I'm running into a strange problem regarding test assertions on computed enums: ```import org.assert...

# getting-started

[David Kubecka]

I'm running into a strange problem regarding test assertions on computed enums:

import org.assertj.core.api.Assertions.assertThat

enum class X(val input: String) { A("1"), B("2") }

fun test() {
    assertThat(X::input.of("1"))
}

// generic enum reverse lookup
inline fun <reified E : Enum<E>, V> ((E) -> V).of(value: V): E =
    enumValues<E>().firstOrNull { this(it) == value } ?: error("No enum constant ${E::class}.$value")

The assertThat expression fails to compile with Overload resolution ambiguity. All these functions match. To fix the issue it suffices to extract the computed enum value into a variable (but still having the type inferred):

val actual = X::input.of("1")
        assertThat(actual)

What's going on?

(I have briefly tried to simplify the reproducer, e.g. by using a simpler enum-returning function, but to no avail.)

[CLOVIS]

> Overload resolution ambiguity. All these functions match.
The error message should give you the list of functions that do match. One of them should be your function, the other ones will tell you why the compiler is confused.

[David Kubecka]

Sure, there is quite a huge list of those functions. That's why I didn't even try to paste it here 🙂 But there are obvious nonsenses such as

public open fun assertThat(actual: File!): AbstractFileAssert<*>! defined in org.assertj.core.api.Assertions

Surely the return value of of is not File... But mainly wonder why the simple extraction to a val "fixes" the problem. That seems strange and that's why I think there must be something more going on.

[CLOVIS]

Looks like a resolution bug, you should report it: https://kotl.in/issue