“Cascade if can be replaced with when” warning but...

# announcements

[Mark]

“Cascade if can be replaced with when” warning but sometimes it’s a false positive, for example if I have an if condition (at least 3 branches) where the checks are things like Build.VERSION.SDK_INT > 12 and then branch depends on such a later SDK level. How to suppress this warning?

[CLOVIS]

All warnings can be suppressed by clicking the right arrow on the warning list.
Keyboard: ALT ENTER, select the warning, right arrow

[CLOVIS]

Do you have an example of such a false positive? It might be useful to report it to the team

[Mark]

I only have an Android example. Maybe there’s a way to contrive something similar in pur Kotlin:

if (Build.VERSION.SDK_INT < Build.VERSION_CODES.N) {
    getVolumePathPre24(volumeId)
} else if (Build.VERSION.SDK_INT < Build.VERSION_CODES.R) {
    getVolumePathApi24Pre30(volumeId)
} else {
    getVolumePathApi30(volumeId)
}

The called functions have the appropriate annotations like @RequiresApi(Build.VERSION_CODES.N)

[CLOVIS]

Why is that a false-positive? Converting it to when would give the exact same behavior since it's else-if

[Mark]

All warnings can be suppressed by clicking the right arrow on the warning list.

Ah, thanks, I was wondering why sometimes I was seeing the suppress options, and other times not.

[Mark]

Why is that a false-positive?

Because with when it won’t compile. The compiler doesn’t seem to figure out the API levels, unlike with if

[Mark]

Call requires API level 24 (current min is 23): getVolumePathApi24Pre30

[CLOVIS]

Ah, that looks like an Android bug? Not sure who this should be reported to

[CLOVIS]

Still though the bug isn't a false positive on when, it's just that when is apparently broken. That code should be correct.

[ephemient]

https://issuetracker.google.com/issues/189459502

[Mark]

Thanks @ephemient I’ve added some code there that minimally reproduces the issue.