Type narrowing: checking variable object key existence when noUncheckedIndexedAccess is true

Question

I have "noUncheckedIndexedAccess": true in my tsconfig.json. The whole point of the switch is to force the check of existence of the item at an index before accessing it.

👉 I struggle to do the check for object with a variable key:

Say I have the following structure:

const items: Record<string, {name: string}> = {
  '123': {
    name: 'asdf'
  }
}

when I try to check the existence using a literal key, the type narrowing works ok:

if (items['123']) {
  // OK: Compiles no problem
  console.log(items['123'].name)
}

If I try to check the existence using a variable key, the compiler starts to complain.

const id = '123';
if (items[id]) {
  // ERROR: items[id] - Object possibly undefined
  console.log(items[id].name)
}

👉 Why is it not possible to check the existence that way?

I tried even different checks:

if (id in items) {}
if (items.hasOwnProperty(id)) {}
if (typeof items[id] !== 'undefined') {}

no luck there.

The only thing that worked was

const id = '123';
const item = items[id];
if (item) {
  // OK
  console.log(item.name)
}

I find it a bit too chatty, though.

▶️ Examples above in TypeScript Playground

Environment: TypeScript v4.5.4