Are inline functions like `forEach`, `forEachIndex...

# announcements

[v79]

Are inline functions like forEach, forEachIndex, File.walk() just syntactic sugar that I can use instead of (for x in y) or should I be much for careful when using them? I've discovered that forEach cannot be mocked with a library like mockk and that's playing havoc with my testing.

[Hanno]

You really need to mock an iteration? Hell, it's getting out of control :D how would you mock (for x in y) though??

[SiebelsTim]

Why would you want to mock that? You can't mock for either?

[SiebelsTim]

Oh well, I'm to slow.

[v79]

It's straightforward to mock a Java Iterator in Mockito so it's not so had to mock a Java for(int x : y), isn't it?

[SiebelsTim]

You can mock the Iterable. In both languages and mocking libraries

[v79]

I think my app needs a massive refactoring to make it testable! Though my original question still stands - should I use forEach liberally, instead of the for loop, or only in a few specific scenarios?

[SiebelsTim]

I think it's mostly the same, except a few corner cases for example regarding ranges if I remember correctly.

I would use for whenever it fits. I use forEach usually when it's a longer chain.

Also see https://kotlinlang.org/docs/reference/coding-conventions.html#using-loops

[Leon K]

they mostly get inlined, altough it is recommended to use regular for loops as long as its not as part of a chain ;D Using `map`/`reduce` is recommended though

[Tim Schraepen]

@v79 can you share the code your testing?

[Frank Harper]

@v79 What is the advantage of mocking forEach vs mocking at a higher level ?

[v79]

I'd be ashamed to share my code, there was about 150 lines of code inside that forEach block. It's prompted some long-overdue refactoring.

[Tim Schraepen]

You should never be ashamed of learning opportunities!
I didn’t want to shame you or your code, but it can be really helpful for other people to learn from.
Now you can share your code before and after your refactoring!
I understand if you don’t feel comfortable sharing your code.