Method class enumerable

[sant123]

TypeScript Version: 2.2.2

Code

class Person {
    greet() { }
    bye() { }
}

function checkProperties(obj) {
    console.log("Keys found in (for-in):");
    for (let key in obj) {
        console.log(`Found key: ${key}`);
    }
}

let p = new Person();

checkProperties(p);

Expected behavior:
ES5 or ES6 target, the methods should be non-enumerable.

Actual behavior:
In ES5 the methods are enumerable.

[jwbay]

Duplicate of #782? Also see #9769

[sant123]

None of them @jwbay, properties should be enumerable according with ES6 Classes. Using Object.keys() or for-in loop shows the properties. However, this is not the case for methods.

[jwbay]

When dealing with ES5 class constructs, methods are just prototype 'properties' that happen to be functions.

[sant123]

Exactly but not in ES6, and the transpile from ES6 to ES5 should be equal right? I mean, if I change my target from ES5 to ES6 and in a part of my code I was using Object.keys() or for-in loop for getting name methods; the code will not work.

[MadaraUchiha]

As mentioned in #22354, also applies to static methods. Still occurs in 2.7.0.

[RyanCavanaugh]

The impact of this is pretty small in practice and ES5 runtimes are getting pretty rare. We don't intend to address this given the other churn it would necessitate.