Can you make mockito (1.10.17) work with default methods in interfaces?

java mockito java-8 default-method
fge picture fge · Dec 27, 2014 · Viewed 13.1k times · Source

I am a big fan of mockito, unfortunately for one of my projects which uses Java 8, it fails on me...

Scenario:

public final class MockTest
{
    @Test
    public void testDefaultMethodsWithMocks()
    {
        final Foo foo = mock(Foo.class);

        //when(foo.bar()).thenCallRealMethod();

        assertThat(foo.bar()).isEqualTo(42);
    }

    @FunctionalInterface
    private interface Foo
    {
        int foo();

        default int bar()
        {
            return 42;
        }
    }
}

Unfortunately, the test fails and foo.bar() returns 0.

When I uncomment the when() line, I get a stack trace...

java.lang.NoSuchMethodError: java.lang.Object.bar()I
    at com.github.fge.lambdas.MockTest.testDefaultMethodsWithMocks(MockTest.java:18)

This is the latest stable version available on maven; googling around didn't tell me much about the status of mockito with regards to this new functionality in Java 8...

Can you make it work in some other way than implementing interfaces and spy() on them (this works)?

Answer

Brice picture Brice · Dec 27, 2014

With mockito 2.x, JDK 8 default methods are supported.

With mockito 1.x it's not possible,

Old answer

Unfortunately it's not yet possible (mockito 1.10.19), from the README.md on the github'page

JDK8 status

Mockito should work fine with JDK8 if you stay away from default methods (aka defender methods). Lambda usage may work just as good for Answers. We're unsure about every JDK8 features at the moment, like serializing a mock that uses a lambda. Error report and pull request are welcome though (contributing guide).

EDIT 1: defender methods and default methods are different names for the same thing.

I hope for a mockmaker replacement that will handle java 8 opcodes properly for such cases as some opcodes have a different semantic in Java 8.

EDIT 2: Updated the mockito readme, and this quote accordingly

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