What is the Difference Between unit tests and integration tests? with Proper Definition and Brief Explanation

The main difference between unit tests and integration tests is that the unit test checks if individual modules work as expected while the integration test checks a combination of individual modules to see if they work correctly as a group.

Software testing is an important phase in software development. Helps to find out if the software meets business requirements. In addition, software tests help reduce errors and provide a functional product to the end customer. In addition, there are several levels of evidence. And, two of them are unit tests and integration tests.

Key areas covered

1. What is unit testing?
      – Definition, Functionality
2. What is the integration test?
     – Definition, Functionality
3. What is the difference between unit tests and integration tests?
     – Comparison of key differences

Key terms                         

Integration Testing, Unit Testing

What is unit testing?

Unit test is the type of test that verifies whether individual modules are working properly. It helps to verify the functional correctness of the independent modules. The primary purpose of unit testing is to identify, analyze, and correct defects in each unit by isolating it from the system.

For example, suppose a banking application. First, the user must log into the system by entering the username and password. The login is a module in the system. Some unit test cases for unit testing in the login module are as follows.

Check the answer for a valid username and password.

Check the answer for invalid username and password.

Check the answer when username and password are empty.

Typically, developers perform unit tests. They can use software like JUnit to perform unit tests.

What is the integration test?

The integration test is a type of test that combines individual modules and tests them as a group. Check data transfer between multiple modules. For example, suppose a banking application. The user verifies the current balance module. Show 2000. Then visit the transfer module and transfer 1000 to a third party. Once again, check the current balance. The integration tests check the data transfer between these two individual modules (current balance, transfer module) to see if they work properly as a group.

If the current balance module is ready, but the transfer module is not, then the software tester can create a stub for the transfer module. It is not a full implementation of the staging module, but it does send data between modules to continue testing. Similarly, if the transfer module is ready, but the current balance module is not ready, then the software tester can create a driver instead of the current balance module. It is not a full implementation of the current balance module, but it sends data between modules to continue testing.

There are mainly two approaches to integration testing. They are as follows:

Top-down approach – Try the top-level modules first. May require creating stubs.

Bottom-up approach – Try the lower-level modules first. It may require the creation of drivers.

Difference between unit tests and integration tests

Definition

Unit testing is a level of software testing where individual units of a software are tested. In contrast, integration testing is a level of software testing where individual units are combined and tested as a group. This is the main difference between unit tests and integration tests.

Functionality

Another difference between the unit test and the integration test is that the unit test checks the functionality of the modules or units, while the integration test verifies the data transfer between multiple modules or units.

Interpreted by

Developers perform unit tests while software testers perform integration tests.

conclusion

Unit tests and integration tests are two levels of testing. The main difference between the unit test and the integration test is that the unit test checks if individual modules work as expected, while the integration test checks a combination of individual modules to see if they work correctly as a group.

Reference:

1. “ Software Trial Levels”, TutorialRide.com, Available here.

Courtesy Image:

1. “762486” (CC0) via Pixabay

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