当使用原始参数模拟方法时，Mockito中的NullPointerException

Question

I've spent the last little while pulling out my hair trying to find the problem in my test, and eventually figured out it has to do with mocking a method that takes primitive arguments. Here's a sample test that demos the problem:

import static org.mockito.Matchers.any;
import static org.mockito.Mockito.mock;
import static org.mockito.Mockito.times;
import static org.mockito.Mockito.verify;

import org.junit.Test;

public class MockitoTest {
    public static interface Foo {
        public Object causeProblems(long arg);
    }

    @Test
    public void testFoo() {
        Foo foo = mock(Foo.class);
        foo.causeProblems(123);
        verify(foo, times(1)).causeProblems(any());
    }
}

When running this test (I'm using Mockito 1.10 and Java8), and for some reason my stack trace is showing an NPE on the verify line:

java.lang.NullPointerException
    at com.amazon.jetstream.executor.worker.invoke.MockitoTest.testFoo(MockitoTest.java:19)
    at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
....

I think part of my stack trace is being suppressed (?) Digging into it a bit further, I can get slightly more info out of it if I run it in Eclipse and "inspect" the line, which tells me simply:

java.lang.NullPointerException at longValue()

Questions:

1. Does anyone know how to workaround this bug?
2. If you can reproduce this, can you get more info out of your stack trace?

Answer 1

You should matcher that matches long not any object:

verify(foo, times(1)).causeProblems(anyLong());

I checked that it runs correctly.