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Distinguish missing and undefined #16524
Description
Typescript should distinguish missing and undefined at the type level in order to distinguish the following two statements:
// @strictNullChecks: true
type A = { x?: string }
let x: A = {}
let y: A = { x: undefined } // should not be allowed, but currently is
Activity
dgoldstein0 commentedon Jun 14, 2017
I believe this is a dupe of #13195
mhegazy commentedon Jun 14, 2017
you are right. closing.