LibJS: Convert all remaining non-Array tests to the new system :)

13 files changed, 898 insertions, 269 deletions

diff --git a/Libraries/LibJS/Tests/classes/class-advanced-extends.js b/Libraries/LibJS/Tests/classes/class-advanced-extends.js
new file mode 100644
index 0000000000..749f65003c
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-advanced-extends.js
@@ -0,0 +1,35 @@
+test("extending function", () => {
+  class A extends function () {
+    this.foo = 10;
+  } {}
+
+  expect(new A().foo).toBe(10);
+});
+
+test("extending null", () => {
+  class A extends null {}
+
+  expect(Object.getPrototypeOf(A.prototype)).toBeNull();
+
+  expect(() => {
+    new A();
+  }).toThrowWithMessage(ReferenceError, "|this| has not been initialized");
+});
+
+test("extending String", () => {
+  class MyString extends String {}
+
+  const ms = new MyString("abc");
+  expect(ms).toBeInstanceOf(MyString);
+  expect(ms).toBeInstanceOf(String);
+  expect(ms.charAt(1)).toBe("b");
+
+  class MyString2 extends MyString {
+    charAt(i) {
+      return `#${super.charAt(i)}`;
+    }
+  }
+
+  const ms2 = new MyString2("abc");
+  expect(ms2.charAt(1)).toBe("#b");
+});
diff --git a/Libraries/LibJS/Tests/classes/class-basic.js b/Libraries/LibJS/Tests/classes/class-basic.js
index 2fd856ac36..844bbe68fc 100644
--- a/Libraries/LibJS/Tests/classes/class-basic.js
+++ b/Libraries/LibJS/Tests/classes/class-basic.js
@@ -1,269 +1,5 @@
-load("test-common.js");
-
-try {
-  class X {
-    constructor() {
-      this.x = 3;
-    }
-    getX() {
-      return 3;
-    }
-
-    init() {
-      this.y = 3;
-    }
-  }
-
-  assert(X.name === "X");
-  assert(X.length === 0);
-
-  class Y extends X {
-    init() {
-      super.init();
-      this.y += 3;
-    }
-  }
-
-  assert(new Y().getX() === 3);
-  assert(new Y().x === 3);
-
-  let x = new X();
-  assert(x.x === 3);
-  assert(x.getX() === 3);
-
-  let y = new Y();
-  assert(y.x === 3);
-  assert(y.y === undefined);
-  y.init();
-  assert(y.y === 6);
-  assert(y.hasOwnProperty("y"));
-
-  class Foo {
-    constructor(x) {
-      this.x = x;
-    }
-  }
-  assert(Foo.length === 1);
-
-  class Bar extends Foo {
-    constructor() {
-      super(5);
-    }
-  }
-
-  class Baz {
-    constructor() {
-      this.foo = 55;
-      this._bar = 33;
-    }
-
-    get bar() {
-      return this._bar;
-    }
-
-    set bar(value) {
-      this._bar = value;
-    }
-
-    ["get" + "Foo"]() {
-      return this.foo;
-    }
-
-    static get staticFoo() {
-      assert(this === Baz);
-      return 11;
-    }
-  }
-
-  let barPropertyDescriptor = Object.getOwnPropertyDescriptor(Baz.prototype, "bar");
-  assert(barPropertyDescriptor.get.name === "get bar");
-  assert(barPropertyDescriptor.set.name === "set bar");
-
-  let baz = new Baz();
-  assert(baz.foo === 55);
-  assert(baz.bar === 33);
-  baz.bar = 22;
-  assert(baz.bar === 22);
-
-  assert(baz.getFoo() === 55);
-  assert(Baz.staticFoo === 11);
-
-  assert(new Bar().x === 5);
-
-  class ExtendsFunction extends function () {
-    this.foo = 22;
-  } {}
-  assert(new ExtendsFunction().foo === 22);
-
-  class ExtendsString extends String {}
-  assert(new ExtendsString() instanceof String);
-  assert(new ExtendsString() instanceof ExtendsString);
-  assert(new ExtendsString("abc").charAt(1) === "b");
-
-  class MyWeirdString extends ExtendsString {
-    charAt(i) {
-      return "#" + super.charAt(i);
-    }
-  }
-  assert(new MyWeirdString("abc").charAt(1) === "#b");
-
-  class ExtendsNull extends null {}
-
-  assertThrowsError(
-    () => {
-      new ExtendsNull();
-    },
-    {
-      error: ReferenceError,
-    }
-  );
-  assert(Object.getPrototypeOf(ExtendsNull.prototype) === null);
-
-  class ExtendsClassExpression extends class {
-    constructor(x) {
-      this.x = x;
-    }
-  } {
-    constructor(y) {
-      super(5);
-      this.y = 6;
-    }
-  }
-  let extendsClassExpression = new ExtendsClassExpression();
-  assert(extendsClassExpression.x === 5);
-  assert(extendsClassExpression.y === 6);
-
-  class InStrictMode {
-    constructor() {
-      assert(isStrictMode());
-    }
-
-    method() {
-      assert(isStrictMode());
-    }
-  }
-
-  let resultOfAnExpression = new (class {
-    constructor(x) {
-      this.x = x;
-    }
-    getX() {
-      return this.x + 10;
-    }
-  })(55);
-  assert(resultOfAnExpression.x === 55);
-  assert(resultOfAnExpression.getX() === 65);
-
-  let ClassExpression = class Foo {};
-  assert(ClassExpression.name === "Foo");
-
-  new InStrictMode().method();
-  assert(!isStrictMode());
-
-  assertIsSyntaxError(`
-        class GetterWithArgument {
-            get foo(bar) {
-                return 0;
-            }
-        }
-    `);
-
-  assertIsSyntaxError(`
-        class SetterWithNoArgumetns {
-            set foo() {
-            }
-        }
-    `);
-
-  assertIsSyntaxError(`
-        class SetterWithMoreThanOneArgument {
-            set foo(bar, baz) {
-            }
-        }
-    `);
-
-  assertIsSyntaxError(`
-        class FooBase {}
-        class IsASyntaxError extends FooBase {
-            bar() {
-                function f() { super.baz; }
-            }
-        }
-    `);
-
-  assertIsSyntaxError(`
-        class NoBaseSuper {
-            constructor() {
-                super();
-            }
-        }
-    `);
-
-  assertThrowsError(
-    () => {
-      class BadExtends extends 3 {}
-    },
-    {
-      error: TypeError,
-    }
-  );
-
-  assertThrowsError(
-    () => {
-      class BadExtends extends undefined {}
-    },
-    {
-      error: TypeError,
-    }
-  );
-
-  class SuperNotASyntaxError {
-    bar() {
-      () => {
-        super.baz;
-      };
-    }
-  }
-
-  class SuperNoBasePropertyLookup {
-    constructor() {
-      super.foo;
-    }
-  }
-
-  assertThrowsError(
-    () => {
-      class Base {}
-      class DerivedDoesntCallSuper extends Base {
-        constructor() {
-          this;
-        }
-      }
-
-      new DerivedDoesntCallSuper();
-    },
-    {
-      error: ReferenceError,
-    }
-  );
-  assertThrowsError(
-    () => {
-      class Base {}
-      class CallsSuperTwice extends Base {
-        constructor() {
-          super();
-          super();
-        }
-      }
-
-      new CallsSuperTwice();
-    },
-    {
-      error: ReferenceError,
-    }
-  );
-
-  console.log("PASS");
-} catch (e) {
-  console.log("FAIL: " + e);
-}
+test("class properties", () => {
+  class A {}
+  expect(A.name).toBe("A");
+  expect(A).toHaveLength(0);
+});
diff --git a/Libraries/LibJS/Tests/classes/class-constructor.js b/Libraries/LibJS/Tests/classes/class-constructor.js
new file mode 100644
index 0000000000..367c1e77ea
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-constructor.js
@@ -0,0 +1,67 @@
+test("property initialization", () => {
+  class A {
+    constructor() {
+      this.x = 3;
+    }
+  }
+
+  expect(new A().x).toBe(3);
+});
+
+test("method initialization", () => {
+  class A {
+    constructor() {
+      this.x = () => 10;
+    }
+  }
+
+  expect(new A().x()).toBe(10);
+});
+
+test("initialize to class method", () => {
+  class A {
+    constructor() {
+      this.x = this.method;
+    }
+
+    method() {
+      return 10;
+    }
+  }
+
+  expect(new A().x()).toBe(10);
+});
+
+test("constructor length affects class length", () => {
+  class A {
+    constructor() {}
+  }
+
+  expect(A).toHaveLength(0);
+
+  class B {
+    constructor(a, b, c = 2) {}
+  }
+
+  expect(B).toHaveLength(2);
+});
+
+test.skip("must be invoked with 'new'", () => {
+  class A {
+    constructor() {}
+  }
+
+  expect(() => {
+    A();
+  }).toThrow(TypeError); // FIXME: Add message when this test works
+
+  expect(() => {
+    A.prototype.constructor();
+  }).toThrow(TypeError); // FIXME: Add message when this test works
+});
+
+test("implicit constructor", () => {
+  class A {}
+
+  expect(new A()).toBeInstanceOf(A);
+});
diff --git a/Libraries/LibJS/Tests/classes/class-errors.js b/Libraries/LibJS/Tests/classes/class-errors.js
new file mode 100644
index 0000000000..acef9ee3c9
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-errors.js
@@ -0,0 +1,95 @@
+describe("non-syntax errors", () => {
+  test("super reference inside nested-but-same |this| scope with no base class", () => {
+    expect(`
+    class A {
+      foo() {
+        () => { super.bar; }
+      }
+    }`).toEval();
+  });
+
+  test("super reference property lookup with no base class", () => {
+    expect(`
+    class A {
+      constructor() {
+        super.foo;
+      }
+    }`).toEval();
+  });
+});
+
+describe("reference errors", () => {
+  test("derived class doesn't call super in constructor before using this", () => {
+    class Parent {}
+    class Child extends Parent {
+      constructor() {
+        this;
+      }
+    }
+
+    expect(() => {
+      new Child();
+    }).toThrowWithMessage(ReferenceError, "|this| has not been initialized");
+  });
+
+  test("derived class calls super twice in constructor", () => {
+    class Parent {}
+    class Child extends Parent {
+      constructor() {
+        super();
+        super();
+      }
+    }
+
+    expect(() => {
+      new Child();
+    }).toThrowWithMessage(ReferenceError, "|this| is already initialized");
+  });
+});
+
+describe("syntax errors", () => {
+  test("getter with argument", () => {
+    expect(`
+    class A {
+      get foo(v) {
+        return 0;
+      }
+    }`).not.toEval();
+  });
+
+  test("setter with no arguments", () => {
+    expect(`
+    class A {
+      set foo() {
+      }
+    }`).not.toEval();
+  });
+
+  test("setter with more than one argument", () => {
+    expect(`
+    class A {
+      set foo(bar, baz) {
+      }
+    }`).not.toEval();
+  });
+
+  test("super reference inside different |this| scope", () => {
+    expect(`
+    class Parent {}
+
+    class Child extends Parent {
+      foo() {
+        function f() { super.foo; }
+      }
+    }`).not.toEval();
+  });
+
+  test("super reference call with no base class", () => {
+    expect(`
+    class A {
+      constructor() {
+        super();
+      }
+    }`).not.toEval();
+  });
+});
diff --git a/Libraries/LibJS/Tests/classes/class-expressions.js b/Libraries/LibJS/Tests/classes/class-expressions.js
new file mode 100644
index 0000000000..3dbea6d8fc
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-expressions.js
@@ -0,0 +1,69 @@
+// This file must not be formatted by prettier. Make sure your IDE
+// respects the .prettierignore file!
+
+test("basic functionality", () => {
+  const A = class {
+    constructor(x) {
+      this.x = x;
+    }
+
+    getX() {
+      return this.x * 2;
+    }
+  };
+
+  expect(new A(10).getX()).toBe(20);
+});
+
+test("inline instantiation", () => {
+  const a = new class {
+    constructor() {
+      this.x = 10;
+    }
+
+    getX() {
+      return this.x * 2;
+    }
+  };
+
+  expect(a.getX()).toBe(20);
+});
+
+test("inline instantiation with argument", () => {
+  const a = new class {
+    constructor(x) {
+      this.x = x;
+    }
+
+    getX() {
+      return this.x * 2;
+    }
+  }(10);
+
+  expect(a.getX()).toBe(20);
+});
+
+test("extending class expressions", () => {
+  class A extends class {
+    constructor(x) {
+      this.x = x;
+    }
+  } {
+    constructor(y) {
+      super(y);
+      this.y = y * 2;
+    }
+  };
+
+  const a = new A(10);
+  expect(a.x).toBe(10);
+  expect(a.y).toBe(20);
+});
+
+test("class expression name", () => {
+  let A = class {}
+  expect(A.name).toBe("A");
+
+  let B = class C {}
+  expect(B.name).toBe("C");
+});
diff --git a/Libraries/LibJS/Tests/classes/class-getters.js b/Libraries/LibJS/Tests/classes/class-getters.js
new file mode 100644
index 0000000000..b1cf7ad229
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-getters.js
@@ -0,0 +1,68 @@
+test("basic functionality", () => {
+  class A {
+    get x() {
+      return 10;
+    }
+  }
+
+  expect(A).not.toHaveProperty("x");
+  expect(new A().x).toBe(10);
+});
+test("name", () => {
+  class A {
+    get x() {}
+  }
+
+  const d = Object.getOwnPropertyDescriptor(A.prototype, "x");
+  expect(d.get.name).toBe("get x");
+});
+
+test("extended name syntax", () => {
+  class A {
+    get "method with space"() {
+      return 1;
+    }
+
+    get 12() {
+      return 2;
+    }
+
+    get [`he${"llo"}`]() {
+      return 3;
+    }
+  }
+
+  const a = new A();
+  expect(a["method with space"]).toBe(1);
+  expect(a[12]).toBe(2);
+  expect(a.hello).toBe(3);
+});
+
+test("inherited getter", () => {
+  class Parent {
+    get x() {
+      return 3;
+    }
+  }
+
+  class Child extends Parent {}
+
+  expect(Child).not.toHaveProperty("x");
+  expect(new Child().x).toBe(3);
+});
+
+test("inherited getter overriding", () => {
+  class Parent {
+    get x() {
+      return 3;
+    }
+  }
+
+  class Child extends Parent {
+    get x() {
+      return 10;
+    }
+  }
+
+  expect(new Child().x).toBe(10);
+});
diff --git a/Libraries/LibJS/Tests/classes/class-inheritance.js b/Libraries/LibJS/Tests/classes/class-inheritance.js
new file mode 100644
index 0000000000..5fb273ba52
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-inheritance.js
@@ -0,0 +1,133 @@
+test("method inheritance", () => {
+  class Parent {
+    method() {
+      return 3;
+    }
+  }
+
+  class Child extends Parent {}
+
+  const p = new Parent();
+  const c = new Child();
+  expect(p.method()).toBe(3);
+  expect(c.method()).toBe(3);
+});
+
+test("method overriding", () => {
+  class Parent {
+    method() {
+      return 3;
+    }
+  }
+
+  class Child extends Parent {
+    method() {
+      return 10;
+    }
+  }
+
+  const p = new Parent();
+  const c = new Child();
+  expect(p.method()).toBe(3);
+  expect(c.method()).toBe(10);
+});
+
+test("parent method reference with super", () => {
+  class Parent {
+    method() {
+      return 3;
+    }
+  }
+
+  class Child extends Parent {
+    method() {
+      return super.method() * 2;
+    }
+  }
+
+  const p = new Parent();
+  const c = new Child();
+  expect(p.method()).toBe(3);
+  expect(c.method()).toBe(6);
+});
+
+test("child class access to parent class initialized properties", () => {
+  class Parent {
+    constructor() {
+      this.x = 3;
+    }
+  }
+
+  class Child extends Parent {}
+
+  const p = new Parent();
+  const c = new Child();
+  expect(p.x).toBe(3);
+  expect(c.x).toBe(3);
+});
+
+test("child class modification of parent class properties", () => {
+  class Parent {
+    constructor() {
+      this.x = 3;
+    }
+  }
+
+  class Child extends Parent {
+    change() {
+      this.x = 10;
+    }
+  }
+
+  const p = new Parent();
+  const c = new Child();
+  expect(p.x).toBe(3);
+  expect(c.x).toBe(3);
+
+  c.change();
+  expect(c.x).toBe(10);
+});
+
+test("inheritance and hasOwnProperty", () => {
+  class Parent {
+    constructor() {
+      this.x = 3;
+    }
+  }
+
+  class Child extends Parent {
+    method() {
+      this.y = 10;
+    }
+  }
+
+  const p = new Parent();
+  const c = new Child();
+  expect(p.hasOwnProperty("x")).toBeTrue();
+  expect(p.hasOwnProperty("y")).toBeFalse();
+  expect(c.hasOwnProperty("x")).toBeTrue();
+  expect(c.hasOwnProperty("y")).toBeFalse();
+
+  c.method();
+  expect(c.hasOwnProperty("x")).toBeTrue();
+  expect(c.hasOwnProperty("y")).toBeTrue();
+});
+
+test("super constructor call from child class with argument", () => {
+  class Parent {
+    constructor(x) {
+      this.x = x;
+    }
+  }
+
+  class Child extends Parent {
+    constructor() {
+      super(10);
+    }
+  }
+
+  const p = new Parent(3);
+  const c = new Child(3);
+  expect(p.x).toBe(3);
+  expect(c.x).toBe(10);
+});
diff --git a/Libraries/LibJS/Tests/classes/class-methods.js b/Libraries/LibJS/Tests/classes/class-methods.js
new file mode 100644
index 0000000000..4bc04ea5a5
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-methods.js
@@ -0,0 +1,51 @@
+test("basic functionality", () => {
+  class A {
+    number() {
+      return 2;
+    }
+
+    string() {
+      return "foo";
+    }
+  }
+
+  const a = new A();
+  expect(a.number()).toBe(2);
+  expect(a.string()).toBe("foo");
+});
+
+test("length", () => {
+  class A {
+    method1() {}
+
+    method2(a, b, c, d) {}
+
+    method3(a, b, ...c) {}
+  }
+
+  const a = new A();
+  expect(a.method1).toHaveLength(0);
+  expect(a.method2).toHaveLength(4);
+  expect(a.method3).toHaveLength(2);
+});
+
+test("extended name syntax", () => {
+  class A {
+    "method with space"() {
+      return 1;
+    }
+
+    12() {
+      return 2;
+    }
+
+    [`he${"llo"}`]() {
+      return 3;
+    }
+  }
+
+  const a = new A();
+  expect(a["method with space"]()).toBe(1);
+  expect(a[12]()).toBe(2);
+  expect(a.hello()).toBe(3);
+});
diff --git a/Libraries/LibJS/Tests/classes/class-setters.js b/Libraries/LibJS/Tests/classes/class-setters.js
new file mode 100644
index 0000000000..19dbd6ecd2
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-setters.js
@@ -0,0 +1,100 @@
+test("basic functionality", () => {
+  class A {
+    get x() {
+      return this._x;
+    }
+
+    set x(value) {
+      this._x = value * 2;
+    }
+  }
+
+  expect(A.x).toBeUndefined();
+  expect(A).not.toHaveProperty("_x");
+  const a = new A();
+  expect(a.x).toBeUndefined();
+  expect(a).not.toHaveProperty("_x");
+  a.x = 3;
+  expect(a.x).toBe(6);
+  expect(a).toHaveProperty("_x", 6);
+});
+
+test("name", () => {
+  class A {
+    set x(v) {}
+  }
+
+  const d = Object.getOwnPropertyDescriptor(A.prototype, "x");
+  expect(d.set.name).toBe("set x");
+});
+
+test("extended name syntax", () => {
+  class A {
+    set "method with space"(value) {
+      this.a = value;
+    }
+
+    set 12(value) {
+      this.b = value;
+    }
+
+    set [`he${"llo"}`](value) {
+      this.c = value;
+    }
+  }
+
+  const a = new A();
+  a["method with space"] = 1;
+  a[12] = 2;
+  a.hello = 3;
+  expect(a.a).toBe(1);
+  expect(a.b).toBe(2);
+  expect(a.c).toBe(3);
+});
+
+test("inherited setter", () => {
+  class Parent {
+    get x() {
+      return this._x;
+    }
+
+    set x(value) {
+      this._x = value * 2;
+    }
+  }
+
+  class Child extends Parent {}
+
+  const c = new Child();
+
+  expect(c.x).toBeUndefined();
+  c.x = 10;
+  expect(c.x).toBe(20);
+});
+
+test("inherited static setter overriding", () => {
+  class Parent {
+    get x() {
+      return this._x;
+    }
+
+    set x(value) {
+      this._x = value * 2;
+    }
+  }
+
+  class Child extends Parent {
+    get x() {
+      return this._x;
+    }
+
+    set x(value) {
+      this._x = value * 3;
+    }
+  }
+
+  const c = new Child();
+  expect(c.x).toBeUndefined();
+  c.x = 10;
+  expect(c.x).toBe(30);
+});
diff --git a/Libraries/LibJS/Tests/classes/class-static-getters.js b/Libraries/LibJS/Tests/classes/class-static-getters.js
new file mode 100644
index 0000000000..0407bd9a48
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-static-getters.js
@@ -0,0 +1,80 @@
+describe("correct behavior", () => {
+  test("basic functionality", () => {
+    class A {
+      static get x() {
+        return 10;
+      }
+    }
+
+    expect(A.x).toBe(10);
+    expect(new A()).not.toHaveProperty("x");
+  });
+
+  test("name", () => {
+    class A {
+      static get x() {}
+    }
+
+    const d = Object.getOwnPropertyDescriptor(A, "x");
+    expect(d.get.name).toBe("get x");
+  });
+
+  test("extended name syntax", () => {
+    class A {
+      static get "method with space"() {
+        return 1;
+      }
+
+      static get 12() {
+        return 2;
+      }
+
+      static get [`he${"llo"}`]() {
+        return 3;
+      }
+    }
+
+    expect(A["method with space"]).toBe(1);
+    expect(A[12]).toBe(2);
+    expect(A.hello).toBe(3);
+  });
+
+  test("inherited static getter", () => {
+    class Parent {
+      static get x() {
+        return 3;
+      }
+    }
+
+    class Child extends Parent {}
+
+    expect(Parent.x).toBe(3);
+    expect(Child.x).toBe(3);
+  });
+
+  test("inherited static getter overriding", () => {
+    class Parent {
+      static get x() {
+        return 3;
+      }
+    }
+
+    class Child extends Parent {
+      static get x() {
+        return 10;
+      }
+    }
+
+    expect(Parent.x).toBe(3);
+    expect(Child.x).toBe(10);
+  });
+});
+
+describe("errors", () => {
+  test('"get static" is a syntax error', () => {
+    expect(`
+    class A {
+      get static foo() {}
+    }`).not.toEval();
+  });
+});
diff --git a/Libraries/LibJS/Tests/classes/class-static-setters.js b/Libraries/LibJS/Tests/classes/class-static-setters.js
new file mode 100644
index 0000000000..41d867a7e5
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-static-setters.js
@@ -0,0 +1,104 @@
+describe("correct behavior", () => {
+  test("basic functionality", () => {
+    class A {
+      static get x() {
+        return this._x;
+      }
+
+      static set x(value) {
+        this._x = value * 2;
+      }
+    }
+
+    expect(A.x).toBeUndefined();
+    expect(A).not.toHaveProperty("_x");
+    A.x = 3;
+    expect(A.x).toBe(6);
+    expect(A).toHaveProperty("_x", 6);
+  });
+
+  test("name", () => {
+    class A {
+      static set x(v) {}
+    }
+
+    const d = Object.getOwnPropertyDescriptor(A, "x");
+    expect(d.set.name).toBe("set x");
+  });
+
+  test("extended name syntax", () => {
+    class A {
+      static set "method with space"(value) {
+        this.a = value;
+      }
+
+      static set 12(value) {
+        this.b = value;
+      }
+
+      static set [`he${"llo"}`](value) {
+        this.c = value;
+      }
+    }
+
+    A["method with space"] = 1;
+    A[12] = 2;
+    A.hello = 3;
+    expect(A.a).toBe(1);
+    expect(A.b).toBe(2);
+    expect(A.c).toBe(3);
+  });
+
+  test("inherited static setter", () => {
+    class Parent {
+      static get x() {
+        return this._x;
+      }
+
+      static set x(value) {
+        this._x = value * 2;
+      }
+    }
+
+    class Child extends Parent {}
+
+    expect(Child.x).toBeUndefined();
+    Child.x = 10;
+    expect(Child.x).toBe(20);
+  });
+
+  test("inherited static setter overriding", () => {
+    class Parent {
+      static get x() {
+        return this._x;
+      }
+
+      static set x(value) {
+        this._x = value * 2;
+      }
+    }
+
+    class Child extends Parent {
+      static get x() {
+        return this._x;
+      }
+
+      static set x(value) {
+        this._x = value * 3;
+      }
+    }
+
+    expect(Child.x).toBeUndefined();
+    Child.x = 10;
+    expect(Child.x).toBe(30);
+  });
+});
+
+describe("errors", () => {
+  test('"set static" is a syntax error', () => {
+    expect(`
+    class A {
+      set static foo(value) {}
+    }`).not.toEval();
+  });
+});
diff --git a/Libraries/LibJS/Tests/classes/class-static.js b/Libraries/LibJS/Tests/classes/class-static.js
new file mode 100644
index 0000000000..a58cdd7f5d
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-static.js
@@ -0,0 +1,72 @@
+test("basic functionality", () => {
+  class A {
+    static method() {
+      return 10;
+    }
+  }
+
+  expect(A.method()).toBe(10);
+  expect(new A().method).toBeUndefined();
+});
+
+test("extended name syntax", () => {
+  class A {
+    static method() {
+      return 1;
+    }
+
+    static 12() {
+      return 2;
+    }
+
+    static [`he${"llo"}`]() {
+      return 3;
+    }
+  }
+
+  expect(A.method()).toBe(1);
+  expect(A[12]()).toBe(2);
+  expect(A.hello()).toBe(3);
+});
+
+test("bound |this|", () => {
+  class A {
+    static method() {
+      expect(this).toBe(A);
+    }
+  }
+
+  A.method();
+});
+
+test("inherited static methods", () => {
+  class Parent {
+    static method() {
+      return 3;
+    }
+  }
+
+  class Child extends Parent {}
+
+  expect(Parent.method()).toBe(3);
+  expect(Child.method()).toBe(3);
+  expect(new Parent()).not.toHaveProperty("method");
+  expect(new Child()).not.toHaveProperty("method");
+});
+
+test("static method overriding", () => {
+  class Parent {
+    static method() {
+      return 3;
+    }
+  }
+
+  class Child extends Parent {
+    static method() {
+      return 10;
+    }
+  }
+
+  expect(Parent.method()).toBe(3);
+  expect(Child.method()).toBe(10);
+});
diff --git a/Libraries/LibJS/Tests/classes/class-strict-mode.js b/Libraries/LibJS/Tests/classes/class-strict-mode.js
new file mode 100644
index 0000000000..90ead4490f
--- /dev/null
+++ b/Libraries/LibJS/Tests/classes/class-strict-mode.js
@@ -0,0 +1,19 @@
+test("constructors are always strict mode", () => {
+  class A {
+    constructor() {
+      expect(isStrictMode()).toBeTrue();
+    }
+  }
+
+  new A();
+});
+
+test("methods are always strict mode", () => {
+  class A {
+    method() {
+      expect(isStrictMode()).toBeTrue();
+    }
+  }
+
+  new A().method();
+});