Implementation of inheritance not compatible with Object.getOwnPropertyNames()

[haseebeqx]

TypeScript Version: 2.12.0

Code

class A{
private n :number= 1;
public x :number =2;
protected y: number =3;
}
class B extends A{
private m :number = 2;
}

var obj = new B();
console.log(Object.getOwnPropertyNames(obj)); 

Expected behavior:
this should only give ['m']

Actual behavior:
this when running with nodejs compiled with commonjs module gives [ 'n', 'x', 'y', 'm' ]

[aluanhaddad]

See this comment #10425 (comment) and the question above it.

[mhegazy]

should be addressed by #12488

[RyanCavanaugh]

This is the expected behavior