[FIR] KT-55552: Report type mismatch for delegated properties

^KT-55552 Fixed

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/CommonDeclarationCheckers.kt

@@ -120,6 +120,7 @@ object CommonDeclarationCheckers : DeclarationCheckers() {
             FirValueClassDeclarationChecker,
             FirOuterClassArgumentsRequiredChecker,
             FirPropertyInitializationChecker,
+            FirDelegateFieldTypeMismatchChecker,
         )
 
     override val constructorCheckers: Set<FirConstructorChecker>

compiler/fir/checkers/src/org/jetbrains/kotlin/fir/analysis/checkers/declaration/FirDelegateFieldTypeMismatchChecker.kt

@@ -0,0 +1,45 @@
+/*
+ * Copyright 2010-2023 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.analysis.checkers.declaration
+
+import org.jetbrains.kotlin.fir.analysis.checkers.context.CheckerContext
+import org.jetbrains.kotlin.diagnostics.DiagnosticReporter
+import org.jetbrains.kotlin.fir.analysis.diagnostics.FirErrors
+import org.jetbrains.kotlin.diagnostics.reportOn
+import org.jetbrains.kotlin.fir.declarations.FirRegularClass
+import org.jetbrains.kotlin.fir.declarations.delegateFieldsMap
+import org.jetbrains.kotlin.fir.expressions.FirCall
+import org.jetbrains.kotlin.fir.expressions.calleeReference
+import org.jetbrains.kotlin.fir.references.isError
+import org.jetbrains.kotlin.fir.symbols.SymbolInternals
+import org.jetbrains.kotlin.fir.types.coneType
+import org.jetbrains.kotlin.fir.types.isSubtypeOf
+
+object FirDelegateFieldTypeMismatchChecker : FirRegularClassChecker() {
+    @SymbolInternals
+    override fun check(declaration: FirRegularClass, context: CheckerContext, reporter: DiagnosticReporter) {
+        for (it in declaration.superTypeRefs.indices) {
+            val supertype = declaration.superTypeRefs[it]
+            val field = declaration.delegateFieldsMap?.get(it)?.fir ?: continue
+            val initializer = field.initializer ?: continue
+            val isReportedByErrorNodeDiagnosticCollector = initializer is FirCall && initializer.calleeReference?.isError() == true
+
+            if (
+                !isReportedByErrorNodeDiagnosticCollector &&
+                !initializer.typeRef.coneType.isSubtypeOf(supertype.coneType, context.session, true)
+            ) {
+                reporter.reportOn(
+                    initializer.source,
+                    FirErrors.TYPE_MISMATCH,
+                    field.returnTypeRef.coneType,
+                    initializer.typeRef.coneType,
+                    false,
+                    context,
+                )
+            }
+        }
+    }
+}

compiler/testData/diagnostics/tests/delegationTypeMismatch.fir.kt

@@ -1,13 +0,0 @@
-// ISSUE: KT-55552
-
-interface B2 {
-  fun d()
-}
-
-class B
-
-open class C(b: B) : B2 by b {} //no error in K2, K1 - [TYPE_MISMATCH] Type mismatch: inferred type is B but B2 was expected
-
-fun main() {
-  val c = C(B()).d() //runtime AbstractMethodError
-}

compiler/testData/diagnostics/tests/delegationTypeMismatch.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // ISSUE: KT-55552
 
 interface B2 {

compiler/testData/diagnostics/tests/platformTypes/nullabilityWarnings/delegation.fir.kt

@@ -1,18 +0,0 @@
-// FILE: J.java
-
-import org.jetbrains.annotations.*;
-import java.util.*;
-
-public class J {
-    @NotNull
-    public static List<String> staticNN;
-    @Nullable
-    public static List<String> staticN;
-    public static List<String> staticJ;
-}
-
-// FILE: k.kt
-
-class A : List<String> by J.staticNN
-class B : List<String> by J.staticN
-class C : List<String> by J.staticJ

compiler/testData/diagnostics/tests/platformTypes/nullabilityWarnings/delegation.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 // FILE: J.java
 
 import org.jetbrains.annotations.*;

compiler/tests-spec/testData/diagnostics/notLinked/dfa/neg/30.fir.kt

@@ -25,7 +25,7 @@ class Case4(val y: Any?): ClassWithCostructorParam(y!!) {
 }
 
 // TESTCASE NUMBER: 5
-class Case5(val y: Any?): ClassWithCostructorParam(y as Interface1), Interface1 by y {}
+class Case5(val y: Any?): ClassWithCostructorParam(y as Interface1), Interface1 by <!TYPE_MISMATCH!>y<!> {}
 
 // TESTCASE NUMBER: 6
 fun case_6(a: Int?) = object : ClassWithCostructorParam(a!!) {