createStandardAction / createAsyncAction with optional payload not working after upgrade from v3 to v4

[unekinn]

Description

As described in the migration guide, I've replaced void with undefined in calls to createStandardAction and createAsyncAction.

However, this breaks a few actions where the payload type was SomeType | void. This would previously create an action that could be called both with and without a payload. Now, I have to explicitly send undefined as the payload.

Interestingly, if I revert the change of void to undefined throughout my codebase's calls to create*Action, everything seems to work as expected. Is the move to undefined actually necessary?

Steps to Reproduce

import { createStandardAction } from 'typesafe-actions'
const payloadOrUndefined = createStandardAction('ACTION1')<
  number | undefined
>();
// Fails to typecheck:
// Expected 1 arguments, but got 0
// type-helpers.d.ts(69, 72): An argument for 'payload' was not provided.
payloadOrUndefined();

CodeSandbox to help you reproduce issue in isolation https://codesandbox.io/s/typesafe-actions-reference-project-85nbn

Expected behavior

payloadOrUndefined() defined above should return an action with type

{ type: 'ACTION1', payload: number | undefined }

instead of failing to typecheck

Suggested solution(s)

Project Dependencies

• Typesafe-Actions Version: 4.4.2
• TypeScript Version: 3.6.3
• tsconfig.json:

  {
  "compilerOptions": {
  "strict": true
  }
  }

[piotrwitek]

Hey @larskinn I confirm it is working in the most recent version so I might update the migration guide on this point.

[piotrwitek]

Closed by 8f6b2a40a04f4c99baf49dd3120271d439a3a0b0