keyof works for dynamic properties where keys are strings (although not quite as expected) but not so much with numbers.
TypeScript Version: 2.2.1
Code
const getProperty = <T, P extends keyof T>(key: P, obj: T) => obj[key]
interface Iobj {
[key: number]: any
}
const obj: Iobj = {5: 5}
getProperty(5, obj) // Error: 'Argument of type '5' is not assignable to parameter of type 'never'.'Expected behavior:
No errors (ts should infer that key is of type number here)
Actual behavior:
Error: 'Argument of type '5' is not assignable to parameter of type 'never'.'
keyofworks for dynamic properties where keys are strings (although not quite as expected) but not so much with numbers.TypeScript Version: 2.2.1
Code
Expected behavior:
Actual behavior: