[JS IR] Remove redundant guard assertion for extension funs with default params

Introduce corresponding test
See https://youtrack.jetbrains.com/issue/KT-41076

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

@@ -3840,6 +3840,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             runTest("compiler/testData/codegen/box/classes/exceptionConstructor.kt");
         }
 
+        @TestMetadata("extensionFunWithDefaultParam.kt")
+        public void testExtensionFunWithDefaultParam() throws Exception {
+            runTest("compiler/testData/codegen/box/classes/extensionFunWithDefaultParam.kt");
+        }
+
         @TestMetadata("extensionOnNamedClassObject.kt")
         public void testExtensionOnNamedClassObject() throws Exception {
             runTest("compiler/testData/codegen/box/classes/extensionOnNamedClassObject.kt");

compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/JsDefaultArgumentStubGenerator.kt

@@ -37,11 +37,12 @@ class JsDefaultArgumentStubGenerator(override val context: JsIrBackendContext) :
     ): IrExpression {
         val paramCount = oldIrFunction.valueParameters.size
         val invokeFunctionN = resolveInvoke(paramCount)
-        // NOTE: currently we do not have a syntax to perform super extension call
+
-        // but in case we have such functionality in the future the logic bellow should be fixed
         return irCall(invokeFunctionN, IrStatementOrigin.INVOKE).apply {
             dispatchReceiver = irImplicitCast(irGet(handlerDeclaration), invokeFunctionN.dispatchReceiverParameter!!.type)
-            assert(newIrFunction.extensionReceiverParameter == null)
+            // NOTE: currently we do not have a syntax to perform super extension call
+            // that's why we've used to just fail with an exception in case we have extension function in for JS IR compilation
+            // TODO: that was overkill, however, we still need to revisit this issue later on
             params.forEachIndexed { i, variable -> putValueArgument(i, irGet(variable)) }
         }
     }

compiler/testData/codegen/box/classes/extensionFunWithDefaultParam.kt

@@ -0,0 +1,38 @@
+// DONT_TARGET_EXACT_BACKEND: WASM
+// WASM_MUTE_REASON: IGNORED_IN_JS
+// IGNORE_BACKEND: NATIVE
+
+open class MyLogic {
+    protected open val postfix = "ZZZ"
+    open fun String.foo(prefix: String = "XXX"): String = transform(prefix + this + postfix)
+    protected fun transform(a: String) = "$a:$a"
+    fun result(): String {
+        return "YYY".foo()
+    }
+}
+open class MyLogicWithDifferentPostfix : MyLogic() {
+    override val postfix = "WWW"
+}
+
+class MyLogicSpecified : MyLogic() {
+    override fun String.foo(prefix: String): String = "$prefix::$this::$postfix"
+}
+
+fun box(): String {
+    val result1 = MyLogic().result()
+    if (result1 != "XXXYYYZZZ:XXXYYYZZZ") {
+        return "fail1: ${result1}"
+    }
+
+    val result2 = MyLogicWithDifferentPostfix().result()
+    if (result2 != "XXXYYYWWW:XXXYYYWWW") {
+        return "fail2: ${result2}"
+    }
+
+    val result3 = MyLogicSpecified().result()
+    if (result3 != "XXX::YYY::ZZZ") {
+        return "fail3: ${result3}"
+    }
+
+    return  "OK"
+}

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

@@ -3860,6 +3860,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             runTest("compiler/testData/codegen/box/classes/exceptionConstructor.kt");
         }
 
+        @TestMetadata("extensionFunWithDefaultParam.kt")
+        public void testExtensionFunWithDefaultParam() throws Exception {
+            runTest("compiler/testData/codegen/box/classes/extensionFunWithDefaultParam.kt");
+        }
+
         @TestMetadata("extensionOnNamedClassObject.kt")
         public void testExtensionOnNamedClassObject() throws Exception {
             runTest("compiler/testData/codegen/box/classes/extensionOnNamedClassObject.kt");

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

@@ -3865,6 +3865,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             runTest("compiler/testData/codegen/box/classes/exceptionConstructor.kt");
         }
 
+        @TestMetadata("extensionFunWithDefaultParam.kt")
+        public void testExtensionFunWithDefaultParam() throws Exception {
+            runTest("compiler/testData/codegen/box/classes/extensionFunWithDefaultParam.kt");
+        }
+
         @TestMetadata("extensionOnNamedClassObject.kt")
         public void testExtensionOnNamedClassObject() throws Exception {
             runTest("compiler/testData/codegen/box/classes/extensionOnNamedClassObject.kt");

compiler/tests-gen/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -3840,6 +3840,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             runTest("compiler/testData/codegen/box/classes/exceptionConstructor.kt");
         }
 
+        @TestMetadata("extensionFunWithDefaultParam.kt")
+        public void testExtensionFunWithDefaultParam() throws Exception {
+            runTest("compiler/testData/codegen/box/classes/extensionFunWithDefaultParam.kt");
+        }
+
         @TestMetadata("extensionOnNamedClassObject.kt")
         public void testExtensionOnNamedClassObject() throws Exception {
             runTest("compiler/testData/codegen/box/classes/extensionOnNamedClassObject.kt");

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/es6/semantics/IrJsCodegenBoxES6TestGenerated.java

@@ -3015,6 +3015,11 @@ public class IrJsCodegenBoxES6TestGenerated extends AbstractIrJsCodegenBoxES6Tes
             runTest("compiler/testData/codegen/box/classes/exceptionConstructor.kt");
         }
 
+        @TestMetadata("extensionFunWithDefaultParam.kt")
+        public void testExtensionFunWithDefaultParam() throws Exception {
+            runTest("compiler/testData/codegen/box/classes/extensionFunWithDefaultParam.kt");
+        }
+
         @TestMetadata("extensionOnNamedClassObject.kt")
         public void testExtensionOnNamedClassObject() throws Exception {
             runTest("compiler/testData/codegen/box/classes/extensionOnNamedClassObject.kt");

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

@@ -3015,6 +3015,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/classes/exceptionConstructor.kt");
         }
 
+        @TestMetadata("extensionFunWithDefaultParam.kt")
+        public void testExtensionFunWithDefaultParam() throws Exception {
+            runTest("compiler/testData/codegen/box/classes/extensionFunWithDefaultParam.kt");
+        }
+
         @TestMetadata("extensionOnNamedClassObject.kt")
         public void testExtensionOnNamedClassObject() throws Exception {
             runTest("compiler/testData/codegen/box/classes/extensionOnNamedClassObject.kt");

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

@@ -3015,6 +3015,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             runTest("compiler/testData/codegen/box/classes/exceptionConstructor.kt");
         }
 
+        @TestMetadata("extensionFunWithDefaultParam.kt")
+        public void testExtensionFunWithDefaultParam() throws Exception {
+            runTest("compiler/testData/codegen/box/classes/extensionFunWithDefaultParam.kt");
+        }
+
         @TestMetadata("extensionOnNamedClassObject.kt")
         public void testExtensionOnNamedClassObject() throws Exception {
             runTest("compiler/testData/codegen/box/classes/extensionOnNamedClassObject.kt");