What is Selenium? Why do we use Selenium for automation?
Published: 2024-06-09 21:25:09

     Selenium is a automation tool used for web application testing. It is a popular open source testing tool. Selenium enables testers to write automated tests in various programming languages to test the functionality of web applications. It can be run in many different browsers and operating systems. It can be used to test the functionality of web applications on various browsers and operating systems. Selenium Software Testing is a great way to automate your web application testing.

**_Components of Selenium_**

Selenium is a collection that consists of three major components:

_Selenium IDE:_ Selenium IDE is a Firefox add-on that enables testers to record and playback the recorded automated tests. Selenium IDE is easy to use and lets you create and run automated tests quickly. Selenium IDE Chrome also includes a built-in debugger that enables you to troubleshoot your tests. To use Selenium IDE, you first need to install the Selenium add-on for Firefox or Chrome. You can then open Selenium IDE by clicking on the "Selenium" icon in the Firefox or Chrome toolbar.

Once the Selenium IDE is open, then you can start recording your tests by clicking on the "Record" button. Selenium will then begin recording all of your actions as you perform them in the browser. To stop the test recording, click on the "Stop" button. You can then playback your tests by clicking on the "Play" button. Selenium will then replay all of the actions that you recorded.

_Selenium WebDriver:_ The Selenium WebDriver is an open-source tool used for automating web browser interaction from a user perspective. With it, you can write tests that simulate user interactions with a web application. It is available for many different programming languages, such as Java, C#, Python, and Perl.

WebDriver provides a powerful and flexible test automation framework that enables you to create automated tests for your web applications easily. It also includes several over-the-top features, such as automatically discovering elements on a web page and capturing screenshots of your tests.

_Selenium Grid:_ The Selenium Grid distributes your tests across multiple machines or virtual machines (VMs). Selenium Grid enables you to test parallelly on various devices or VMs, allowing you to scale your test automation quickly. Selenium Grid is a crucial part of the overall Selenium testing suite and will enable you to execute your automated tests much faster. The Selenium Server is a part of Selenium Grid that can be installed locally on your device or hosted on a separate system/server.

**_Using Selenium for automation:_**
Testing is a vital part of the development cycle and is essential for ensuring the quality and stability of your applications. By performing application testing, you can find and fix bugs in your code before they have a chance to cause problems for your users. Additionally, application testing can help you verify that your application is working correctly on different browsers and operating systems.

Testing is performed in several ways, including manual, automated, and performance testing. Automated testing is a popular approach for performing application testing, as it enables you to test your applications quickly and efficiently. Selenium Testing is a popular tool for automated testing, as it allows you to write tests in various programming languages and run them on many different browsers and operating systems.

**_Benefits of Selenium Testing:_**

1. Efficient and accurate web application testing.
2. The ability to test your web application on multiple browsers and 
   operating systems.
3. The ability to run more than one test at the same time.

You can significantly reduce your time to test your web application with a selenium grid. And by using a selenium grid, you can ensure that your web application is fully functional before releasing it to users. Therefore, if you want to improve your web application testing, consider using the selenium grid. Its one of the best ways to automate your web application testing.

The important things to keep in mind while writing Selenium tests.
1. The goal of our selenium test is to find the bugs in your web application.
2. your selenium test should be concise.
3. You should only use the selenium web driver when you are sure about how to use the tools and scripts

Once you have written your selenium test, you can run them on different browsers and operating systems. To do this, you will need to use a selenium grid. A selenium grid is a server that enables you to run multiple selenium tests simultaneously on different browsers and operating systems.

There are different types of Selenium tests that you can write. The most common types of selenium tests are

- Unit Tests
- Functional Tests
- Integration Tests
- Regression Tests
- End-to-End Tests


**_Unit Tests_**

Unit Tests are the simplest type of Selenium tests. A Unit Test verifies that a single unit of code behaves as expected. 

When writing a Unit Test, you should first create a test case. A test case is a set of instructions that tests a particular feature or function of your code. To create a test case, you will need to:

- Define the expected outcome of the test.
- Verify that the code under test behaves as expected.

Once your test case is written, you can run it using the WebDriver. Open your browser and go to the page where your test is located. Then, enter your test case into the browser's address bar and press "Enter." Your Unit Test should automatically run, and you will be able to see if the code under test behaved as expected.

**_Functional Test_**

Functional Tests are similar to Unit Tests, but they test the functionality f an entire web application. When writing a Functional Test, you should always keep in mind the following:

1. The goal of your Functional Test is to find bugs in all the functional components of your web application.

2. Your Functional Test should be concise but have to be written for each functional module of your app.
 
3. You should only use the WebDriver functional tests when all your components are passed from the development stage.

When writing a Functional Test, you will first need to identify the different areas of your web application that you want to test. Once you have selected these areas, you can create a test case for each one. Once your test cases are written, you can run them using the WebDriver. Open your browser and go to the page where your tests are located. Then, enter your test case into the browser's address bar and press "Enter." Your Functional Test should automatically run, and you will be able to see if the code under test behaved as expected.

**_Integration Tests_**

Integration Tests are used to test the integration between different parts of your web application. When writing an Integration Test, you should always keep in mind the following:

- The goal of Integration Testing in Selenium is to find bugs in your web application that arise from integrating multiple components.
- Your Integration Test should be short, and it should verify that all individual components work properly when integrated.

**_Regression Tests_**

Usually, regression suites include a huge number of test cases and it takes time and effort to execute them manually every time when a code change has been introduced. Hence almost every organization looks after automating regression test cases to reduce the time and effort. Choosing the right automation framework/ tool completely depends upon the application, technology used, testing requirements, and skill sets required for performing automation testing. It helps in automating functional and regression test cases that reduce the manual testing effort.

Automation completely depends on the framework that you choose to develop, and there is no such tool dedicated to performing only regression testing. The automation framework you select should be designed such that it supports regression testing effectively.

You can develop the regression suite for automation and keep adding new test scripts/test cases as and when required. Selenium Framework contains many reusable modules/functions that make it easy to maintain the existing code or add any new code. 

**_End-to-End Tests_**
End-to-End Tests are used to test an entire web application from start to finish. When writing an end-to-end test, you should always keep in mind the following:

- The goal of your End-to-End Test is to find bugs in your web application that arise as a result of the correlation between multiple components.
- Your End-to-End Test should be concise, and it should verify that all individual components work properly when integrated.

Once your test cases are written, you can run them using the WebDriver. Open your browser and go to the page where your tests are located. Then, enter your test case into the browser's address bar and press "Enter." Your End-to-End Test should automatically run, and you will be able to see if the code under test behaved as expected.

**Limitations of Selenium WebDriver**
Although Selenium is one of the best tools for automating your tests on multiple devices, it still has limitations. Some of them are mentioned below:

1. WebDriver cannot interact with flash or Java applets.
2. WebDriver is not capable of handling complex animations.
3. WebDriver cannot recognize text inside images.
4. WebDriver has some difficulty dealing with dynamically generated 
   pages.
5. WebDriver can be difficult to use when testing web applications that 
   use Ajax or ReactJS.

**_Advantages of Selenium Automation Testing_**

_Language Agnostic:_ 
Selenium WebDriver offers native bindings for JavaScript, Python, Java, C#, and Ruby, eliminating the need to learn a new programming language solely for testing. While Selenium has its syntax, having proficiency in one of these languages proves beneficial.
_Cross-Browser Compatibility:_ 
Selenium communicates with browsers through drivers and is adaptable to different browser versions. With the appropriate driver, Selenium seamlessly supports significant browsers like Chrome, Firefox, Safari, Edge, and Opera.
_Cross-Platform Compatibility:_
 Extending its versatility, Selenium is cross-platform compatible, allowing test creation on one platform and execution on another. It effortlessly functions across Windows, Mac OS, and various Linux distributions.
_Community Support:_
 As an open-source tool with a substantial history, Selenium boasts a strong community. This support extends beyond regular updates and upgrades to encompass comprehensive documentation and a wealth of learning resources.
_Integrations with Third Parties:_
 Selenium excels in integrations, providing the flexibility to extend functionality through third-party plugins. Users can leverage existing plugins or create custom ones to enhance Selenium's capabilities.
_Parallel Test Execution:_ 
Selenium supports parallel test execution across multiple machines, facilitated by Selenium Grid. This feature enables users to conduct tests simultaneously on various browsers and platforms, centralizing the management of browser configurations.

**Drawbacks of Selenium Automation Testing**

- High Test Maintenance
- No Build-in Capabilities
- No Reliable Tech Support
- Learning Curve