Verify on Scala method with by-name parameters always fails

Given a Scala trait with a method that has a call-by-name parameter, e.g.

trait Foo {
def bar(a: => String)
}

Mock and verify the method:

val foo = mock[Foo]
foo.bar("BAZ")
verify(foo).bar(anyString)

I would expect this to pass. It actually fails, as it is comparing the lambda 
that generates the parameter.

There is a painful workaround, that involves creating an anonymous Function 
object to represent the parameter lambda, then override the equals method to 
evaluate the function and compare results (see 
http://stackoverflow.com/a/2158709/323177)

This uses Scala 2.10.0 and Mockito 1.9.0.

Original issue reported on code.google.com by richardw...@googlemail.com on 12 Jun 2013 at 11:45

mensahs / mockito

Verify on Scala method with by-name parameters always fails #439