LibJS: Add tests for %TypedArray%.prototype.toReversed

Userland/Libraries/LibJS/Tests/builtins/TypedArray/TypedArray.prototype.toReversed.js

@@ -0,0 +1,68 @@
+const TYPED_ARRAYS = [
+    Uint8Array,
+    Uint8ClampedArray,
+    Uint16Array,
+    Uint32Array,
+    Int8Array,
+    Int16Array,
+    Int32Array,
+    Float32Array,
+    Float64Array,
+];
+
+const BIGINT_TYPED_ARRAYS = [BigUint64Array, BigInt64Array];
+
+test("length is 0", () => {
+    TYPED_ARRAYS.forEach(T => {
+        expect(T.prototype.toReversed).toHaveLength(0);
+    });
+
+    BIGINT_TYPED_ARRAYS.forEach(T => {
+        expect(T.prototype.toReversed).toHaveLength(0);
+    });
+});
+
+describe("basic functionality", () => {
+    test("Odd length array", () => {
+        TYPED_ARRAYS.forEach(T => {
+            const array = new T([1, 2, 3]);
+
+            expect(array.toReversed()).toEqual([3, 2, 1]);
+            expect(array).toEqual([1, 2, 3]);
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            const array = new T([1n, 2n, 3n]);
+            expect(array.toReversed()).toEqual([3n, 2n, 1n]);
+            expect(array).toEqual([1n, 2n, 3n]);
+        });
+    });
+
+    test("Even length array", () => {
+        TYPED_ARRAYS.forEach(T => {
+            const array = new T([1, 2]);
+            expect(array.toReversed()).toEqual([2, 1]);
+            expect(array).toEqual([1, 2]);
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            const array = new T([1n, 2n]);
+            expect(array.toReversed()).toEqual([2n, 1n]);
+            expect(array).toEqual([1n, 2n]);
+        });
+    });
+
+    test("Empty array", () => {
+        TYPED_ARRAYS.forEach(T => {
+            const array = new T([]);
+            expect(array.toReversed()).toEqual([]);
+            expect(array).toEqual([]);
+        });
+
+        BIGINT_TYPED_ARRAYS.forEach(T => {
+            const array = new T([]);
+            expect(array.toReversed()).toEqual([]);
+            expect(array).toEqual([]);
+        });
+    });
+});