The Importance of Unit Testing in Software Testing


The Importance of Unit Testing in Software Testing

Deployment is the last stage in application development process and before that, any application undergoes a comprehensive testing process to validate that the system meets its functional and non-functional requirements. Plenty of testing types we have heard and in all unit testing, integration testing, system testing, and acceptance testing are the main phases of testing. The software is released after performing these software testing stages. Unit testing is the first stage in software testing mainly focus on the proper functionality of each and all units or components. An application comprises several functions, classes, procedures which are referred to a unit. The objective in unit testing is to isolate each unit of the system and validate its precision by identifying and fixing the defects and bugs and benefit of unit testing is that issues can be identified on earlier stages.

White box testing method is employed in this first round of testing and usually, these test cases are created by the software developers and sometimes white box testers.

In Nutshell, Main Features of Unit testing are: –

  • Software developers write and execute Unit test cases.
  • The purpose of unit testing is to isolate each part of the program and make sure each of them working seamlessly.
  • It occurs just after coding and debugging and before integration.

Unit Testing Frameworks

To develop programming code we have several famous frameworks and on the front of Unit testing, we also have various frameworks or Third party open source and commercial tools which allow testers or developer to write cases quickly and easily.

List of popular unit testing tools for different programming languages:-

  1. Java framework – JUnit
  2. PHP framework – PHPUnit
  3. C++ frameworks – UnitTest++ and Google C++
  4. .NET framework – NUnit
  5. Python framework – py.test

Programming Language-level unit testing support
We also have an array of languages such as Apex, Cobra, Crystal, D, Go, LabVIEW, MATLAB, Ruby, Rust etc supporting unit testing as they are incorporated with built-in testing features. C#,Clojure,Elixir,Java,JavaScript,Obix,Objective-C,PHP,PowerShell,Python,Racket,Scala,Tcl,Visual Basic .NET languages having excellent unit testing libraries/frameworks.

Benefits of writing good unit tests or unit testing:-
Unit testing supplies plentiful benefits: finding software bugs early, simplifying integration, providing a source of documentation, and many others, which I am going to share in more detail.

  • Unit testing reduces the number of bugs in the system and acceptance testing.
  • Cost of locating and fixing bugs in unit testing is very less as they are captured in very early phase.
  • Automated tests can run as frequently as required.
  • Unit testing makes it easier to change and refactor the code.
  • Unit testing can improve code design, especially with test-driven development.
  • Overall development time can be used for unit testing.
  • Unit tests are a form of documentation.
  • Unit testing improves teamwork.
  • Code coverage can be measured.

How to write good unit tests?

  • Being a software developer, I know what the good and bad test cases are and as per my software developing experience I can enlighten you what are the key features of good unit test cases.
  • One of the most important things we should keep in our mind while writing unit test cases is that a unit test should be independent. They should be written to verify single unit of code and not the integration.
  • Ensure you are creating small and isolated unit tests with proper and clear naming conventions as it would be easier to write and locate.
  • Isolation is the main parameter that developer should focus while creating test cases as changing another part of the software should not affect on the unit test if those are isolated and written for a specific unit of code.
  • We all are in hurry to deliver the best product to our clients and in the rush, we give less time to, testing. So make sure it should develop and run quickly and seamlessly.
  • Make sure you develop reusable Unit test cases as testing is a continuous process.
  • Ensure you are testing one code at a time.

Challenges in Unit testing:-

  • Writing good Unit Tests can take much more time than the time to write the code being tested.
  • Things like boundary conditions or different combinations of inputs and much more you need to understand and learn in unit testing.
  • It can’t be expected to catch every error in a unit.
  • It requires good design- well-defined modules, each with simple well-understood interfaces.