Can't call functions of classes derived from built-in classes #113
Description
Consider the following code that works as expected:
class Base {
fn() { return 'fn'; }
}
class Derived extends Base {
constructor() {
super();
this.foo = () => { return 'foo'; };
}
bar() { return 'bar'; }
get baz() { return 'baz'; }
}
const obj = new Derived();
console.log(Object.getOwnPropertyNames(Base.prototype)); // constructor,fn
console.log(Object.getOwnPropertyNames(Derived.prototype)); // constructor,bar,baz
console.log(Object.getOwnPropertyNames(obj)); // foo
console.log(obj.fn()); // fn
console.log(obj.foo()); // foo
console.log(obj.bar()); // bar
console.log(obj.baz); // baz
console.log(obj.foo === undefined); // false
console.log(obj.bar === undefined); // false
console.log(obj.baz === undefined); // falseWhen you try to do the same thing by extending builtins:
class MyRequest extends Request {
constructor(input, init) {
super(input, init);
this.foo = () => { return 'foo'; };
}
bar() { return 'bar'; }
get baz() { return 'baz'; }
}
const request = new MyRequest('https://www.google.com/');
console.log(Object.getOwnPropertyNames(Request.prototype)); // constructor,method,url,version,headers,body,bodyUsed,arrayBuffer,json,text,setCacheOverride
console.log(Object.getOwnPropertyNames(MyRequest.prototype)); // ** constructor,bar,baz
console.log(Object.getOwnPropertyNames(request)); // foo
console.log(request.url); // https://www.google.com/
console.log(request.foo()); // foo
console.log(request.bar()); // ** Error: request.bar is not a function
console.log(request.baz); // ** undefined
console.log(request.foo === undefined); // false
console.log(request.bar === undefined); // ** true
console.log(request.baz === undefined); // ** trueLook at the logs relating to bar and baz (marked with asterisks above). You can see that the two methods (bar method and baz getter) added through the class definition are added to the prototype but have undefined values. Note that the property added in the constructor (foo) does work, however.
The same problem happens whether we are extending Request, Response, Headers, URL, URLSearchParams, etc. so I believe it is just for the builtins, and I believe it's a bug.
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