🔎 Search Terms

T to null

🕗 Version & Regression Information

• This is a type narrowing issue
• This is the behavior in every version I tried

⏯ Playground Link

https://www.typescriptlang.org/play?ts=5.5.0-pr-57465-110#code/GYVwdgxgLglg9mABDAzgORAG0wHgCoB8AFAG4CGmIApgFyJ4CUiA3gFAD07i3P3AegH5W3GMESkK1RAF5ZiMFkxM2vcpSrdO9ADSIUACzhYAJogBGGhdmGIAvqxsAnKlBCOkaqbOnzFAblZ7IA

💻 Code

function isNull<T>(value: T) {
  if (value === null) {
    value  // T, should be null
  }

  return value === null;
}

🙁 Actual behavior

value is T inside the if block of value === null (explicit comparison)

🙂 Expected behavior

value should be of type null inside the if block of value === null

Additional information about the issue

No response