Add TypedArray.prototype.toReversed polyfill

PiperOrigin-RevId: 810668960

Author: trevorade

externs/es6.js

@@ -709,6 +709,16 @@ TypedArray.prototype.subarray = function(begin, opt_end) {};
  */
 TypedArray.prototype.values = function() {};
 
+/**
+ * NOTE: this is an ES2023 extern.
+ * @return {THIS}
+ * @this {THIS}
+ * @template THIS
+ * @nosideeffects
+ * @see https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/TypedArray/toReversed
+ */
+TypedArray.prototype.toReversed = function() {};
+
 /**
  * @return {string}
  * @nosideeffects

src/com/google/javascript/jscomp/js/es6/typed_array.js

@@ -23,3 +23,4 @@
 'require es6/typedarray/fill';
 'require es6/typedarray/findlast';
 'require es6/typedarray/findlastindex';
+'require es6/typedarray/toreversed';

src/com/google/javascript/jscomp/js/es6/typedarray/toreversed.js

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2025 The Closure Compiler Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+'require util/polyfill';
+
+/**
+ * @param {*} orig
+ * @return {*}
+ */
+$jscomp.typedArrayToReversed = function(orig) {
+  if (orig) return orig;
+
+  /**
+   * Returns a new typed array with all elements reversed.
+   *
+   * Note: This polyfill purposefully is NOT spec compliant in order to minimize
+   * code size. See skipped unit tests for specific gaps.
+   *
+   * @see https://tc39.es/ecma262/multipage/indexed-collections.html#sec-%typedarray%.prototype.toreversed
+   *
+   * @return {THIS}
+   * @this {THIS}
+   * @template THIS
+   */
+  var polyfill = function() {
+    return this.slice().reverse();
+  };
+
+  return polyfill;
+};
+
+$jscomp.polyfillTypedArrayMethod(
+    'toReversed', $jscomp.typedArrayToReversed, 'es_next', 'es5');