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scalamockitoscalatest

Is it possible to stub or mock a method of a class under test?

In this Scala class

class A{
def a() = {b();}
def b() = {...}
}

If I want to test a(), is it possible to mock or stub b()

Solution

  • Mocks override all methods (usually with return null unless explicitly stated to return something else) while here you want to override just one method. Since your class isn't final it would be easier to do something like

    val tested: A = new A {
  override def b = ...
}

    than mock it (actually mocking final classes is also impossible without something like PowerMock)

    val tested = mock[A]
(tested.b _) returning (...)
// tested.a returns null and ignores b

    because mock would also override a making your tests useless. You could "fix" it by mocking a to have the same implementation as the original... but this is absurd for many reasons.

    So mocking method of a tested class with a mocking framework is possible but it's getting in the way rather than helping.