CODEWITHSUNDEEP
scalamockitostub
Adrien Devillers
Adrien Devillers

Reputation: 45

Unable to properly stub a method with an argument instanciating a new Date

I'm working on a scala project and in my unit test I have to stub a method that takes as argument a Date(that is instanciated when calling the method), and I can't get to stub it porperly

However, I was able to find a turnaround using this post How to mock new Date() in java using Mockito But I wonder if there is a better way to do this because I find that solution not very satisfying ...

here is the code I try to stub :

def foo(): Future[JsonObject] ={
 [...]
        for {
            a <- b.bar(arg,atDate = Some(Date.from(Instant.now())))
        } yield a
    }

I tried to stub it like that

val b = mock[B]
 when(b.bar(arg, _:Option[Date])).thenReturn(Future.successful(List()))

this doesn't parse,so I have to change it to :

val b = mock[B]
 when(b.bar(arg, _:Option[Date])).thenReturn({ d:Date => Future.successful(List())})

and when I run it I have the following error :

when() requires an argument which has to be 'a method call on a mock'.
For example:
    when(mock.getArticles()).thenReturn(articles);

Also, this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
   Those methods *cannot* be stubbed/verified.
   Mocking methods declared on non-public parent classes is not supported.
2. inside when() you don't call method on mock but on some other object.

org.mockito.exceptions.misusing.MissingMethodInvocationException: 
when() requires an argument which has to be 'a method call on a mock'.
For example:
    when(mock.getArticles()).thenReturn(articles);

Also, this error might show up because:
1. you stub either of: final/private/equals()/hashCode() methods.
   Those methods *cannot* be stubbed/verified.
   Mocking methods declared on non-public parent classes is not supported.
2. inside when() you don't call method on mock but on some other object.

Maybe I'm missing something in the error message but I don't find it helpful. Is there any way to tell the stub to take whatever value for the date? Also why does it require to put a function in thenReturn part, although the return type of the function is Future[List[A]]?

thanks in advance

Upvotes: 1

Views: 594

Answers (1)

ultrasecr.eth
ultrasecr.eth

Reputation: 1497

You have to use the any matcher, so your code looks like (here I'm assuming arg is a variable defined somewhere else in your test code)

when(b.bar(ArgumentMatchers.eq(arg), ArgumentMatchers.any())).thenReturn(Future.successful(List()))

Now that's a bit verbose, so if you upgrade to mockito-scala and use the idiomatic syntax it would look like

b.bar(arg, *) returns Future.successful(List())

if you have/use cats, you can even do

b.bar(arg, *) returnsF List()

for more info check the docs here

Upvotes: 1

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