Incorrect type inference with nullish coalescing operator

[starsolaris]

TypeScript Version: 3.8.3, Nightly

Search Terms: nullish coalescing operator, type inference

Code

(a: { a: {} | undefined}) => {
    const b = a?.a ?? "";    
}

Expected behavior:
type of b should inferred as: {} | ""
Actual behavior:
type of b is inferred as: {}

Playground Link: Provided

Related Issues: #36393

[DanielRosenwasser]

This is because {} is a supertype of string. The object type has the same structure implied by {}, but explicitly rejects direct compatibility with primitives like string.

[typescript-bot]

This issue has been marked 'Working as Intended' and has seen no recent activity. It has been automatically closed for house-keeping purposes.