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/loops/for-in-basic.js

@@ -0,0 +1,132 @@
+test("iterate through empty string", () => {
+    const a = [];
+    for (const property in "") {
+        a.push(property);
+    }
+    expect(a).toEqual([]);
+});
+
+test("iterate through number", () => {
+    const a = [];
+    for (const property in 123) {
+        a.push(property);
+    }
+    expect(a).toEqual([]);
+});
+
+test("iterate through empty object", () => {
+    const a = [];
+    for (const property in {}) {
+        a.push(property);
+    }
+    expect(a).toEqual([]);
+});
+
+test("iterate through string", () => {
+    const a = [];
+    for (const property in "hello") {
+        a.push(property);
+    }
+    expect(a).toEqual(["0", "1", "2", "3", "4"]);
+});
+
+test("iterate through object", () => {
+    const a = [];
+    for (const property in { a: 1, b: 2, c: 2 }) {
+        a.push(property);
+    }
+    expect(a).toEqual(["a", "b", "c"]);
+});
+
+test("iterate through undefined", () => {
+    for (const property in undefined) {
+        expect.fail();
+    }
+});
+
+test("use already-declared variable", () => {
+    var property;
+    for (property in "abc");
+    expect(property).toBe("2");
+});
+
+test("allow binding patterns", () => {
+    const expected = [
+        ["1", "3", []],
+        ["s", undefined, []],
+        ["l", "n", ["g", "N", "a", "m", "e"]],
+    ];
+    let counter = 0;
+
+    for (let [a, , b, ...c] in { 123: 1, sm: 2, longName: 3 }) {
+        expect(a).toBe(expected[counter][0]);
+        expect(b).toBe(expected[counter][1]);
+        expect(c).toEqual(expected[counter][2]);
+        counter++;
+    }
+    expect(counter).toBe(3);
+});
+
+describe("special left hand sides", () => {
+    test("allow member expression as variable", () => {
+        const f = {};
+        for (f.a in "abc");
+        expect(f.a).toBe("2");
+    });
+
+    test("allow member expression of function call", () => {
+        const b = {};
+        function f() {
+            return b;
+        }
+
+        for (f().a in "abc");
+
+        expect(f().a).toBe("2");
+        expect(b.a).toBe("2");
+    });
+
+    test.xfail("call function is allowed in parsing but fails in runtime", () => {
+        function f() {
+            expect().fail();
+        }
+
+        // Does not fail since it does not iterate
+        expect("for (f() in []);").toEvalTo(undefined);
+
+        expect(() => {
+            eval("for (f() in [0]) { expect().fail() }");
+        }).toThrowWithMessage(ReferenceError, "Invalid left-hand side in assignment");
+    });
+
+    test("Cannot change constant declaration in body", () => {
+        const vals = [];
+        for (const v in [1, 2]) {
+            expect(() => v++).toThrowWithMessage(TypeError, "Invalid assignment to const variable");
+            vals.push(v);
+        }
+
+        expect(vals).toEqual(["0", "1"]);
+    });
+});
+
+test("remove properties while iterating", () => {
+    const from = [1, 2, 3];
+    const to = [];
+    for (const prop in from) {
+        to.push(prop);
+        from.pop();
+    }
+    expect(to).toEqual(["0", "1"]);
+});
+
+test("duplicated properties in prototype", () => {
+    const object = { a: 1 };
+    const proto = { a: 2 };
+    Object.setPrototypeOf(object, proto);
+    const a = [];
+    for (const prop in object) {
+        a.push(prop);
+    }
+    expect(a).toEqual(["a"]);
+});