Polyfill Array copying methods (#59091)

Summary:
Pull Request resolved: #59091

Install guarded `Array.prototype.toSorted` and `Array.prototype.toReversed` polyfills during React Native environment setup. Both methods return shallow copies and preserve native implementations when the runtime already provides them.

Register the language polyfills from the default environment setup rather than coupling them to generic global-variable setup.

Changelog:
[General][Added] - Polyfill `Array.prototype.toSorted` and `Array.prototype.toReversed` when the JavaScript runtime does not provide them

Reviewed By: mweststrate

Differential Revision: D125283374

fbshipit-source-id: 7b195319f6ba316fc73ede4d81c6431cb46ccb23

Author: javache

packages/react-native/Libraries/Core/__tests__/polyfillArrayES2023Methods-itest.js

@@ -0,0 +1,48 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict-local
+ * @format
+ * @fantom_hermes_variant *
+ */
+
+'use strict';
+
+const originalToSorted = Array.prototype.toSorted;
+const originalToReversed = Array.prototype.toReversed;
+
+require('@react-native/fantom/src/setUpDefaultReactNativeEnvironment');
+
+describe('Array ES2023 method polyfills', () => {
+  it('preserves native methods and fills missing methods', () => {
+    if (originalToSorted == null) {
+      expect(Array.prototype.toSorted).toBeDefined();
+    } else {
+      expect(Array.prototype.toSorted).toBe(originalToSorted);
+    }
+
+    if (originalToReversed == null) {
+      expect(Array.prototype.toReversed).toBeDefined();
+    } else {
+      expect(Array.prototype.toReversed).toBe(originalToReversed);
+    }
+  });
+
+  it('provides non-mutating copying behavior', () => {
+    const input = [3, 1, 2];
+
+    expect(input.toSorted((a, b) => a - b)).toEqual([1, 2, 3]);
+    expect(input.toReversed()).toEqual([2, 1, 3]);
+    expect(input).toEqual([3, 1, 2]);
+    expect(
+      Object.getOwnPropertyDescriptor(Array.prototype, 'toSorted')?.enumerable,
+    ).toBe(false);
+    expect(
+      Object.getOwnPropertyDescriptor(Array.prototype, 'toReversed')
+        ?.enumerable,
+    ).toBe(false);
+  });
+});

packages/react-native/Libraries/Core/polyfillArrayES2023Methods.js

@@ -0,0 +1,40 @@
+/**
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ *
+ * @flow strict
+ * @format
+ */
+
+'use strict';
+
+const arrayPrototype = Array.prototype;
+
+if (arrayPrototype.toSorted == null) {
+  Object.defineProperty(arrayPrototype, 'toSorted' as string, {
+    configurable: true,
+    value: function <T>(
+      this: Array<T>,
+      compareFn?: (a: T, b: T) => number,
+    ): Array<T> {
+      const copy = Array.from(this);
+      copy.sort(compareFn);
+      return copy;
+    },
+    writable: true,
+  });
+}
+
+if (arrayPrototype.toReversed == null) {
+  Object.defineProperty(arrayPrototype, 'toReversed' as string, {
+    configurable: true,
+    value: function <T>(this: Array<T>): Array<T> {
+      const copy = Array.from(this);
+      copy.reverse();
+      return copy;
+    },
+    writable: true,
+  });
+}

packages/react-native/src/private/setup/setUpDefaultReactNativeEnvironment.js

@@ -23,6 +23,7 @@ export default function setUpDefaultReactNativeEnvironment(
   require('./setUpDOM').default();
   require('./setUpPerformance').default();
   require('../../../Libraries/Core/polyfillPromise');
+  require('../../../Libraries/Core/polyfillArrayES2023Methods');
   require('../../../Libraries/Core/setUpTimers');
   if (__DEV__ && enableDeveloperTools) {
     require('../../../Libraries/Core/setUpReactDevTools');