How to mock a class with ScalaMock

Question

In the doc of ScalaMock, it is said that:

mocking classes, traits and case classes

is one of the feature supported.

I have the following case class:

case class Thing(private val item: Item)

When I do:

val item = mock[Thing]

I get the following error:

Error:(18, 24) not enough arguments for constructor Thing:

 (item: org.dspace.content.Item)org.iadb.poolpartyconnector.dspaceutils.Thing.
Unspecified value parameter item.
    val item = mock[Thing]
                   ^

I know I could implement an interface for it, but in any case, this would help me better understand how to mock a case class/a class that has a constructor.

Related: https://stackoverflow.com/questions/14274020/scalamock-mock-a-class-that-takes-arguments — dskrvk, Feb 12 '16 at 17:56

score 16 · Accepted Answer · edited Jul 06 '18 at 18:27

16

Currently, you cannot mock classes that do not have a default constructor defined.

You can workaround it by creating a subclass that has default constructor defined and mocking that subclass:

class MockableThing extends Thing(null)
val item = mock[MockableThing]

edited Jul 06 '18 at 18:27

Neil

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answered Jun 15 '15 at 19:44

Pawel Wiejacha

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There's a feature request to make it possible: https://github.com/paulbutcher/ScalaMock/issues/56 – Eyal Roth Dec 08 '15 at 15:27
That feature request has now been merged, so it should be possible. – Neil Jul 06 '18 at 20:07

How to mock a class with ScalaMock

1 Answers1