Selenium

Selenium:

A set of tools that allows automate web testing is known as Selenium.

Selenium is a free of cost and open-source automated testing framework used for validating and supporting web applications and automation across different platforms, browsers and programming languages. Selenium is not the name of just a single tool but rather a suite of software, each with a different approach to support automation testing where each piece caters to an organization’s various Selenium QA testing needs.

Introduction to Selenium: 

Selenium was originally conceptualized and developed by a software engineer at ThoughtWorks named Jason Huggins, primarily as an internal software testing tool in 2004. At that time he was working on a web application that required frequent manual testing. He ultimately developed the JavaScript code that enabled the  automation control of the browser which significantly streamlined the testing process. The code that was open-sourced later the same year came to be known as “Selenium Remote Control”. Several other software developers got involved in the Selenium Project over the next few years and a number of Selenium-related projects were spawned, including Selenium IDE, Selenium Grid, and Selenium WebDriver. As of now, this increasingly powerful set of tools is essentially one fully coordinated test framework.

Selenium is one of the most widely used open-source Web UI (User Interface) automation testing suite.

Selenium can be used to automate functional tests. It can also be integrated with automation test tools for achieving continuous testing including Maven, Jenkins,  and Docker. In order to help manage test cases and generate reports, Selenium is also integrated with tools such as TestNG and JUnit.

Reason behind Selenium naming:

The name Selenium originated from a joke that it’s developer Jason once cracked to his team. Another automated testing framework was made by Mercury Interactive was quite popular during Selenium’s development. Mercury Interactive is the company that originally developed QTP before being acquired by HP. Jason Huggins suggested the name Selenium because of it being a well-known antidote for Mercury Poisoning, and his team gladly accepted the idea.

Four Components of Selenium Platform: 

Selenium is a powerful tool for controlling web browser through program. It is functional for all browsers, works on all major Operating Systems (OS) and its scripts are written in various languages i.e Python, Java, and C# etc. Selenium has been used in the industry by automation testers all around the world for a long time.

Not only is Selenium a collection of different tools but it rather had a number of software developers with some key software engineers making notable contributions to this selenium development project.

After realizing that the repetitious Manual Testing of their web application had become inefficient, Huggins developed a JavaScript Program that could control the web browser’s actions automatically. The software program was named as the “JavaScriptTestRunner.”

As the idea potentially helped automate other web applications, it’s developer made JavaScriptRunner an open-source web application and re-named it as Selenium Core.

There are four major components in the Selenium Platform including Selenium RC, Selenium IDE, Selenium WebDriver, and Selenium Grid.

I. Selenium Remote Control (Selenium RC):

All major Web Browsers are supported by Selenium Remote Control (Selenium RC). Commands are interpreted by this web tool for converting them into JavaScript. The scripts are then injected into the browser. Selenium RC is a server that accepts commands for the browser via HTTP and is written in Java. Selenium RC allows writing automated tests for a web application in any programming language. This makes better integration of Selenium in the existing unit test frameworks possible. Presently, Selenium project provides client drivers for PHP, Python, Ruby, .NET, Perl and Java for making writing tests easier. 

The Java driver is also used with JavaScript via the Rhino engine. An instance of Selenium RC server is required for launching an Html test case. This means that the port must be different for each parallel run. However, only a single Selenium RC instance is required to run continuously for a Java/PHP test case. 

Primarily, the whole application under test and the web server was required to be installed on their computers by testers using Selenium Core due to restrictions imposed by the same origin policy.  A software engineer named Paul Hammant at ThoughtWorks created a server that acted as an HTTP proxy and was able to “trick” the browser into believing that the web application being tested and Selenium Core came from the same domain. This system came to be known as Selenium 1 or the Selenium Remote Control (Selenium RC).

II. Selenium IDE (Selenium Integrated Development Environment):

Selenium IDE is a simple record-and-playback featured tool that is only available for Firefox as an add-on. The Selenium IDE is a browser-plugin-based Graphical User Interface (GUI) tool. Recording, playback, and testing of user actions is facilitated by this component of the Selenium in the browser. It’s the best way for users to get a feel for the multiple things Selenium is able to do in software testing. Quick and simple test scripts can be created by the Selenium IDE for basic functional testing and bug hunting. The Selenium IDE project was redesigned quite recently and it now works on both Firefox and Chrome browsers.

Selenium IDE is the main tool in the Selenium Suite. It is a complete integrated development environment for Selenium tests.

Selenium IDE is implemented both as a Chrome Extension and a Firefox Add-On. Recording, editing and debugging of functional tests is carried out by this browser platform. Selenium IDE was previously little-maintained and known as the Selenium Recorder. It began being actively maintained in 2018. Scripts are recorded automatically and manually edited that provide autocompletion support and also enabling you to quickly move commands around. Selenese is a special test scripting language for Selenium and scripts are recorded in this language. The Selenese language helps provide commands to perform actions in a browser by clicking a link and selecting an option in order to retrieve data from the resulting pages.

Selenium IDE, a Firefox extension was created by Shinya Kasatani that could automate the browser through a record-and-playback feature by coming up with the idea of further increasing the speed in the creation of test cases. He donated it to the Selenium Project in 2006.

III. Selenium WebDriver  (aka Selenium 2.0):

One of the most vital tools of the Selenium Suite is the Selenium WebDriver. This web tool does not require any manual processes like the Selenium Server. A direct communication between code and browser exists in this kind of tool. WebDriver is also referred to as “Selenium 2.0”. It improves and expands on Selenium Remote Control (SRC) and does what it says. Web browsers are driven by WebDriver at a lower level as compared to Selenium IDE.

Consisting of a set of APIs, Selenium 2.0 allows the tester to control the browser from an Operating System (OS) level which leads to greater efficiencies in complex automation setups. Headless browsers are supported by the Selenium 2.0 that are able to greatly speed up software testing. WebDriver is suitable for scalable, advanced, and more complex automation. Not only is WebDriver protocol currently W3C compliant but also in the upcoming Selenium 4 version. The older JSON Wire Protocol has been replaced by this version.

Selenium WebDriver is the platform that is a successor to Selenium RC. The Selenium WebDriver platform accepts commands that are sent in Selenese, or via a Client API and then sends them to a browser. This process gets implemented through a browser driver that is browser-specific, and which retrieves results by sending commands to a browser. Most browser drivers literally launch and access browser applications such as Firefox, Google Chrome, Internet Explorer, Safari, and Microsoft Edge etc. A browser using the headless browser HtmlUnit is also stimulated by an HtmlUnit browser driver. A special server is not required by Selenium WebDriver for executing the tests. The WebDriver instead starts a browser instance directly and then controls it. Nonetheless, Selenium Grid is used with WebDriver for executing tests on remote systems. Native operating system level functionality is used by WebDriver instead of browser-based JavaScript commands for driving the browser wherever possible. This helps bypass issues with subtle differences between native and JavaScript commands that include the security restrictions as well. 

In 2006, at a time when Web Applications and Browsers were becoming more restrictive and more powerful with JavaScript programs like Selenium Core, Simon Stewart was able to create the WebDriver. This tool was the first cross-platform software testing framework which controlled the browser from the Operating System (OS) level.

IV. Selenium Grid:

The last component of Selenium Suite is known as the Selenium Grid. 

It is usually used for Parallel Testing. This web tool at times even supports the Distributive Testing Process.

Tests are allowed to use web browser instances running on remote machines by Selenium Grid server. One server acts as the hub with Selenium Grid. The hub is contacted by hub for obtaining access to browser instances. The hub has got a list of servers which provides access to browser instances or WebDriver nodes, and allows the use of these instances by the tests. Selenium Grid can run tests in parallel on multiple machines and also manage different browser configurations and browser versions  centrally, instead of in each individual test. The ability of running tests on remote browser instances is useful for spreading the load of testing across several machines and running tests in browsers that run on different platforms or operating systems (OS). The latter is one specifically useful in those cases where not all the browsers to be used for testing are able to run on the same platform.

In an effort to address the need of minimizing test execution times, Patrick Lightbody was able to develop the Selenium Grid, initially calling the system “Hosted QA.” Selenium Grid was could capture Browser Screenshots during significant stages, and was also capable of simultaneously sending out Selenium commands to various machines.

With WebDriver being the core, in 2008, the Selenium Team merged WebDriver and Selenium RC to create a more powerful Software Tool known as Selenium 2. Selenium RC is still being developed in Maintenance Mode only. The entire efforts of the Selenium Project are currently being focused on Selenium 2 development. 

Selenium Testing:

Multiple programming languages like Java, C#, Python etc can be used for creating Selenium Test Scripts. Testing done by using the Selenium Testing Tool (STT) is normally referred to as Selenium Testing.

The list of Selenium Software Testing Tools include:

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

Selenium for Automated Testing:

Selenium is an automated testing framework. Test scripts against different web browsers can be executed using this framework including Chrome, Safari and Firefox.

Types of Testing Using Selenium: 

Selenium can be used to do many types of testing including smoke testing, sanity testing, UI testing, and regression testing etc. 

Writing a Selenium Test:

Numerous coding languages are supported by the Selenium framework. A test script can be written using Ruby, C#, Java, Perl, Python, JavaScript, and PHP etc. A few statements or packages may be needed to be imported into your code. XPath in Selenium can also be used for finding objects.

Benefits of Selenium: 

I. Transparency: Ensures transparency and agility across the cross-functional teams of SDLC process including the developers, quality assurance, operations, clients and the management teams. 

II. Platform Independent: The time in writing test scripts by Software Testers for each platform to be tested is avoided because the principle of writing one test script and running it on any platform is followed. 

III. Quickening TTM and TTD: Manual Software Testing is a very hectic, time consuming and uncertain process. Product delivery and time to market schedules are rarely missed by the use of an automated software testing process. Manual Testing also happens to increase the overall project costs. Avoiding the writing of test script for each platform separately by testers in Selenium saves precious time and also eliminates the regression testing process. All this not only helps quicken the TTM and TTD but also greatly optimizes testing time.

IV. Fostering Continuous Integration Efforts: The modern day Agile-Enablers of the Software Development Process are Continuous Delivery and Continuous Integration. Selenium acts as a catalyst to nurture the efforts of organizations in successfully implementing the Continuous Integration (CI) practice by automating the overall test process. 

V. End-to-End Testing Visibility: The Selenium Platform provides a greater visibility in case of End-to-End Applications Testing. 

VI. Reduction of Turnaround Time:

The testing teams are facilitated to automatically run multiple test cases in parallel with multi-browser platforms by the Selenium Framework. This not only ensures an extreme testing quality but also helps reduce the turnaround time. 

VII. Integration With Other Tools: Selenium with Java is popular just like certain other available jars including Sikuli, Appium, and ExtentReports etc. 

Selenium tool provides 

Flexibility for testing teams is provided by Selenium tool for getting integrated with these jars and help in extending its functionalities to uncharted territories:

a. Graphs and reports are generated with “ExtentReports” by Selenium Integration that are used for providing a deeper insight to potential clients on the testing status.

b. Web applications involving videos and images can be tested through the integration of Selenium with “Sikuli”. 

c. An integration of Selenium with Appium can achieve testing of web apps on Android or iOS platforms. 

Benefits of Selenium: 

I. Transparency: Ensures transparency and agility across the cross-functional teams of SDLC process including the developers, quality assurance, operations, clients and the management teams. 

II. Platform Independent: The time in writing test scripts by Software Testers for each platform to be tested is avoided because the principle of writing one test script and running it on any platform is followed. 

III. Quickening TTM and TTD: Manual Software Testing is a very hectic, time consuming and uncertain process. Product delivery and time to market schedules are rarely missed by the use of an automated software testing process. Manual Testing also happens to increase the overall project costs. Avoiding the writing of test script for each platform separately by testers in Selenium saves precious time and also eliminates the regression testing process. All this not only helps quicken the TTM and TTD but also greatly optimizes testing time.

IV. Fostering Continuous Integration Efforts: The modern day Agile-Enablers of the Software Development Process are Continuous Delivery and Continuous Integration. Selenium acts as a catalyst to nurture the efforts of organizations in successfully implementing the Continuous Integration (CI) practice by automating the overall test process. 

V. End-to-End Testing Visibility: The Selenium Platform provides a greater visibility in case of End-to-End Applications Testing. 

VI. Reduction of Turnaround Time:

The testing teams are facilitated to automatically run multiple test cases in parallel with multi-browser platforms by the Selenium Framework. This not only ensures an extreme testing quality but also helps reduce the turnaround time. 

VII. Integration With Other Tools: Selenium with Java is popular just like certain other available jars including Sikuli, Appium, and ExtentReports etc. 

Selenium tool provides 

Flexibility for testing teams is provided by Selenium tool for getting integrated with these jars and help in extending its functionalities to uncharted territories:

a. Graphs and reports are generated with “ExtentReports” by Selenium Integration that are used for providing a deeper insight to potential clients on the testing status.

b. Web applications involving videos and images can be tested through the integration of Selenium with “Sikuli”. 

c. An integration of Selenium with Appium can achieve testing of web apps on Android or iOS platforms.