Changing object property type with Object.assign()

[quarryman]

Given I have value of exact type A and want to transform it to exact type B using Object.assign

type Coordinates = {|
  lat: number,
  lon: number,
|}

type RawCoordinates = {|
  lat: number,
  lon: string,
|}

const c1: Coordinates = { lat: 1, lon: 2 }
const c2: RawCoordinates = { lat: 1, lon: 'two' }

const merged: RawCoordinates = Object.assign(c1, c2);

const merged2: RawCoordinates = Object.assign({}, c1, c2);

How to avoid flow error using Object.assign/spread/ any other option of changing property type?

Try Flow

There are similar issues however they address reassigning object property to the value of the same type, while I need reassign to another type

[jamesisaac]

I think this would be solved by #7298

[SamChou19815]

Going forward, we will likely only supporting object spreads well.