fix KSPropertyDeclarationParameterImpl for override checking when there is no overridden symbols

Author: neetopia

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/processor/OverrideeProcessor.kt

@@ -31,6 +31,7 @@ class OverrideeProcessor: AbstractTestProcessor() {
     override fun toResult() = results
 
     override fun process(resolver: Resolver) {
+        logSubject(resolver, "NoOverride")
         logSubject(resolver, "Subject")
         logSubject(resolver, "JavaSubject.Subject")
         logSubject(resolver, "lib.Subject")

compiler-plugin/src/main/kotlin/com/google/devtools/ksp/symbol/impl/kotlin/KSPropertyDeclarationParameterImpl.kt

@@ -78,7 +78,7 @@ class KSPropertyDeclarationParameterImpl private constructor(val ktParameter: Kt
     override fun isDelegated(): Boolean = false
 
     override fun findOverridee(): KSPropertyDeclaration? {
-        return ResolverImpl.instance.resolvePropertyDeclaration(this)?.original?.overriddenDescriptors?.single { it.overriddenDescriptors.isEmpty() }
+        return ResolverImpl.instance.resolvePropertyDeclaration(this)?.original?.overriddenDescriptors?.singleOrNull { it.overriddenDescriptors.isEmpty() }
             ?.toKSPropertyDeclaration()
     }
 

compiler-plugin/testData/api/overridee.kt

@@ -18,6 +18,10 @@
 // WITH_RUNTIME
 // TEST PROCESSOR: OverrideeProcessor
 // EXPECTED:
+// NoOverride:
+// NoOverride.prop -> null
+// NoOverride.propInParam -> null
+// NoOverride.func(param:Int) -> null
 // Subject:
 // Companion.companionMethod() -> null
 // Subject.notOverridingProp -> null
@@ -127,6 +131,13 @@ abstract class Subject: Base<String>() {
 }
 // MODULE: main(lib)
 // FILE: a.kt
+class NoOverride(val propInParam: Int) {
+    val prop: Int
+    fun func(val param: Int) {
+
+    }
+}
+
 abstract class GrandBase {
     open var openGrandBaseProp: Int = 0
     abstract var abstractGrandBaseProp: Int = 0