Hey folks, I’ve got a method that takes, as one of...

# announcements

[Michael]

Hey folks, I’ve got a method that takes, as one of its arguments, func: Function<Foo, Bar>. Elsewhere in the code, when calling it, I’m trying to pass in { it.baz } where it is type Foo, and baz is type Bar. But it’s giving me unresolved reference: it and saying that the type of the lambda is () -> [ERROR:]. If I prefix it with the word Function, Function { it.baz} it works.

[Andreas Sinz]

Function<Foo, Bar> is a java interface?

[Michael]

Yeah. I’m realizing now (trying to debug a coworker’s code) that he was using “kotlin.test.assertEquals”, which is <T,T> which is also breaking the compiler, because the literal on the left isn’t nullable. I thought that was junit’s assertEquals.

[Michael]

Why wouldn’t assertEquals take a nullable value?

[Michael]

Well, I solved it. By replacing the java Function<Foo, Bar> with (Foo) -> Bar