Test automation is a critical aspect to develop high quality top-of-the-line product. The importance of test automation should be understood to conduct rapid and efficient productive testing. Also, automation allows a process to be completed with little or no human intervention and makes collective testing of millions of lines of code in the shortest period possible.
Introduction to automation testing
Automation testing is a code, or a process built with a different software framework or programming language to check an application program under test. This aids in the validation of checks against expected and desired results obtained through the use of automation scripts and software. The primary goal of test automation software is to automate manual tasks, which are redundant and monotonous. Some advanced test automation software can fully automate the validation of software applications end-to-end.
Software test automation can be used at every stage of SDLC (Software Development Life Cycle). Initially, it all starts from unit testing where the code is first written. The final phase is known as ‘production deployment’ where the deployed code can be checked for working functionality. Test automation can also be used to validate functionalities at various layers to ensure that the application software under development meets the necessary requirements. Some common examples of such layers and interfaces are:
- Graphical User Layer (GUI)
- Application Programming Interface (API)
- Database layer
Benefits of test automation
Processes like test-driven development, model-specific language for testing, and behavioral-driven testing should be performed correctly to improve the efficiency, coverage, and quality of the work produced. Furthermore, with good test automation, the ability to create reusable libraries and code modularization is another benefit that can save a lot of time and money across the project.
Some advantages of test automation include:
- Avoiding bugs and errors
- Ability to test around the clock across multiple systems and platforms
- Ability to test the same functionality with different or multiple data sets and platforms
- Faster time to market
- Quick removal of defects
- Increase in test coverage
- Cost-saving: Automation testing results in cost-cutting due to the minimization of human errors
- Reusability: It is the ability to write code once and utilize it multiple times
- Modularity: It is the ability to write code in small chunks without the need of writing the whole code again
- Reduction in human errors: Manual errors such as mistyping, clicking the wrong buttons, and other types of errors can be avoided
- Reduction in execution time: Efficient automation helps to reduce test execution time
Test automation with the advent of DevOps, continuous integration, and automating end-to-end software processes have eliminated the need for any manual interference and verification. With software automation, the test cases can be run in parallel, unattended, and across platforms. A testing team’s test coverage for stability can be improved with test automation. However, on the other hand, important code branches and business functions must be automated by leveraging manual testing experts. Automation can assist skilled manual testers in concentrating their efforts on areas requiring immense business and functional knowledge.
Test automation has been advancing at a rapid pace over the last three decades. The computer industry has grown tremendously since the advent of the World Wide Web and the emergence of Internet-based websites and applications. With the availability of websites and apps across multiple platforms, browsers, and devices, testing a web application has become a difficult and time-consuming task. Nonetheless, the emergence of Selenium and its features has aided software testers in propelling the testing process to deliver faster turnaround time through its purpose-driven automation framework and flexibility. Due to its open-source nature and outstanding community support, Selenium has emerged as the de-facto tool of choice for all web application automation specialists.
History of Selenium
Selenium has previously released models, which are summarized below.
Selenium Core: A core library that provides language support and functions for the automation of applications.
Source: Science of Selenium by Kalilur Rahman
Selenium Remote Control: It is an older version of proxy-server-based automation that runs through a server and a driver concept.
Note: Selenium Remote Control is no longer used in newer versions of Selenium and has been replaced by Selenium Web Driver.
Selenium Web Driver: It is a more structured web browser platform-centric web driver that enables truly distributed automated testing across different browsers and platforms.
Selenium IDE: It is an IDE that allows non-programmers to automate web applications with the use of Selenium IDE (Selenese) commands.
Selenium Grid: An advanced feature that of this version allows parallel test execution in a grid (hub and node) fashion to complete large amounts of automation testing in a short period. Due to advanced features, Selenium Grid has gained increasing popularity among technologists and programmers.
Why use Selenium?
There are numerous technical reasons to use Selenium for automated testing. Some of them are as follows:
- The simplicity of implementation: Selenium is very simple to set up and use
- Selenium has an excellent user interface
- Selenium programming is simple to integrate with other popular IDEs such as Eclipse IDE, Spyder, Atom, etc
- It is open-source and widely used
- All open-source software is free to use and comes at no cost to organizations
- It is freely available for download and has a sizable fan base. Selenium is also very well supported and maintained
- Selenium framework is reusable and extensible
Challenges and Limitations of using Selenium
Selenium is an excellent automation tool, however, there are some obstacles to overcome before using it for automation testing.
It is an open-source tool, and various enterprises are concerned about the lack of guaranteed support. This is not particularly true in the case of Selenium. Though Selenium is open-source software, it has an online community, which is well endowed with solid sponsors. Selenium was designed primarily to support only web applications.
Some of these applications can be extended and automated. To perform meaningful automation, an automation specialist with strong programming skills is required. Due to its scripted nature, the cost of automation maintenance could be expensive if not coded efficiently. There are no built-in test management integration capabilities, as seen in other popular software. However, there are plug-ins and extensions available to help with these issues. Automation may take longer if skilled developers are not available.
Top Seven Most Popular Challenges Faced In Selenium Test Automation
- System pop-ups
Pop-ups that appear on the screen during automation testing are part of the operating system, which makes it difficult for Selenium to automate these in web applications. Due to this reason, Selenium’s inability to automate any system software such as Windows-based alerts is quite obvious.
- Lack of good reporting
Every tester requires a good testing report post-execution of a test, which helps them to analyze the entire test scenario and find bugs. Without a doubt, Selenium can vastly improve automated testing capabilities, but due to some limitations, it is unable to generate good testing reports.
- Timeout Issue
One of the most common Selenium test automation challenges a timeout issue. It is extremely critical to deal with this issue with extreme care. Most of your testing scripts may fail if you do not handle this issue carefully. Majority of testing scripts malfunction due to improper synchronization while performing automation testing. Testers can use some inbuilt features meant for this purpose such as Implicit waits and Explicit waits, which are available within Selenium.
- Cross Browser Testing
Selenium is a multilingual and cross-platform compatible testing software, which is widely used for, automated cross-browser testing of web apps. However, testers sometimes have noticed that Selenium fails to run an automation test for certain browsers which hampers cross-browser testing to a significant level. It is critical to ensure that web apps should work properly and correctly in all browsers otherwise the risk of losing a high traffic rate is inevitable. To deal with this problem, Selenium test scripts should run multiple times on different browsers and results should be constantly examined.
Testers from across the world relies on a platform called LambdaTest in order to perform cross browser compatibility testing of their website on 2000+ browsers & OS. LambdaTest offers an amazing and superfast selenium grid which is scalable as per user requirement.
- Mobile apps testing
Selenium does not support mobile app testing on operating systems such as Android and iOS. It only allows testers to test web apps on other operating systems and browsers. Android and iOS are mostly used web platforms nowadays, hence this restriction limits Selenium’s capability to a major extent. An alternative solution to this problem is to use Appium, which is an open-source automation-testing framework that drives native as well as hybrid iOS and Android mobile apps using the Web Driver protocol.
- Loading issue
Certain web pages in some web apps are user-specific, which load according to the user profile. The display of some features is based on the user’s previous activity. Sometimes Selenium script is not able to identify the user-specific element during execution. To solve this problem, the tester can use explicit waits to give enough time to load and discover the element.
Selenium is not considered the most scalable solution for automation testing. Comprehensive test coverage in the shortest amount of time is essential for automation testing which makes it essential to run as many tests as possible in a limited time. Selenium, as an open-source platform, allows you to test on almost every browser and operating system, but still, there are some limitations to the number of tests that can be executed in a single go. The primary goal of automation testing is to run as many tests as possible to achieve wide test coverage. At first, your web app might have short test builds, but as it grows, the test will iterate itself with each sprint. You can perform sequential automation testing with Selenium WebDriver, but it may not be as effective.
However, Selenium Grid can improve this iteration test problem by enabling parallel testing but it does not allow testing web apps across multiple OS and browser combinations. It only supports you to run tests on a single browser and operating system at a time. Using a cloud-based tool seems to be a solution to this problem by which a tester can test web apps across multiple browsers and operating systems at the same time. Although using a cloud tool shortens the time it takes to run automated tests but increases the number of configurations a tester can test on. Thus, Selenium is not used as a promising scalable solution.
Selenium and its features aid software testers in propelling the testing process to deliver a faster turnaround time. Selenium has emerged as the de-facto tool of choice for all web application automation specialists due to its open-source nature and outstanding community support. Through purpose-driven automation testing and the flexibility of the Selenium framework, Selenium has emerged as a popular choice amongst testers in recent years.