[FIR2IR] Properly calculate the type of delegated function call

```
interface A {
    fun <T> foo(): T
}

class B(val a: A) : A by A {
    generated fun <T'> foo(): T' {
        return a.foo() // <------
    }
}
```

There was a problem that type of generated delegated call used
  an unsubstituted type of the original delegated declaration, which led
  to a situation when (see example) type of call `a.foo()` was not `T'`
  but `T`, which led to incorrect IR and further exceptions on backend

^KT-64257 Fixed
^KT-64284 Obsolete

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirBlackBoxCodegenBasedTestGenerated.java

@@ -16784,6 +16784,12 @@ public class LLFirBlackBoxCodegenBasedTestGenerated extends AbstractLLFirBlackBo
             runTest("compiler/testData/codegen/box/delegation/doubleDelegationEqualsHashcode.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

analysis/low-level-api-fir/tests/org/jetbrains/kotlin/analysis/low/level/api/fir/diagnostic/compiler/based/LLFirReversedBlackBoxCodegenBasedTestGenerated.java

@@ -16784,6 +16784,12 @@ public class LLFirReversedBlackBoxCodegenBasedTestGenerated extends AbstractLLFi
             runTest("compiler/testData/codegen/box/delegation/doubleDelegationEqualsHashcode.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/DelegatedMemberGenerator.kt

@@ -11,9 +11,11 @@ import org.jetbrains.kotlin.fir.backend.*
 import org.jetbrains.kotlin.fir.declarations.*
 import org.jetbrains.kotlin.fir.declarations.utils.modality
 import org.jetbrains.kotlin.fir.lazy.Fir2IrLazyClass
+import org.jetbrains.kotlin.fir.resolve.defaultType
 import org.jetbrains.kotlin.fir.resolve.dfa.cfg.isLocalClassOrAnonymousObject
 import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
 import org.jetbrains.kotlin.fir.resolve.scope
+import org.jetbrains.kotlin.fir.resolve.substitution.substitutorByMap
 import org.jetbrains.kotlin.fir.scopes.*
 import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
@@ -51,8 +53,9 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
     private val basePropertySymbols: MutableMap<IrProperty, Collection<FirPropertySymbol>> = mutableMapOf()
 
     private data class DeclarationBodyInfo(
-        val declaration: IrDeclaration,
-        val field: IrField,
+        val delegatedFirDeclaration: FirCallableDeclaration,
+        val delegatedIrDeclaration: IrDeclaration,
+        val irField: IrField,
         val delegateToSymbol: FirCallableSymbol<*>,
         val delegateToLookupTag: ConeClassLikeLookupTag?
     )
@@ -60,36 +63,36 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
     private val bodiesInfo = mutableListOf<DeclarationBodyInfo>()
 
     fun generateBodies() {
-        for ((declaration, irField, delegateToFirSymbol, delegateToLookupTag) in bodiesInfo) {
-            val delegatedDeclarationType = delegateToFirSymbol.fir.returnTypeRef.coneType.fullyExpandedType(session)
-            val callTypeCanBeNullable = Fir2IrImplicitCastInserter.typeCanBeEnhancedOrFlexibleNullable(delegatedDeclarationType)
-            when (declaration) {
+        for ((delegatedFirDeclaration, delegatedIrDeclaration, irField, delegateToFirSymbol, delegateToLookupTag) in bodiesInfo) {
+            when (delegatedIrDeclaration) {
                 is IrSimpleFunction -> {
                     val delegateToIrFunctionSymbol = declarationStorage.getIrFunctionSymbol(
-                        delegateToFirSymbol as FirNamedFunctionSymbol, delegateToLookupTag
+                        delegateToFirSymbol.unwrapCallRepresentative(delegateToLookupTag) as FirNamedFunctionSymbol,
+                        delegateToLookupTag
                     ) as? IrSimpleFunctionSymbol ?: continue
                     val body = createDelegateBody(
-                        irField, declaration, delegateToFirSymbol.fir, delegateToIrFunctionSymbol,
-                        callTypeCanBeNullable, isSetter = false
+                        irField, delegatedFirDeclaration, delegatedIrDeclaration, delegateToFirSymbol.fir, delegateToIrFunctionSymbol,
+                        isSetter = false
                     )
-                    declaration.body = body
+                    delegatedIrDeclaration.body = body
                 }
                 is IrProperty -> {
                     val delegateToIrPropertySymbol = declarationStorage.getIrPropertySymbol(
-                        delegateToFirSymbol as FirPropertySymbol, delegateToLookupTag
+                        delegateToFirSymbol.unwrapCallRepresentative(delegateToLookupTag) as FirPropertySymbol,
+                        delegateToLookupTag
                     ) as? IrPropertySymbol ?: continue
                     val delegateToGetterSymbol = declarationStorage.findGetterOfProperty(delegateToIrPropertySymbol)!!
-                    val getter = declaration.getter!!
+                    val getter = delegatedIrDeclaration.getter!!
                     getter.body = createDelegateBody(
-                        irField, getter, delegateToFirSymbol.fir, delegateToGetterSymbol,
-                        callTypeCanBeNullable, isSetter = false
+                        irField, delegatedFirDeclaration, getter, delegateToFirSymbol.fir, delegateToGetterSymbol,
+                        isSetter = false
                     )
-                    if (declaration.isVar) {
+                    if (delegatedIrDeclaration.isVar) {
                         val delegateToSetterSymbol = declarationStorage.findSetterOfProperty(delegateToIrPropertySymbol)!!
-                        val setter = declaration.setter!!
+                        val setter = delegatedIrDeclaration.setter!!
                         setter.body = createDelegateBody(
-                            irField, setter, delegateToFirSymbol.fir, delegateToSetterSymbol,
-                            callTypeCanBeNullable = false, isSetter = true
+                            irField, delegatedFirDeclaration, setter, delegateToFirSymbol.fir, delegateToSetterSymbol,
+                            isSetter = true
                         )
                     }
                 }
@@ -130,20 +133,16 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
             val delegateToLookupTag = delegateToSymbol.dispatchReceiverClassLookupTagOrNull()
                 ?: return@processAllFunctions
 
-            val irSubFunction = generateDelegatedFunction(
-                subClass, firSubClass, functionSymbol.fir
-            )
-
-            bodiesInfo += DeclarationBodyInfo(irSubFunction, irField, delegateToSymbol, delegateToLookupTag)
-            declarationStorage.cacheDelegationFunction(functionSymbol.fir, irSubFunction)
+            val delegatedFunction = functionSymbol.fir
+            val irSubFunction = generateDelegatedFunction(subClass, firSubClass, delegatedFunction)
+            bodiesInfo += DeclarationBodyInfo(delegatedFunction, irSubFunction, irField, delegateToSymbol, delegateToLookupTag)
+            declarationStorage.cacheDelegationFunction(delegatedFunction, irSubFunction)
         }
 
         subClassScope.processAllProperties { propertySymbol ->
             if (propertySymbol !is FirPropertySymbol) return@processAllProperties
 
-            val unwrapped =
-                propertySymbol.unwrapDelegateTarget(subClassLookupTag, firField)
-                    ?: return@processAllProperties
+            val unwrapped = propertySymbol.unwrapDelegateTarget(subClassLookupTag, firField) ?: return@processAllProperties
 
             val delegateToSymbol = findDelegateToSymbol(
                 unwrapped.symbol,
@@ -156,14 +155,11 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
                 delegateToScope::processOverriddenProperties
             ) ?: return@processAllProperties
 
-            val delegateToLookupTag = delegateToSymbol.dispatchReceiverClassLookupTagOrNull()
-                ?: return@processAllProperties
-
-            val irSubProperty = generateDelegatedProperty(
-                subClass, firSubClass, propertySymbol.fir
-            )
-            bodiesInfo += DeclarationBodyInfo(irSubProperty, irField, delegateToSymbol, delegateToLookupTag)
-            declarationStorage.cacheDelegatedProperty(propertySymbol.fir, irSubProperty)
+            val delegateToLookupTag = delegateToSymbol.dispatchReceiverClassLookupTagOrNull() ?: return@processAllProperties
+            val delegatedProperty = propertySymbol.fir
+            val irSubProperty = generateDelegatedProperty(subClass, firSubClass, delegatedProperty)
+            bodiesInfo += DeclarationBodyInfo(delegatedProperty, irSubProperty, irField, delegateToSymbol, delegateToLookupTag)
+            declarationStorage.cacheDelegatedProperty(delegatedProperty, irSubProperty)
         }
     }
 
@@ -174,19 +170,24 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
     ): S? {
         val unwrappedSymbol = symbol.unwrapUseSiteSubstitutionOverrides()
         var result: S? = null
-        // The purpose of this code is to find member in delegate-to scope
-        // which matches or overrides unwrappedSymbol (which is in turn taken from subclass scope).
+        /*
+         * The purpose of this code is to find member in delegate-to scope
+         * which matches or overrides unwrappedSymbol (which is in turn taken from subclass scope).
+         *
+         * Note that it's important to not unwrap call-site substitution override of the found function, because
+         *   later it will be used to compute the proper substituted type for call of this function
+         */
         processCallables(unwrappedSymbol.name) { candidateSymbol ->
             if (result != null) return@processCallables
             val unwrappedCandidateSymbol = candidateSymbol.unwrapUseSiteSubstitutionOverrides()
             if (unwrappedCandidateSymbol === unwrappedSymbol) {
-                result = unwrappedCandidateSymbol
+                result = candidateSymbol
                 return@processCallables
             }
             processOverridden(candidateSymbol) { overriddenSymbol ->
                 val unwrappedOverriddenSymbol = overriddenSymbol.unwrapUseSiteSubstitutionOverrides()
                 if (unwrappedOverriddenSymbol === unwrappedSymbol) {
-                    result = unwrappedCandidateSymbol
+                    result = candidateSymbol
                     ProcessorAction.STOP
                 } else {
                     ProcessorAction.NEXT
@@ -277,23 +278,38 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
      */
     private fun createDelegateBody(
         irField: IrField,
-        delegateFunction: IrSimpleFunction,
+        delegatedFirDeclaration: FirCallableDeclaration,
+        delegatedIrFunction: IrSimpleFunction,
         originalFirDeclaration: FirCallableDeclaration,
         originalFunctionSymbol: IrSimpleFunctionSymbol,
-        callTypeCanBeNullable: Boolean,
         isSetter: Boolean
     ): IrBlockBody {
         val startOffset = SYNTHETIC_OFFSET
         val endOffset = SYNTHETIC_OFFSET
         val body = irFactory.createBlockBody(startOffset, endOffset)
+
         val typeOrigin = when {
             originalFirDeclaration is FirPropertyAccessor && originalFirDeclaration.isSetter -> ConversionTypeOrigin.SETTER
             else -> ConversionTypeOrigin.DEFAULT
         }
 
+        val callTypeCanBeNullable: Boolean
         val callReturnType = when (isSetter) {
-            false -> originalFirDeclaration.returnTypeRef.toIrType(typeOrigin)
-            true -> irBuiltIns.unitType
+            false -> {
+                val substitution = originalFirDeclaration.typeParameters.zip(delegatedFirDeclaration.typeParameters)
+                    .map { (original, delegated) ->
+                        original.symbol to delegated.symbol.defaultType
+                    }.toMap()
+
+                val substitutor = substitutorByMap(substitution, session)
+                val substitutedType = substitutor.substituteOrSelf(originalFirDeclaration.returnTypeRef.coneType)
+                callTypeCanBeNullable = Fir2IrImplicitCastInserter.typeCanBeEnhancedOrFlexibleNullable(substitutedType)
+                substitutedType.toIrType(typeOrigin)
+            }
+            true -> {
+                callTypeCanBeNullable = false
+                irBuiltIns.unitType
+            }
         }
 
         val irCall = IrCallImpl(
@@ -310,8 +326,8 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
                 irField.type,
                 IrGetValueImpl(
                     startOffset, endOffset,
-                    delegateFunction.dispatchReceiverParameter?.type!!,
-                    delegateFunction.dispatchReceiverParameter?.symbol!!
+                    delegatedIrFunction.dispatchReceiverParameter?.type!!,
+                    delegatedIrFunction.dispatchReceiverParameter?.symbol!!
                 )
             )
 
@@ -327,16 +343,16 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
             }
 
             extensionReceiver =
-                delegateFunction.extensionReceiverParameter?.let { extensionReceiver ->
+                delegatedIrFunction.extensionReceiverParameter?.let { extensionReceiver ->
                     IrGetValueImpl(startOffset, endOffset, extensionReceiver.type, extensionReceiver.symbol)
                 }
-            delegateFunction.valueParameters.forEach {
+            delegatedIrFunction.valueParameters.forEach {
                 putValueArgument(it.index, IrGetValueImpl(startOffset, endOffset, it.type, it.symbol))
             }
             for (index in originalFirDeclaration.typeParameters.indices) {
                 putTypeArgument(
                     index, IrSimpleTypeImpl(
-                        delegateFunction.typeParameters[index].symbol,
+                        delegatedIrFunction.typeParameters[index].symbol,
                         hasQuestionMark = false,
                         arguments = emptyList(),
                         annotations = emptyList()
@@ -344,7 +360,7 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
                 )
             }
         }
-        val resultType = delegateFunction.returnType
+        val resultType = delegatedIrFunction.returnType
 
         val irCastOrCall =
             if (callTypeCanBeNullable && !resultType.isNullable()) Fir2IrImplicitCastInserter.implicitNotNullCast(irCall)
@@ -353,7 +369,7 @@ class DelegatedMemberGenerator(private val components: Fir2IrComponents) : Fir2I
         if (isSetter || originalDeclarationReturnType.isUnit || originalDeclarationReturnType.isNothing) {
             body.statements.add(irCastOrCall)
         } else {
-            val irReturn = IrReturnImpl(startOffset, endOffset, irBuiltIns.nothingType, delegateFunction.symbol, irCastOrCall)
+            val irReturn = IrReturnImpl(startOffset, endOffset, irBuiltIns.nothingType, delegatedIrFunction.symbol, irCastOrCall)
             body.statements.add(irReturn)
         }
         return body

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenTestGenerated.java

@@ -16725,6 +16725,12 @@ public class FirLightTreeBlackBoxCodegenTestGenerated extends AbstractFirLightTr
             runTest("compiler/testData/codegen/box/delegation/doubleDelegationEqualsHashcode.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated.java

@@ -16725,6 +16725,12 @@ public class FirLightTreeBlackBoxCodegenWithIrFakeOverrideGeneratorTestGenerated
             runTest("compiler/testData/codegen/box/delegation/doubleDelegationEqualsHashcode.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirPsiBlackBoxCodegenTestGenerated.java

@@ -16725,6 +16725,12 @@ public class FirPsiBlackBoxCodegenTestGenerated extends AbstractFirPsiBlackBoxCo
             runTest("compiler/testData/codegen/box/delegation/doubleDelegationEqualsHashcode.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

compiler/testData/codegen/box/delegation/delegationToIntersectionType2.kt

@@ -23,4 +23,4 @@ fun test(c: C, d: D): String {
     return object: A by intersection {}.foo().toString()
 }
 
-fun box() = test(C(), D())
+fun box() = test(C(), D())

compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt

@@ -0,0 +1,15 @@
+// ISSUE: KT-64257
+
+interface Base {
+    fun <R> fold(initial: R, operation: (R, String) -> R): R = operation(initial, "K")
+}
+
+interface Derived<T> : Base
+
+class Impl<T> : Derived<T>
+
+fun box(): String {
+    val impl = Impl<String>()
+    val delegated = object : Derived<String> by impl {}
+    return delegated.fold("O") { a, b -> a + b }
+}

compiler/testData/codegen/box/functions/delegatedPropertyWithMultipleOverriddens_generics.fir.ir.txt

@@ -207,7 +207,7 @@ FILE fqName:<root> fileName:/delegatedPropertyWithMultipleOverriddens_generics.k
       $this: VALUE_PARAMETER name:<this> type:<root>.MC
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='public open fun foo (): kotlin.String declared in <root>.MC'
-          CALL 'public open fun foo (): E6 of <root>.MyArrayList declared in <root>.MyArrayList' type=E6 of <root>.MyArrayList origin=null
+          CALL 'public open fun foo (): E6 of <root>.MyArrayList declared in <root>.MyArrayList' type=kotlin.String origin=null
             $this: GET_FIELD 'FIELD DELEGATE name:$$delegate_0 type:<root>.MyArrayList<kotlin.String> visibility:private [final]' type=<root>.MyArrayList<kotlin.String> origin=null
               receiver: GET_VAR '<this>: <root>.MC declared in <root>.MC.foo' type=<root>.MC origin=null
     PROPERTY DELEGATED_MEMBER name:bar visibility:public modality:OPEN [val]
@@ -220,7 +220,7 @@ FILE fqName:<root> fileName:/delegatedPropertyWithMultipleOverriddens_generics.k
         $this: VALUE_PARAMETER name:<this> type:<root>.MC
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-bar> (): kotlin.String declared in <root>.MC'
-            CALL 'public open fun <get-bar> (): E6 of <root>.MyArrayList declared in <root>.MyArrayList' type=E6 of <root>.MyArrayList origin=null
+            CALL 'public open fun <get-bar> (): E6 of <root>.MyArrayList declared in <root>.MyArrayList' type=kotlin.String origin=null
               $this: GET_FIELD 'FIELD DELEGATE name:$$delegate_0 type:<root>.MyArrayList<kotlin.String> visibility:private [final]' type=<root>.MyArrayList<kotlin.String> origin=null
                 receiver: GET_VAR '<this>: <root>.MC declared in <root>.MC.<get-bar>' type=<root>.MC origin=null
     FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]

compiler/testData/ir/irText/classes/delegatedGenericImplementation.fir.ir.txt

@@ -75,7 +75,7 @@ FILE fqName:<root> fileName:/delegatedGenericImplementation.kt
         $receiver: VALUE_PARAMETER name:<this> type:C of <root>.Test1.<get-id>
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-id> <C> (): kotlin.collections.Map<E of <root>.Test1, C of <root>.Test1.<get-id>>? declared in <root>.Test1'
-            CALL 'public abstract fun <get-id> <C> (): kotlin.collections.Map<A of <root>.IBase, C of <root>.IBase.<get-id>>? declared in <root>.IBase' type=kotlin.collections.Map<A of <root>.IBase, C of <root>.IBase.<get-id>>? origin=null
+            CALL 'public abstract fun <get-id> <C> (): kotlin.collections.Map<A of <root>.IBase, C of <root>.IBase.<get-id>>? declared in <root>.IBase' type=kotlin.collections.Map<E of <root>.Test1, C of <root>.Test1.<get-id>>? origin=null
               <C>: C of <root>.Test1.<get-id>
               $this: GET_FIELD 'FIELD DELEGATE name:$$delegate_0 type:<root>.IBase<E of <root>.Test1> visibility:private [final]' type=<root>.IBase<E of <root>.Test1> origin=null
                 receiver: GET_VAR '<this>: <root>.Test1<E of <root>.Test1> declared in <root>.Test1.<get-id>' type=<root>.Test1<E of <root>.Test1> origin=null
@@ -92,7 +92,7 @@ FILE fqName:<root> fileName:/delegatedGenericImplementation.kt
         $receiver: VALUE_PARAMETER name:<this> type:kotlin.collections.List<D of <root>.Test1.<get-x>>
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-x> <D> (): D of <root>.Test1.<get-x>? declared in <root>.Test1'
-            CALL 'public abstract fun <get-x> <D> (): D of <root>.IBase.<get-x>? declared in <root>.IBase' type=D of <root>.IBase.<get-x>? origin=null
+            CALL 'public abstract fun <get-x> <D> (): D of <root>.IBase.<get-x>? declared in <root>.IBase' type=D of <root>.Test1.<get-x>? origin=null
               <D>: D of <root>.Test1.<get-x>
               $this: GET_FIELD 'FIELD DELEGATE name:$$delegate_0 type:<root>.IBase<E of <root>.Test1> visibility:private [final]' type=<root>.IBase<E of <root>.Test1> origin=null
                 receiver: GET_VAR '<this>: <root>.Test1<E of <root>.Test1> declared in <root>.Test1.<get-x>' type=<root>.Test1<E of <root>.Test1> origin=null
@@ -177,7 +177,7 @@ FILE fqName:<root> fileName:/delegatedGenericImplementation.kt
         $receiver: VALUE_PARAMETER name:<this> type:C of <root>.Test2.<get-id>
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-id> <C> (): kotlin.collections.Map<kotlin.String, C of <root>.Test2.<get-id>>? declared in <root>.Test2'
-            CALL 'public abstract fun <get-id> <C> (): kotlin.collections.Map<A of <root>.IBase, C of <root>.IBase.<get-id>>? declared in <root>.IBase' type=kotlin.collections.Map<A of <root>.IBase, C of <root>.IBase.<get-id>>? origin=null
+            CALL 'public abstract fun <get-id> <C> (): kotlin.collections.Map<A of <root>.IBase, C of <root>.IBase.<get-id>>? declared in <root>.IBase' type=kotlin.collections.Map<kotlin.String, C of <root>.Test2.<get-id>>? origin=null
               <C>: C of <root>.Test2.<get-id>
               $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:j type:<root>.IBase<kotlin.String> visibility:private' type=<root>.IBase<kotlin.String> origin=null
                 receiver: GET_VAR '<this>: <root>.Test2 declared in <root>.Test2.<get-id>' type=<root>.Test2 origin=null
@@ -194,7 +194,7 @@ FILE fqName:<root> fileName:/delegatedGenericImplementation.kt
         $receiver: VALUE_PARAMETER name:<this> type:kotlin.collections.List<D of <root>.Test2.<get-x>>
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-x> <D> (): D of <root>.Test2.<get-x>? declared in <root>.Test2'
-            CALL 'public abstract fun <get-x> <D> (): D of <root>.IBase.<get-x>? declared in <root>.IBase' type=D of <root>.IBase.<get-x>? origin=null
+            CALL 'public abstract fun <get-x> <D> (): D of <root>.IBase.<get-x>? declared in <root>.IBase' type=D of <root>.Test2.<get-x>? origin=null
               <D>: D of <root>.Test2.<get-x>
               $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:j type:<root>.IBase<kotlin.String> visibility:private' type=<root>.IBase<kotlin.String> origin=null
                 receiver: GET_VAR '<this>: <root>.Test2 declared in <root>.Test2.<get-x>' type=<root>.Test2 origin=null

compiler/testData/ir/irText/declarations/kt35550.fir.ir.txt

@@ -1,65 +0,0 @@
-FILE fqName:<root> fileName:/kt35550.kt
-  CLASS INTERFACE name:I modality:ABSTRACT visibility:public superTypes:[kotlin.Any]
-    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.I
-    PROPERTY name:id visibility:public modality:OPEN [val]
-      FUN name:<get-id> visibility:public modality:OPEN <T> ($this:<root>.I, $receiver:T of <root>.I.<get-id>) returnType:T of <root>.I.<get-id>
-        correspondingProperty: PROPERTY name:id visibility:public modality:OPEN [val]
-        TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?] reified:false
-        $this: VALUE_PARAMETER name:<this> type:<root>.I
-        $receiver: VALUE_PARAMETER name:<this> type:T of <root>.I.<get-id>
-        BLOCK_BODY
-          RETURN type=kotlin.Nothing from='public open fun <get-id> <T> (): T of <root>.I.<get-id> declared in <root>.I'
-            GET_VAR '<this>: T of <root>.I.<get-id> declared in <root>.I.<get-id>' type=T of <root>.I.<get-id> origin=null
-    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
-      overridden:
-        public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in kotlin.Any
-      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
-      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
-    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
-      overridden:
-        public open fun hashCode (): kotlin.Int declared in kotlin.Any
-      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
-    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
-      overridden:
-        public open fun toString (): kotlin.String declared in kotlin.Any
-      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
-  CLASS CLASS name:A modality:FINAL visibility:public superTypes:[<root>.I]
-    $this: VALUE_PARAMETER INSTANCE_RECEIVER name:<this> type:<root>.A
-    CONSTRUCTOR visibility:public <> (i:<root>.I) returnType:<root>.A [primary]
-      VALUE_PARAMETER name:i index:0 type:<root>.I
-      BLOCK_BODY
-        DELEGATING_CONSTRUCTOR_CALL 'public constructor <init> () declared in kotlin.Any'
-        INSTANCE_INITIALIZER_CALL classDescriptor='CLASS CLASS name:A modality:FINAL visibility:public superTypes:[<root>.I]'
-    FIELD DELEGATE name:$$delegate_0 type:<root>.I visibility:private [final]
-      EXPRESSION_BODY
-        GET_VAR 'i: <root>.I declared in <root>.A.<init>' type=<root>.I origin=null
-    PROPERTY DELEGATED_MEMBER name:id visibility:public modality:OPEN [val]
-      overridden:
-        public open id: T of <root>.I.<get-id>
-      FUN DELEGATED_MEMBER name:<get-id> visibility:public modality:OPEN <T> ($this:<root>.A, $receiver:T of <root>.A.<get-id>) returnType:T of <root>.A.<get-id>
-        correspondingProperty: PROPERTY DELEGATED_MEMBER name:id visibility:public modality:OPEN [val]
-        overridden:
-          public open fun <get-id> <T> (): T of <root>.I.<get-id> declared in <root>.I
-        TYPE_PARAMETER name:T index:0 variance: superTypes:[kotlin.Any?] reified:false
-        $this: VALUE_PARAMETER name:<this> type:<root>.A
-        $receiver: VALUE_PARAMETER name:<this> type:T of <root>.A.<get-id>
-        BLOCK_BODY
-          RETURN type=kotlin.Nothing from='public open fun <get-id> <T> (): T of <root>.A.<get-id> declared in <root>.A'
-            CALL 'public open fun <get-id> <T> (): T of <root>.I.<get-id> declared in <root>.I' type=T of <root>.I.<get-id> origin=null
-              <T>: T of <root>.A.<get-id>
-              $this: GET_FIELD 'FIELD DELEGATE name:$$delegate_0 type:<root>.I visibility:private [final]' type=<root>.I origin=null
-                receiver: GET_VAR '<this>: <root>.A declared in <root>.A.<get-id>' type=<root>.A origin=null
-              $receiver: GET_VAR '<this>: T of <root>.A.<get-id> declared in <root>.A.<get-id>' type=T of <root>.A.<get-id> origin=null
-    FUN FAKE_OVERRIDE name:equals visibility:public modality:OPEN <> ($this:kotlin.Any, other:kotlin.Any?) returnType:kotlin.Boolean [fake_override,operator]
-      overridden:
-        public open fun equals (other: kotlin.Any?): kotlin.Boolean declared in <root>.I
-      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
-      VALUE_PARAMETER name:other index:0 type:kotlin.Any?
-    FUN FAKE_OVERRIDE name:hashCode visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.Int [fake_override]
-      overridden:
-        public open fun hashCode (): kotlin.Int declared in <root>.I
-      $this: VALUE_PARAMETER name:<this> type:kotlin.Any
-    FUN FAKE_OVERRIDE name:toString visibility:public modality:OPEN <> ($this:kotlin.Any) returnType:kotlin.String [fake_override]
-      overridden:
-        public open fun toString (): kotlin.String declared in <root>.I
-      $this: VALUE_PARAMETER name:<this> type:kotlin.Any

compiler/testData/ir/irText/declarations/kt35550.fir.kt.txt

@@ -1,22 +0,0 @@
-interface I {
-  val <T : Any?> T.id: T
-    get(): T {
-      return <this>
-    }
-
-}
-
-class A : I {
-  constructor(i: I) /* primary */ {
-    super/*Any*/()
-    /* <init>() */
-
-  }
-
-  private /* final field */ val $$delegate_0: I = i
-  override val <T : Any?> T.id: T
-    override get(): T {
-      return (<this>.#$$delegate_0, <this>).<get-id><T>()
-    }
-
-}

compiler/testData/ir/irText/declarations/kt35550.kt

@@ -1,3 +1,4 @@
+// FIR_IDENTICAL
 interface I {
     val <T> T.id: T
         get() = this

compiler/testData/ir/irText/firProblems/kt43342.fir.ir.txt

@@ -48,7 +48,7 @@ FILE fqName:<root> fileName:/kt43342.kt
       VALUE_PARAMETER name:key index:0 type:K of <root>.ControlFlowInfo
       BLOCK_BODY
         RETURN type=kotlin.Nothing from='public open fun get (key: K of <root>.ControlFlowInfo): V of <root>.ControlFlowInfo? declared in <root>.ControlFlowInfo'
-          CALL 'public abstract fun get (key: K of kotlin.collections.Map): V of kotlin.collections.Map? declared in kotlin.collections.Map' type=V of kotlin.collections.Map? origin=null
+          CALL 'public abstract fun get (key: K of kotlin.collections.Map): V of kotlin.collections.Map? declared in kotlin.collections.Map' type=V of <root>.ControlFlowInfo? origin=null
             $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:map type:kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> visibility:private [final]' type=kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> origin=null
               receiver: GET_VAR '<this>: <root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> declared in <root>.ControlFlowInfo.get' type=<root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> origin=null
             key: GET_VAR 'key: K of <root>.ControlFlowInfo declared in <root>.ControlFlowInfo.get' type=K of <root>.ControlFlowInfo origin=null
@@ -71,7 +71,7 @@ FILE fqName:<root> fileName:/kt43342.kt
         $this: VALUE_PARAMETER name:<this> type:<root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo>
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-entries> (): kotlin.collections.Set<kotlin.collections.Map.Entry<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo>> declared in <root>.ControlFlowInfo'
-            CALL 'public abstract fun <get-entries> (): kotlin.collections.Set<kotlin.collections.Map.Entry<K of kotlin.collections.Map, V of kotlin.collections.Map>> declared in kotlin.collections.Map' type=kotlin.collections.Set<kotlin.collections.Map.Entry<K of kotlin.collections.Map, V of kotlin.collections.Map>> origin=null
+            CALL 'public abstract fun <get-entries> (): kotlin.collections.Set<kotlin.collections.Map.Entry<K of kotlin.collections.Map, V of kotlin.collections.Map>> declared in kotlin.collections.Map' type=kotlin.collections.Set<kotlin.collections.Map.Entry<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo>> origin=null
               $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:map type:kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> visibility:private [final]' type=kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> origin=null
                 receiver: GET_VAR '<this>: <root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> declared in <root>.ControlFlowInfo.<get-entries>' type=<root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> origin=null
     PROPERTY DELEGATED_MEMBER name:keys visibility:public modality:OPEN [val]
@@ -84,7 +84,7 @@ FILE fqName:<root> fileName:/kt43342.kt
         $this: VALUE_PARAMETER name:<this> type:<root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo>
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-keys> (): kotlin.collections.Set<K of <root>.ControlFlowInfo> declared in <root>.ControlFlowInfo'
-            CALL 'public abstract fun <get-keys> (): kotlin.collections.Set<K of kotlin.collections.Map> declared in kotlin.collections.Map' type=kotlin.collections.Set<K of kotlin.collections.Map> origin=null
+            CALL 'public abstract fun <get-keys> (): kotlin.collections.Set<K of kotlin.collections.Map> declared in kotlin.collections.Map' type=kotlin.collections.Set<K of <root>.ControlFlowInfo> origin=null
               $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:map type:kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> visibility:private [final]' type=kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> origin=null
                 receiver: GET_VAR '<this>: <root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> declared in <root>.ControlFlowInfo.<get-keys>' type=<root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> origin=null
     PROPERTY DELEGATED_MEMBER name:size visibility:public modality:OPEN [val]
@@ -110,7 +110,7 @@ FILE fqName:<root> fileName:/kt43342.kt
         $this: VALUE_PARAMETER name:<this> type:<root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo>
         BLOCK_BODY
           RETURN type=kotlin.Nothing from='public open fun <get-values> (): kotlin.collections.Collection<V of <root>.ControlFlowInfo> declared in <root>.ControlFlowInfo'
-            CALL 'public abstract fun <get-values> (): kotlin.collections.Collection<V of kotlin.collections.Map> declared in kotlin.collections.Map' type=kotlin.collections.Collection<V of kotlin.collections.Map> origin=null
+            CALL 'public abstract fun <get-values> (): kotlin.collections.Collection<V of kotlin.collections.Map> declared in kotlin.collections.Map' type=kotlin.collections.Collection<V of <root>.ControlFlowInfo> origin=null
               $this: GET_FIELD 'FIELD PROPERTY_BACKING_FIELD name:map type:kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> visibility:private [final]' type=kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> origin=null
                 receiver: GET_VAR '<this>: <root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> declared in <root>.ControlFlowInfo.<get-values>' type=<root>.ControlFlowInfo<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo> origin=null
     FUN FAKE_OVERRIDE name:getOrDefault visibility:public modality:OPEN <> ($this:kotlin.collections.Map<K of <root>.ControlFlowInfo, V of <root>.ControlFlowInfo>, key:K of <root>.ControlFlowInfo, defaultValue:V of <root>.ControlFlowInfo) returnType:V of <root>.ControlFlowInfo [fake_override]

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -16359,6 +16359,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/delegation/doubleDelegationEqualsHashcode.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -16725,6 +16725,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/delegation/doubleDelegationEqualsHashcode.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenWithIrInlinerTestGenerated.java

@@ -16725,6 +16725,12 @@ public class IrBlackBoxCodegenWithIrInlinerTestGenerated extends AbstractIrBlack
             runTest("compiler/testData/codegen/box/delegation/doubleDelegationEqualsHashcode.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

compiler/tests-gen/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -13794,6 +13794,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/delegation/differentModules.kt");
         }
 
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {
             runTest("compiler/testData/codegen/box/delegation/genericProperty.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsCodegenBoxTestGenerated.java

@@ -12681,6 +12681,12 @@ public class FirJsCodegenBoxTestGenerated extends AbstractFirJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/fir/FirJsES6CodegenBoxTestGenerated.java

@@ -12681,6 +12681,12 @@ public class FirJsES6CodegenBoxTestGenerated extends AbstractFirJsES6CodegenBoxT
             runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java

@@ -12681,6 +12681,12 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsES6CodegenBoxTestGenerated.java

@@ -12681,6 +12681,12 @@ public class IrJsES6CodegenBoxTestGenerated extends AbstractIrJsES6CodegenBoxTes
             runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestGenerated.java

@@ -13736,6 +13736,12 @@ public class FirNativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTe
                 runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
             }
 
+            @Test
+            @TestMetadata("genericFunctionInGenericInterface.kt")
+            public void testGenericFunctionInGenericInterface() throws Exception {
+                runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+            }
+
             @Test
             @TestMetadata("genericProperty.kt")
             public void testGenericProperty() throws Exception {

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/FirNativeCodegenBoxTestNoPLGenerated.java

@@ -14050,6 +14050,12 @@ public class FirNativeCodegenBoxTestNoPLGenerated extends AbstractNativeCodegenB
                 runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
             }
 
+            @Test
+            @TestMetadata("genericFunctionInGenericInterface.kt")
+            public void testGenericFunctionInGenericInterface() throws Exception {
+                runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+            }
+
             @Test
             @TestMetadata("genericProperty.kt")
             public void testGenericProperty() throws Exception {

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestGenerated.java

@@ -13422,6 +13422,12 @@ public class NativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTest
                 runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
             }
 
+            @Test
+            @TestMetadata("genericFunctionInGenericInterface.kt")
+            public void testGenericFunctionInGenericInterface() throws Exception {
+                runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+            }
+
             @Test
             @TestMetadata("genericProperty.kt")
             public void testGenericProperty() throws Exception {

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/test/blackbox/NativeCodegenBoxTestNoPLGenerated.java

@@ -13737,6 +13737,12 @@ public class NativeCodegenBoxTestNoPLGenerated extends AbstractNativeCodegenBoxT
                 runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
             }
 
+            @Test
+            @TestMetadata("genericFunctionInGenericInterface.kt")
+            public void testGenericFunctionInGenericInterface() throws Exception {
+                runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+            }
+
             @Test
             @TestMetadata("genericProperty.kt")
             public void testGenericProperty() throws Exception {

wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/FirWasmCodegenBoxTestGenerated.java

@@ -12657,6 +12657,12 @@ public class FirWasmCodegenBoxTestGenerated extends AbstractFirWasmCodegenBoxTes
             runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {

wasm/wasm.tests/tests-gen/org/jetbrains/kotlin/wasm/test/K1WasmCodegenBoxTestGenerated.java

@@ -12657,6 +12657,12 @@ public class K1WasmCodegenBoxTestGenerated extends AbstractK1WasmCodegenBoxTest
             runTest("compiler/testData/codegen/box/delegation/delegationWithPrivateConstructor.kt");
         }
 
+        @Test
+        @TestMetadata("genericFunctionInGenericInterface.kt")
+        public void testGenericFunctionInGenericInterface() throws Exception {
+            runTest("compiler/testData/codegen/box/delegation/genericFunctionInGenericInterface.kt");
+        }
+
         @Test
         @TestMetadata("genericProperty.kt")
         public void testGenericProperty() throws Exception {