Spread operator fails when deeply overriding objects

[pierpo]

Hi,

I am trying to override an object with an enriched version of it using the spread operator but flow does not seem to understand.

Am I doing something wrong?

Example here

As you can see, the A and B types are the same, but the key user of the type B has one more field.
When I create a new object of type B by copying my object of type A with a spread operation and adding the new value through it, Flow gives an error.

// @flow

type A = {|
  stuff: string,
  user: {|
    name: string,
  |}
|}

type B = {|
  stuff: string,
  user: {|
    name: string,
    address: string,
  |},
|}

function tester(a: A): B {
  const b = {
    ...a,
    user: {
      ...a.user,
      address: 'hello'
    }
  };

  return b;
}

gives

27:   return b;
             ^ Cannot return `b` because property `address` is missing in object type [1] but exists in object type [2] in property `user`.
References:
5:   user: {|           ^ [1]
12:   user: {|            ^ [2]

Might be related to this issue.

Thanks for your help :)

[wchargin]

Duplicate of #6108.

[pierpo]

Indeed. Didn't find it, sorry about that 😉

[wchargin]

No problem.