Revert "throw if getState, subscribe, or unsubscribe called while dispatching" (#1882)

Author: gaearon

src/createStore.js

@@ -72,14 +72,6 @@ export default function createStore(reducer, preloadedState, enhancer) {
    * @returns {any} The current state tree of your application.
    */
   function getState() {
-    if (isDispatching) {
-      throw new Error(
-        'You may not call store.getState() while the reducer is executing. ' +
-        'The reducer has already received the state as an argument. ' +
-        'Pass it down from the top reducer instead of reading it from the store.'
-      )
-    }
-
     return currentState
   }
 
@@ -111,15 +103,6 @@ export default function createStore(reducer, preloadedState, enhancer) {
       throw new Error('Expected listener to be a function.')
     }
 
-    if (isDispatching) {
-      throw new Error(
-        'You may not call store.subscribe() while the reducer is executing. ' +
-        'If you would like to be notified after the store has been updated, subscribe from a ' +
-        'component and invoke store.getState() in the callback to access the latest state. ' +
-        'See http://redux.js.org/docs/api/Store.html#subscribe for more details.'
-      )
-    }
-
     var isSubscribed = true
 
     ensureCanMutateNextListeners()
@@ -130,13 +113,6 @@ export default function createStore(reducer, preloadedState, enhancer) {
         return
       }
 
-      if (isDispatching) {
-        throw new Error(
-          'You may not unsubscribe from a store listener while the reducer is executing. ' +
-          'See http://redux.js.org/docs/api/Store.html#subscribe for more details.'
-        )
-      }
-
       isSubscribed = false
 
       ensureCanMutateNextListeners()

test/createStore.spec.js

@@ -1,14 +1,6 @@
 import expect from 'expect'
 import { createStore, combineReducers } from '../src/index'
-import { 
-  addTodo, 
-  dispatchInMiddle, 
-  getStateInMiddle,
-  subscribeInMiddle,
-  unsubscribeInMiddle,
-  throwError, 
-  unknownAction 
-} from './helpers/actionCreators'
+import { addTodo, dispatchInMiddle, throwError, unknownAction } from './helpers/actionCreators'
 import * as reducers from './helpers/reducers'
 import * as Rx from 'rxjs'
 import $$observable from 'symbol-observable'
@@ -461,31 +453,6 @@ describe('createStore', () => {
     ).toThrow(/may not dispatch/)
   })
 
-  it('does not allow getState() from within a reducer', () => {
-    const store = createStore(reducers.getStateInTheMiddleOfReducer)
-
-    expect(() =>
-      store.dispatch(getStateInMiddle(store.getState.bind(store)))
-    ).toThrow(/You may not call store.getState()/)
-  })
-
-  it('does not allow subscribe() from within a reducer', () => {
-    const store = createStore(reducers.subscribeInTheMiddleOfReducer)
-
-    expect(() =>
-      store.dispatch(subscribeInMiddle(store.subscribe.bind(store, () => {})))
-    ).toThrow(/You may not call store.subscribe()/)
-  })
-
-  it('does not allow unsubscribe from subscribe() from within a reducer', () => {
-    const store = createStore(reducers.unsubscribeInTheMiddleOfReducer)
-    const unsubscribe = store.subscribe(() => {})
-
-    expect(() =>
-      store.dispatch(unsubscribeInMiddle(unsubscribe.bind(store)))
-    ).toThrow(/You may not unsubscribe from a store/)
-  })
-
   it('recovers from an error within a reducer', () => {
     const store = createStore(reducers.errorThrowingReducer)
     expect(() =>

test/helpers/actionCreators.js

@@ -1,12 +1,4 @@
-import { 
-  ADD_TODO, 
-  DISPATCH_IN_MIDDLE, 
-  GET_STATE_IN_MIDDLE, 
-  SUBSCRIBE_IN_MIDDLE,
-  UNSUBSCRIBE_IN_MIDDLE, 
-  THROW_ERROR, 
-  UNKNOWN_ACTION 
-} from './actionTypes'
+import { ADD_TODO, DISPATCH_IN_MIDDLE, THROW_ERROR, UNKNOWN_ACTION } from './actionTypes'
 
 export function addTodo(text) {
   return { type: ADD_TODO, text }
@@ -34,27 +26,6 @@ export function dispatchInMiddle(boundDispatchFn) {
   }
 }
 
-export function getStateInMiddle(boundGetStateFn) {
-  return {
-    type: GET_STATE_IN_MIDDLE,
-    boundGetStateFn
-  }
-}
-
-export function subscribeInMiddle(boundSubscribeFn) {
-  return {
-    type: SUBSCRIBE_IN_MIDDLE,
-    boundSubscribeFn
-  }
-}
-
-export function unsubscribeInMiddle(boundUnsubscribeFn) {
-  return {
-    type: UNSUBSCRIBE_IN_MIDDLE,
-    boundUnsubscribeFn
-  }
-}
-
 export function throwError() {
   return {
     type: THROW_ERROR

test/helpers/actionTypes.js

@@ -1,7 +1,4 @@
 export const ADD_TODO = 'ADD_TODO'
 export const DISPATCH_IN_MIDDLE = 'DISPATCH_IN_MIDDLE'
-export const GET_STATE_IN_MIDDLE = 'GET_STATE_IN_MIDDLE'
-export const SUBSCRIBE_IN_MIDDLE = 'SUBSCRIBE_IN_MIDDLE'
-export const UNSUBSCRIBE_IN_MIDDLE = 'UNSUBSCRIBE_IN_MIDDLE'
 export const THROW_ERROR = 'THROW_ERROR'
 export const UNKNOWN_ACTION = 'UNKNOWN_ACTION'

test/helpers/reducers.js

@@ -1,11 +1,4 @@
-import { 
-  ADD_TODO, 
-  DISPATCH_IN_MIDDLE, 
-  GET_STATE_IN_MIDDLE, 
-  SUBSCRIBE_IN_MIDDLE,
-  UNSUBSCRIBE_IN_MIDDLE,
-  THROW_ERROR 
-} from './actionTypes'
+import { ADD_TODO, DISPATCH_IN_MIDDLE, THROW_ERROR } from './actionTypes'
 
 
 function id(state = []) {
@@ -53,36 +46,6 @@ export function dispatchInTheMiddleOfReducer(state = [], action) {
   }
 }
 
-export function getStateInTheMiddleOfReducer(state = [], action) {
-  switch (action.type) {
-    case GET_STATE_IN_MIDDLE:
-      action.boundGetStateFn()
-      return state
-    default:
-      return state
-  }
-}
-
-export function subscribeInTheMiddleOfReducer(state = [], action) {
-  switch (action.type) {
-    case SUBSCRIBE_IN_MIDDLE:
-      action.boundSubscribeFn()
-      return state
-    default:
-      return state
-  }
-}
-
-export function unsubscribeInTheMiddleOfReducer(state = [], action) {
-  switch (action.type) {
-    case UNSUBSCRIBE_IN_MIDDLE:
-      action.boundUnsubscribeFn()
-      return state
-    default:
-      return state
-  }
-}
-
 export function errorThrowingReducer(state = [], action) {
   switch (action.type) {
     case THROW_ERROR: