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Abeer Mishra
Abeer Mishra

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11 Best Unit Testing Frameworks For Selenium Automation

In every software development life cycle (SDLC), unit testing is considered as the first level of testing, which is performed before integration testing. Earlier, manual methods were used to carry out unit testing of an app, which was very time consuming and hectic. However, with time, automation has taken the place of manual approaches that make it easier for programmers to perform unit tests quickly. To automate unit testing, developers need a reliable and secure testing framework that can test all components of the web app with ease. For most testing scenarios, Selenium Automation Testing is considered an ideal option. But, when it comes to unit testing, developers need a modern automated unit testing framework that can create automated unit test cases and quickly integrates with Selenium. Also, as various web apps are developed with different programming languages like Java, C#, Python, etc., a compatible Unit Test Framework is required for every programming language.

Today, we will talk about automated unit testing of a web application, and what is the best Unit Test Framework for most popular programming languages for Selenium Test Automation.

What is Unit Testing?

Unit testing is the first stage of web application testing, in which specific components or units of a web app are tested. The primary purpose of unit testing is to verify whether each component of the app works as expected. It is carried during the development phase of the application by breaking the application code into smaller units, and then developers test each unit separately. Most developers prefer to skip unit testing during the development phase, which later leads to higher bugs, increased bug fixing costs, and many other problems. However, if it is executed during the development phase, then it becomes easier to understand the code base and fix bugs early in the development cycle.

Developers use a Unit Test Framework to automate unit tests, which also allow them to verify the correctness of the code. The process of unit testing follows four steps, which includes:

  • Generating test cases – Involves writing various test cases for multiple components of a web app
  • Review/Rewrite – Reviewing the test cases, and if there are any mistakes, then rewriting the test cases
  • Baseline – Determining whether every code line is in a manner or not
  • Execution – Finally, executing test cases with the help of a Selenium Grid.

If you are planning to run unit tests with Selenium Grid, then you must use the best Unit Test Framework that is ideal for the programming language used in your web app. Below, we have covered the most popular programming languages with their compatible Unit Test Framework.

Selenium JavaFrameworks for Unit Testing

Java has always been used as the first language for developing dynamic and robust web applications. It provides the flexibility that developers need to create effective web apps. So, when it comes to unit testing of Java-based web apps, there are minimal Unit Test Frameworks available, such as:

1. JUnit

JUnit has always been the first choice of developers to automate unit testing of a java-based application. It was developed by Erich Gamma and Kent Beck as an instance of xUnit. JUnit was specially developed for scripting and performing repetitive test cases. But, it can also be utilized to automate testing of web applications by integrating it with selenium webdriver.


JUnit is a java-based framework, but you still need access to a few things for using this framework to its full potential.

  • The latest version of JDK installed on your system
  • Adequate knowledge of application development in an object-oriented programming language like Java
  • Knowledge of setting up the JUnit test environment on your workstation

Benefits of JUnit

JUnit offers several benefits to testers to automate unit testing of web apps:

  • Early detection of defects in code, making the code more readable
  • With JUnit 4, you can easily find the exception in the code, as well as execute test cases generated in the older versions of JUnit
  • Offers a test-driven environment, which forces developers to read the code
  • Allow creating readable and error-free test cases
  • Compatible with Java 5 and other versions of Java programming language


There is only one major drawback of using the JUnit framework – it is not capable of executing dependency tests. For that, you need to use TestNG.

2. TestNG

TestNG is an open-source testing framework created by Cedric Beust. TestNG covers a wide range of test categories which includes unit, functional, end-to-end, integration. It is being widely used by Java developers to unit test developed web applications. It was designed to overcome the competencies of JUnit. That’s why it is more robust, reliable, and featureful than JUnit. It provides developers with various functionalities, such as grouping, sequencing, and parameterizing, which allow them to create more flexible test cases while eliminating the drawbacks of JUnit and to automate unit tests.


To install and run TestNG scripts on your workstation, you need the following things that are almost similar to JUnit installation:

  • Installation of the latest version of JDK on your system
  • Adequate knowledge of java programming language
  • Experience in installing and using the latest version of Eclipse on the workstation

Benefits of TestNG

Apart from eliminating the disadvantages of JUnit and other java-based testing frameworks, TestNG offers some additional advantages as well, such as:

  • Allow developers to run parallel tests across various code snippets
  • Grouping test cases as per your requirements
  • Generating HTML report while executing test cases
  • Set priorities for the unit test by parameterizing the data or using annotations


There aren’t any such drawbacks of using TestNG unless it doesn’t meet your testing requirements. Also, setting up TestNG on your system takes a little longer than other Java-based testing frameworks.

Both JUnit and TestNG are similar to each other in most cases. However, TestNG is integrated with some advanced features that make it a better option than JUnit. Apart from these two, there are other Java-based Unit Test Frameworks as well, such as Selenide, Serenity, JBehave, etc.

Selenium JavaScript Frameworks for Unit Testing

JavaScript is also amongst some of the most dynamic, high level, and interpreted languages, which is ideally used for HTML Web applications. Besides, it is also used for accessible web documents like PDFs or Desktop widgets. JavaScript unit testing is either performed in the browser or on the frontend. But, developers often face multiple challenges while executing it, such as ‘unable to load example.js,’ version control, etc., which results in the requirement of a robust JavaScript Unit testing framework.

There are more than 10 JavaScript unit testing frameworks available in the market, but two of the most widely used frameworks are:


JEST is an open-source JavaScript testing framework, which is maintained by Facebook. It is the first choice of developers for JavaScript testing. Although JEST can cover unit, functional, end-to-end, integration tests, a significant number of JavaScript developers use JEST to automate unit tests. What makes it an ideal choice for developers is the zero-configuration testing experience that it offers. Although it is a universal unit testing framework, it is widely used for applications based on React and ReactJS. Moreover, the convenient and unambiguous interface of the framework makes it even more comfortable for developers to execute unit testing.


JEST requires minimal configuration and maintenance to automate testing of your web app. Few resources that you need to run your tests on JEST include:

  • Installation of Node on your system to set up NPM environment
  • Adequate knowledge of the JEST library before generating unit tests


JEST provides plenty of benefits to developers for JavaScript unit testing; some of the primary benefits are:

  • JEST works out of the box with zero configuration on every JavaScript project
  • The snapshot feature allows you to keep track of large objects with ease
  • Tests can be parallelized by running in their own processes for maximum performance
  • Ideal for React, ReactJS, NodeJS, VueJS, and Babel-based projects
  • Provide standard syntax with documentation support


While JEST is compatible with almost every JavaScript-based application, it cannot be used for larger projects that utilize different types of testing. The reason being less tooling and library support available for it.

2. Jasmine

Jasmine is another open-source JavaScript testing framework introduced in 2010. It can test every JavaScript application, which is not even supported by JEST. Besides, it provides additional support for Behavior-Driven Development (BDD), which ensures that each code snippet of the JavaScript statement is appropriately unit tested. Jasmine proved to be very useful for frontend testing, which includes both responsiveness and visibility testing of web app UI across multiple devices and resolutions. Although majorly used for asynchronous testing, it can be a pretty good Selenium JavaScript framework to automate unit testing.


It’s pretty easy and straightforward to implement Jasmine on your workstation. All you need is a little knowledge of the following things:

  • Installation of standalone library files from Jasmine official website
  • Installation of the latest version of the Jasmine – Edge
  • Adequate knowledge of installing and using IDE like NetBeans


Jasmine is integrated with advanced features and utilities, which provide numerous benefits to the users, such as:

  • Offers a clean, small, and straightforward syntax for easy web app testing
  • Execute test cases that are similar to user behavior on a JavaScript-based app
  • Provide additional support for both frontend and backend tests
  • Doesn’t require any document object model
  • Available with substantial documentation and community support


The only disadvantage of Jasmine is that it cannot run against the real Document Object Model, so it manipulates the components of real DOM to test the JavaScript functions. Another minor drawback is that it is only good with the JavaScript engine it is run against.

Both JEST and Jasmine are ideal unit testing frameworks for JavaScript unit testing. There might be similar functionalities, but the installation and working process of both the frameworks is entirely different.

Selenium Python Frameworks for Unit Testing

If there is one language that is known to almost every developer and widely used in almost every application, then it is Python. It is a general-purpose programming language ideally used for developing desktop GUI applications and web applications. It allows developers to focus on the core capabilities of a web app while taking care of the common programming tasks.

In 2018, it was even voted as the best programming language of the year. With time, the use of Python is growing at a faster pace, which results in the requirement of automated testing frameworks that are based on Python. Here are two unit testing framework that you can use.

1. PyTest

PyTest is an excellent python-based automation testing framework that can be used for all types of software testing. Apart from being an open-source Unit Test Framework, it is easy to learn and implement on any workstation. With features like assert writing, PyTest has become the first choice of major projects on the internet, such as Dropbox, Mozilla, etc.


It doesn’t require large resources to set up and run the PyTest framework with Selenium Automation Testing. However, you might consider the below points before using it:

  • Proper working knowledge of Python programming
  • A working desktop with the command line interface
  • Access to Python package manager and IDE for development


PyTest is well-merged with multiple testing benefits that allow developers to perform quick and easy unit testing of their web apps, such as:

  • Allow developers to write test cases in a compact manner
  • Provide the ability to store all the values inside the test cases while informing you which value has failed and which one is asserted
  • With multiple fixtures of the framework, you can cover all the parameter combinations without rewriting the test cases
  • Execute parallel testing easily with the help of PyTest-xdist


One of the significant drawbacks of using PyTest is that the test cases generated by PyTest cannot be used with any other testing framework, which means you will have to comprise test compatibility.

2. PyUnit

Also known as UnitTest – PyUnit is the standard unit testing framework for Python-based applications. In PyUnit, the base class ‘TestCase’ is used for all the assertion methods, code cleanup, and set up routines. Other than that, you can also use the load methods and the ‘TestSuite’ class for grouping and loading of test cases. And if you use them together, then you can build customized test runners.


UnitTest is available with Python library by default, so it doesn’t require much configuration for installation. However, to use the framework, you need:

  • Sufficient knowledge of Python framework
  • Installation of pip along with an IDE for installing additional modules


PyUnit is a part of a standard library of Python language, and it offers several benefits to developers, which include:

  • Doesn’t require additional installation of nay modules as it is available with the box
  • Works on the same principle of xUnit, as UnitTest is a derivative of it
  • Allowing running individual test cases in a simple manner
  • Offer a flexible working process while executing unit tests
  • Generates test reports within milliseconds


PyUnit is majorly inspired by the JUnit framework, so the traditional camelCase naming methods are used in it rather than snake_case, which could be confusing for developers. Another drawback of PyTest is that it requires a higher amount of boilerplate code.

Amongst these two Unit Test Frameworks , PyTest is majorly considered as the first choice of developers. However, there are other Unit Test Frameworks as well, such as Robot, Behave, Lettuce, etc.

Selenium C# Frameworks for Unit Testing

C# is a modern, object-oriented programming language developed by Microsoft community members. It was developed with an aim to combine the competencies of C++ and Visual Basic. It provides almost similar features to Java, which makes it an ideal option for building dynamic software applications. When it comes to select a Unit Test Framework for C# based applications, developers often find it difficult to choose between NUnit and MS Visual Studio. Below, we have described both the testing frameworks.

1. MSTest

MSTest comes with an in-built testing framework provided by Microsoft known as Visual Studio. So, it doesn’t require additional downloading or installation on your system, as you will get it out of the box in your IDE. It is particularly used to run tests on .NET applications. And if you’re using TestComplete, then you can easily integrate the MSTest tests in your test scripts and execute them as a part of your testing process.


As it is available directly out of the box, it doesn’t require additional installation of any other modules. However, for unit testing of C# application, you need to –

  • Specify the full path of MSTest executable in the Unit Testing Options dialog box
  • Sufficient knowledge of the .NET language and C#


One of the killer features of MSTest is its ability to run test cases directly with a simple process. Apart from that, it offers better capabilities for integration-based testing, such as:

  • Allow executing data-driven tests from a DB data source
  • Determine the order of tests in which they are arranged
  • Quick setup and teardown while generating an efficient database
  • Flexible integration with team systems that report LOADS of statistics


MSTest might offer great flexibility for unit testing of C#-based applications. Still, it lacks a lot of functionalities, such as it doesn’t contain a TestCase attribute that enables parameterized testing, the ExpectedException attribute of MSTest has a bug, where the expected message never really asserts. To overcome the obligations of the MSTest framework, NUnit was introduced.

2. NUnit

NUnit is an open-source unit testing framework that is entirely written in C#. It belongs to the xUnit family and can be used for almost every .Net application. Having user-friendly attributes, NUnit offers a simple and easy working process for developers. Moreover, it doesn’t require a specific project type; you can add a class library to differentiate your code from the unit tests.


To run the NUnit framework with Selenium Automation Testing, you need access to the following resources:

  • Installation of .NET Core 2.1 SDK or later version on your desktop
  • NuGet package, which can be searched within Visual Studio
  • A text editor or code editor as per your requirements and knowledge
  • Adequate knowledge of .Net frameworks


NUnit offers the same functionality and features as JUnit. It is equipped with multiple testing benefits, which include:

  • A powerful and broad unit testing framework that is compatible with all .Net applications
  • Contains the TestCase attribute that enables developers to implement parameterized tests
  • Included with a fluent version of Assert API (Assert.That), which allow testing exceptions in specific lines of code
  • Capable of running tests in both 32 and 64 bit systems
  • Have a reputed position in the market for fast testing and executing tests cases


We haven’t found any drawbacks in NUnit yet. However, one thing that we noticed so far is that it cannot be integrated with MS Visual Studio.

NUnit has always given the first priority than MSTest when it comes to unit testing of .NET applications, and the above point clearly defines the reason behind it.

3. xUnit

xUnit.Net is a popular unit test framework used for Selenium test automation. ‘x’ in xUnit stands for the programming language for which the test framework is built i.e. JUnit for Java, NUnit for C#, etc. It is a unit test framework that is built by the creators of the NUnit framework.


There are a few requirements for Xunit, which you need to keep in mind before you start to automate unit testing. You need to have:

  • Enough knowledge of xUnit frameworks and C# language
  • Installation knowledge of xunit, xunit.runner.visualstudio andMicrosoft.NET.Test.Sdk


Since xUnit framework is built around it’s rapid increasing community. It has led to the fact that the majority of the shortcomings which were present in the NUnit framework didn’t get picked up while designing the xUnit framework. Below are a few reasons why this unit test framework is gaining popularity:

  • It provides a better test isolation as a new test class is instantiated for each test case
  • Handling generic assert is significantly better in xUnit due to the usage of Assert.throws in place of [ExpectedException].
  • Code flow is more legible and code duplication is avoided in this unit test framework as the [Setup] and [TearDown] annotations are not included in xUnit.


Major Scope of improvement for xUnit lies in its Documentation. Yet it is also getting better with time.

Selenium Perl Frameworks for Unit Testing

Perl was originally developed for text manipulation, but now it is used for various purposes, such as system administration, web development, GUI development, and many more. It is a stable and cross-platform programming language created by Larry Wall. Though it is not that popular, it offers excellent features as compared to other programming languages like C, AWK, BASIC, SED, etc. It is also not that easy to learn and implement; thus, the unit testing framework for Perl-based applications is very limited.


The only general unit testing framework available for Perl-based applications is PerlUnit, which is a xUnit testing framework. It was initially designed for testing of Perl-based applications, but now it is available as a project on SourceForge. It is based on the JUnit 3.2 model and capable of producing a ‘Green Bar.’ Like JUnit, it is also an open-source Unit Test Framework that can be integrated with the Selenium Grid to automate unit testing.


There are not any specific requirements for using PerlUnit, but it is based on xUnit, so you need to have:

  • Enough knowledge of xUnit frameworks and Perl language
  • Installation knowledge of perlmodiInstall


There are very limited features and functionalities available with PerlUnit, such as:

  • It supports older versions of Perl
  • Included with two mailing lists – perlunit-devel for low volume discussion, and perlunit-users


There are no drawbacks to using PerlUnit unless you want to test other web applications with it because it is only compatible with Perl-based applications and xUnit frameworks.

Selenium Ruby Frameworks for Unit Testing

Ruby is an object-oriented, high-level, general-purpose programming language that is mostly used for developing web applications. In most cases, it is almost similar to Python, which makes it ideal for data analysis, prototyping, etc. It is merely used in most web applications because it offers a faster development code as compared to other languages. There are multiple unit testing frameworks available for Ruby that can be used with the Selenium Grid, but the most popular framework is – Test: Unit.

Test: Unit

Test: Unit is based on xUnit principles, and it is available with the standard library of Ruby. It was designed by Kent Beck for the unit testing of web applications. Using this framework, you can easily create unit tests, check results, and to automate unit testing in Ruby.


Test: Unit 1.2.3 is the same version, which is bundled in Ruby 1.8. Thus, it doesn’t require additional downloading of packages. You can install it directly from the library. However, to use the framework, you need prior knowledge of XUnit frameworks and Ruby programming language.


Test: Unit consists of various features and capabilities, but there are a few features that make it different than other frameworks, such as it provides three basic functionalities, which include:

  • Ideal tools for executing single tests or a whole group of tests
  • A simplified way to define basic pass/fail tests
  • Allow gathering related tests together and run them in a group
  • Features like GUI test runner, GTK, Fox, make it ideal for splitting some packages


The only drawback of Test: Unit is that it is only suitable for unit testing of Ruby-based applications, and offers compatibility with xUnit frameworks, which means you cannot use it for other testing scenarios.

Wrapping it Up

Performing unit tests during the development phase help in a faster go-to-market for your web application. Thus, it is pivotal to use a Unit Test Framework which can be used to generate rapid unit tests for the required language, as well as offers compatibility with Selenium Automation Testing. In this article, we discussed some Unit Test Frameworks that can be used for specific programming languages. However, if you are finding it difficult to automate the cross browser testing of your web app, then you can use LambdaTest, which is an ideal platform for cross browser testing of web apps.

Original Source: LambdaTest

Top comments (2)

zuchers profile image

well written!