About initialState

[namjul]

I am wondering why redux-immutable has no default state.

redux-immutable/src/combineReducers.js

Line 13 in ac78103

return (inputState, action) => {

Redux combineReducers has a default value. https://github.com/reactjs/redux/blob/6870b826b6b1bea7e7aec67a4ed88d139bd382cd/src/combineReducers.js#L111

I tried to nest redux-immutable combineReducers but it throws Cannot read property 'withMutations' of undefined because I did not specify the nested property in my global initialState Object.

Shouldn't it work without specifying the initialState.

[gajus]

What is the problem with explicitly passing Immutable.Map() as the initial value?

[namjul]

thats fine, just pointing out that without it, it throws an error and because of
reduxjs/redux#1189 (comment)
that maybe it should be possible to not specific an initialstate

[lukaskostial]

Shouldn't there be an option to let reducers (even those dynamically loaded) to define their initial state via default parameter ?

[gajus]

Shouldn't there be an option to let reducers (even those dynamically loaded) to define their initial state via default parameter ?

Are you saying something different from what was already said?

[lukaskostial]

What is the problem with explicitly passing Immutable.Map() as the initial value?

The problem is when you dynamically load a module and want to updateReducers but don't what to update initialState (not sure if it's even possible but I'm not that familiar with redux yet). Plus your dynamically-loaded reducer is also produced by redux-immutable combineReducers.

[gajus]

I am just not following you, at all. For me to further assist with this issue, I'd need a code example.

[lukaskostial]

I'm sorry I didn't make myself clear. What I meant is below:

import { createStore } from 'redux'
import { combineReducers } from 'redux-immutable'
import { Map } from 'immutable'

const reducerA = (state = "A", action) => state
const reducerB = (state = "B", action) => state

const createReducer = (additionalReducers) => {
    return combineReducers({
      ...additionalReducers,
      a: reducerA,
      b: reducerB
    })
}
// Create store with empty initial state
const store = createStore(createReducer(), Map({}))
console.log(store.getState().toJS())

// Then dynamically load another module with reducerC (e.g. via SystemJS System.import)

const reducerC = (state = "C", action) => state
const reducerD = (state = "D", action) => state

const newModuleReducer = combineReducers({
  c: reducerC,
  d: reducerD
})

// Add the loaded reducer to the store. The store structure should be:
// {
//  a: "A",
//  b: "B",
//  inner: { c: "C", d: "D" }
// }
store.replaceReducer(createReducer({inner: newModuleReducer}))

console.log(store.getState().toJS())

This works OK with standard redux.