What is Selenium? – Everything you need to know about

• Tue 20-Dec, 2022
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What is Selenium? – Everything you need to know about

Selenium

Selenium is a set of open-source tools that automate web testing in a single interface, allowing you to test in multiple programming languages, including Ruby, Java, NodeJS, PHP, Perl, Python, and C#. t is a free source automation testing tool that is used to automate the tests on web browsers. The first Selenium testing tool was developed by Jason Huggins in the year 2004 who was an engineer at that time at ThoughtWorks. As a part of his work on testing web applications, Jason has realized that manual testing has become more inefficient due to repetitions of the same test cases. He was tired of spending time and energy on web application testing and came up with a Javascript library that allowed him to automatically run tests against multiple browsers. Selenium thus became the first tool that enabled its users to control a browser using any programming language. But although Selenium allowed its users to automate many things, it wasn’t without drawbacks. Because it was based on Javascript, certain things were impossible to do. On top of that, web apps became more complex with time, causing even more restrictions in the tool. A couple of years later, an engineer using the tool at Google named Simon Stewart got fed up with Selenium’s limitations. He wanted a tool that would speak directly to the browser using its ‘native’ language and operating system. Hence WebDriver was born. It took a few years for Selenium to merge with WebDriver, but when they did join forces, it meant taking the best of both worlds, and bringing a massive community of the brightest minds in test automation under one roof. A lot more has happened since then, and in addition to Selenium WebDriver, the Selenium project has evolved into a tool suite that consists of Selenium WebDriver, Selenium IDE, and Selenium Grid. Selenium Remote Control (RC) was also a part of the toolbox but has since been depreciated, mainly because it was incredibly slow.

 

Since Selenium is an open-source tool, there is no licensing cost involved, which is a significant benefit over other testing tools. Other reasons behind Selenium’s ever-growing popularity are as follows:

·         Test scripts are often written in any of these programming languages—Java, Python, C#, PHP, Ruby, Perl, and .Net.

·         Tests can be carried out in any of these operating systems—Windows, Mac, or Linux.

·         Tests can be carried out using any of these browsers—Mozilla Firefox, Internet Explorer, Google Chrome, Safari, or Opera.

·         It can be integrated with tools such as TestNG and JUnit for managing test cases and generating reports.

·         It is integrated with Maven, Jenkins, and Docker to achieve continuous testing.

Now, take a deeper look at Selenium Automation Testing, which has revolutionized the development pipeline.

 

Nomenclature

 

The Name Selenium came from a joke that Jason cracked once to his team. During Selenium’s development, another automated testing framework was popular made by the company called Mercury Interactive (yes, the company who originally made QTP before it was acquired by HP). Since Selenium is a well-known antidote for Mercury poisoning, Jason suggested that name and his teammates took it. So that is how we got to call this framework up to the present.

 

The beginning – How it all started

 

Selenium was the first tool that allowed users to control a browser with the help of any language. It allowed professionals to automate various processes, but it had a set of drawbacks since it was not possible to perform automation testing on certain things with JavaScript. Besides, with web applications getting complex, the restrictions of the tool only started to increase. Soon, Simon Stewart, from Google, got tired of the limitations of Selenium. He required a testing tool that was capable of communicating with the browser directly, and hence, he came up with WebDriver. A few years later, Selenium merged with WebDriver. This tool allowed professionals to do automation testing by using a single tool, which was much more efficient.

 

Why Selenium?

 

Have you ever thought of why testing plays a critical role in the software development lifecycle? Have you ever heard of automation testing? If yes, then you might be aware of what Selenium is. Selenium is considered as a counterpart of Automation testing. If no, then it is time for you to go ahead and get a read on this entire article to understand the importance of Selenium in the IT world. This can change your career drastically and put you on the map of the IT industry. Software testing is a very critical factory for a successful software product run. It must be tested thoroughly before delivering it to users for the software product’s effective performance. All the software in the markets are properly tested, yet they have defects. It is very important to deliver the software without any defects and all test engineers try to catch them before the software release to avoid any issues in the future. Automation testing has become very famous due to its various advantages. It increases the effectiveness and efficiency of the software. Selenium is one of the widely used automation testing tools because of its various advantages. Testers prefer Selenium over any other tool due to its ease of use, availability, and simplicity. Testers' lives have been made easier with the introduction of Selenium for automated testing. It has attracted many eyeballs and has become a favorite tool among automation testers.

 

Selenium is a tool for automating testing across many web browsers. Selenium WebDriver supports a variety of browsers, including Google Chrome, Mozilla Firefox, Safari, and Internet Explorer, and allows you to simply automate browser testing across different browsers.

·         While Selenium has several advantages, the following are a few of the more important ones, which describe why most people choose Selenium over testing tools.

·         It guarantees software development life cycle (SDLC) process agility and transparency among cross-functional teams.

·         It offers less involvement of hardware.

·         It is open-source and platform-independent.

·         It has a user-friendly interface that makes it simple to build and execute test scripts.

·         It provides excellent visibility for testing end-to-end apps.

·         The automation test suites may be reused and tested on a variety of browsers and operating systems.

·         Its flexibility is enhanced by features such as test case regrouping and refactoring

 

Selenium Suite

It is proper to call Selenium as Selenium Suite since it is a collection of four different tools or components namely.

• Selenium Integrated Development Environment (IDE)
• Selenium Remote Control (RC)
• Selenium WebDriver
• Selenium Grid

1. Selenium Integrated Development Environment (IDE)

Selenium Integrated Development Environment (IDE) is the only simplest and easy to learn component or tool in the Selenium automation testing suite. IDE is a Firefox plug-in which can be installed easily to record and execute frequent test cases quickly. The user interactions with the web browser are recorded and test cases are created based on these recordings. You can playback these test cases repeatedly. Though Selenium IDE is simple, it cannot be used as a prototype for writing advanced test cases. 

Selenium IDE was initially created by Shinya Kasatani of Japan as a Firefox plug-in that records and playbacks the user-browser interactions. So initially Selenium IDE was also known as Selenium Recorder.  The other idea behind the development of Selenium IDE was to speed up the creation of test cases. Later in 2006, he donated this Selenium IDE to the Selenium Project.

2. Selenium Remote Control (RC)

Selenium Remote Control has been developed to overcome the issue of the Same Origin Policy (SOP). Under this policy, a JavaScript code cannot access the elements of other domains that are different from its parent domain. For example, if a JavaScript program uses a code written for our site www.mindmajix.com, then SOP allows it to access the pages site such as mindmajix.com/all-courses or mindmajix.com/blog, prohibiting access to other domains like google.com.

Before Selenium RC came into existence, testers used to locally install the copies of Selenium Core and web server with web applications to be tested so that, they both would belong to the single domain.  Observing this, Paul Hammant, another engineer at ThoughtWorks, created Selenium RC which turned out to be the permanent solution for the problem of the SOP. 

How does Selenium RC solve the SOP issue?

Selenium RC tricked the browser to believe that both Selenium Core and the webserver with the web application to be tested belong to the same parent domain. This has been achieved by involving a proxy HTTP server making RC as a dual-component tool – Selenium RC Server and Selenium RC Client.

Selenium RC was the first flagship testing tool of the Selenium project which allows users preferred languages to write the test cases. Selenium RC 2.25.0 supports the following list of languages – 

• C
• Java
• Perl
• PHP
• Python and 
• Ruby

So, it is also called Selenium. But, the major drawback of RC is, it consumes more time for every server communication taking hours to complete even a single test. 

Unfortunately, due to the depreciation, Selenium RC has been renamed as Selenium HQ and shifted to a legacy package. It means, we can still work with Selenium RC, but no support can be availed for it. You may be wondering what would be the replacement for RC. 

3. Selenium WebDriver

Selenium WebDriver was created by Simon Stewart in 2006 as the replacement for Selenium RC. Unlike IDE and RC, Selenium WebDriver provides an interface for creating and executing test cases. These test cases are created in such a way that, web page elements can be easily identified and necessary actions are performed. 

In 2008, Selenium WebDriver has been merged with Selenium RC and evolved as a more potent tool called as Selenium 2, keeping WebDriver as the core. So, Selenium WebDriver can be called as an upgrade version to RC as it employs a contemporary and consistent browser automation approach. WebDriver is much faster than RC because it directly calls the browser whereas RC needs a server to interact with the browser and depends on JavaScript for automated web application testing. Each web browser has its own WebDriver such as,

• Chrome Driver
• Gecko Driver (Firefox)
• HTM Unit Driver
• IE Driver
• Opera Driver and 
• Safari Driver

Selenium WebDriver supports languages similar to that of Selenium RC:

• C#
• Java
• Perl
• PHP
• Python and 
• Ruby

4. Selenium Grid

Selenium Grid is one of the Selenium testing tools used in combination with Selenium RC to execute test cases remotely. It was created by Patrick Lightbody to deal with the minimization of execution times of test cases. Selenium Grid was initially named Hosted QA and was a part of Selenium 1. 

Selenium Grid uses Hub-Node design to support the parallel execution of multiple test cases on multiple machines that are remotely located. In Hub-Node design, one machine is treated as Hub which controls the test cases running on different browsers inside different operating systems. The other machines are treated as Nodes on which test cases can be written in user preferred programming languages.

Here comes the end of the basic introduction of the Selenium QA tool and its components. Now you will be introduced to other testing tools apart from the Selenium tool and why Selenium is the best among them by comparing the top five testing tools.

Advantage of Selenium

• The following list showcases the advantages of the Selenium testing tool that makes it the best among other automation testing tools.
• Selenium is an open-source automation testing tool and it is free of cost to use.
• Selenium provides high tester flexibility to write advanced and complex test cases.
• Supports test scripts written in any user-preferred languages such as C#, Java, Perl, PHP, Python, and Ruby
• Supports test case execution on multiple operating systems such as Windows, Linux, Android, Mac, and iOS.
• Supports testing on different web browsers such as Chrome, Firefox, Internet Explorer (IE), Opera, and Safari.
• Test cases can be executed while the browser window is minimized.
• Selenium supports parallel test execution.
• Selenium can be integrated with TestNG and JUnit to generate test reports and manage test cases.
• Selenium can be integrated with Jenkins, Docker, and Maven to attain continuous testing. 

Conclusion

 

Selenium testing tool has both advantages and shortcomings in comparison to other automation testing tools. But, Selenium overshadows other testing tools in areas of –

·         Cost: Selenium comes free of cost as it is an open-source testing tool.

·         Parallel Testing: Tester can execute test scripts on multiple machines simultaneously.

·         Flexibility: Selenium supports test scripts in multiple languages, execution on multiple browsers and operating systems.

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