Is this a known IDE bug? I’m told the when case is...

# getting-started

[Marcin Wisniowski]

Is this a known IDE bug? I’m told the when case is not exhaustive, but the missing branch was already handled. If I do add the branch, I get a different error that the branch is unreachable, so there is no way to make the IDE happy.

[Priyabrata Naskar]

Make it sealed class or you can use class outside of sealed interface & there you can implement

[Marcin Wisniowski]

Yes there are many ways to workaround it, but it doesn’t change the fact it’s a bug.

[hho]

I don't think it's strictly a bug, more like a missing feature: The compiler just isn't smart enough to figure out that the cases not handled in the if are enough to make the when exhaustive.

And TBH, if I saw this code in a review, I would tell you to use either an if or a when here, but not both…

[Marcin Wisniowski]

This is a minimal example which makes using both if and when useless. The real code needs it.

[Marcin Wisniowski]

> I don't think it's strictly a bug, more like a missing feature
That's a fair explanation for the first error, but then the second lint error is a bug: it suggests to remove a branch, and applying the fix makes the code (that was working) no longer compile.

[ascii]

Lint errors should not be ignored, but warnings can and very well should be suppressed in such cases

[ascii]

Dunno if there's already a bug filed for this

[Marcin Wisniowski]

There is now: https://youtrack.jetbrains.com/issue/KT-62514/False-positive-for-when-expression-must-be-exhaustive-for-cases-that-were-already-handled

[Marcin Wisniowski]

Yes, it can be suppressed, but it's not ideal since you cannot suppress it for just one case, so you lose the lint warnings on all cases, where they could be real issues.

[spleenjack]

https://youtrack.jetbrains.com/issue/KT-8781/Consider-making-smart-casts-smart-enough-to-handle-exhaustive-value-sets

[Marcin Wisniowski]

Thanks, added as a comment on my issue

[okarm]

What is the new * source annotation in the screenshot?

[okarm]

Oh, nevermind, it's the VCS author, isn't it?