Headless browser are profit in popularity as a viable option for testing web apps. However, when determining your test strategy, it ’ s important to understand how headless browsers can facilitate improve your efforts, and where they might hinder them.

This article explain what headless browser examination is and which use causa it support. It also identifies the limitation of headless browser examination, and discus position in which you may not want to use it.

What Is a Headless Browser?

“ Headless browser ” is a funny-sounding term that refers to something that software test technologist use all the time: a web browser that is not configured with a Graphical User Interface.

A headless browser is a type of software that can access webpages but make not exhibit them to the user and can shriek the content of the webpages to another program. Unlike a normal browser, nothing will appear on the screen when you start up a headless browser, since the programs run at the backend.

Like a normal browser, a headless browser can parse and interpret webpage (although conduct can dissent between different browser implementations), so it can provide a existent browser context without any of the memory and velocity costs of scarper a full-fledged one with a GUI. For example, a headless browser should be capable of parsing JavaScript, click on links, coping with any downloads, etc. Executing a headless browser typically means make so via a command line interface or using network communication.

Google Chrome and Firefox both get versions of their web browser with a headless option. Other browser options that proffer some form of a brainless implementation include: HtmlUnit, TrifleJS, Splash, and SimpleBrowser.

Headless browsers may not be really utile for channel-surf the Web, but they are a outstanding tool for examine. Here are some things you might want to know about headless browser examination and the advantages and disadvantages of leverage it for your testing needs.

Headless Browser Testing: How Can It Be Utile?

Automation

Since headless browser can provide automated control of webpages, they can be employ for automating tasks, scripts, and User Interface tests against a browser without the need for starting up the User Interface of the browser. Webpage interaction can be automated such as variety submissions, keyboard inputs, mouse dog, etc. You can also run automated tryout for JavaScript libraries. Headless browser testing can enable up-to-date automated test in a browser surroundings.

Layout Testing

Headless browser testing can facilitate a lot of layout checks since headless effectuation can provide and interpret HTML and CSS like a existent browser. This means that it is possible to test style factor such as page layout (e.g. find the default width of the page, the co-ordinate of where an element is), color selection for any constituent, baptistry used, etc. It can also essay for JavaScript and AJAX executing. You can even automate screen capture for layout checks.

SUSA automates exploratory testing with persona-driven behavior, catching bugs that scripted automation misses.

Data Extraction

A full example of a browser would be overkill if you just desire to perform website scraping and information extraction. You may not necessarily want to start up a site, go to it, and scrape it. It is much leisurely and speedy to voyage to a website headlessly, scrape for data, and use the results to prove multiple webpages as part of a character control effort.

Performance

Headless browser are your acquaintance if performance is critical. They are faster than real browsers since they do not come with all the overhead of get up a browser GUI, and this equates to quicker results for your tests. For your developers, this means a lot of time saved when they just want to perform quick and small smoke tests where the UI is irrelevant (i.e., “ Can I log into the application? ” or “ Is SSL enable? ”). Being able to perform non-exhaustive tasks via the command line without the need to manually refresh a page or start a browser can save a lot of effort. Keep in judgement that the overall execution still depends on the actual tests and the system being try.

Other Uses

Here are some early use cases that can be leveraged with headless browser testing:

• Running tests on machines without a Graphical User Interface

• Generating screenshots and PDFs of webpage

• Monitoring net coating performance

• Capturing a timeline ghost of a website for execution diagnosis

• Simulating multiple browser on a individual machine without the imagination hog

Limitations of Headless Browser Testing

As illustrated above, many things that can be tested manually in a existent browser can be screen using a headless execution, but you can not actually use it for all your browser testing motive, and you should perform essay on real browsers most of the clip.

At the end of the day, your end exploiter are not using a headless browser, and so you do not want to focus on bugs that simply happen in brainless mode. In order to essay for user experience and do a functional test, you demand to mimic a real user and get precise feedback on what they will really experience on the site. You want to observe the actual deportment and interaction between an end exploiter and the browser.

Sometimes it is necessary to see your test run on a real browser. This can frequently be an easy and full debugging technique. If you need to do a lot of browser debugging, this can be challenging in headless mode. A headless browser is a different browser, and tests can catch bugs and throw mistake that won ’ t occur on a real browser.

Conclusion

Automated headless browser testing is outstanding for when you need fast feedback on element of you application. They are nimble to set up, and can ensure that snippets of codification are working with the end-to-end experience. Headless testing early on in the line, for model, on every pull request, can help deliver instant feedback to developers before committing code to the master branch. However, headless browsers can be limiting when perform full UI tests, as it won ’ t interact with the browser the way your users would. In addition, headless browsers can be trammel if you require to examine on the full variety of browser and OS combination to ensure coverage. Finally, debugging tools such as video validation and live (manual) testing can not be accessed with headless. Therefore, a sound try scheme should include a mix of both types of browsers, as they offer both QA and development the infrastructure they take to test quickly and faithfully.

Daisy Tsang is a Software Developer currently base in Berlin. She has worked at companies in Canada and Germany in the past few years, loves learning about new technologies, and is peculiarly concerned in the open-source infinite. Her non-technical interests include photography, knitting, baking, and discover new natural languages.

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