Isnt createAction type parameter redundant when creatorFunction used?

[CzBuCHi]

Why createAction(string, fn) has first parameter pressent? Because i dont see difference between these two:

type TYPE = (param: any) => { type: "AAA", payload: { param: any } };

// yours
const action: TYPE = createAction("AAA", (param: any) => ({
  payload: { param },
  type: "AAA",
}));

// mine defined bellow
const action: TYPE = createAction2((param: any) => ({
  payload: { param },
  type: "AAA",
}));

export function createAction2<T extends string, AC extends (...args: any[]) => FluxStandardAction<T>>(
  creator: T | AC,
): AC & TypeGetter<T> {
  let type: T;
  let actionCreator: AC & TypeGetter<T>;

  if (typeof creator === 'string') {
    actionCreator = (() => ({ type })) as AC & TypeGetter<T>;
    type = creator;
  } else if (typeof creator === 'function') {
    actionCreator = creator as AC & TypeGetter<T>;
    type = actionCreator().type;
  } else {
    throw new Error('argument must be of type string or function');
  }

  (actionCreator as TypeGetter<T>).getType = () => type;
  return actionCreator;
}

only thing, that is funky is calling creatorFunction to determine action type ...

Why? Lazynest :) - currenly i need to write action type twice ....

PS: Tryied to create PR, but same code fails to compile in fork project (compiles in my test project)

[piotrwitek]

The problem is this:

// yours really is these two together
type TYPE = (param: any) => { type: "AAA", payload: { param: any } };
// +
const action: TYPE = createAction2((param: any) => ({
  payload: { param },
  type: "AAA",
}));

// mine is really only a decorator - I do not need the extra TYPE declaration which is twice more boilerplate
// moreover I will get rid of first param in TS 2.8 :) double win
const action = createAction("AAA", (param: any) => ({
  payload: { param },
  type: "AAA",
}));

[CzBuCHi]

thx for explaining this - btw: i used TYPE only to validate creataAction return type ... didnt check "real" return type of my fn ...