Microsoft/TypeScript
Inconsistency between element access and object destruction
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#59.571 geöffnet am 09.08.2024
Domain: check: Type InferenceHelp WantedPossible Improvement
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Beschreibung
🔎 Search Terms
destruct object
🕗 Version & Regression Information
Before v4.4.4, index expression in element access was also not inferred as const. So this issue starts from v4.4.4. Reproducible in Nightly build.
⏯ Playground Link
💻 Code
let n = 1 as const
const o = { a1: "abcd" }
const x = o[`a${n}`]
// ^? : string
const { [`a${n}`]: y } = o
// ^? Errors: Type '{ a1: string; }' has no matching index signature for type 'string'.(2537)
🙁 Actual behavior
`a${n}` in object destruction not inferred as const ("a1")
🙂 Expected behavior
`a${n}` in object destruction should be inferred as "a1", just like the one in element access.
Additional information about the issue
A possible workaround is to add as const after `a${n}`. I think the main problem is the inconsistency between element access and object destruction, which is confusing.