5 Best Practices for Writing Selenium Tests with Mocha

Web applications are getting more complex as a result of continuous developments in digital technologies. A flawless user experience and the development of a reliable, error-free application are essential for every website to succeed in the present competitive environment. Developers and QA engineers will face additional problems due to the requirement to thoroughly test new features across platforms and to release updates regularly. Automation testing has allowed teams to release new features more quickly and with fewer bugs.

It led to a growing reliance on automation to speed up application development‘s testing and coding phases. By automating repetitive processes with a few lines of code, a number of automation frameworks have been developed that enable users to optimize their productivity.

One such tool that enables the execution of automated testing on web applications is Selenium. Let’s begin by providing a brief overview of Selenium and the reasons why it is preferable to other automation testing frameworks. Let’s begin.



One of the most widely used automation testing frameworks in the field of test automation is Selenium, a reliable and well-established open-source tool. Many languages, including Java, Python, C#Perl, Ruby, JavaScript, and PHP are supported by Selenium. 

Using automated testing tools like Selenium has allowed QA engineers to verify that the code functions correctly while reducing the need for manual testing. Selenium makes it possible to verify that the code functions correctly. They also make it possible to do thorough testing more quickly.

The Selenium framework is composed of three different components. These are Selenium Grid, Selenium WebDriver, and Selenium IDE (Integrated Development Environment). These components all share a few common characteristics. However, the entire Selenium framework generally aids in the automated testing of web applications.

What distinguishes Selenium from other testing frameworks and why it is a better option

What distinguishes Selenium from other testing frameworks and why it is a better option
  • The Selenium library manages a web browser and simulates user activity. It provides the user with ‘bindings,’ which are particular language library APIs. There are now bindings for Selenium APIs in all widely used programming languages. These “bindings” function as clients when requesting intermediary components and as servers when controlling a browser.
  • Selenium supports a variety of browsers, making it simple to write test cases that function flawlessly on all popular web browsers. Each update of Selenium includes updated JavaScript and CSS builds for various web browsers thanks to the enhanced plugins.
  • Selenium offers benefits like better code readability, higher scalability, lower script maintenance costs, and enhanced code reusability.
  • It provides users with a range of reporting alternatives, including the list reporter, the progress reporter, and the JSON reporter, allowing them to select the one that most meets their test needs while the default reporter displays the output.
  • Selenium is compatible with several JavaScript assertion libraries, which can lower testing expenses and expedite the process. If everything goes smoothly, developers won’t have to rewrite the test cases because of the various library support, which makes it simpler for testers to create lengthy and complex test cases.
  • Assist in writing high-quality test cases and increasing test coverage by assisting in both behavior-driven development (BDD) and test-driven development (TDD).

Like any other programming language, JavaScript provides a variety of tools that support test-driven development, including Jest, Jasmine, Mocha, Karma, and Cypress. However, picking a JS testing framework is not a simple matter. Mocha JS is the best option when seeking a decent Javascript testing tool to employ. 


A JavaScript test framework running on Node.js and in the browser is Mocha JS or Mocha which makes asynchronous testing easy and enjoyable. With its inherent functionality, Mocha enables quicker creation of simple and organized tests. JavaScript developers utilize it for unit and integration testing. 

It offers a wide range of capabilities, such as the ability to build descriptive auto-tests, flexible and precise reporting, the ability to map uncaught exceptions to the appropriate test cases, the ability to perform automated tests each time the file is locally updated, and many more.

Performing tests on websites are possible using this simple yet reliable test framework. It is frequently used in combination with Chai, an assertion library that provides us with a clear and descriptive syntax for test assertions.

It’s simple to use Selenium and Mocha together. Creating effective, well-structured, and functional tests fast is possible when Selenium techniques are combined with Node testing frameworks. It follows the traditional “describe-it-assert” structure, or behavior-driven development (BDD).

This article will highlight a few best practices that will help QAs improve their Selenium tests using Mocha in a way that will enable them to take advantage of its capacity to give maximum, accurate test coverage in a constrained amount of time. Let’s discuss them.

5 Best Practices for Writing Selenium Tests with Mocha

5 Best Practices for Writing Selenium Tests with Mocha

Incorporate wait commands instead of Thread.sleep()

The time it takes for a web browser to load a single web page varies, and it can be difficult to estimate how long it will take for an application or an element within one to load. It could be because of the server location, network speed, system setups, or several other factors. To address this, it must pause the scripts for a set time while it waits for all the elements to load. This is a useful method for making sure that all the web elements are present while performing tests on them.

Using the Thread.sleep() function is one technique to pause the script for a specified amount of time. Nevertheless, this method is unreliable because the element load time on various machines may change. For instance, the test script will wait the whole 5 seconds if users hard-code Thread.sleep() to 5 seconds but an element loads in 2 seconds. This results in much more time being wasted running Selenium test automation, which slowed down test execution.

Therefore, it is crucial to provide Selenium wait methods such as an implicit or explicit wait statement that handle delays more effectively than sleep to prevent such scenarios. When an expected condition or the passing of time occurs, Explicit Wait dynamically pauses execution. The execution moves to the next line of code if the element is available sooner than the implicit delay period.

Configure reports for Selenium test automation

What cannot be measured can’t be improved. This also applies to Selenium test automation. Without monitoring how tests are performing, one cannot guarantee better Selenium test automation outcomes. The automation testing report reduces the time needed to maintain the test data and helps to make test findings easier to understand. 

And therefore, creating automated test reports using Mocha and Selenium is another excellent practice because it allows testers to manage test data more efficiently while also saving time. By monitoring what occurs during the testing process and analyzing when the test scripts are failing, using this data aids in having greater control over tests.

Use Page Object pattern

QAs must create new test cases for the same page as the UI of a web application changes, which also affects the locators connected to it. However, the Page Object Model can be used as a solution to this. Page Object is a Design Pattern that has gained popularity in test automation for improving test maintenance and minimizing code duplication.

Using POM, developers only need to edit the page objects rather than all of their test scripts because they are all located in one single repository.

Each webpage has its page class, which may be used to locate web items on the page as well as page methods for these web elements. When the tests need to interact with that UI page, they employ the methods of this page object class. This increases the project’s reliability because the developer no longer has to go through the entire code base and test the scripts simply to add a few UI modifications.

Take screenshots when a test fails

Selenium scripts using Mocha could occasionally encounter errors or problems. In these circumstances, it is advised to gather automated screenshots of the test script execution using a Selenium Grid to determine the cause of the failure, whether it is a defect in the AUT or a fault in the code. It only needs to set the capability of the visual flag to true and pass a single capability through the Desired Capabilities class.

It is recommended practice to take a snapshot of a failure since it makes it much simpler to investigate and pinpoint the reason for the test failure, saving the testers’ time and effort.

Plan and design test cases before automation

Before starting Mocha’s Selenium test automation. Directly putting the application through Selenium automation testing can have undesirable effects. Developing test case scenarios, planning, and defining strategy beforehand is a solid practice for the total success of selenium testing. QA engineers must develop detailed test cases and consider all logical scenarios before beginning automation.

Consequently, it’s crucial to consider several potential circumstances from the viewpoint of the end user. The test program’s structure and management must be described in the test architecture, which must be developed by developers. This will make it easier to conduct error-free testing.

Utilize LambdaTest real device cloud to automate Selenium tests using the Mocha framework.

LambdaTest is a framework for testing cross-browser compatibility that enables Selenium Mocha testing at scale on an online cloud Selenium Grid of more than 3000 real devices, browsers, and operating system combinations. Testers can automatically capture screenshots of Selenium tests while running them using LambdaTest cloud Selenium Grid, eliminating the need to explicitly start the process using code.

To help testers quickly start and run Selenium automated testing with Mocha, LambdaTest provides a wide range of extra functionalities. Its primary capabilities include geo-location testing across several regions, support for many browsers, live browser testing, parallel testing, resolution display testing, automatic screenshot testing, and testing in multiple locations at once.

By concurrently running Mocha.js automation testing scripts online, testers can use this platform to speed up their development cycles. To ensure a flawless user experience around the world, LambdaTest additionally enables geolocation testing using Mocha test scripts.

LambdaTest enables testers to find errors earlier and execute tests more quickly by testing the websites and web apps on a variety of real Android and iOS devices, This ensures a seamless user experience and improves application quality while increasing test coverage.


Selenium automation aims to decrease manual testing efforts, speed up execution, and find as many errors as possible early on. However, to create a reliable test cycle to get the most out of their Mocha-based Selenium scripts developers must adhere to the selenium best practices mentioned above.

Also Read: https://donjii.com/reasons-to-use-selenium-with-python-for-automated-testing/

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