Update NativeArray for toReversed()

src/org/mozilla/javascript/NativeArray.java

@@ -154,6 +154,7 @@ protected void fillConstructorProperties(IdFunctionObject ctor) {
         addIdFunctionProperty(ctor, ARRAY_TAG, ConstructorId_isArray, "isArray", 1);
         addIdFunctionProperty(ctor, ARRAY_TAG, ConstructorId_of, "of", 0);
         addIdFunctionProperty(ctor, ARRAY_TAG, ConstructorId_from, "from", 1);
+        addIdFunctionProperty(ctor, ARRAY_TAG, ConstructorId_toReversed, "toReversed", 0);
         super.fillConstructorProperties(ctor);
     }
 
@@ -303,6 +304,10 @@ protected void initPrototypeId(int id) {
                 arity = 1;
                 s = "flatMap";
                 break;
+            case Id_toReversed:
+                arity = 0;
+                s = "toReversed";
+                break;
             default:
                 throw new IllegalArgumentException(String.valueOf(id));
         }
@@ -341,6 +346,7 @@ public Object execIdCall(
                 case ConstructorId_findIndex:
                 case ConstructorId_reduce:
                 case ConstructorId_reduceRight:
+                case ConstructorId_toReversed:
                     {
                         // this is a small trick; we will handle all the ConstructorId_xxx calls
                         // the same way the object calls are processed
@@ -448,6 +454,9 @@ public Object execIdCall(
                 case Id_flatMap:
                     return js_flatMap(cx, scope, thisObj, args);
 
+                case Id_toReversed:
+                    return js_toReversed(cx, scope, thisObj);
+
                 case Id_every:
                 case Id_filter:
                 case Id_forEach:
@@ -2252,6 +2261,17 @@ private static boolean js_isArray(Object o) {
         return "Array".equals(((Scriptable) o).getClassName());
     }
 
+    private static Scriptable js_toReversed(Context cx, Scriptable scope, Scriptable thisObj) {
+        Scriptable o = ScriptRuntime.toObject(cx, scope, thisObj);
+        long len = getLengthProperty(cx, o);
+
+        Scriptable result = cx.newArray(scope, (int) len);
+        for (long k = len - 1; k >= 0; k--) {
+            Object temp1 = getRawElem(o, k);
+            defineElemOrThrow(cx, result, len - k - 1, temp1);
+        }
+        return result;
+    }
     // methods to implement java.util.List
 
     @Override
@@ -2688,6 +2708,9 @@ protected int findPrototypeId(String s) {
             case "flatMap":
                 id = Id_flatMap;
                 break;
+            case "toReversed":
+                id = Id_toReversed;
+                break;
             default:
                 id = 0;
                 break;
@@ -2729,7 +2752,8 @@ protected int findPrototypeId(String s) {
             Id_at = 32,
             Id_flat = 33,
             Id_flatMap = 34,
-            SymbolId_iterator = 35,
+            Id_toReversed = 35,
+            SymbolId_iterator = 36,
             MAX_PROTOTYPE_ID = SymbolId_iterator;
     private static final int ConstructorId_join = -Id_join,
             ConstructorId_reverse = -Id_reverse,
@@ -2752,6 +2776,7 @@ protected int findPrototypeId(String s) {
             ConstructorId_findIndex = -Id_findIndex,
             ConstructorId_reduce = -Id_reduce,
             ConstructorId_reduceRight = -Id_reduceRight,
+            ConstructorId_toReversed = -Id_toReversed,
             ConstructorId_isArray = -26,
             ConstructorId_of = -27,
             ConstructorId_from = -28;

testsrc/jstests/es2023/array-toReversed.js

@@ -0,0 +1,31 @@
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at http://mozilla.org/MPL/2.0/.
+
+load("testsrc/assert.js");
+
+const array1=[1,2,3];
+assertArrayEquals([3,2,1], array1.toReversed());
+assertFalse(arrayEquals(array1,array1.toReversed()));
+
+const array2 = ["321","abc", "def","fgh"];
+assertArrayEquals(["fgh", "def","abc","321"], array2.toReversed());
+assertFalse(arrayEquals(array2,array2.toReversed()));
+
+const array3 = ["321","", "","o"];
+assertArrayEquals(["o", "","","321"], array3.toReversed());
+assertFalse(arrayEquals(array3,array3.toReversed()));
+
+const array4 = ["1",,,"d"];
+assertArrayEquals(["d",,,"1"], array4.toReversed());
+assertFalse(arrayEquals(array4,array4.toReversed()));
+
+function arrayEquals(a, b) {
+    return Array.isArray(a) &&
+        Array.isArray(b) &&
+        a.length === b.length &&
+        a.every((val, index) => val === b[index]);
+}
+
+
+"success"

testsrc/org/mozilla/javascript/tests/es2023/ArrayToReversedTest.java

@@ -0,0 +1,10 @@
+package org.mozilla.javascript.tests.es2023;
+
+import org.mozilla.javascript.Context;
+import org.mozilla.javascript.drivers.LanguageVersion;
+import org.mozilla.javascript.drivers.RhinoTest;
+import org.mozilla.javascript.drivers.ScriptTestsBase;
+
+@RhinoTest("testsrc/jstests/es2023/array-toReversed.js")
+@LanguageVersion(Context.VERSION_ES6)
+public class ArrayToReversedTest extends ScriptTestsBase {}