why do I sometimes get a runtime exception due to ...

# announcements

[David Stolarsky]

why do I sometimes get a runtime exception due to a non optional value being null? at least when interacting with Android platform APIs. does this mean the platform API is not correctly annotated for consumption in Kotlin?

[gildor]

probably you passed null from Java or have some reflections that create nullable values.
Anyway hard to say something particular without details

[David Stolarsky]

c.getString(c.getColumnIndex(StructuredPostal.STREET))

[David Stolarsky]

apparently that returned null.. i just wish i would get a compile error instead of a runtime error

[gildor]

this is Java API, there is no nullability information

[David Stolarsky]

so shouldn't it be a compile error to assign that to a non optional value?

[gildor]

at least until those functions annotated with Nullable/NonNull

[gildor]

no, it’s a very long story whym, but it’s called platform types

[gildor]

https://kotlinlang.org/docs/reference/java-interop.html#null-safety-and-platform-types

[gildor]

so if Java API is not annotated, it concidered as platform type and maybe used as nullable and non-nullable

[David Stolarsky]

got it

[David Stolarsky]

i wonder if there is a linter option that could turn these into compile errors

[gildor]

there is no such option

[David Stolarsky]

ok

[obobo]

for what it's worth there's an inspection for Function or property has a platform type which you could set to error (seems to default to weak warning)

[gildor]

It wouldn't be reported for David's usecase, because platform type passed as argument to another platform type, so there is no warning. You see this warning only when expose it in Kotlin API