When running tests with Junit, per default the test execution order is deterministic. But the order of all the tests is not predictable. But for some reasons, it may be useful to ensure a specific order. E.g. one of your tests is sometimes failing and you have no idea. So maybe your production code is not threadsafe or there are some other effects that influence your test without knowing it. E.g. a cache that is filled with some results by a test running before. Continue reading
When writing unit tests in Java there might be the need to access a resource in the class that should be tested. A common way is to mock the resource. But mocking a simple resource is quite easy. This is supported by mocking frameworks like Mockito, EasyMock or PowerMock. It is a good idea in case you want to test a single action on the mocked resource – e.g. returning a value when accessing a map that contains master data. The following exmaple describes mocking a resource using Mockito. But in case there are complex operations on this resource mocking it is going to be really nasty.