Hi! What is the reason for such behaviour? ``` class A mockk<A> { every { toString() } r...

# mockk

[Mikhail Fedotov]

Hi! What is the reason for such behaviour?

class A

mockk<A> {
    every { toString() } returns “A” // ok
    every { hashCode() } returns 0 // fails with io.mockk.MockKException: Missing mocked calls inside every { ... } block
}

class B {
    override fun hashCode() = 42
}

mockk<B> {
    every { toString() } returns “A” // ok
    every { hashCode() } returns 0 // ok
}

Why mockk cannot mock hashCode() if it is not overriden in class explicitly?

[Mattia Tommasone]

i guess the real question would be “why would you want to mock hashCode in the first place?”

[Mikhail Fedotov]

Actually I need to mock equals method. To make comparable mock instance. That is how I faced this problem.

Comparable mocks are very useful for testing android classes, without using Robolectric and running tests on host machine without real android.jar implementation.

[Mattia Tommasone]

i don’t think mocking equals is a good idea either
it’s used internally by mockk and mocking it may cause weird issues

[Mikhail Fedotov]

As I know mocks use default equals. What kind of problems, any samples? This gives many positive results, so currently I dont want to refuse it without clear reasons.

[Mikhail Fedotov]

My equals implementation does not break java contract so it should work even in library environment (as I expect)..

[Mikhail Fedotov]

Even with some problems on mockk side, i can implement something similar on my own with java dynamic proxies.

So I am more interested in original question why mockk cant mock hashCode() if it is not overriden explicitly?