Is there a "clean" way to enforce an exhaustivenes...

# announcements

[thana]

Is there a "clean" way to enforce an exhaustiveness check for when(someSealedClass)? I just came across a piece of code where it was very natural to use then when without any assignment, hence the compiler would never complain when a branch was missing 🤔

[thana]

i mean, we can rewrite the code so we assign a the outcome of when to a variable, but this way the code actually gets more complicated

[ribesg]

There’s a warning in the IDE for that, you can configure it to be error level, but I don’t think it’ll prevent compilation with Gradle. I don’t know if another tool can do that

[hho]

I use the .exhaustive() trick explained here: https://proandroiddev.com/til-when-is-when-exhaustive-31d69f630a8b

[thana]

wow this trick's great. thank you!

[ribesg]

Yeah really nice trick

[gildor]

Unfortunately it pollutes code-completion

[gildor]

I prefer use `.hashCode()`/`toString()` for the same 😬

[thana]

yeah that's true. OTOH checkForExhaustiveness at least tells what it is good for. i think hashcode is so undescriptive that one day some developer could think about what that is good for and simply remove it, because it doesnt have any obvious use

[gildor]

I agree %)

[hho]

maybe something like .also { /* check exhaustiveness */ } … and have that as a live template …

[gildor]

good idea actually

[Jonathan Mew]

what is a 'live template'?

[Jonathan Mew]

really like this idea in principle 🙂

[hho]

Live Templates: https://www.jetbrains.com/help/idea/using-live-templates.html