Integration Testing

What is integration testing?
Integration Test level is a software testing process in individual units are combined and tested as a group.

The purpose of integration testing is to expose the flaws in the interaction between the integrated units.

Test drivers and test stubs are used to assist in the integration of evidence.

Note: The definition of a unit can vary from person to person and that could mean one of the following:

1. The smallest testable part of a software
2. A "module" that could involve many of ‘1’
3. A "component", which could consist of many of ‘2’

Integration Test Analogy-

During the manufacturing process of a pen cap, body, tail and clip the cartridge and pen ink are produced separately and the test unit separately. When two or more units are ready, meet and Integration Testing. For example, if the cap fits into the body as needed or not.

When performing integration test?
Integration tests are performed after unit testing and assessment system before.

Who conducts integration testing?
Either developers or testers themselves independent to carry out the integration of evidence.

What method was used to test Integration Test?
Either Black box testing, White Box Testing, and gray box testing methods can be used. Typically, the method depends on your definition of "unity."

Integration Testing Approaches-
1. Gigantic Bang is an approach to Integration Testing where all or most of the units are combined together and tested at six go. This approach is taken when the testing team receives the entire application in a bundle. So what is the difference between Gigantic Bang Integration Testing and Process Testing? Well, the former tests only the interactions between the units while the latter tests the entire process.
2. Top Down is an approach to Integration Testing where top level units are tested first and lower level units step by step after that. This approach is taken when top down development approach is followed. Check Stubs are needed to simulate lower level units which may not be obtainable during the initial phases.
3. Bottom Up is an approach to Integration Testing where bottom level units are tested first and upper level units step by step after that. This approach is taken when bottom up development approach is followed. Check Drivers are needed to simulate higher level units which may not be obtainable during the initial phases.
4. Sandwich/Hybrid is an approach to Integration Testing which is a combination of Top Down and Bottom Up approaches.

Advice on the integration test-
* Make sure you have a good detailed design document where interactions between each unit are clearly defined. In fact, you will not be able to perform integration tests without this information.
* Make sure you have a strong system of software configuration management in place. Or, you will have a difficult time monitoring the correct version of each unit, especially if the number of units to be integrated is enormous.
* Make sure each drive is first tested before starting the integration of evidence.
* Wherever possible, automate testing, especially when using the Top Down or Bottom-up approach, since regression testing is increasingly important that integrate a unit, and manual regression testing can be inefficient.