Fix assignable check for function types with deserialized descriptors.

E.g. a `kotlin.Function0` type is a Kotlin "fictional" type;
the real JVM type it is backed by for JVM is `kotlin.jvm.functions.Function0`.
Inside the compiler the backing type is always converted into Kotlin's one.

Yet for KSP the `kotlin.jvm.functions.Function0` with its deserialized descriptor
 can be obtained directly (e.g. via `getJavaClassByName`) and used along with
 the `kotlin.Function0` type.

This CL fixes the assignability check between such types.

1 files changed, 6 insertions, 0 deletions

diff --git a/test-utils/src/main/kotlin/com/google/devtools/ksp/processor/JavaSubtypeProcessor.kt b/test-utils/src/main/kotlin/com/google/devtools/ksp/processor/JavaSubtypeProcessor.kt
index 6f220897..f04b2b5e 100644
--- a/test-utils/src/main/kotlin/com/google/devtools/ksp/processor/JavaSubtypeProcessor.kt
+++ b/test-utils/src/main/kotlin/com/google/devtools/ksp/processor/JavaSubtypeProcessor.kt
@@ -18,8 +18,10 @@ class JavaSubtypeProcessor : AbstractTestProcessor() {
     override fun process(resolver: Resolver): List<KSAnnotated> {
         val javaCollection = resolver.getJavaClassByName("kotlin.collections.Collection")!!.asStarProjectedType()
         val javaSet = resolver.getJavaClassByName("kotlin.collections.Set")!!.asStarProjectedType()
+        val ktFunctionJava = resolver.getJavaClassByName("kotlin.jvm.functions.Function0")!!.asStarProjectedType()
         val ktCollection = resolver.getClassDeclarationByName("kotlin.collections.Collection")!!.asStarProjectedType()
         val ktSet = resolver.getClassDeclarationByName("kotlin.collections.Set")!!.asStarProjectedType()
+        val ktFunction = resolver.getClassDeclarationByName("kotlin.jvm.functions.Function0")!!.asStarProjectedType()
         val javaCollectionRef = resolver.createKSTypeReferenceFromKSType(javaCollection)
         val ktCollectionRef = resolver.createKSTypeReferenceFromKSType(ktCollection)
         val javaSetRef = resolver.createKSTypeReferenceFromKSType(javaSet)
@@ -47,6 +49,7 @@ class JavaSubtypeProcessor : AbstractTestProcessor() {
         )
         val javaStrCollection = javaCollection.replace(listOf(strRef))
         val javaStrSet = javaSet.replace(listOf(strRef))
+        val kotlinFunctionImplementorJava = resolver.getClassDeclarationByName("IntSupplier")!!.asStarProjectedType()
         isOk = isOk && javaCollection.isAssignableFrom(javaSet)
         isOk = isOk && javaCollection.isAssignableFrom(javaStrCollection)
         isOk = isOk && !javaStrCollection.isAssignableFrom(javaCollection)
@@ -67,6 +70,9 @@ class JavaSubtypeProcessor : AbstractTestProcessor() {
         isOk = isOk && javaCollectionOfKtSet.isAssignableFrom(ktCollectionOfJavaSet)
         isOk = isOk && ktCollectionOfJavaCollection.isAssignableFrom(javaSetOfKtCollection)
         isOk = isOk && !javaSetOfKtCollection.isAssignableFrom(ktCollectionOfJavaCollection)
+        isOk = isOk && ktFunction.isAssignableFrom(kotlinFunctionImplementorJava)
+        isOk = isOk && ktFunctionJava.isAssignableFrom(ktFunction) && ktFunction.isAssignableFrom(ktFunctionJava)
+        isOk = isOk && ktFunctionJava.isAssignableFrom(kotlinFunctionImplementorJava)
         return emptyList()
     }
 }