
      build: String(Math.random()),
    },

    // define browsers
    customLaunchers: {
      bs_chrome_win: {
        base: 'BrowserStack',
        browser: 'Chrome',
        os: 'Windows',
        os_version: '10',
        'goog:chromeOptions': {
          args: ['incognito'],
          w3c: true,
        },
      },
      bs_chrome_mac: {
        base: 'BrowserStack',
        browser: 'Chrome',
        os: 'OS X',
        os_version: 'Catalina',
        'goog:chromeOptions': {
          args: ['incognito'],
          w3c: true,
        },
      },
      bs_firefox_win: {
        base: 'BrowserStack',
        browser: 'firefox',
        os: 'Windows',
        os_version: '10',
        'moz:firefoxOptions': {
          prefs: {
            'browser.privatebrowsing.autostart': true,
          },
        },
      },
      bs_firefox_mac: {
        base: 'BrowserStack',
        browser: 'firefox',
        os: 'OS X',
        os_version: 'Catalina',
        'moz:firefoxOptions': {
          prefs: {
            'browser.privatebrowsing.autostart': true,
          },
        },
      },
    },

    captureTimeout: 3e5,
    browserDisconnectTolerance: 0,
    browserDisconnectTimeout: 3e5,
    browserSocketTimeout: 1.2e5,
    browserNoActivityTimeout: 3e5,

    browsers: ['bs_chrome_win', 'bs_chrome_mac', 'bs_firefox_win', 'bs_firefox_mac'],
    // start these browsers
    // available browser launchers: https://npmjs.org/browse/keyword/karma-launcher

    // Continuous Integration mode
    // if true, Karma captures browsers, runs the tests and exits
    singleRun: true
  })
}

I've tried various other custom launcher settings, they all have started Chrome and Firefox in regular mode.

[Finesse]

This is what BrowserStack support says about passing keys to browsers from Karma:

Unfortunately, a PR to fix the runner may not work here as with the JS testing API, chromeOptions will not get honoured.

This would be a feature request with no ETA at the moment.

For every session that you initiate on Browserstack, you will be assigned a clean browser. In case you strictly need to use incognito mode, I will recommend switching to Selenium.

That being said, I have noted down your account details and will reach out to you once we have implemented the feature.

As far as I understand, this feature depends on BrowserStack and not on karma-browserstack-launcher unfortunately.