Typesafe JMock actions

MockingTesting.kt

class MockingTesting {

    @Rule @JvmField val mockery = JUnitRuleMockery()
    val charSequence = mockery.createMock<CharSequence>()

    @Test fun `which will taking untyped Action`() {
        mockery.expecting {
            oneOf(charSequence).length.which will org.jmock.Expectations.returnValue(42)
            oneOf(charSequence).length.which will org.jmock.Expectations.throwException(RuntimeException())
            oneOf(charSequence).length.which will org.jmock.Expectations.returnValue("banana")
        }
        assertEquals(42, charSequence.length)
        assertFails {
            charSequence.length // RuntimeException
        }
        assertFails {
            charSequence.length // class cast from "banana" to Int
        }
    }
    
    @Test fun `which will taking TypedAction`() {
        mockery.expecting {
            oneOf(charSequence).length.which will returnValue(42)
            oneOf(charSequence).length.which will throwException(RuntimeException())
            // oneOf(charSequence).length.which will returnValue("banana") // doesn't compile
        }
        assertEquals(42, charSequence.length)
        assertFails {
            charSequence.length
        }
    }

    @Test fun `which will taking typed lambda`() {
        mockery.expecting {
            oneOf(charSequence).length.which will { 42 }
            oneOf(charSequence).length.which will { throw RuntimeException() }
            // oneOf(charSequence).length.which will { "banana" } // doesn't compile
        }
        assertEquals(42, charSequence.length)
        assertFails {
            charSequence.length
        }
    }
}