String type autocomplete doesn't work with union

[cevek]

TypeScript Version: 3.1.0-dev.20180717

Search Terms:

Code

type A = 'A' | 'B';
type B<T extends A> = {};
type C = B<'A'> // works fine
// but if you want specify second item by using union autocomplete stops working
type C = B<'A' | 'B'>

// helpful usage
var x: Pick<A, 'A' | 'B'>

Expected behavior:

Actual behavior:

Playground Link:

Related Issues: