Using Readonly<Class> makes a type incompatible only if there are private fields

[sceutre]

TypeScript Version: 2.3.2

Code

class A { public x:number; }
class B { private x:number; }

let a:A = new A as Readonly<A>; // succeeds
let b:B = new B as Readonly<B>; // type error: Property x is missing in Readonly<B>

class AA { private x:number; }
class BB extends AA {}

let bb:BB = new BB as Readonly<BB>; // type error: Property x is missing in Readonly<BB>

Expected behavior:

To me it appears B and its Readonly are the same (since there are no external visible properties) while A and its Readonly differ in the mutability in x. Although I also think it would be fine if all assignments worked.

I actually noticed this with the case of BB and it being a private field in the super class that caused the assignment to fail.

Actual behavior:

As per code comments

[mhegazy]

mapped types, which Readonly is one, only operate on public fields of a type.

[sceutre]

Ah ok, I was thinking (not very deeply) that the issue was more that the type of a class should similarly only include its public members.

[mhegazy]

Automatically closing this issue for housekeeping purposes. The issue labels indicate that it is unactionable at the moment or has already been addressed.