Type inference is broken for `array().of(...)`: union type turns into unknown

Describe the bug

import yup from 'yup'

const alphabet = ['a', 'b', 'c'] as const
const letter = yup.mixed().oneOf(alphabet).required() // MixedSchema<"a" | "b" | "c">
const word = yup.array().of(letter) // NotRequiredArraySchema<unknown>, should be <"a" | "b" | "c"> instead of unknown

To Reproduce https://codesandbox.io/s/adoring-wing-xss7k?file=/src/index.ts

Version

@types/yup: 0.29.6
yup: 0.29.3

[vamshisuram]

@amankkg Hey. I am new here. Just trying to check the issue out. It seems the codesandbox is incomplete. Can you please take a look?

[jquense]

types aren’t maintained here currently open an Issue on DT for any type issues please