ladybird/Libraries/LibJS/Tests/classes/class-inheritance.js

534 lines
12 KiB
JavaScript

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);
});
test("advanced 'extends' RHS", () => {
const foo = {
bar() {
return {
baz() {
return function () {
return function () {
return { quux: Number };
};
};
},
};
},
};
class Foo extends foo.bar()["baz"]()`qux`().quux {}
expect(new Foo()).toBeInstanceOf(Number);
});
test("issue #7045, super constructor call from child class in catch {}", () => {
class Parent {
constructor(x) {
this.x = x;
}
}
class Child extends Parent {
constructor() {
try {
throw new Error("Error in Child constructor");
} catch (e) {
super(e.message);
}
}
}
const c = new Child();
expect(c.x).toBe("Error in Child constructor");
});
test("Issue #7044, super property access before super() call", () => {
class Foo {
constructor() {
super.bar;
}
}
new Foo();
});
test("Issue #8574, super property access before super() call", () => {
var hit = false;
class Foo extends Object {
constructor() {
expect(() => {
const foo = super.bar();
}).toThrowWithMessage(ReferenceError, "|this| has not been initialized");
hit = true;
}
}
// Note: We catch two exceptions here.
expect(() => {
new Foo();
}).toThrowWithMessage(ReferenceError, "|this| has not been initialized");
expect(hit).toBeTrue();
});
test("can access super via direct eval", () => {
let superCalled = false;
const aObject = { a: 1 };
const bObject = { b: 2 };
class A {
constructor() {
superCalled = true;
}
foo() {
return aObject;
}
bar() {
return bObject;
}
}
class B extends A {
constructor() {
eval("super()");
}
}
expect(() => {
new B();
}).not.toThrow();
expect(superCalled).toBeTrue();
superCalled = false;
class C extends A {
constructor() {
eval("super()");
return eval("super.foo()");
}
}
expect(() => {
new C();
}).not.toThrow();
expect(superCalled).toBeTrue();
superCalled = false;
expect(new C()).toBe(aObject);
expect(superCalled).toBeTrue();
superCalled = false;
class D extends A {
constructor() {
eval("super()");
return eval("super['bar']()");
}
}
expect(() => {
new D();
}).not.toThrow();
expect(superCalled).toBeTrue();
superCalled = false;
expect(new D()).toBe(bObject);
expect(superCalled).toBeTrue();
});
test("cannot access super via indirect eval", () => {
const indirect = eval;
let superCalled = false;
const aObject = { a: 1 };
const bObject = { b: 1 };
class A {
constructor() {
superCalled = true;
this.a = aObject;
this.c = bObject;
}
}
class B extends A {
constructor() {
indirect("super()");
}
}
expect(() => {
new B();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(superCalled).toBeFalse();
class C extends A {
constructor() {
super();
return indirect("super.a");
}
}
expect(() => {
new C();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(superCalled).toBeTrue();
superCalled = false;
class D extends A {
constructor() {
super();
return indirect("super['b']");
}
}
expect(() => {
new D();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(superCalled).toBeTrue();
});
test("super outside of derived class fails to parse", () => {
expect("super").not.toEval();
expect("super()").not.toEval();
expect("super.a").not.toEval();
expect("super['b']").not.toEval();
expect("function a() { super }").not.toEval();
expect("function a() { super() }").not.toEval();
expect("function a() { super.a }").not.toEval();
expect("function a() { super['b'] }").not.toEval();
expect("() => { super }").not.toEval();
expect("() => { super() }").not.toEval();
expect("() => { super.a }").not.toEval();
expect("() => { super['b'] }").not.toEval();
expect("class A { constructor() { super } }").not.toEval();
expect("class A { constructor() { super() } }").not.toEval();
expect(() => {
eval("super");
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(() => {
eval("super()");
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(() => {
eval("super.a");
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(() => {
eval("super['b']");
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
function a() {
eval("super");
}
expect(() => {
a();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(() => {
new a();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
function b() {
eval("super()");
}
expect(() => {
b();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(() => {
new b();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
function c() {
eval("super.a");
}
expect(() => {
c();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(() => {
new c();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
function d() {
eval("super['b']");
}
expect(() => {
d();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
expect(() => {
new d();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
const e = () => eval("super");
expect(() => {
e();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
const f = () => eval("super()");
expect(() => {
f();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
const g = () => eval("super.a");
expect(() => {
g();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
const h = () => eval("super['b']");
expect(() => {
h();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
class I {
constructor() {
eval("super");
}
}
expect(() => {
new I();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
class J {
constructor() {
eval("super()");
}
}
expect(() => {
new J();
}).toThrowWithMessage(SyntaxError, "'super' keyword unexpected here");
});
test("When no constructor on deriving class @@iterator of %Array.prototype% is not visibly called", () => {
const oldIterator = Array.prototype[Symbol.iterator];
var calls = 0;
Array.prototype[Symbol.iterator] = function () {
++calls;
expect().fail("Called @@iterator");
};
class Base {
constructor(value1, value2) {
this.value1 = value1;
this.value2 = value2;
}
}
class Derived extends Base {}
const noArgumentsDerived = new Derived();
expect(noArgumentsDerived.value1).toBeUndefined();
expect(noArgumentsDerived.value2).toBeUndefined();
expect(noArgumentsDerived).toBeInstanceOf(Base);
expect(noArgumentsDerived).toBeInstanceOf(Derived);
const singleArgumentDerived = new Derived(1);
expect(singleArgumentDerived.value1).toBe(1);
expect(singleArgumentDerived.value2).toBeUndefined();
const singleArrayArgumentDerived = new Derived([1, 2]);
expect(singleArrayArgumentDerived.value1).toEqual([1, 2]);
expect(singleArrayArgumentDerived.value2).toBeUndefined();
const doubleArgumentDerived = new Derived(1, 2);
expect(doubleArgumentDerived.value1).toBe(1);
expect(doubleArgumentDerived.value2).toBe(2);
expect(calls).toBe(0);
class Derived2 extends Base {
constructor(...args) {
super(...args);
}
}
expect(() => {
new Derived2();
}).toThrowWithMessage(ExpectationError, "Called @@iterator");
expect(calls).toBe(1);
Array.prototype[Symbol.iterator] = oldIterator;
// Now Derived2 is fine again.
expect(new Derived2()).toBeInstanceOf(Derived2);
expect(calls).toBe(1);
});
test("constructor return value overrides inheritance and property initialization", () => {
let calls = 0;
class Base {
constructor() {
this.prop = 1;
calls++;
}
}
class Derived extends Base {
constructor() {
super();
// Return an empty object instead of Derived/Base object
return {};
}
}
let object = new Derived();
expect(calls).toBe(1);
expect(typeof object.prop).toBe("undefined");
expect(object instanceof Derived).toBe(false);
expect(object instanceof Base).toBe(false);
});