hello all i have a question regarding mockk kotlin mocking f

Question

hello all i have a question regarding mockk kotlin mocking framework how can i mock all instances of an class i tried ```val ibMock = mockkClass InstalledBase class every ibMock getModelDescriptions returns emptyList lt ModelDescription gt ``` but it doesnt work getModelDescriptions still returns another list i have no access to the object instaledbase in my test but i want that getModelDescriptions always returns an empty list

Stephan Schroeder · Answer

you don t mock the behaviour of a method on all instances you only mock the behaviour on the specific mock instance ```val ibMock = mockkClass InstalledBase class every ibMock getModelDescriptions returns emptyList lt ModelDescription gt ``` effects ```ibMock getModelDescription ``` but not ```installedbase getModelDescription ```

Andreas Unterweger · Answer

but how can i mock it on all instances

Stephan Schroeder · Answer

you can t

Andreas Unterweger · Answer

i thought so hmmm this is a limitation other mocking libs can do this

Stephan Schroeder · Answer

nope

Andreas Unterweger · Answer

so no solution to this one

Stephan Schroeder · Answer

not in the way you formulated the question Your approach is probably mistaken but it s hard to fix your approach without knowing more about the original problem you re trying to solve It s strange that `installedbase` is a normal non mocked object You probably need to be able to replace `installedbase` with a mocked object within the context of the unit test

Andreas Unterweger · Answer

its a loader implementation which returns a list of installedbases an ex should be thrown when model descs is empty in one of them so no access to the creation of the instBase but i changed the test now and it works still this remains a limitation of mockk in jmockit this was possible with a MockUp whatsoever thank you very much for your quick replies

Stephan Schroeder · Answer

if there is no way to do it in mockk it s probably a code smell hinting at that you don t use enough dependency injection in your code wink because as soon as you have dependency injection you can inject mocks instead of runtime instances into the code to be tested

Mike · Answer

Just read docs on JMockit It s written intentionally to be different from other mocking frameworks It mocks the class rather than the instances based on what I skimmed Not sure how it accomplishes it but I agree with Stephan s assessment that it s not a weakness of MockK It s a design difference between how JMockit allows you to test and the way MockK does I ve only worked with mocking frameworks like MockK and use injection so there s more isolation of implementation from consumer Design choices

Andreas Unterweger · Answer

hello to get back to this with help from mockk guys on github

Andreas Unterweger · Answer

``` internal class ObjTest FreeSpec obj mockkConstructor Obj class every anyConstructed lt Obj gt i returns 4 ObjProvider obj i shouldBe 4 data class Obj val i Int = 1 object ObjProvider fun obj = Obj ```