Everywhere: Hoist the Libraries folder to the top-level

Author: https://github.com/trflynn89
Commit: 93712b24bf
Pull-request: https://github.com/LadybirdBrowser/ladybird/pull/2256
Reviewed-by: https://github.com/sideshowbarker

Libraries/LibJS/Tests/builtins/Reflect/Reflect.preventExtensions.js

@@ -0,0 +1,39 @@
+describe("errors", () => {
+    test("target must be an object", () => {
+        [null, undefined, "foo", 123, NaN, Infinity].forEach(value => {
+            expect(() => {
+                Reflect.preventExtensions(value);
+            }).toThrowWithMessage(TypeError, `${value} is not an object`);
+        });
+    });
+});
+
+describe("normal behavior", () => {
+    test("length is 1", () => {
+        expect(Reflect.preventExtensions).toHaveLength(1);
+    });
+
+    test("properties cannot be added", () => {
+        var o = {};
+        o.foo = "foo";
+        expect(Reflect.preventExtensions(o)).toBeTrue();
+        o.bar = "bar";
+        expect(o.foo).toBe("foo");
+        expect(o.bar).toBeUndefined();
+    });
+
+    test("modifying existing properties", () => {
+        const o = {};
+        o.foo = "foo";
+        expect(Reflect.preventExtensions(o)).toBeTrue();
+        o.foo = "bar";
+        expect(o.foo).toBe("bar");
+    });
+
+    test("deleting existing properties", () => {
+        const o = { foo: "bar" };
+        Reflect.preventExtensions(o);
+        delete o.foo;
+        expect(o).not.toHaveProperty("foo");
+    });
+});