Browser extension testing with selenium c# in Saucelabs
For Firefox and chrome it is possible by providing capabilities or profile. For Example in case of firefox:
File file = new File("firebug-1.8.1.xpi"); FirefoxProfile firefoxProfile = new FirefoxProfile(); firefoxProfile.addExtension(file); firefoxProfile.setPreference("extensions.firebug.currentVersion", "1.8.1"); // Avoid startup screen
WebDriver driver = new FirefoxDriver(firefoxProfile);