Mocking out all overlaoded versions of a method in scala mockito

Question

In Mockito-Scala you can stub out methods like so:

myMock.doIt(*) returns 1
myMock.doIt(*,*) returns 1
myMock.doIt(*,*)(*) returns 1

Is there a way to mock all overloaded methods at once?

Answer 1

ScalaAnswer[T] can be used to configure mock's answers like so

object AnswerAllFoo extends ScalaAnswer[Any] {
  def answer(invocation: InvocationOnMock): Any = {
    if (invocation.getMethod.getName == "foo") 42 else ReturnsDefaults.answer(invocation)
  }
}

and then pass it in on mock creation like so

mock[Qux](AnswerAllFoo)

Here is a complete working example

import org.mockito.invocation.InvocationOnMock
import org.mockito.stubbing.{ReturnsDefaults, ScalaAnswer}
import org.scalatest.{FlatSpec, Matchers}
import org.mockito.{ArgumentMatchersSugar, IdiomaticMockito}

trait Qux {
  def foo(s: Seq[Int]): Int
  def foo(i: Int, j: String): Int
  def bar(s: String): String
}

object AnswerAllFoo extends ScalaAnswer[Any] {
  def answer(invocation: InvocationOnMock): Any = {
    if (invocation.getMethod.getName == "foo") 42 else ReturnsDefaults.answer(invocation)
  }
}

class MockAnyOverload extends FlatSpec with Matchers with IdiomaticMockito with ArgumentMatchersSugar {
  "Answer[T]" should "should answer all overloaded methods foo" in {
    val qux = mock[Qux](AnswerAllFoo)

    qux.foo((Seq(1,0))) shouldBe (42)
    qux.foo(1, "zar") shouldBe (42)

    qux.bar(*) returns "corge"
    qux.bar("") shouldBe ("corge")
  }
}