One of the most used automation testing frameworks by developers and testers is Selenium which allows testing the quality of software applications. This framework involves the use of Selenium components with Jest, which helps in easing automation testing.
Selenium is an automation testing framework that comes with libraries and packages which allow the testers and developers to verify and validate the software applications. These packages give freedom of testing across various browsers and platforms using different languages. Like Selenium, Jest is also an open-source framework that is JavaScript based. It is built by Meta on top of Jasmine to test software applications. Jest comes with some in-built packages, libraries, and a test runner, which ease the process of software application testing.
The use of Selenium WebDriver and Jest testing framework simplifies the automation testing process. Here, Jest helps the tester and developers to write accurate test cases, whereas Selenium allows them to interact with the online features of software applications.
In this tutorial, we will learn how to get started with Selenium Jest for automation testing.
What is Selenium?
Selenium is one of the most used automation testing frameworks, which is built upon Java programming language. It is an open-source framework which means that it is freely available for testing software applications. It comes with various features that help in automating the test. This includes writing test scripts as per the preferred programming language like Java, Ruby, and others. Further, it is structured based on three crucial tools, which include Selenium IDE, Selenium WebDriver, and Selenium Grid. This provides an environment for cross-browser testing and parallel testing of the software application.
What is Jest?
Jest is an open-source JavaScript-based framework used for automation testing. It was initially developed by Meta to test React-based software applications. Later, it was modified, and now it can test Babel, Vue, JavaScript, Node, and Angular-based software applications. It can also be best used for testing NestJS, Next.JS, and GraphQL-based software applications. Today, it is used for testing front-end as well as back-end software applications.
Selenium with Jest
The combination of Selenium and Jest provides testers and developers with a sophisticated testing environment. Jest helps in the running of the Test cases, whereas Selenium provides a platform for cross-browser automation testing. It’s as simple as that. This combination benefits by providing an easy setup for cross-browser and parallel test execution.
For leveraging automation, testing with Selenium with Jest can be done by a cloud-based platform like LambdaTest. It offers a detailed solution for executing automation testing across a large online farm of real browsers and devices. The online Selenium Grid allows running automation testing scripts on cloud infrastructure. With this, it integrates Selenium with Jest, and you can run your test on scalable cloud infrastructure. This means that you can leverage the capability of both Selenium and Jest for efficient test automation.
LambdaTest allows you to run your Selenium tests in parallel across multiple browsers, which often leads to lower test execution time. This will result in the development of quality software applications with the increasing speed of the development life cycle.
Prerequisite for Getting Started with Selenium Jest
Before getting started with Selenium Jest automation testing, we need to have the following packages and libraries installed on the system:
- Node JS and Node Package Manager (npm): Node JS can be installed from the Node JS official website, nodejs.org.
- Selenium Web Driver: The Selenium WebDriver must be installed at the root directory as it is required as a dependency for the Jest Module. The Selenium WebDriver can be installed using the command ‘$ npm install selenium-webdriver’.
- Jest Package Module: The Jest package module can be installed using the Node package manager. The following commands can be used to install the Jest modules:
$ npm install -g Jest
$ npm install –save-dev jest
Before installing the Jest module, you have to initialize the npm using the command ‘$ npm init –y’
- Java – SDK: A Java Development Kit needs to be installed on the system, and its configuration with the Java environment is required to test the software applications using the Jest testing framework. The Java environment is required because the Jest testing framework uses Selenium tools for automation testing. And selenium was designed using Java.
- Browser Driver: To place the test cases inside the root directory so that they can be executed, a suitable driver is required to launch the browser. This can be done using the following command:
$ npm install -g chromedriver
Now that we have installed and downloaded all the requirements needed to perform automation testing using Selenium Jest, we will move on to performing automation testing using Selenium Jest step-by-step.
Steps Involved in Getting Started with Selenium Jest for Automation Testing
The instructions below can be used to perform automation testing using Selenium Jest.
- Install Selenium IDE: Firstly, you need to download Selenium IDE from the official website of Selenium. After that, installation of the downloaded IDE should be done on the system. In Chrome and Firefox it is available as a browser extension.
- Launch Selenium IDE: Once the installation process of Selenium IDE is completed, the next step is carried out. That is, the Selenium IDE is launched. This can be done by opening the web browser. There you will see the Selenium IDE interface, with the option to create a new project or open an existing one.
- Record Test Scenario: After opening the project file, you need to click on the “Record” button and start recording the test actions. Here, you must also reach out to various functions of your software applications to test them according to your will. The recorded action is then transformed into a set of test scripts by the Selenium IDE.
- Enhance the Test Scenario: The test cases designed by the Selenium IDE are then improved by the developers. For this, a set of test commands are used, which is provided by the Selenium IDE. Along with test commands, assertions, and verifications can also be added to it. These additions allow testers to validate the functionality of the software application during its testing process.
- Export the Test Scenario: Once the test cases are designed and improved, you have to export them as a Jest-compatible JavaScript file. The file export can be done by choosing the option ‘export the test as a JEST script or JavaScript’ in the Selenium IDE.
- Set Up a Project: Now you have to create a new project or open the existing project directory wherever you want to execute the designed and exported test script. Here, you need to run ‘npm init’ or ‘yarn init’ to initialize the project with a package.json file.
- Install Dependencies: To run the exported test cases, you will need some of the necessary packages. These packages are Selenium WebDriver, Jest, and some other dependencies according to your project. The packages need to be installed if they are not available on your system. The following command can be run at the system’s command prompt in order to install the required dependencies:
npm install selenium-webdriver jest <other-dependencies> –save-dev
- Configure Jest: Now, you have to configure Jest according to the project requirements. For this, you need to create a ‘jest.config.js’ file in the root of the project directory.
- Run the Test: After the configuration is done, the exported test cases from the Selenium IDE are placed into an appropriate project directory. Here, we will run the jest using the command ‘npm jest’. The JEST framework will execute the Javascript Test case, and Selenium WebDriver will automate the browser action. This will generate a test report for the software applications.
The test result will be displayed on the command line interface of your system. This was a brief instruction on how we can test our software applications using Selenium Jest.
Best Practice of Automation Testing with Selenium Jest
Automation testing with Selenium Jest can be carried out to its fullest using several best practices. The practices ensure the software applications are verified and validated according to the Software Requirements Specification. Following are a few of them:
- Isolate Test Cases: Isolating test cases means that each test case must be self-sufficient and independent. This means that each test case must contain its own test objective and test details rather than being dependent upon other test cases for input or data. The habit of designing isolated test cases maintains test reliability.
- Utilize Test Data Management: This simply means that the testers and developers must build a habit of storing test data in a separate file rather than integrating them with the test cases. This practice will ensure that testers will not have to write the same test data repeatedly.
- Use Descriptive and Meaningful Test Names: Revising the entire test case to understand its purpose is time-consuming. This can be handled by adding a descriptive name to your test case, as it will help you understand the purpose of your test script without going through it.
- Parallelize Test Execution: Execution of Test Cases one by one can be time-consuming when you have a large number of test cases. This can be solved by testing several test cases at a time. This is known as parallel execution.
Conclusion
With this, we have understood that Jest is a simple automation testing framework that is easy to use with multiple in-built packages. Also, aligning Jest with Selenium tools will provide testers and developers with a bunch of additional benefits. Using Selenium Jest allows developers and testers to perform cross-browser testing by executing parallel test scripts. This increases the test coverage and cuts down the test execution time. This is all we need to know about Selenium Jest for performing automation testing as beginners.
