LibJS: Implement Object.create()

Userland/Libraries/LibJS/Tests/builtins/Object/Object.create.js

@@ -0,0 +1,57 @@
+test("length is 2", () => {
+    expect(Object.create).toHaveLength(2);
+});
+
+describe("errors", () => {
+    test("non-object protpotype value", () => {
+        expect(() => Object.create(42)).toThrowWithMessage(
+            TypeError,
+            "Prototype must be an object or null"
+        );
+    });
+});
+
+describe("normal behavior", () => {
+    test("creates object with given prototype", () => {
+        let o;
+
+        o = Object.create(null);
+        expect(o).toEqual({});
+        expect(Object.getPrototypeOf(o)).toBe(null);
+
+        const p = {};
+        o = Object.create(p);
+        expect(o).toEqual({});
+        expect(Object.getPrototypeOf(o)).toBe(p);
+    });
+
+    test("creates object with properties from propertiesObject, if given", () => {
+        const o = Object.create(
+            {},
+            {
+                foo: {
+                    writable: true,
+                    configurable: true,
+                    value: "foo",
+                },
+                bar: {
+                    enumerable: true,
+                    value: "bar",
+                },
+            }
+        );
+        expect(Object.getOwnPropertyNames(o)).toEqual(["foo", "bar"]);
+        expect(Object.getOwnPropertyDescriptor(o, "foo")).toEqual({
+            value: "foo",
+            writable: true,
+            enumerable: false,
+            configurable: true,
+        });
+        expect(Object.getOwnPropertyDescriptor(o, "bar")).toEqual({
+            value: "bar",
+            writable: false,
+            enumerable: true,
+            configurable: false,
+        });
+    });
+});