We all know that integration testing is nothing but a type of testing that combines different components (both software and hardware) to confirm that they work properly together to meet the set expectations. By definition, Integration Testing is the same for both Agile and Waterfall. We also know they are an important type of testing that has to be performed irrespective of the software development model. But when it comes to integration testing in Agile, there is a lot more weightage for it as the DoD (Definition of Done) principle is a core concept in Agile. Being a leading agile testing service provider, we wanted to take a deeper dive and explain how integration testing plays a major role in being agile.
Agile vs Waterfall
In the conventional waterfall approach, integration testing would mostly happen at the very end of the development cycle. Performing integration testing for the entire application itself can be hard. Moreover, solving the issues or bugs that are found can become even harder as it might require a lot of rework. But since the agile methodology employs a more test-driven approach, we would test smaller modules of the application by using unit tests. Since we start integration testing in Agile during the early stages of development, we will identify any integration issues early on and resolve them easily in comparison to the conventional methods.
But the catch here is that these smaller unit tests are all isolated modules. So there is no way you can write them off as tested completely in agile until you have performed integrated testing. There is no point in each of the modules working well on its own. It should all be able to work seamlessly together for the app to function effectively. So integration testing will be an important part of your Definition of Done checklist. But you have to make sure that the modules that are about to be tested are bug-free. In addition to that, the workflow in agile is such that there will be various changes to the modules that have already been tested earlier. So regression tests and smoke tests would come in to verify nothing is broken after the changes.
How to do Integration Testing in Agile Right?
You should have the proper environment and sufficient data to perform effective integration tests. Without a proper test environment that doesn’t mimic the hardware and software configuration in which the app will eventually run when released will only provide unreliable results. So test data plays an important role in developing a comprehensive test plan that will be useful in creating the required test environment.
Let’s take a look at two metaphors now and once again answer the question of why Integration testing is important in both agile and waterfall methodologies. If you are using the waterfall method, then very late integration testing can break your app as finding the issues can be like finding a needle in a haystack. Likewise, if you are using the agile method and fail to perform integration tests during the early stages, then you would end up with a set of puzzle pieces that don’t fit. So we hope you now understand the importance of integration testing in Agile.