Question

When I’m testing this static method

public class SomeClass {
    public static long someMethod(Map map, String string, Long l, Log log) {
        ...
    }
}

with

import org.apache.commons.logging.Log;

@RunWith(PowerMockRunner.class)
//@PrepareForTest(SomeClass.class)
public class Tests {
    @Test
    public void test() {
        ...
        PowerMockito.mockStatic(SomeClass.class);
        Mockito.when(SomeClass.someMethod(anyMap(), anyString(), anyLong(), isA(Log.class))).thenReturn(1L);
        ...
    }
}

I got InvalidUseOfMatchersException. My questions are:

1. Why I got this exception when all the arguments are using matchers? How to solve it? I have debugged it, found the isA(Log.class) returns null.
2. When I add the @PrepareForTest annotation to the test class and run the test, the junit makes no response. Why?

EDIT

I tried not to use argument matchers, and got

org.mockito.exceptions.misusing.MissingMethodInvocationException:
when() requires an argument which has to be ‘a method call on a mock’.
For example:
when(mock.getArticles()).thenReturn(articles);

Also, this error might show up because:

1. you stub either of: final/private/equals()/hashCode() methods.
   Those methods cannot be stubbed/verified.

2. inside when() you don’t call method on mock but on some other object.

at …

So it seems due to the someMethod itself. There are synchronized block in the method. I’m wondering if Powermockito can mock that kind of method or not.

Answer 1

Try replacing the isA() to another any() call like this

Mockito.when(SomeClass.someMethod(anyMap(), anyString(), anyLong(), any(Log.class))).thenReturn(1L);

[EDIT]

Check your stacktrace when you get the exception. Are you seeing any NoClassDefFoundError reported? I noticed when I hadn’t included the javassist.jar in my project I got a similar error to you.

I use PowerMockito and these are the jars I added to a brand new project to run the code that @Tom posted

• powermock-mockito-1.4.10-full.jar
• mockito-all-1.8.5.jar
• javassist-3.15.0-GA.jar
• junit-4.8.2.jar
• common-logging-1.1.1.jar

Always a good idea to check that you’re using compatible JAR versions, and also check if there are any other conflicting JARs in your projects classpath.