Change position of extra arguments from `withExtraArgument`

[smeijer]

I love to use the feature of thunk.withExtraArgument to pass along a context to my thunks. For example an API or in my case meteor / mongo collections.

However what's confusing me, and to be honest doesn't look very nice in my code. Is that redux-thunk has a different signature than redux-saga regarding to passing along extra arguments.

Redux-saga supports passing along extra arguments when starting the sagas trough: sagaMiddleware.run(saga, context). I'm not talking about the initialization code, just adding that snippet to add some context.

// store init code
const context = { fetch: () => ({ data: 'foobar' }) };
thunkMiddleware.withExtraArgument(context)
sagaMiddleware.run(saga, context);

What I'm talking about is the next two signatures. One of a thunk and a saga.

// thunk signature
export function (payload) {
  return function(dispatch, getState, context) {
    const { data } = context.fetch(payload);
    dispatch({ type: 'FETCH_SUCCESS', payload: data });
  }
}

// saga signature
export function* saga(context, { payload }) {
  const { data } = yield call(context.fetch, payload);
  yield put({ type: 'FETCH_SUCCESS', payload: data });
}

Where redux-thunk adds context as last argument to the thunk, redux-saga adds it as first argument to the saga. This difference is somewhat error-prone.

Is it possible to change the behavior of withExtraArgument to add the context as first argument? I guess it shouldn't be that difficult to make it configurable, due to the decision to only support a single extra argument, as written here: #70 (comment)

It's not that it is a big issue, or a deal-braker or anything like that. But it can be confusing sometimes.

[batjko]

FWIW, having the context as its first argument, would also enable some nice currying use cases, people might want to make use of.
Not that the other way around isn't attractive for the same reason.