Software is made up of small units that are closely integrated with each other. But these small units and interactions among these units need effective testing to ensure that these modules work fine with each other and as expected. This is where unit testing and integration testing plays their role. However there are some differences between these testing types, let’s have a look at these differences in more detail.
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What is unit testing?
It is a software testing method where individual units/components of the software are tested in isolation to check whether these units are working fine and as expected or not. This test is usually done at the first level in the software testing lifecycle.
What is integration testing?
It is a software testing methodology in which individually unit tested modules of the software are integrated into the software to ensure that these units work fine and as expected after integration. This test is usually performed after unit testing.
Why are these testing types required?
Unit testing is required to ensure that the smallest possible units of the software function properly and that are ready to be integrated into the software. While on the other hand, integration testing is required to ensure that the units that were tested earlier can be integrated or not and also to determine that integrated units are functioning properly with each other or not.
What are the major differences between unit tests and integration tests?
Below mentioned are the major points of difference between these two testing types:
| Unit testing | Integration testing |
| This test is performed to check the smallest possible units of the software and to ensure that the units are correct | This test checks the integration of these units and ensures that’s these units work well after combining |
| Performed by developers or sometimes even testers | Performed by testing teams |
| It is a white box testing | It is black box testing |
| Performed at the first stage of the SDLC process | Performed after unit test and before system testing |
| It checks the functionality of the modules | It checks the integration errors present if any |
| It starts with the module specification | It starts with the interface specification |
| It does not verify whether the code works fine with external dependencies | It verifies that the code works with external dependencies |
| It is not sub-divided in to further types | It is sub-divided into further types such as Top-down, bottom-up, and so on. |
Conclusion: Before the software is released it is tested thoroughly with different types of tests such as unit test, integration test, system test, etc. Each of these testing types is different from the other. Therefore, in this article, we have tried to explain the major difference between unit and integration tests. Leverage end-to-end software testing from a next-gen QA and software testing services provider to achieve high-quality software to deliver an unmatched UX.
About the author: I am a technical content writer and I write articles on various IT-related topics. In this article, I have tried to share my views on the difference between unit testing and integration testing.
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