String literal types aren't inferred from object literals when using generics #26621

declare function f<T>(arg:  T ): void

f({ someKey: 'C' }) // someKey's type is (incorrectly) inferred as 'C'
f<{someKey: 'C'}>({ someKey: 'C' }) // someKey's type is (correctly) inferred as 'C'

import {Option, some, none} from 'fp-ts/lib/Option'

type Player = 'black' | 'white'

type WinCondition =
    | { type: 'win', player: Player }
    | { type: 'draw' }```

const checkWin = (someArg: number): Option<WinCondition> => {
    return some({ type: 'draw' })
  // ^-- Type '{ type: string; }' is not assignable to type '{ type: "draw"; }'
}