Software Testing – Unit Testing Tools

Unit Testing is a part of software testing where testing is performed on isolated small parts of the code. The objective of  Unit Testing is to isolate small portions of application code that could be individually tested and verified, provided all the isolated code units have been developed in the correct procedure.

• It is performed by the development Team in the SDLC process. 
• There are a set of valid inputs that would be provided to a unit of code to verify whether the expected values are returned or not. 
• At the same time, a set of invalid inputs would also be done to check how the system would handle errors.

Unit Testing tools are used for this reason i.e. they would help in reducing the number of bugs and as well as improve the security aspect of our software design. These tools test the source code.

Criteria For Choosing Unit Testing Tools

Some of the most important criteria for choosing Unit Testing Tools are as follows: 

1. Learning Curve of the tool: When Picking a tool one should be wary of the learning curve of the tool. From the tool’s learning curve one should know whether the time one is willing to invest would be worth it or not.
2. Stability as well as the customer support of the tool: A good unit testing tool should have great customer support as well as online resources and documentation to help the users if they get stuck.
3. Simple Graphical User Interface (GUI): The tools should have an excellent reporting Interface so that clear reports once generated would help the users to conclude the test results in fewer time intervals.
4. Ability to test data input data for load testing or difficult test scenarios: The unit testing tool should be such that it supports test data input from various types of data files such as Excel, and XML. This would help the automation Testers in a great way.
5. Ability to maintain the test scripts: In automation testing, the Record and playback feature is extremely important and the ability of a tool to maintain and record scripts would be a great solution for the Automation testers.
6. Types of Testing supported: The unit testing tool should be such that it could support maximum testing types namely Unit, regression, etc.  The tool should be good enough for automating our complex test case requirements.
7. Allocated Budget: Above all, the budget should be carefully considered before coming to a decision.

Why Choosing Correct Unit Testing Tool Important?

Choosing the correct unit testing tool is important for the following reasons:

• Ensures that every system component is benefitted from achieving better product quality.
• The debugging process is simplified.
• Code Refactoring and debugging of the code becomes simpler.
• If bugs are present, they would be defined earlier in the SDLC process.
• Bug fixing costs would be reduced significantly

Following are some of the unit testing tools:

1. JUnit
2. NUnit
3. TestNG
4. PHPUnit
5. Mockito
6. Cantata
7. Karma
8. Mocha
9. TypeMock.
10. Jasmine

Let’s discuss each of these tools in detail.

1. JUnit

JUnit is a java driven open source unit testing tool used to test small/large units of code. For running JUnit tests,  we don’t require creating class objects or defining the main method. Junit provides an assertion library that is used to evaluate test results. Annotations of JUnit are used to run the test method. JUnit is extensively used to run the Automation suite having multiple test cases. 

Key Features: 

• It provides a test-driven development.
• It has support for Maven and Gradle integration.
• It has support for the execution of Tests in groups.
• Can be integrated with popular IDEs like Netbeans, Eclipse, IntelliJ, etc.
• It has Fixtures that provide an environment for running repeated tests.
• Using the @RunWith and @Suite annotation Test suite annotations we can run unit test cases.
• It provides Test runners for executing the test cases.

2. NUnit

NUnit is a . NET-based open source unit testing framework that has directly inherited most of its features from JUnit. NUnit has extensive support for Test-Driven development like JUnit and has most of its features similar to JUnit. NUnit provides a console runner that helps in the batch execution of automated tests.

Key Features:

• It has support for multiple assemblies.
• Extensive support for Assertions 
• It provides various attributes for running tests with different parameters.
• It has support for data-driven testing.
• It has support for Microsoft family languages-.NETcore, Xamarin forms.
• We can run parallel tests too using NUnit.
• For running batch tests, a console runner is present that is provided by NUnit.

3. TestNG

TestNG stands for Test Next Generation. TestNG is a robust framework as we can have full control over the testing and execution of Test cases. It has features from both JUnit and NUnit. TestNG supports a variety of test categories which includes unit, functional, integration, etc, with easier-to-use functionalities and hence considered one of the most powerful unit testing tools.

Key Features:

• It has support for testing integrated classes.
• It provides HTML reports and generates logs.
• It has support for the parallel execution of test cases.
• It can read keywords/data from logs.
• It has an inbuilt exception handling feature.
• It has support for multi-threaded execution.
• It is completely object-oriented and therefore has easier annotations
• All the test configurations are XML based.

4. PHPUnit

It is basically a programmer-oriented unit-testing framework for PHP. It is an instance of the xUnit architecture which is used for unit testing frameworks (like NUnit, JUnit). PHPUnit uses a command line to run throughout and we cannot run it directly on the browser. 

Features:

• It has support for code coverage analysis and mock objects.
• It has provision for Test-driven development
• It has support for logging with the help of the xUnit library.
• Mocking objects is supported
• It has support for New Assertions – assertXMLFileTag(), assertXMLNotTag(),etc
• It provides an error Handler support in its current release.
• The test cases can be extended as per the programmer’s requirements.
• We can create multiple test reports.

5. Mockito

It is a unit testing framework in Java. Mockito is mainly used to mock interfaces so that dummy functionalities can be added to mock interfaces for unit testing. Mockito helps in creating mock objects easily. To obtain this, Mockito uses Java Reflection API for creating mock objects for a given interface. 

Key Features:

• Methods like verify() and mock() have extensive use in testing Java applications
• Has support for annotation feature for testing mocks.
• Mockito is extensively powerful as it allows us to not write mock objects of our own.
• Better readability for error messages.
• It supports safe refactoring, exception support, returns value support, etc.
• We do not need to write mock objects on our own.

6. Cantata

It is a unit testing tool in C/C++. It helps developers to verify standard-compliant or business-critical code on specific hosted platforms. As C/C++ is closer to hardware, therefore Cantata finds extensive application in embedded systems. For this reason, It can be easily integrated with desktop compilers and embedded target platforms. It also checks the testing requirements compliance by automating text executions. 

Key Features:

• It can automate Regression testing or Continuous Integration
• It generates and edits test reports written in C/C++.
• Particularly helpful for large data sets.
• It has support for test-driven development
• Many types of testing like Object-oriented testing, isolation testing, and structural testing can be performed. 

7. Karma

It is a Javascript unit testing tool that allows us to test the code in browsers using the Nodejs engine. Karma has an in-built Test Runner that allows starting the web server and serves our JavaScript file and tests the respective files on that server. We need to use the ‘npminit‘ command for loading the dependencies and loading of the package.json file.

Key Features:

• It is used for testing front-end applications, particularly AngularJS.
• Karma has a test runner which helps the code test in the browser.
• Facilitates easy debugging and can be used with CI-CD tools like Jenkins.
• It has support for test-driven development.
• It is mainly used for testing Angular applications.

8. Mocha

Mocha is a javascript framework that runs on Node.js and helps in the ease of testing of asynchronous javascript codes.  Mocha has a powerful functionality of mapping exceptions to correct test cases and also thereby allowing the tests to run serially. It is becoming popular due to its extensive support for generating meta-suites and test cases.

Key Features:

• It has support for test coverage reports, and report test durations.
• Using the JavaScript API, Mocha helps in running tests.
• It can run node Node.js tests parallelly.
• It has support for async test timeout.
• We can use any assertion library as we want.
• It has support for node debuggers.

9. TypeMock

TypeMock is unit-testing tool for  .NET and C++ legacy codes. Typemock has an Isolator ++  that encourages the developers to not change their production code for the sake of testing Typemock Isolator++  also provides more coverage with a powerful mocking framework that supports testing legacy code.

Key Features:

• It has simple entry methods which do not require changing legacy codes.
• It has great readability and provides extensive code coverage.
• It has the ability to mock the code without changing it.
• It has provisions for faking methods (Static & Private), members.

10. Jasmine

Jasmine is a JavaScript open-source unit testing framework that tests both synchronous and asynchronous JavaScript code. Jasmine finds extensive applications used for Behaviour driven development scenarios. Jasmine has batteries included that offer everything we need to test our code.

Key Features:

• It provides behavior-driven testing.
• It is extremely fast due to no dependency management.
• It can be used with languages like Python and Ruby and can be run on Node and browser. 
• For writing test cases, DOM is not required.
• It has support for asynchronous JavaScript specifications.