Software testing-Integration Testing Method

I want to talk about the integration test, which is familiar to everyone. But if you know the specific test method of the integration test, let me introduce the integration test methods, hope to help new users.
Integration TestIs the logical extension of unit test. The simplest form is to combine two tested units into one component and test the interfaces between them. In this sense, components refer to the integration and aggregation of multiple units. In practical scenarios, many units are combined into components, and these components are aggregated into a larger part of the program. The method is to test the combination of fragments and expand the process to test your modules with modules in other groups. Finally, all modules that constitute the process are tested together. In addition, if a program is composed of multiple processes, test them in pairs instead of testing all processes at the same time.
Integration TestIdentify issues that occur when combining units. By using a test plan that requires testing each unit before the unit is combined and ensuring the viability of each unit, it can be seen that any errors found during unit combination may be related to interfaces between units. This method reduces the number of possible cases to a simpler analysis level.
You can perform integration testing in multiple ways, and the following are three common categories:

1) Top-down: the top-down integration test method requires testing and integrating the highest level of modules first. This allows Advanced logic and data flow to be tested early in the process, helping minimize driver requirements. However, the requirements for stubs (stub, also known as "piles") complicate test management, and low-level utility testing is relatively late in the development cycle. Another drawback of up-down integration testing is that it does not support early release of limited functions.

2) Bottom-up: the bottom-up method requires testing and integrating the lowest-level units first. These units are often called utility modules. By using this method, the utility module is tested in the early stages of the development process, minimizing the requirements for the stub. However, the disadvantage is that the demand for drivers complicate test management, and advanced logic and data stream are tested in the late stage. Like the top-down method, the bottom-up method does not support the early release of limited functions.

3) The third method (also known as the umbrella method) requires testing along the functional data and control flow path. First, the input of the function is discussed above in the lower-level mode integration. Then, the output of each function is integrated from top to bottom. The main advantage of this method is the degree of support for the early release of limited functions. It also helps minimize requirements for stubs and drivers. However, the potential disadvantage of this method is obvious because it may be less systematic than the other two methods, resulting in a greater demand for regression testing.