How can you mock a static method with parameters using `Mockito.mockedStatic()`?

General Discussions
1

All examples of mockedStatic() in Mockito show how to mock methods without parameters. However, when trying to mock a static method that takes arguments, such as Foo.methodWithParams("SomeValue"), it doesn’t seem to work. Is there a correct way to mock static methods that accept parameters in Mockito?

2

Yes, you can mock static methods with parameters using mockedStatic(). The trick is to use the when method and match arguments using either exact values or ArgumentMatchers. For example:

try (MockedStatic<Foo> mocked = Mockito.mockStatic(Foo.class)) {
    mocked.when(() -> Foo.methodWithParams("SomeValue")).thenReturn("MockedResult");

    String result = Foo.methodWithParams("SomeValue"); // returns "MockedResult"
}

If you want to handle any value for the parameter, you can use Mockito.any(): `` mocked.when(() → Foo.methodWithParams(Mockito.anyString())).thenReturn(“MockedResult”);


This approach works for methods with one or multiple parameters.
3

Yep, exactly, mockedStatic() works with parameters. I ran into the same confusion at first. One tip: always wrap the static mocking in a try-with-resources block; otherwise, Mockito may not restore the original behavior, which can cause tests to fail unpredictably.

4

a useful trick: if you need to verify that the static method was called with specific arguments, you can do this:

mocked.verify(() -> Foo.methodWithParams("SomeValue"), Mockito.times(1));

This lets you both mock the return value and verify the call, which is handy for more complex test scenarios.