State getter should return state when it is nested in an immutable ob…

…ject (#153)

State getter returns state when it is nested in an immutable object and has immutable state, update docs to reflect usage.

docs/USING_GRID_REDUCERS.md

@@ -109,15 +109,15 @@ If you want to hide grid reducers from the root of your state:
 
 ````js
 import { combineReducers } from 'redux';
-import { GridRootReducer } from 'react-redux-grid';
+import { Reducers as rootReducer } from 'react-redux-grid';
 
 import myAppReducer from './customReducers/app';
 import myDataReducer from './customReducers/data';
 
 export const rootReducer = combineReducers({
     myAppReducer,
     myDataReducer,
-    nested: GridRootReducer
+    nested: rootReducer
 });
 
 export default rootReducer;

src/util/stateGetter.js

@@ -12,7 +12,11 @@ export const stateGetter = (state, props, key, entry) => {
 
     if (props && props.reducerKeys) {
         if (typeof props.reducerKeys === 'string') {
-            return get(state[props.reducerKeys], key, entry);
+            const nestedInImmutable = typeof state.get === 'function';
+            const nestedState = nestedInImmutable
+                ? state.get(props.reducerKeys)
+                : state[props.reducerKeys];
+            return get(nestedState , key, entry);
         }
         else if (typeof props.reducerKeys === 'object'
             && Object.keys(props.reducerKeys).length > 0

test/util/stateGetter.test.js

@@ -106,6 +106,22 @@ describe('State Getter Function', () => {
         }));
     });
 
+    it(['Should return state when it is nested in an immutable object ',
+        'and has immutable state'].join(''), () => {
+        const state = Map({
+            nested: { filterState: { get: getStateWithImmutable } }
+        });
+
+        const props = {
+            reducerKeys: 'nested'
+        };
+        expect(
+            stateGetter(state, props, 'filterState', 'someProp')
+        ).toEqual(Map({
+            x: 1
+        }));
+    });
+
     it('Should return null if state is nested and not registered', () => {
         const state = { nested: {} };
         const props = {