Web - Headless browser (Test automation)

A headless browser is an application/library that emulates a web browser but without a graphical user interface ie (without DOM / without the Web api)

They are the basis to build a web bot.

• Build a robot
• Test automation
• Taking screenshots of web pages.
• Running automated tests for JavaScript libraries.
• Scraping web sites for data.
• Crawl a SPA (Single-Page Application) and generate pre-rendered content (i.e. SSR (Server-Side Rendering)).
• Automating interaction of web pages:
  • form submission,
  • UI testing,
  • keyboard input, etc.
• Capture a timeline trace of your site to help diagnose performance issues.

Browser Driver Library:

• Browser Automation - Selenium - Headless browser - WebDriver / ChromeDriver (automated testing - W3C WebDriver API ) - Selenium/WebDriver focuses on cross-browser automation. Its value proposition is a single standard API that works across all major browsers.
• puppeteer focuses on Chromium; its value proposition is richer functionality and higher reliability.
• Jsdom
• Headless Chrome
• PhantomJS – a headless web browser using WebKit layout engine for rendering web pages and JavaScriptCore for executing scripted tests.
• HtmlUnit – a headless browser written in Java (Rhino engine to provide JavaScript and AJAX)
• Geb - groovy browser automation… web testing, screen scraping and more
• http://casperjs.org/ based on
  • SlimerJS is similar to PhantomJs, except that it runs on top of Gecko, the browser engine of Mozilla Firefox instead
  • PhantomJS runs on top of Webkit,
  • http://triflejs.org/ API is coded as a port of PhantomJS. Internet Explorer browser that runs on top of the V8 engine
• https://electronjs.org/spectron for electron app

Proxy Script Injection:

• https://github.com/DevExpress/testcafe - TestCafe uses a URL-rewriting proxy which allows it to work without the WebDriver (selenium). This proxy injects the driver script that emulates user actions into the tested page.

• Google Chrome - Headless mode
• Firefox – headless mode

Headless browser command line:

• wget,
• curl
• chrome headless cli

Test runners are wrapping them around launcher to facilitate testing.

List:

• Karna

• Headless_browser