1 files changed, 102 insertions, 0 deletions
diff --git a/Userland/Libraries/LibJS/Tests/builtins/Reflect/Reflect.set.js b/Userland/Libraries/LibJS/Tests/builtins/Reflect/Reflect.set.js
new file mode 100644
index 0000000000..854fb23888
--- /dev/null
+++ b/Userland/Libraries/LibJS/Tests/builtins/Reflect/Reflect.set.js
@@ -0,0 +1,102 @@
+test("length is 3", () => {
+    expect(Reflect.set).toHaveLength(3);
+});
+
+describe("errors", () => {
+    test("target must be an object", () => {
+        [null, undefined, "foo", 123, NaN, Infinity].forEach(value => {
+            expect(() => {
+                Reflect.set(value);
+            }).toThrowWithMessage(TypeError, "First argument of Reflect.set() must be an object");
+        });
+    });
+});
+
+describe("normal behavior", () => {
+    test("setting properties of regular object", () => {
+        var o = {};
+
+        expect(Reflect.set(o)).toBeTrue();
+        expect(o.undefined).toBeUndefined();
+
+        expect(Reflect.set(o, "foo")).toBeTrue();
+        expect(o.foo).toBeUndefined();
+
+        expect(Reflect.set(o, "foo", "bar")).toBeTrue();
+        expect(o.foo).toBe("bar");
+
+        expect(Reflect.set(o, "foo", 42)).toBeTrue();
+        expect(o.foo).toBe(42);
+    });
+
+    test("setting configurable, non-writable property of regular object", () => {
+        var o = {};
+        Object.defineProperty(o, "foo", { value: 1, configurable: true, writable: false });
+        expect(Reflect.set(o, "foo", 2)).toBeFalse();
+        expect(o.foo).toBe(1);
+    });
+
+    test("setting non-configurable, writable property of regular object", () => {
+        var o = {};
+        Object.defineProperty(o, "foo", { value: 1, configurable: false, writable: true });
+        expect(Reflect.set(o, "foo", 2)).toBeTrue();
+        expect(o.foo).toBe(2);
+    });
+
+    test("", () => {
+        var a = [];
+        expect(a.length === 0);
+        expect(Reflect.set(a, "0")).toBeTrue();
+        expect(a.length === 1);
+        expect(a[0]).toBeUndefined();
+        expect(Reflect.set(a, 1, "foo")).toBeTrue();
+        expect(a.length === 2);
+        expect(a[0]).toBeUndefined();
+        expect(a[1] === "foo");
+        expect(Reflect.set(a, 4, "bar")).toBeTrue();
+        expect(a.length === 5);
+        expect(a[0]).toBeUndefined();
+        expect(a[1] === "foo");
+        expect(a[2]).toBeUndefined();
+        expect(a[3]).toBeUndefined();
+        expect(a[4] === "bar");
+    });
+
+    test("setting setter property of regular object", () => {
+        const foo = {
+            set prop(value) {
+                this.setPropCalled = true;
+            },
+        };
+        expect(foo.setPropCalled).toBeUndefined();
+        Reflect.set(foo, "prop", 42);
+        expect(foo.setPropCalled).toBeTrue();
+    });
+
+    test("setting setter property of regular object with different receiver", () => {
+        const foo = {
+            set prop(value) {
+                this.setPropCalled = true;
+            },
+        };
+        const bar = {};
+        Object.setPrototypeOf(bar, foo);
+
+        expect(foo.setPropCalled).toBeUndefined();
+        expect(bar.setPropCalled).toBeUndefined();
+
+        Reflect.set(bar, "prop", 42);
+        expect(foo.setPropCalled).toBeUndefined();
+        expect(bar.setPropCalled).toBeTrue();
+
+        Reflect.set(bar, "prop", 42, foo);
+        expect(foo.setPropCalled).toBeTrue();
+        expect(bar.setPropCalled).toBeTrue();
+    });
+
+    test("native setter function", () => {
+        const e = new Error();
+        Reflect.set(Error.prototype, "name", "Foo", e);
+        expect(e.name).toBe("Foo");
+    });
+});