Union of objects with union property is not eliminated

[awerlogus]

Bug Report

🔎 Search Terms object property union elimination

⏯ Playground Link

Playground link with relevant code

💻 Code

type A = { a: '1', b: string } | { a: '2' | '3' }

declare const a: A

if (a.a !== '2' && a.a !== '3') {
  // (property) a: "1"
  a.a

  // Property 'b' does not exist on type 'A'.
  //   Property 'b' does not exist on type '{ a: "2" | "3"; }'.(2339)
  a.b
}

🙁 Actual behavior

Error: Property 'b' does not exist on type 'A'.

🙂 Expected behavior

No error

[MartinJohns]

Duplicate of #43026 (comment).

[typescript-bot]

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