Mockito is used to test the execution of overloaded methods.

Question

I'm attempting to have Mockito validate a call to a library function whose code cannot be altered; otherwise, the signature of varargs would have changed to publish(Record record, Record... records).

publish(Record record)
publish(Record... records)

To test the execution of the second function, use the code below.

verify(publisher).publish(ArgumentMatchers.<Record>any());

However, the preceding call always tries to check for a publish call with the NonArgs function and fails. Any ideas on how to make Mockito check for the var args function?

For this test, I used mockito 3.11.2.

As I looked around, I came across this lesson from here (https://www.scaler.com/topics/marker-interface-in-java/) that featured a similar example that advised selecting the correct overload when using the check function. Furthermore, it states that any() implements VarargMatcher - a specific marker interface, implying that this matcher can be used repeatedly.

Answer 1

To verify the execution of the publish(Record... records) method using Mockito, you can use the ArgumentMatchers.anyVararg() method instead of ArgumentMatchers.any().

Here's an example:

verify(publisher).publish(ArgumentMatchers.anyVararg());

This will match any invocation of the publish method with any number of Record arguments.

Note that anyVararg() is a shorthand for argThat(new ArrayContainingMatcher<>(Matchers.any())). If you need to perform more complex matching on the varargs argument, you can use the argThat method with a custom matcher.

Also, make sure that you are mocking the correct instance of the publisher object and that the publish method is actually being called in your test code.