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Unit testing in real world: what to consider

Unit testing (known as component testing) refers to a type of software testing. In which software development teams test each individual unit. Explore more in the article below!

Unit testing is an essential part of any software development project toolbox. Nevertheless, it sometimes can be hard to write a good unit test for a piece of code. Having trouble with code testing, software developers often imply their difficulties coming from the lack of fundamental testing knowledge.

The problems of complicated unit testing are a result of poorly-designed and untestable code. In this article, we have provided you with definitions, types, benefits, and tools of unit testing. We discuss what makes code difficult for testing, and anti-pattern and bad practices software development team should avoid. So that it can improve testability and benefits we can get by writing testable code. Hopefully, you will gain some ideas from our post.

What is unit testing?

Unit testing is a type of software testing in which a software development team will test individual units or software elements. The concept of unit testing is to validate every unit of the software code compared with expectation. Besides, the unit testing isolates a code section and identifies its correctness. It means the software unit can be a function, method, procedure, or even module.

In software development life cycle, unit testing is the first level of the software testing process before integration testing. Unit testing in software engineering is a white box testing technique that developers will execute. In a practical landscape, quality assurance also does unit testing owing to time crunch or even reluctance of developers.

Types of unit testing in the software development life cycle

Software development teams can implement unit testing in two ways regardless of manual testing and automated testing.

Manual Testing

A tester manually implements test cases without using any automation tool. She will manually execute each stage of unit testing. Manual testing is quite tedious and time-consuming, especially for tests that are repetitive.

Besides, it requires more effort to implement every test case. This type of unit testing does not require any background in unit testing tools. In fact, it is impossible to use 100% of automation testing during software development projects. Thus, there are some levels of manual testing executed. For some custom software development projects, manual testing is a fundamental part.

Automated Testing

Another type of unit testing is automated testing. Software development teams use unit testing tools for automating test and test cases. The automation tool records and saves your time by replaying as many times as needed without any further interventions.

This unit testing type uses various automation tools to enter test data into the system. Furthermore, automated testing can compare the expected outcomes to the actual ones and automatically create the reports. Nevertheless, the initial cost of building the unit testing automation tools is pretty high.

For unit testing, software development teams utilize manual testing or automated tests to meet customer requirements. This unit testing can be an individual function, method, procedure, and module in the custom software development project.

What are the tremendous benefits of unit testing?

Software development teams use unit testing to design robust software elements that maintain code and diminish issues inside code units. It is essential to perceive the importance of identifying and fixing defects in the early stages of the software development life cycle. This unit testing serves various purposes. Here are the tremendous benefits of unit testing.

Process becomes agile software development: To add more new features to the existing software solution, we have to change the old source code. However, changing things in the already tested code can be risky and costly.

Improving the code quality: Using unit testing can automatically improve the code quality. Software development teams identify the bugs throughout this unit testing process before sending them for the integration testing phase. It results in a robust software development product since developers write test cases by understanding specific features.

Detecting bugs in the early stage: Running unit testing, developers detect bugs and resolve them early in the software development life cycle. There can be flaws, missing parts, and bugs in the programmers’ implementation.

Easy to change and simplify integrations: Using unit testing makes it easy to restructure, change, and maintain the code. Besides, it makes testing the code more efficient after integration. Fixing a problem in the unit testing process can alter other parts of the software development process and testing stages.

Lowering cost: When software development teams can detect bugs and resolve them during unit testing, they help save cost and development time. Without unit testing, testers might detect bugs in a further stage after integration testing. So it is hard to trace and resolve the bugs, making it more time-consuming and costly.

Available for documentation: Developers can refer to the unit testing documentation when looking at the functionality at the further app development stage. Besides, it is easy to find the unit testing interface and work fast.

Easy to debug: Unit testing helps simplify the debugging processes. If the unit testing fails at any custom software development stage, developers need to debug the code again.

Demonstrating the code completeness: This is more useful in the agile software development processes. The software development company don’t get functionality built until they finish the integration process. People cannot justify the code completion since it will show that you have checked the code. However, running unit testing will demonstrate code completion.

Software developers

Different unit testing tools in 2022


As an IDE plugin, Parasoft Jtest can leverage an open-source framework such as JUnit, Mockito, PowerMock, and Spring with guidelines. It also provides one-click actions to generate, scale, and maintain unit testing. Besides, this unit testing tool takes advantage of time-consuming aspects of unit testing. Thus, it can focus on business logic and make more meaningful test cases. Jtest has become one of the most popular units testing tools in 2022.


It is a free unit testing tool for the Java programming language. JUnit helps provide support for assertions to define test approaches. It is a unit testing tool that tests data first then inserts them into a piece of code.


Being used as a unit testing framework, NUnit is another unit testing tool for 2022. NUnit is an open-source tool for writing scripts manually. Moreover, NUnit also supports data-driven tests.


As an open-source testing tool, JMockit is a code coverage tool. It helps mock API with recording and verification of syntax. JMockit also offers line coverage and data coverage.


This unit testing tool is an open-source toolkit for analyzing and reporting code in a Java programming language. EMMA supports coverage types such as method, line, and basic block.


It is a unit testing tool for the PHP language. PHP Unit takes a small percentage of code called units, and testers will test each unit separately. This testing tool uses predefined methods to assert that the system should run in a specific manner.

Unit testing vs. integration testing

Another thing is the difference between unit testing and integration testing. Unit testing in software engineering verifies the performance of a small piece of code from other parts. Unit testing allows us to cover all test cases with a narrow scope, ensuring operation correctly in all parts.

However, integration testing shows that various parts of a system work together in the real-life programming environment. It can be a user performing high-level operations within the system. Besides, it enables validating complex situations that required external resources (databases, web servers)

When combining the unit testing and integration testing, tests ensure that each unit works correctly and independently from each other. Furthermore, all these unit testings work correctly when being integrated. It leads to a high level of confidence that the whole system will work as expected.

We need to detect what kind of test we are executing regardless of a unit and integration test. The difference can be deceiving. If we tend to write a unit test to verify some edge case in a business class, it will require external resources such as web servers and databases. Thus, software development teams might understand the differences between unit testing and integration testing when using each unit testing separately or both of them.

Unit Testing Example

It is suitable for you to do function testing whether a loop and statement in a program are working accurately or not. A beneficial unit testing example can be JUnit, XUnit, etc. Here are some explanations of unit testing examples:

  • Module Interface: In the module interface test, testers check whether they properly flow into the program unit or module.
  • Local data structures: The software development team inquires about the local data within various modules to be stored properly or not.
  • Boundary limitations: For example, many custom software development products often fail at boundaries regardless of conditions. That’s why the boundary related conditions will be tested. It makes sure that the program is appropriately working at that boundary.
  • Independent & errors solving paths: The software development teams use unit testing to see they are implementing their tasks at the end of the program. Besides, testers will review the unit testing to review in case of solving the errors properly by themselves or not. At last, it concludes that the unit testing focuses on the different modules of the custom software development products.

Closing thoughts

It is essential to conclude that tests can only test each software function independently. This type of unit testing saves time and cost. Furthermore, there is sometimes a requirement to generate mock objects to fulfill the dependency of a function. In this post, we have only provided the importance of unit testing regardless of definition, benefits, types, and tools. Besides, we also define the difference between unit testing and integration testing. Software development teams might consider various aspects of unit testing to develop custom software development projects.

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