Fixes #582 (Nested Provider subscriptions) (#584)

Author: jimbolla

src/components/Provider.js

@@ -1,4 +1,5 @@
 import { Component, PropTypes, Children } from 'react'
+import Subscription from '../utils/Subscription'
 import storeShape from '../utils/storeShape'
 import warning from '../utils/warning'
 
@@ -20,7 +21,7 @@ function warnAboutReceivingStore() {
 
 export default class Provider extends Component {
   getChildContext() {
-    return { store: this.store }
+    return { store: this.store, storeSubscription: null }
   }
 
   constructor(props, context) {
@@ -49,6 +50,7 @@ Provider.propTypes = {
   children: PropTypes.element.isRequired
 }
 Provider.childContextTypes = {
-  store: storeShape.isRequired
+  store: storeShape.isRequired,
+  storeSubscription: PropTypes.instanceOf(Subscription)
 }
 Provider.displayName = 'Provider'

test/components/Provider.spec.js

@@ -109,6 +109,29 @@ describe('React', () => {
       expect(child.context.store.getState()).toEqual(11)
       expect(spy.calls.length).toBe(0)
     })
+
+    it('should handle subscriptions correctly when there is nested Providers', () => {
+      const reducer = (state = 0, action) => (action.type === 'INC' ? state + 1 : state)
+      
+      const innerStore = createStore(reducer)
+      const innerMapStateToProps = expect.createSpy().andCall(state => ({ count: state }))
+      @connect(innerMapStateToProps)
+      class Inner extends Component {
+        render() { return <div>{this.props.count}</div> }
+      }
+
+      const outerStore = createStore(reducer)
+      @connect(state => ({ count: state }))
+      class Outer extends Component {
+        render() { return <Provider store={innerStore}><Inner /></Provider> }
+      }
+      
+      TestUtils.renderIntoDocument(<Provider store={outerStore}><Outer /></Provider>)
+      expect(innerMapStateToProps.calls.length).toBe(1)
+
+      innerStore.dispatch({ type: 'INC'})
+      expect(innerMapStateToProps.calls.length).toBe(2)
+    })
   })
 
   it('should pass state consistently to mapState', () => {