fix ''should not push route with duplicated key" issue (#7)

* fix ''should not push route with duplicated key" issue

* added test spec for the fix "should not push route with duplicated key"

Author: kyaroru

src/reducers/card-stack.js

@@ -29,6 +29,7 @@ export function cardStackReducer(initialState) {
 
     switch (action.type) {
       case PUSH_ROUTE:
+      if (state.routes[state.index].key === (action.payload && action.payload.route.key)) return state;
         return StateUtils.push(state, action.payload.route);
       case POP_ROUTE:
         return StateUtils.pop(state);

test/unit/reducers.js

@@ -21,6 +21,11 @@ const cardStackInitialState = {
   }]
 };
 
+const repeatedRoute = {
+  key: 'route-1',
+  title: 'Route 1'
+};
+
 const tabInitialState = {
   key: 'ta-key',
   index: 0,
@@ -151,6 +156,14 @@ describe('reducers', () => {
       expect(returnValue).to.equal('StateUtils.push');
     });
 
+    it('does not call RN\'s StateUtils.push when pushRoute action has payload.key same with current route state.key and returns current nav state', () => {
+      const action = pushRoute({ key: 'route' }, repeatedRoute.key);
+
+      const returnValue = reducer(cardStackInitialState, action);
+      expect(pushSpy.callCount).to.equal(0);
+      expect(returnValue).to.equal(cardStackInitialState);
+    });
+
     it('does not call RN\'s StateUtils.push when pushRoute action has payload.key different from state.key and returns current nav state', () => {
       const action = pushRoute({ key: 'route' }, 'nav');