Failure to use typeof of imports in unions

[joaosoares]

Hello,

I am having a problem when creating unions that use typeof to determine the type of imported variables. So, for example, the following doesn't work:

Example that doesn't work

constants.js

export const PRODUCT_SET_ID: 'PRODUCT_SET_ID' = "PRODUCT_SET_ID"
export const PRODUCT_RESET: 'PRODUCT_RESET' = "PRODUCT_RESET"

actions.js

import {
  PRODUCT_SET_ID,
  PRODUCT_RESET
} from './constants'

export type Action =
  {| type: typeof PRODUCT_SET_ID, id: number |} |
  {| type: typeof PRODUCT_RESET, id: number |}

export const productSetId = (id: number) : Action => ({
  type: PRODUCT_SET_ID,
  id,
})

This returns the error object literal Could not decide which case to select union type Case 1 may work: exact type: object type But if it doesn't, case 2 looks promising too: exact type: object type Please provide additional annotation(s) to determine whether case 1 works (or consider merging it with case 2): identifier 'PRODUCT_SET_ID'

Works without import

If I substitute the imports for inline declarations, the whole example works.

actions.js

export const PRODUCT_SET_ID: 'PRODUCT_SET_ID' = "PRODUCT_SET_ID"
export const PRODUCT_RESET: 'PRODUCT_RESET' = "PRODUCT_RESET"

export type Action =
  {| type: typeof PRODUCT_SET_ID, id: number |} |
  {| type: typeof PRODUCT_RESET, id: number |}

export const productSetId = (id: number) : Action => ({
  type: PRODUCT_SET_ID,
  id,
})

I don't think this should happen, as it makes it harder to separate code into modular files. Any solutions or workarounds to continue using import?

[Hypnosphi]

This reproduces for me in 0.114