Difference Between Regression and Integration Testing: The terms Regression Testing and Integration Testing are often used in a very loose manner by those involved in software testing. Both these kinds of testing have become synonymous with the term checking, assuming that all they mean is to check whether the program has worked as intended or not. This blog post intends to rectify this misconception and elaborate on the differences between, as well as the similarities of the two kinds of testing.
Regression testing involves re-testing the application using the previously executed test data to check for any defects (bugs). In short, regression testing tries to ensure that a newly added feature or modified code does not break any functionality already working in the existing system. Regression testing is done on each build after it passes all unit tests.
Integration testing tests the entire system to see it all works together correctly, as a whole. It tries to detect integration-related defects by ensuring that the different modules of the software work together correctly and provide the expected results when they are used with each other. Integration testing is performed after all the modules are integrated, and unit testing has been completed.
In short, Regression Testing checks if adding a new feature or modifying existing code has broken any previously working functionality. While Integration Testing ensures that a new module’s integration with the rest of the system works properly.
Difference Between Regression and Integration Testing
Now we are going to discuss the Regression Testing and Integration Testing differences in detail. Both these testing types are similar in many ways but differ with respect to their objectives.
The major differences between Regression Testing and Integration Testing are summarized in the table below:
There are some differences in the results of these two testing types as well. Both kinds of test data should be run at any point to see whether the program is in accordance with the requirements or not.
However, with Regression Testing, we verify that the existing functionality still works after adding a new feature or modifying code; whereas, Integration testing verifies that the new feature or modification is able to operate correctly with all other existing modules.
So, Regression Testing tests functionalities, whereas Integration Testing tests features and modules.
Regression testing is done before every build that makes a change in the system and ensures that it has not affected previously worked on code or functionality. On the other hand, integration testing is done after all the modules are integrated and unit testing has been completed, while it ensures that the newly added feature or modified code works properly with existing code.
Integration Testing also includes Performance Testing and Sanity Testing of an already tested system to see if it can function as expected in real-time conditions.
So, Regression Testing comes under white box testing and Integration Testing comes under black-box testing.
Regression Testing aims at re-validation of the system, whereas integration testing aims at validating the software as a whole.
As Regression Testing is done with previously executed test data, it is also called retesting or re-testing.
While we do Integration Testing with new test data for each iteration, as it aims at ensuring that the different modules work together correctly.
Regression testing is mainly used to check whether a bug has been fixed or not and if it still exists in the build after a change. This means that we do Regression Testing by re-running previously executed tests. While in the case of Integration Testing we run new test data for each iteration to ensure that the various modules work together correctly.
Integration testing is just not retesting; it also aims at ensuring that newly added features or modified code work properly with existing features and modules. This means integration testing should be done in a way that will make sure that any modification done to one part of the application will not affect other modules.
Regression testing is also called re-testing or retesting, while Integration Testing is mainly used for validating software systems as a whole and ensuring that all features work together appropriately.
Regression testing verifies only whether previously executed tests are still being passed after making changes to a system, whereas integration testing verifies whether newly added features or modified code works properly with existing features and modules.
Regression test is more focused on the functionalities of an application, while integration testing also ensures that new features and modifications will work properly with all other modules as well.