ladybird/Libraries/LibJS/Tests/functions/constructor-basic.js

test("basic functionality", () => {
  function Foo() {
    this.x = 123;
  }

  expect(Foo.prototype.constructor).toBe(Foo);

  const foo = new Foo();
  expect(foo.constructor).toBe(Foo);
  expect(foo.x).toBe(123);
});