JS frontend: additional check for nativeSetter -- check that the return type is either Unit or a supertype of the second parameter's type.

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onLocalExtensionFun.kt

@@ -5,10 +5,19 @@ fun foo() {
     fun Int.set(a: String, v: Int) {}
 
     [nativeSetter]
-    fun Int.set2(a: Number, v: String?) = "OK"
+    fun Int.set2(a: Number, v: String?): Any? = null
 
     [nativeSetter]
-    fun Int.set3(a: Double, v: String?) = "OK"
+    fun Int.set3(a: Double, v: String) = "OK"
+
+    [nativeSetter]
+    fun Int.set4(a: Double, v: String): Any = 1
+
+    [nativeSetter]
+    fun Int.set5(a: Double, v: String): CharSequence = "OK"
+
+    [nativeSetter]
+    fun Int.set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = 1
 
     <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>[nativeSetter]
     fun Int.set(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: Any<!>): Int?<!> = 1
@@ -20,5 +29,5 @@ fun foo() {
     fun Int.set3(<!NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER!>a: Any<!>, b: Int, c: Any?)<!> {}
 
     [nativeSetter]
-    fun Any.foo(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: Double = 0.0<!>, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String? = null<!>) = "OK"
+    fun Any.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>foo<!>(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: Double = 0.0<!>, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String? = null<!>) = "OK"
 }

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onLocalNativeClassMembers.kt

@@ -11,6 +11,12 @@ fun foo() {
 
         nativeSetter
         fun foo(a: Int, v: String) {}
+
+        nativeSetter
+        fun set4(a: Double, v: String): Any = 1
+
+        nativeSetter
+        fun set5(a: Double, v: String): CharSequence = "OK"
     }
 
     [native]
@@ -25,10 +31,13 @@ fun foo() {
         fun Int.set(a: String, v: Int)<!> {}
 
         <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-        fun Int.set2(a: Number, v: String?)<!> = "OK"
+        fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
         <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-        fun Int.set3(a: Double, v: String?)<!> = "OK"
+        fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
+
+        nativeSetter
+        fun set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = 1
 
         <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
         fun set(): Any?<!> = null

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onLocalNonNativeClassMembers.kt

@@ -22,10 +22,10 @@ fun foo() {
         fun Int.set(a: String, v: Int)<!> {}
 
         <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-        fun Int.set2(a: Number, v: String?)<!> = "OK"
+        fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
         <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-        fun Int.set3(a: Double, v: String?)<!> = "OK"
+        fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
 
         <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN, NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
         fun set(): Any?<!> = null

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.kt

@@ -11,6 +11,12 @@ class A {
     nativeSetter
     fun foo(a: Int, v: String) {}
 
+    nativeSetter
+    fun set4(a: Double, v: String): Any = 1
+
+    nativeSetter
+    fun set5(a: Double, v: String): CharSequence = "OK"
+
     class object {
         nativeSetter
         fun set(a: String, v: Any?): Any? = null
@@ -20,6 +26,12 @@ class A {
 
         nativeSetter
         fun foo(a: Int, v: String) {}
+
+        nativeSetter
+        fun set4(a: Double, v: String): Any = 1
+
+        nativeSetter
+        fun set5(a: Double, v: String): CharSequence = "OK"
     }
 }
 
@@ -46,10 +58,13 @@ class C {
     fun Int.set(a: String, v: Int)<!> {}
 
     <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-    fun Int.set2(a: Number, v: String?)<!> = "OK"
+    fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
     <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-    fun Int.set3(a: Double, v: String?)<!> = "OK"
+    fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
+
+    nativeSetter
+    fun set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = 1
 
     <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
     fun set(): Any?<!> = null

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNativeClassMembers.txt

@@ -7,6 +7,8 @@ kotlin.js.native() internal final class A {
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     kotlin.js.nativeSetter() internal final fun put(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String): kotlin.Unit
     kotlin.js.nativeSetter() internal final fun set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Any?): kotlin.Any?
+    kotlin.js.nativeSetter() internal final fun set4(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Any
+    kotlin.js.nativeSetter() internal final fun set5(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.CharSequence
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
     internal class object <class-object-for-A> {
@@ -16,6 +18,8 @@ kotlin.js.native() internal final class A {
         public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
         kotlin.js.nativeSetter() internal final fun put(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String): kotlin.Unit
         kotlin.js.nativeSetter() internal final fun set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Any?): kotlin.Any?
+        kotlin.js.nativeSetter() internal final fun set4(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Any
+        kotlin.js.nativeSetter() internal final fun set5(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.CharSequence
         public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
     }
 }
@@ -73,6 +77,7 @@ kotlin.js.native() internal final class C {
     kotlin.js.nativeSetter() internal final fun set(/*0*/ a: A): kotlin.Any?
     kotlin.js.nativeSetter() internal final fun set(/*0*/ a: A, /*1*/ v: kotlin.Any?): kotlin.Unit
     kotlin.js.nativeSetter() internal final fun set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Any, /*2*/ v2: kotlin.Any): kotlin.Unit
+    kotlin.js.nativeSetter() internal final fun set6(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Number
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
     kotlin.js.nativeSetter() internal final fun kotlin.Int.set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Int): kotlin.Unit
     kotlin.js.nativeSetter() internal final fun kotlin.Int.set2(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String?): kotlin.String

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.kt

@@ -13,6 +13,12 @@ class A {
             nativeSetter
             fun foo(a: Int, v: String) {}
 
+            nativeSetter
+            fun set4(a: Double, v: String): Any = 1
+
+            nativeSetter
+            fun set5(a: Double, v: String): CharSequence = "OK"
+
             class object {
                 nativeSetter
                 fun set(a: String, v: Any?): Any? = null
@@ -22,6 +28,12 @@ class A {
 
                 nativeSetter
                 fun foo(a: Int, v: String) {}
+
+                nativeSetter
+                fun set4(a: Double, v: String): Any = 1
+
+                nativeSetter
+                fun set5(a: Double, v: String): CharSequence = "OK"
             }
         }
 
@@ -46,10 +58,13 @@ class A {
             fun Int.set(a: String, v: Int)<!> {}
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set2(a: Number, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set3(a: Double, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
+
+            nativeSetter
+            fun set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = 1
 
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
             fun set(): Any?<!> = null
@@ -72,10 +87,10 @@ class A {
             fun Int.set(a: String, v: Int)<!> {}
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set2(a: Number, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set3(a: Double, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
 
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
             fun set(): Any?<!> = null
@@ -98,10 +113,10 @@ class A {
             fun Int.set(a: String, v: Int)<!> {}
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set2(a: Number, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set3(a: Double, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
 
             <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
             fun set(): Any?<!> = null

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNativeClass.txt

@@ -20,6 +20,8 @@ kotlin.js.native() internal final class A {
             public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
             kotlin.js.nativeSetter() internal final fun put(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String): kotlin.Unit
             kotlin.js.nativeSetter() internal final fun set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Any?): kotlin.Any?
+            kotlin.js.nativeSetter() internal final fun set4(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Any
+            kotlin.js.nativeSetter() internal final fun set5(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.CharSequence
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
             internal class object <class-object-for-A> {
@@ -29,6 +31,8 @@ kotlin.js.native() internal final class A {
                 public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
                 kotlin.js.nativeSetter() internal final fun put(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String): kotlin.Unit
                 kotlin.js.nativeSetter() internal final fun set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Any?): kotlin.Any?
+                kotlin.js.nativeSetter() internal final fun set4(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Any
+                kotlin.js.nativeSetter() internal final fun set5(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.CharSequence
                 public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
             }
         }
@@ -86,6 +90,7 @@ kotlin.js.native() internal final class A {
             kotlin.js.nativeSetter() internal final fun set(/*0*/ a: A.B.A): kotlin.Any?
             kotlin.js.nativeSetter() internal final fun set(/*0*/ a: A.B.A, /*1*/ v: kotlin.Any?): kotlin.Unit
             kotlin.js.nativeSetter() internal final fun set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Any, /*2*/ v2: kotlin.Any): kotlin.Unit
+            kotlin.js.nativeSetter() internal final fun set6(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Number
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
             kotlin.js.nativeSetter() internal final fun kotlin.Int.set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Int): kotlin.Unit
             kotlin.js.nativeSetter() internal final fun kotlin.Int.set2(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String?): kotlin.String

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNonNativeClass.kt

@@ -12,6 +12,12 @@ class A {
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
             fun foo(a: Int, v: String)<!> {}
 
+            <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
+            fun set4(a: Double, v: String): Any<!> = 1
+
+            <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
+            fun set5(a: Double, v: String): CharSequence<!> = "OK"
+
             class object {
                 <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
                 fun set(a: String, v: Any?): Any?<!> = null
@@ -45,10 +51,13 @@ class A {
             fun Int.set(a: String, v: Int)<!> {}
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set2(a: Number, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set3(a: Double, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
+
+            <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
+            fun Int.set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!><!> = 1
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN, NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
             fun set(): Any?<!> = null
@@ -71,10 +80,10 @@ class A {
             fun Int.set(a: String, v: Int)<!> {}
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set2(a: Number, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set3(a: Double, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN, NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
             fun set(): Any?<!> = null
@@ -97,10 +106,10 @@ class A {
             fun Int.set(a: String, v: Int)<!> {}
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set2(a: Number, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-            fun Int.set3(a: Double, v: String?)<!> = "OK"
+            fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
 
             <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN, NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
             fun set(): Any?<!> = null

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNestedDeclarationsInsideNonNativeClass.txt

@@ -20,6 +20,8 @@ internal final class A {
             public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
             kotlin.js.nativeSetter() internal final fun put(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String): kotlin.Unit
             kotlin.js.nativeSetter() internal final fun set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Any?): kotlin.Any?
+            kotlin.js.nativeSetter() internal final fun set4(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Any
+            kotlin.js.nativeSetter() internal final fun set5(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.CharSequence
             public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 
             internal class object <class-object-for-A> {
@@ -90,6 +92,7 @@ internal final class A {
             kotlin.js.nativeSetter() internal final fun kotlin.Int.set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Int): kotlin.Unit
             kotlin.js.nativeSetter() internal final fun kotlin.Int.set2(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String?): kotlin.String
             kotlin.js.nativeSetter() internal final fun kotlin.Int.set3(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String?): kotlin.String
+            kotlin.js.nativeSetter() internal final fun kotlin.Int.set6(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Number
         }
 
         internal object obj {

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onNonNativeClassMembers.kt

@@ -43,10 +43,10 @@ class C {
     fun Int.set(a: String, v: Int)<!> {}
 
     <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-    fun Int.set2(a: Number, v: String?)<!> = "OK"
+    fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set2<!>(a: Number, v: String?)<!> = "OK"
 
     <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN!>nativeSetter
-    fun Int.set3(a: Double, v: String?)<!> = "OK"
+    fun Int.<!NATIVE_SETTER_WRONG_RETURN_TYPE!>set3<!>(a: Double, v: String?)<!> = "OK"
 
     <!NATIVE_ANNOTATIONS_ALLOWED_ONLY_ON_MEMBER_OR_EXTENSION_FUN, NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter
     fun set(): Any?<!> = null

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onToplevelExtensionFun.kt

@@ -4,12 +4,21 @@ nativeSetter
 fun Int.set(a: String, v: Int) {}
 
 nativeSetter
-fun Int.set2(a: Number, v: String?) = "OK"
+fun Int.set2(a: Number, v: String?): Any? = null
 
 nativeSetter
-fun Int.set3(a: Double, v: String?) = "OK"
+fun Int.set3(a: Double, v: String) = "OK"
 
-[nativeSetter]
+nativeSetter
+fun Int.set4(a: Double, v: String): Any = 1
+
+nativeSetter
+fun Int.set5(a: Double, v: String): CharSequence = "OK"
+
+nativeSetter
+fun Int.set6(a: Double, v: String): <!NATIVE_SETTER_WRONG_RETURN_TYPE!>Number<!> = 1
+
+nativeSetter
 fun Any.foo(<!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>a: String = "0.0"<!>, <!NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS!>v: String = "str"<!>) = "OK"
 
 <!NATIVE_INDEXER_WRONG_PARAMETER_COUNT!>nativeSetter

compiler/testData/diagnostics/testsWithJsStdLib/native/nativeSetter/onToplevelExtensionFun.txt

@@ -4,6 +4,9 @@ kotlin.js.nativeSetter() internal fun kotlin.Any.foo(/*0*/ a: kotlin.String = ..
 kotlin.js.nativeSetter() internal fun kotlin.Int.set(/*0*/ a: [ERROR : A]): kotlin.Int?
 kotlin.js.nativeSetter() internal fun kotlin.Int.set(/*0*/ a: kotlin.String, /*1*/ v: kotlin.Int): kotlin.Unit
 kotlin.js.nativeSetter() internal fun kotlin.Int.set2(): kotlin.String?
-kotlin.js.nativeSetter() internal fun kotlin.Int.set2(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String?): kotlin.String
+kotlin.js.nativeSetter() internal fun kotlin.Int.set2(/*0*/ a: kotlin.Number, /*1*/ v: kotlin.String?): kotlin.Any?
 kotlin.js.nativeSetter() internal fun kotlin.Int.set3(/*0*/ a: kotlin.Any, /*1*/ b: kotlin.Int, /*2*/ c: kotlin.Any?): kotlin.Unit
-kotlin.js.nativeSetter() internal fun kotlin.Int.set3(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String?): kotlin.String
+kotlin.js.nativeSetter() internal fun kotlin.Int.set3(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.String
+kotlin.js.nativeSetter() internal fun kotlin.Int.set4(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Any
+kotlin.js.nativeSetter() internal fun kotlin.Int.set5(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.CharSequence
+kotlin.js.nativeSetter() internal fun kotlin.Int.set6(/*0*/ a: kotlin.Double, /*1*/ v: kotlin.String): kotlin.Number

compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/nativeSetter.kt

@@ -7,7 +7,7 @@ fun String.bar(n: Int, v: Any) {}
 native
 class C {
     nativeSetter
-    fun foo(d: Double, v: Any): String?
+    fun foo(d: Double, v: Any): Any
     nativeSetter
-    fun bar(d: Double, v: Any): String? = noImpl
+    fun bar(d: Double, v: Any): Any = noImpl
 }

compiler/testData/diagnostics/testsWithJsStdLib/native/optionlBody/nativeSetter.txt

@@ -5,9 +5,9 @@ kotlin.js.nativeSetter() internal fun kotlin.String.foo(/*0*/ n: kotlin.Int, /*1
 
 kotlin.js.native() internal final class C {
     public constructor C()
-    kotlin.js.nativeSetter() internal final fun bar(/*0*/ d: kotlin.Double, /*1*/ v: kotlin.Any): kotlin.String?
+    kotlin.js.nativeSetter() internal final fun bar(/*0*/ d: kotlin.Double, /*1*/ v: kotlin.Any): kotlin.Any
     public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
-    kotlin.js.nativeSetter() internal final fun foo(/*0*/ d: kotlin.Double, /*1*/ v: kotlin.Any): kotlin.String?
+    kotlin.js.nativeSetter() internal final fun foo(/*0*/ d: kotlin.Double, /*1*/ v: kotlin.Any): kotlin.Any
     public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
     public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
 }

js/js.frontend/src/org/jetbrains/k2js/resolve/KotlinJsDeclarationCheckerProvider.kt

@@ -30,6 +30,7 @@ import org.jetbrains.k2js.PredefinedAnnotation
 import org.jetbrains.jet.lang.resolve.DescriptorUtils
 import org.jetbrains.k2js.translate.utils.AnnotationsUtils
 import org.jetbrains.jet.lang.descriptors.Visibilities
+import org.jetbrains.jet.lang.types.typeUtil.isSubtypeOf
 
 public object KotlinJsDeclarationCheckerProvider : AdditionalCheckerProvider {
     override val annotationCheckers: List<AnnotationChecker> = listOf(NativeInvokeChecker(), NativeGetterChecker(), NativeSetterChecker())
@@ -76,7 +77,7 @@ private abstract class AbstractNativeIndexerChecker(
             if (firstParamClassDescriptor != KotlinBuiltIns.getInstance().getString() &&
                 !DescriptorUtils.isSubclass(firstParamClassDescriptor, KotlinBuiltIns.getInstance().getNumber())
             ) {
-                diagnosticHolder.report(ErrorsJs.NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER.on(declaration.getValueParameters().first, indexerKind))
+                diagnosticHolder.report(ErrorsJs.NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER.on(declaration.getValueParameters().firstOrNull(), indexerKind))
             }
         }
 
@@ -102,4 +103,19 @@ public class NativeGetterChecker : AbstractNativeIndexerChecker(PredefinedAnnota
     }
 }
 
-public class NativeSetterChecker : AbstractNativeIndexerChecker(PredefinedAnnotation.NATIVE_SETTER, "setter", requiredParametersCount = 2)
+public class NativeSetterChecker : AbstractNativeIndexerChecker(PredefinedAnnotation.NATIVE_SETTER, "setter", requiredParametersCount = 2) {
+    override fun additionalCheck(declaration: JetNamedFunction, descriptor: FunctionDescriptor, diagnosticHolder: DiagnosticSink) {
+        super.additionalCheck(declaration, descriptor, diagnosticHolder)
+
+        val returnType = descriptor.getReturnType()
+        if (KotlinBuiltIns.isUnit(returnType)) return
+
+        val parameters = descriptor.getValueParameters()
+        if (parameters.size() < 2) return
+
+        val secondParameterType = parameters.get(1).getType()
+        if (secondParameterType isSubtypeOf returnType) return
+
+        diagnosticHolder.report(ErrorsJs.NATIVE_SETTER_WRONG_RETURN_TYPE.on(declaration))
+    }
+}

js/js.frontend/src/org/jetbrains/k2js/resolve/diagnostics/DefaultErrorMessagesJs.kt

@@ -29,6 +29,7 @@ private val DIAGNOSTIC_FACTORY_TO_RENDERER by Delegates.lazy {
         put(ErrorsJs.NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER, "Native {0}''s first parameter type should be ''kotlin.String'' or subtype of ''kotlin.Number''", Renderers.STRING)
         put(ErrorsJs.NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS, "Native {0}''s parameter can not have default value", Renderers.STRING)
         put(ErrorsJs.NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE, "Native getter''s return type should be nullable")
+        put(ErrorsJs.NATIVE_SETTER_WRONG_RETURN_TYPE, "Native setter''s return type should be ''Unit'' or a supertype of the second parameter''s type")
         put(ErrorsJs.NATIVE_INDEXER_WRONG_PARAMETER_COUNT, "Expected {0} parameters for native {1}", Renderers.TO_STRING, Renderers.STRING)
         put(ErrorsJs.JSCODE_ERROR, "JavaScript: {0}", Renderers.TO_STRING, Renderers.TO_STRING)
         put(ErrorsJs.JSCODE_WARNING, "JavaScript: {0}", Renderers.TO_STRING, Renderers.TO_STRING)

js/js.frontend/src/org/jetbrains/k2js/resolve/diagnostics/ErrorsJs.java

@@ -36,6 +36,7 @@ public interface ErrorsJs {
     DiagnosticFactory1<JetElement, String> NATIVE_INDEXER_KEY_SHOULD_BE_STRING_OR_NUMBER = DiagnosticFactory1.create(ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);
     DiagnosticFactory1<JetElement, String> NATIVE_INDEXER_CAN_NOT_HAVE_DEFAULT_ARGUMENTS = DiagnosticFactory1.create(ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);
     DiagnosticFactory0<JetDeclaration> NATIVE_GETTER_RETURN_TYPE_SHOULD_BE_NULLABLE = DiagnosticFactory0.create(ERROR, DECLARATION_RETURN_TYPE);
+    DiagnosticFactory0<JetDeclaration> NATIVE_SETTER_WRONG_RETURN_TYPE = DiagnosticFactory0.create(ERROR, DECLARATION_RETURN_TYPE);
     DiagnosticFactory2<JetElement, Integer, String> NATIVE_INDEXER_WRONG_PARAMETER_COUNT = DiagnosticFactory2.create(ERROR, DECLARATION_SIGNATURE_OR_DEFAULT);
     DiagnosticFactory2<JetExpression, String, List<TextRange>> JSCODE_ERROR = DiagnosticFactory2.create(ERROR, JsCodePositioningStrategy.INSTANCE$);
     DiagnosticFactory2<JetExpression, String, List<TextRange>> JSCODE_WARNING = DiagnosticFactory2.create(WARNING, JsCodePositioningStrategy.INSTANCE$);