Fix suspend function with default argument

In JS BE, fix translation of suspend function with default argument
inherited from interface.

See KT-16658

js/js.inliner/src/org/jetbrains/kotlin/js/coroutine/CoroutineFunctionTransformer.kt

@@ -179,8 +179,7 @@ class CoroutineFunctionTransformer(private val program: JsProgram, private val f
 
         val invokeResume = JsReturn(JsInvocation(JsNameRef(context.metadata.doResumeName, instanceName.makeRef()), JsLiteral.NULL))
 
-        functionWithBody.body.statements += JsIf(
-                suspendedName.makeRef(), JsReturn(instanceName.makeRef()), invokeResume)
+        functionWithBody.body.statements += JsIf(suspendedName.makeRef(), JsReturn(instanceName.makeRef()), invokeResume)
     }
 
     private fun generateCoroutineBody(

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

@@ -5781,6 +5781,12 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             doTest(fileName);
         }
 
+        @TestMetadata("overrideDefaultArgument.kt")
+        public void testOverrideDefaultArgument() throws Exception {
+            String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/coroutines/overrideDefaultArgument.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("returnByLabel.kt")
         public void testReturnByLabel() throws Exception {
             String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/box/coroutines/returnByLabel.kt");

js/js.translator/src/org/jetbrains/kotlin/js/translate/declaration/DeclarationBodyVisitor.kt

@@ -118,7 +118,7 @@ class DeclarationBodyVisitor(
                 val callbackName = caller.scope.declareTemporaryName("callback" + Namer.DEFAULT_PARAMETER_IMPLEMENTOR_SUFFIX)
                 val callee = JsNameRef(bodyName, JsLiteral.THIS)
 
-                val defaultInvocation = JsInvocation(callee, java.util.ArrayList<JsExpression>())
+                val defaultInvocation = JsInvocation(callee, listOf<JsExpression>())
                 val callbackInvocation = JsInvocation(callbackName.makeRef())
                 val chosenInvocation = JsConditional(callbackName.makeRef(), callbackInvocation, defaultInvocation)
                 defaultInvocation.arguments += caller.parameters.map { it.name.makeRef() }
@@ -128,7 +128,12 @@ class DeclarationBodyVisitor(
                 caller.body.statements += FunctionBodyTranslator.setDefaultValueForArguments(descriptor, callerContext)
 
                 val returnType = descriptor.returnType!!
-                val statement = if (KotlinBuiltIns.isUnit(returnType)) chosenInvocation.makeStmt() else JsReturn(chosenInvocation)
+                val statement = if (KotlinBuiltIns.isUnit(returnType) && !descriptor.isSuspend) {
+                    chosenInvocation.makeStmt()
+                }
+                else {
+                    JsReturn(chosenInvocation)
+                }
                 caller.body.statements += statement
 
                 context.addFunctionToPrototype(containingClass, descriptor, caller)

js/js.translator/src/org/jetbrains/kotlin/js/translate/utils/FunctionBodyTranslator.java

@@ -18,7 +18,6 @@ package org.jetbrains.kotlin.js.translate.utils;
 
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns;
-import org.jetbrains.kotlin.descriptors.CallableDescriptor;
 import org.jetbrains.kotlin.descriptors.DeclarationDescriptor;
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor;
 import org.jetbrains.kotlin.descriptors.ValueParameterDescriptor;
@@ -34,7 +33,6 @@ import org.jetbrains.kotlin.js.translate.utils.mutator.Mutator;
 import org.jetbrains.kotlin.psi.KtDeclarationWithBody;
 import org.jetbrains.kotlin.psi.KtExpression;
 import org.jetbrains.kotlin.types.KotlinType;
-import org.jetbrains.kotlin.types.TypeUtils;
 
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -144,6 +142,8 @@ public final class FunctionBodyTranslator extends AbstractTranslator {
                     return node;
                 }
 
+                assert declaration.getBodyExpression() != null;
+                assert descriptor.getReturnType() != null;
                 KotlinType bodyType = context().bindingContext().getType(declaration.getBodyExpression());
                 if (bodyType == null && KotlinBuiltIns.isCharOrNullableChar(descriptor.getReturnType()) ||
                     bodyType != null && KotlinBuiltIns.isCharOrNullableChar(bodyType) && TranslationUtils.shouldBoxReturnValue(descriptor)) {