Today, Selenium is one of the most extensively used automation tools. Many of the tasks involved in online testing are automated, such as title verification, website navigating, and link clicking. Many developers are already familiar with Selenium's full range of capabilities, but few are aware of the ability to perform tests in headless browsers. This method is used by even fewer persons in their daily testing. With headless browser testing, you can take your testing to new heights. Selenium WebDriver's UI automation relies heavily on web browsers. The launch of a browser is required for web automation testing, followed by the execution of test cases on the browsers.
When we run Selenium tests on any browser, however, we frequently run into problems like poor browser rendering, interference from other apps on the system, and so on. Apart from these, the majority of today's CI systems lack a user interface (such as Unix based systems). As a result, we need a mechanism to run the test cases in non-GUI mode on such platforms in order to execute them. This is when the headless browser comes into play, assisting in the Selenium test execution.
Why do we need headless browser testing?
1) Headless browser testing is generally faster than traditional UI testing since it does not wait for the entire page to display before taking any action.
2) The test can be performed even if no real browser is installed on the system.
3) In parallel testing, multiple sessions can be launched at the same time, allowing the testing to be performed without the need for human participation. In the same way, the user can work on numerous projects at once.
4) Only a few Headless Browsers, such as Chrome and Firefox, support screenshots.
5) We can temporarily disable headless mode in Chrome and Firefox for Selenium script debugging.
Is headless browser testing with Selenium possible?
Selenium allows for headless testing. In previous Selenium versions, we generally used the HTMLUnitDriver, a headless driver that provides a non-GUI implementation of Selenium WebDriver. In the current versions of SeleniumWebDriver 3 and Selenium Webdriver 4, Selenium now supports headless versions of genuine browsers like Chrome, Firefox, and Edge. Furthermore, selenium offers a number of alternatives for running various browsers in headless mode.
Running Selenium headless browser tests using Headless Chrome
Headless Chrome is a technique for using the Chrome browser without the entire user interface in a headless environment. Headless Chrome gives you a real browser experience without the memory drain that comes with running Chrome full version. Google Chrome has allowed headless execution since version 59. The "ChromeOptions" class in Selenium WebDriver allows you to change Chrome's default behaviour by setting various options. The "headless" mode is one of these options, and it executes the test cases while Chrome is in headless mode. The following code snippet shows how to pass the "headless" option using the ChromeOptions class.
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