Flowtype and Promise.resolve

index.js

// @flow

// BAD
// Will throw this type error:
// ‘undefined This type is incompatible with some incompatible instantiation of `T`’
const resolve = <T> (init?: T): Promise<T>  => Promise.resolve(init)

// GOOD
// The return promise type is `?T`, i.e. nullable T
const resolve = <T> (init?: T): Promise<?T> => Promise.resolve(init)

flow shouldn't throw anything if you make init required :)

@stryju, Yeah, but then it would be kind of simple, right? 😄

I mean, I want init optional. (BTW, as it is for Promise.resolve.)