你测试的性质

模块X的单元测试是仅在模块X中预期(并检查)问题的测试。

许多模块的集成测试是一种预期由模块之间的合作产生的问题的测试，这样单独使用单元测试就很难发现这些问题。

从以下方面考虑测试的性质:

Risk reduction: That's what tests are for. Only a combination of unit tests and integration tests can give you full risk reduction, because on the one hand unit tests can inherently not test the proper interaction between modules and on the other hand integration tests can exercise the functionality of a non-trivial module only to a small degree. Test writing effort: Integration tests can save effort because you may then not need to write stubs/fakes/mocks. But unit tests can save effort, too, when implementing (and maintaining!) those stubs/fakes/mocks happens to be easier than configuring the test setup without them. Test execution delay: Integration tests involving heavyweight operations (such as access to external systems like DBs or remote servers) tend to be slow(er). This means unit tests can be executed far more frequently, which reduces debugging effort if anything fails, because you have a better idea what you have changed in the meantime. This becomes particularly important if you use test-driven development (TDD). Debugging effort: If an integration test fails, but none of the unit tests does, this can be very inconvenient, because there is so much code involved that may contain the problem. This is not a big problem if you have previously changed only a few lines -- but as integration tests run slowly, you perhaps did not run them in such short intervals...

记住，集成测试仍然可能存根/伪造/模拟它的一些依赖项。 这在单元测试和系统测试(最全面的集成测试，测试所有系统)之间提供了大量的中间地带。

务实的方法使用两者

因此，一种务实的方法是:尽可能灵活地依赖集成测试，在风险太大或不方便的地方使用单元测试。 这种思维方式可能比单元测试和集成测试的一些教条主义区分更有用。

A little bit academic this question, isn't it? ;-) My point of view: For me an integration test is the test of the whole part, not if two parts out of ten are going together. Our integration test shows, if the master build (containing 40 projects) will succeed. For the projects we have tons of unit tests. The most important thing concerning unit tests for me is, that one unit test must not be dependent on another unit test. So for me both test you describe above are unit tests, if they are independent. For integration tests this need not to be important.

我也这么做——我把它们都称为单元测试，但在某些时候，我有一个“单元测试”，它涵盖了太多内容，我经常把它重命名为“..IntegrationTest”——只是名字改变了，其他的都没有改变。

我认为从“原子测试”(测试一个微小的类或方法)到单元测试(类级别)和集成测试——然后是功能测试(通常从上到下覆盖了更多的东西)——有一个延续——似乎没有一个干净的分界线。

如果您的测试设置了数据，可能还加载了数据库/文件等，那么它可能更像是一个集成测试(我发现集成测试使用更少的模拟和更多的真实类，但这并不意味着您不能模拟出系统的某些部分)。

你测试的性质

模块X的单元测试是仅在模块X中预期(并检查)问题的测试。

许多模块的集成测试是一种预期由模块之间的合作产生的问题的测试，这样单独使用单元测试就很难发现这些问题。

从以下方面考虑测试的性质:

Risk reduction: That's what tests are for. Only a combination of unit tests and integration tests can give you full risk reduction, because on the one hand unit tests can inherently not test the proper interaction between modules and on the other hand integration tests can exercise the functionality of a non-trivial module only to a small degree. Test writing effort: Integration tests can save effort because you may then not need to write stubs/fakes/mocks. But unit tests can save effort, too, when implementing (and maintaining!) those stubs/fakes/mocks happens to be easier than configuring the test setup without them. Test execution delay: Integration tests involving heavyweight operations (such as access to external systems like DBs or remote servers) tend to be slow(er). This means unit tests can be executed far more frequently, which reduces debugging effort if anything fails, because you have a better idea what you have changed in the meantime. This becomes particularly important if you use test-driven development (TDD). Debugging effort: If an integration test fails, but none of the unit tests does, this can be very inconvenient, because there is so much code involved that may contain the problem. This is not a big problem if you have previously changed only a few lines -- but as integration tests run slowly, you perhaps did not run them in such short intervals...

记住，集成测试仍然可能存根/伪造/模拟它的一些依赖项。 这在单元测试和系统测试(最全面的集成测试，测试所有系统)之间提供了大量的中间地带。

务实的方法使用两者

因此，一种务实的方法是:尽可能灵活地依赖集成测试，在风险太大或不方便的地方使用单元测试。 这种思维方式可能比单元测试和集成测试的一些教条主义区分更有用。

在单元测试中，你要测试每个独立的部分:

在集成测试中，您将测试系统的许多模块:

这是当你只使用单元测试时发生的事情(通常两个Windows都可以工作，不幸的是不能一起工作):

来源: source1 source2

集成测试:测试数据库持久性。 单元测试:模拟数据库访问。对代码方法进行测试。