Hello, I have a trouble testing a class, that uses platform specific API inside. I would like to tes...

# multiplatform

[David Holas]

Hello, I have a trouble testing a class, that uses platform specific API inside. I would like to test that both platforms behave identically.

I have a CustomFormatter interface that uses NumberFormatter on android side which needs withLocale method to be mocked. I can make NumberFormatter a dependency of AndroidCustomFormatter but still MocKMP cannot mock NumberFormatter because it is not an interface.

I could mock the whole CustomFormatter, but that kinda defeats the purpose. Is there any way around it?

Thank you

https://pl.kotl.in/-SpBAWQl-

[spand]

Create a common test and one for each platform ie. https://pl.kotl.in/m68rt-zut

[spand]

Maybe its not even needed to have that test case. Isnt what you have working ?

[spand]

Its a bit difficult to know without having Config also

[David Holas]

It is on ios, but on android it says:

Method withLocale in android.icu.number.NumberFormatter not mocked.

[David Holas]

Its a bit difficult to know without having Config also

There is actually no Config, I just pass some parameters regarding the formatting, like units the formatter should use, etc. I didn't wanna write the all out as they are really not relevant

[David Holas]

Create a common test and one for each platform

I don't really understand how to make it work. Should I then override the @Test fun inside the subclass on android side?

[spand]

Look at the buttom of my link

[spand]

But I have doubts about your actual problem without the actual "Config" or its replacements

[spand]

ie. it looks like its platform specific since you have withLocale(config.locale)

[David Holas]

Yeah, maybe I simplified it too much for sake of the minimal example. Hold up, ill expand it

[David Holas]

Ok, I actually simplified it, because the way I pass Locale to the CustomFormatter is super complex and would require me to add multiple classes to the example just for that. Also the source of locale is irrelevant in this, the issue persists even with Locale.ENGLISH . I also removed the Config entirely as it just does not exist in my code.
https://pl.kotl.in/yoeYRvCmK

[spand]

And doesnt your example work ?

[David Holas]

Nope, it does this:

It is on ios, but on android it says:

Method withLocale in android.icu.number.NumberFormatter not mocked.

[David Holas]

U mean that it does work for you?

[David Holas]

Here is the example with all the implementation, I copied this into my project and it does not work. Running IOSCustomFormatterTest is fine, but running AndroidCustomFormatterTest crashes with

Method withLocale in android.icu.number.NumberFormatter not mocked.

https://pl.kotl.in/OZIRgOKcV

[spand]

Ok. That sounds like an android specific problem. Maybe this https://stackoverflow.com/a/75278020

[David Holas]

Hmm, ok, I had to use mockito inside androidTest to be able to test my android code. Thanks

[David Holas]

Ok, I did some more research and it turns out, that I was doing unit tests instead of instrumented tests. When doing instrumented tests on android, your solution works well. Thank you

[spand]

Cheers!