createAsyncAction incorrect ReturnType for an array with 2 elements whose types are known

[egonm12]

Description

The return type of my async actions are not as expected. When I want my payload shape to be [string, string] it somehow returns payload: string; meta: string. This is not the case when I would do [string, string, string]. In that case payload is of type [string, string, string].

How to Reproduce

import { createAsyncAction } from "typesafe-actions";

const myAsyncActions = createAsyncAction(
  "FETCH_BEGIN",
  "FETCH_SUCCESS",
  "FETCH_FAILURE",
)<[string, string], undefined, undefined>()

type MyType = ReturnType<typeof myAsyncActions.request>;

Expected behavior

MyType = {
  type: "FETCH_BEGIN";
  payload: [string, string]
}

Actual behavior

MyType = {
  type: "FETCH_BEGIN";
  payload: string;
  meta: string;
}

Suggested solution(s)

Not looked into possible solutions yet

Project Dependencies

• Typesafe-Actions Version: ^5.1.0
• TypeScript Version:^3.6.3
• tsconfig.json:

  {
  "compilerOptions": {
    "experimentalDecorators": true,
  "target": "es5",
  "lib": [
    "dom",
    "dom.iterable",
    "esnext"
  ],
  "allowJs": true,
  "baseUrl": ".",
  "skipLibCheck": true,
  "esModuleInterop": true,
  "allowSyntheticDefaultImports": true,
  "strict": true,
  "forceConsistentCasingInFileNames": true,
  "module": "esnext",
  "moduleResolution": "node",
  "resolveJsonModule": true,
  "noEmit": true,
  "jsx": "preserve",
  "isolatedModules": true
  },
  "include": [
  "src",
  "node_modules/eslint-plugin-react/lib/types.d.ts"
  ]
  }

[piotrwitek]

It's by design to allow a way to define both payload and meta. If you want to use a tuple as type argument please use payload + meta syntax:

const myAsyncActions = createAsyncAction(
  'FETCH_BEGIN',
  'FETCH_SUCCESS',
  'FETCH_FAILURE'
)<[[string, string], undefined], undefined, undefined>();