Closed
Description
Bug Report
π Search Terms
narrow property const
π Version & Regression Information
4.9.0-dev.20221025
β― Playground Link
Playground link with relevant code
π» Code
interface Data {
a?: number
}
declare const data: Data
let key = 'a' as const
if (data.a !== undefined) {
key // "a"
const a = data[key] // number | undefined
const b = data['a'] // number
}
π Actual behavior
data[key]
is number | undefined
π Expected behavior
data[key]
is narrowed to number