Libraries: Move to Userland/Libraries/

Userland/Libraries/LibJS/Tests/iterators/%IteratorPrototype%.js

@@ -0,0 +1,12 @@
+const getIteratorPrototype = () =>
+    Object.getPrototypeOf(Object.getPrototypeOf([][Symbol.iterator]()));
+
+test("prototype of %IteratorPrototype% is %ObjectPrototype%", () => {
+    let itProto = getIteratorPrototype();
+    expect(Object.getPrototypeOf(itProto)).toBe(Object.getPrototypeOf({}));
+});
+
+test("@@iterator of %IteratorPrototype% is itself", () => {
+    let itProto = getIteratorPrototype();
+    expect(itProto[Symbol.iterator]()).toBe(itProto);
+});

Userland/Libraries/LibJS/Tests/iterators/array-iterator.js

@@ -0,0 +1,53 @@
+test("length", () => {
+    expect(Array.prototype[Symbol.iterator]).toHaveLength(0);
+});
+
+test("@@toStringTag", () => {
+    expect([].values()[Symbol.toStringTag]).toBe("Array Iterator");
+    expect([].values().toString()).toBe("[object Array Iterator]");
+});
+
+test("same function as Array.prototype.values", () => {
+    expect(Array.prototype[Symbol.iterator]).toBe(Array.prototype.values);
+});
+
+test("basic functionality", () => {
+    const a = [1, 2, 3];
+    const it = a[Symbol.iterator]();
+    expect(it.next()).toEqual({ value: 1, done: false });
+    expect(it.next()).toEqual({ value: 2, done: false });
+    expect(it.next()).toEqual({ value: 3, done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+});
+
+test("works when applied to non-object", () => {
+    [true, false, 9, 2n, Symbol()].forEach(primitive => {
+        const it = [][Symbol.iterator].call(primitive);
+        expect(it.next()).toEqual({ value: undefined, done: true });
+        expect(it.next()).toEqual({ value: undefined, done: true });
+        expect(it.next()).toEqual({ value: undefined, done: true });
+    });
+});
+
+test("item added to array before exhaustion is accessible", () => {
+    const a = [1, 2];
+    const it = a[Symbol.iterator]();
+    expect(it.next()).toEqual({ value: 1, done: false });
+    expect(it.next()).toEqual({ value: 2, done: false });
+    a.push(3);
+    expect(it.next()).toEqual({ value: 3, done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+});
+
+test("item added to array after exhaustion is inaccessible", () => {
+    const a = [1, 2];
+    const it = a[Symbol.iterator]();
+    expect(it.next()).toEqual({ value: 1, done: false });
+    expect(it.next()).toEqual({ value: 2, done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+    a.push(3);
+    expect(it.next()).toEqual({ value: undefined, done: true });
+});

Userland/Libraries/LibJS/Tests/iterators/string-iterator.js

@@ -0,0 +1,48 @@
+test("length", () => {
+    expect(String.prototype[Symbol.iterator]).toHaveLength(0);
+});
+
+test("basic functionality", () => {
+    const s = "abcd";
+    const it = s[Symbol.iterator]();
+    expect(it.next()).toEqual({ value: "a", done: false });
+    expect(it.next()).toEqual({ value: "b", done: false });
+    expect(it.next()).toEqual({ value: "c", done: false });
+    expect(it.next()).toEqual({ value: "d", done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+});
+
+test("casts |this| to string", () => {
+    const it = String.prototype[Symbol.iterator].call(45);
+    expect(it.next()).toEqual({ value: "4", done: false });
+    expect(it.next()).toEqual({ value: "5", done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+
+    const it = String.prototype[Symbol.iterator].call(false);
+    expect(it.next()).toEqual({ value: "f", done: false });
+    expect(it.next()).toEqual({ value: "a", done: false });
+    expect(it.next()).toEqual({ value: "l", done: false });
+    expect(it.next()).toEqual({ value: "s", done: false });
+    expect(it.next()).toEqual({ value: "e", done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+
+    expect(() => {
+        String.prototype[Symbol.iterator].call(null);
+    }).toThrowWithMessage(TypeError, "ToObject on null or undefined");
+    expect(() => {
+        String.prototype[Symbol.iterator].call(undefined);
+    }).toThrowWithMessage(TypeError, "ToObject on null or undefined");
+});
+
+test("utf8 compatible", () => {
+    const it = "ab\u{1f41e}cde"[Symbol.iterator]();
+    expect(it.next()).toEqual({ value: "a", done: false });
+    expect(it.next()).toEqual({ value: "b", done: false });
+    expect(it.next()).toEqual({ value: "🐞", done: false });
+    expect(it.next()).toEqual({ value: "c", done: false });
+    expect(it.next()).toEqual({ value: "d", done: false });
+    expect(it.next()).toEqual({ value: "e", done: false });
+    expect(it.next()).toEqual({ value: undefined, done: true });
+});