Unit testing

30.03.2021 / 17:30

What is unit testing in software testing and why is it important?

In the software development process, there are often situations when a system does not work due to the existence of a small bug. In order not to waste time and money on fixing such errors, QA engineers and developers use unit testing, checking the performance of each piece of the software immediately after it is written. 

What is unit testing in computer programming? 

Unit testing is one of the levels of software testing that helps to test individual units of source code to determine whether they are usable. A unit is the smallest software component that usually performs a single cohesive function: it is small, so defects identified during unit testing are easy to discover and fix.

The pyramid of test

Unit testing ensures that all code meets quality standards before it is deployed, which provides a reliable engineering environment. 

Usually, unit testing is automated, although developers can do it manually. If developers use test automation, they create the code of the test and embed it directly into the code of a unit. Then the test code is removed when the testing is completed. 

In order to achieve full automation and protect the process from the human factor, programmers use specialized frameworks that allow them to embed performance criteria in test conditions and keep error logs.

What benefits can unit testing bring to you? 

The main purpose of unit testing is to isolate each part of the program and prove that the individual parts work correctly. Why is unit testing important?

Benefits of unit testing

  • Facilitates Safe Refactoring
    If you use CI/CD practices in your project development, you can add features to the software throughout the SDLC, which leads to changes in code. Unit testing makes the coding process simpler and more agile: developers check each unit for bugs, fix errors, and connect tested units to other parts of the product.
  • Improves Code Quality
    Sometimes developers write tests before actually coding. This process is also called test-driven development and makes developers think more about the possible problems, which leads to writing code better.

    Unit testing also accelerates the process of finding bugs. If future changes break something in the code, developers will be able to immediately identify the cause of the problem rather than coming through an unwieldy codebase to find the issue. 
  • Provides Quick Access to Code Documentation
    Unit testing provides documentation of the system that allows developers to learn what functionality is provided by a unit and how to use it.

    It is very useful in the case of changing a developer: any software engineer who needs to know what features a module provides and how to use it can just take a look at the unit tests to get a general understanding of the module's interface (API).
  • Reduces Costs
    The cost of detecting an error in a unit is significantly lower than the cost of detecting, identifying, and correcting the error on other levels of software testing. When errors are discovered at later stages, it usually leads to many system changes and a loss of time and money. Performing unit testing saves development time and, consequently, reduces costs.

Unit testing is an essential part of the software development process that helps you ensure the high quality of your product: it allows developers to check the performance of each unit and prevent possible problems in advance. Throughout the product development lifecycle, unit tests save your time and money and help make code quality better. 

Exposit Team uses unit testing to improve the development process of your software, increase the quality of the product and save you time and money. Contact us if you need a team that delivers high-quality software products to market, using the most suitable testing approaches and techniques.