Hi there mates QQ about `CompositionLocal`s kotlinlang #compose

. The thing is, if we forget to set the `CompositionLocal`s in any of those, we end up with a crash at runtime with a stack trace that's way far from explicit (full stack trace in this Google Issue Tracker report) I'd like to hook into any call to

setContent

and provide a meaningful error if those implicit dependencies are not provided. Is there a way to do this? If that's not feasible, I may consider some type of lint

Stylianos Gakis

10/20/2023, 3:53 PM

What you get by default from a CL is defined by you right? You could definitely have something like

Copy code

internal val Foo = staticCompositionLocalOf<Foo> {
  error("Foo not provided")
}

Would that be sufficient for you here?

xoangon

10/20/2023, 4:37 PM

That seems to be what I was looking for! On my way to test that out

Stylianos Gakis

10/20/2023, 4:41 PM

You could also consider not crashing in production but providing a sane default (as material3 color scheme does with light color scheme for example) but still log a high severity warning.

xoangon

10/20/2023, 4:55 PM

The snippet above is what I was looking for, thanks!

I used to do super-defensive programming with no errors at runtime at my previous company and were I am right now we do offensive programming with development under feature-flag. I was a bit shocked at first, but by providing meaningful errors and having an easy roll-back setup, I'm amazed by the time saved! Opposite to what I was expecting, our app ends up being more robust as we realise early when something's not working well instead of having a ton of users falling in undesired weird states with missing information

Stylianos Gakis

10/20/2023, 5:01 PM

Yep, as long as you got an easy way to roll back that is 😅

xoangon

10/20/2023, 5:02 PM

Yup, it would be crazy without that 🤣

myanmarking

10/21/2023, 8:57 PM

If it is a developer error, crash always. Going otherwise is making it worst

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