Add another test for KT-49715 and fix JS IR behavior

#KT-49715
 #KT-51798 Fixed

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

@@ -13143,6 +13143,12 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/dataClasses/kt49715.kt");
         }
 
+        @Test
+        @TestMetadata("kt49715_behaviorChange.kt")
+        public void testKt49715_behaviorChange() throws Exception {
+            runTest("compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt");
+        }
+
         @Test
         @TestMetadata("kt5002.kt")
         public void testKt5002() throws Exception {

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/utils/misc.kt

@@ -23,6 +23,7 @@ import org.jetbrains.kotlin.ir.types.isNullableAny
 import org.jetbrains.kotlin.ir.util.isEffectivelyExternal
 import org.jetbrains.kotlin.ir.util.isTopLevelDeclaration
 import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.util.OperatorNameConventions
 
 fun TODO(element: IrElement): Nothing = TODO(element::class.java.simpleName + " is not supported yet here")
 
@@ -58,9 +59,10 @@ fun IrFunction.hasStableJsName(context: JsIrBackendContext): Boolean {
     return (isEffectivelyExternal() || getJsName() != null || isExported(context)) && namedOrMissingGetter
 }
 
-fun IrFunction.isEqualsInheritedFromAny() =
+fun IrFunction.isEqualsInheritedFromAny(): Boolean =
-    name == Name.identifier("equals") &&
+    name == OperatorNameConventions.EQUALS &&
             dispatchReceiverParameter != null &&
+            extensionReceiverParameter == null &&
             valueParameters.size == 1 &&
             valueParameters[0].type.isNullableAny()
 

compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt

@@ -0,0 +1,17 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+// FIR status: [IR VALIDATION] Duplicate IR node: FUN GENERATED_DATA_CLASS_MEMBER name:equals
+
+interface A {
+    fun Any.equals(other: Any?): Boolean = false
+    fun Any.hashCode(): Int = 0
+    fun Any.toString(): String = ""
+}
+
+data class B(val x: Int) : A
+
+fun box(): String {
+    if (B(42) != B(42)) return "Fail equals"
+    if (B(42).hashCode() != B(42).hashCode()) return "Fail hashCode"
+    if (B(42).toString() != B(42).toString()) return "Fail toString"
+    return "OK"
+}

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

@@ -13017,6 +13017,12 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/dataClasses/kt49715.kt");
         }
 
+        @Test
+        @TestMetadata("kt49715_behaviorChange.kt")
+        public void testKt49715_behaviorChange() throws Exception {
+            runTest("compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt");
+        }
+
         @Test
         @TestMetadata("kt5002.kt")
         public void testKt5002() throws Exception {

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

@@ -13143,6 +13143,12 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/dataClasses/kt49715.kt");
         }
 
+        @Test
+        @TestMetadata("kt49715_behaviorChange.kt")
+        public void testKt49715_behaviorChange() throws Exception {
+            runTest("compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt");
+        }
+
         @Test
         @TestMetadata("kt5002.kt")
         public void testKt5002() throws Exception {

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

@@ -10542,6 +10542,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/dataClasses/kt49715.kt");
         }
 
+        @TestMetadata("kt49715_behaviorChange.kt")
+        public void testKt49715_behaviorChange() throws Exception {
+            runTest("compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt");
+        }
+
         @TestMetadata("kt5002.kt")
         public void testKt5002() throws Exception {
             runTest("compiler/testData/codegen/box/dataClasses/kt5002.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/JsCodegenBoxTestGenerated.java

@@ -9731,6 +9731,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/dataClasses/kt49715.kt");
         }
 
+        @Test
+        @TestMetadata("kt49715_behaviorChange.kt")
+        public void testKt49715_behaviorChange() throws Exception {
+            runTest("compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt");
+        }
+
         @Test
         @TestMetadata("mixedParams.kt")
         public void testMixedParams() throws Exception {

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

@@ -9773,6 +9773,12 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/dataClasses/kt49715.kt");
         }
 
+        @Test
+        @TestMetadata("kt49715_behaviorChange.kt")
+        public void testKt49715_behaviorChange() throws Exception {
+            runTest("compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt");
+        }
+
         @Test
         @TestMetadata("mixedParams.kt")
         public void testMixedParams() throws Exception {

js/js.tests/tests-gen/org/jetbrains/kotlin/js/testOld/wasm/semantics/IrCodegenBoxWasmTestGenerated.java

@@ -8554,6 +8554,11 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             runTest("compiler/testData/codegen/box/dataClasses/kt49715.kt");
         }
 
+        @TestMetadata("kt49715_behaviorChange.kt")
+        public void testKt49715_behaviorChange() throws Exception {
+            runTest("compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt");
+        }
+
         @TestMetadata("mixedParams.kt")
         public void testMixedParams() throws Exception {
             runTest("compiler/testData/codegen/box/dataClasses/mixedParams.kt");

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

@@ -10687,6 +10687,12 @@ public class NativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTest
                 runTest("compiler/testData/codegen/box/dataClasses/kt49715.kt");
             }
 
+            @Test
+            @TestMetadata("kt49715_behaviorChange.kt")
+            public void testKt49715_behaviorChange() throws Exception {
+                runTest("compiler/testData/codegen/box/dataClasses/kt49715_behaviorChange.kt");
+            }
+
             @Test
             @TestMetadata("mixedParams.kt")
             public void testMixedParams() throws Exception {