Description

Given a setup that defines a graph extension using @ContributesGraphExtension and multiple contributed interfaces that contain properties with the same name, but different types, like so:

@ContributesGraphExtension(ChildScope::class)
interface ChildGraph {

    @ContributesGraphExtension.Factory(AppScope::class)
    interface Factory {
        fun createChild(): ChildGraph
    }
}

@ContributesTo(ChildScope::class)
interface StringProvider {
    val foo: String

    @Provides
    fun provideString(): String = "test"
}

@ContributesTo(ChildScope::class)
interface IntProvider {
    val foo: Int

    @Provides
    fun provideInt(): Int = 1
}

I expect Metro to fail at compile-time, because the two properties clash. Instead, Metro compiles successfully and the code eventually crashes at runtime when recovering the contributed type:

Exception in thread "main" java.lang.ClassCastException: class java.lang.Integer cannot be cast to class java.lang.String (java.lang.Integer and java.lang.String are in module java.base of loader 'bootstrap')
	at metro.reproducer.AppGraph$$$ContributedChildGraph.getFoo(AppGraph.kt)
	at metro.reproducer.AppGraphKt.main(AppGraph.kt:45)
	at metro.reproducer.AppGraphKt.main(AppGraph.kt)

Self-contained Reproducer

Complete reproducer: metro-reproducer-clashing-properties.zip

Metro version

0.5.5

Context

For "normal" dependency graphs (using @DependencyGraph), this fails at compile-time as expected:

'val foo: Int' defined in 'metro/reproducer/IntProvider' clashes with 'val foo: String' defined in 'metro/reproducer/StringProvider': property types are incompatible.

I think I remember Dagger/Anvil failing at compile-time as well in such scenarios (although I did not verify this right now).