Selenium in Test Automation: Automated Quality Assurance for Web Applications

Selenium enables the automation of browser-interactive tests, leading to accelerated test execution and improved quality of web applications. We provide an overview of the most important information, prerequisites, and what you need to know when using Selenium.

The digital world, including software development, is constantly evolving. The complexity of high-quality software has significantly increased, partly due to recent rapid AI developments. This brings more complex software requirements, necessitating efficient and reliable software tests. In many cases, automating these tests is essential. Among the numerous tools available for this automation, Selenium stands out as one of the leading options.

Introduction to Selenium

What is Selenium?

Selenium is an open-source framework developed for test automation of web applications. It stands out for its flexibility, supporting various browsers, operating systems, and programming languages. Selenium offers two different ways to create automated tests for validating web applications: Selenium IDE and Selenium WebDriver. The Selenium IDE provides a capture-and-replay option for Firefox and Chrome. However, you'll quickly find that you can't avoid Selenium WebDriver if you want to automate robust regression tests. The WebDriver allows you to code robust scripts in your favorite programming language.

The Importance of Selenium in Test Automation

Selenium is used by some of the world's most significant software companies. For example, Google, Microsoft, Amazon, and Facebook test their web applications with Selenium automations. The advantages that make Selenium valued by these companies and others are numerous:

• The Selenium community is large and continuously develops the framework
• It's easy for beginners to learn due to its simple handling
• Selenium offers market-specific advantages
• Tests can be automated in complex scenarios, in parallel, and across different browsers simultaneously

One of Selenium's most popular test frameworks is JUnit, a Java-based framework that offers a range of special functions for test cases

Basics of Selenium Test Automation

Prerequisites for Using Selenium

Selenium was developed to automate testing of web applications. Other applications, such as desktop or mobile apps, are not suitable for test automation with Selenium. The WebDriver offers libraries for many different languages, allowing you to choose your favorite programming language for validating your application.

Even if you have no coding experience, creating test scripts is not an insurmountable challenge due to the concise code required and the large number of good tutorials available. However, some hard skills are still highly advantageous. For example, you should have HTML and CSS knowledge or take a crash course on website source code beforehand.

Setup

If you've decided to use Selenium, you must first set up the framework correctly. This requires a current version of the programming language you want to use for your test project. You also need a suitable IDE to code the test scripts and implement the test project.

The basis of the actual Selenium framework is so-called 'Language Bindings'. These contain the clients and libraries for the Selenium WebDriver for a variety of different programming languages. In addition to the 'Language Bindings', the driver of the browser through which the automation is to run must be installed.

Practical Application of Selenium

Structure of an Automation Script

A Selenium WebDriver script always follows a similar structure, so a test always runs according to the same scheme. At the beginning, the browser is started via the WebDriver and navigated to the target website. A web element on the website is located via XPaths, with which one or more user actions are then performed. Finally, the actual test takes place, and it is validated whether the actual browser response to the executed action matches the expected reaction to the executed action.

Cross-Browser Testing / Scalability / Test Coverage

Scalability is always an important topic in the automation of web applications. If you can test on different browsers with different versions and operating systems, test coverage can be maximized in the smallest possible time window. The Selenium WebDriver itself offers the possibility to run tests sequentially. However, this can also lead to problems with a large number of tests.

Selenium Grid can help here. It specializes in running tests under multiple combinations of browsers and operating systems, but this also doesn't happen simultaneously. To run tests simultaneously, a cloud-based solution is best suited. This allows tests to run on multiple operating devices with different browsers at the same time.

Challenges and Solutions with Selenium

Those who want to build test automation with Selenium must be aware of several challenges. Perhaps the most common challenge is handling popups and alerts. These are notification windows that require data input or confirmation to proceed. There are different types: browser-level notifications, web-based warnings, and operating system-level popups.

Another challenge that repeatedly causes problems in test automation is dynamic content. These are characterized by the following properties:

1. They appear on the page only after a certain time
2. Elements become visible/invisible through certain user actions
3. The availability of elements differs depending on user rights
4. Elements can have dynamic attributes, such as constantly changing IDs

For the first case, content that appears after a certain time, it's advisable to wait for this content. A distinction is made between implicit and explicit waits.

__In conclusion, Selenium opens up possibilities for efficient and reliable software tests. With its versatile functions, it offers clear added value for developers and testers. Use Selenium's versatility to increase the quality of your software. __