Add SetParams handling in TabRouter.js (react-navigation#132)

src/routers/TabRouter.js

@@ -128,6 +128,24 @@ export default (
         }
         // console.log({navId: order.join('-'), action, order, lastIndex: state.index, index: activeTabIndex});
       }
+      if (action.type === NavigationActions.SET_PARAMS) {
+        const lastRoute = state.routes.find(route => route.key === action.key);
+        if (lastRoute) {
+          const params = {
+            ...lastRoute.params,
+            ...action.params,
+          };
+          const routes = [...state.routes];
+          routes[state.routes.indexOf(lastRoute)] = {
+            ...lastRoute,
+            params,
+          };
+          return {
+            ...state,
+            routes,
+          };
+        }
+      }
       if (activeTabIndex !== state.index) {
         // console.log(`${order.join('-')}: Normal navigation`, {lastIndex: state.index, newIndex: activeTabIndex});
         return {

src/routers/__tests__/TabRouter-test.js

@@ -73,6 +73,23 @@ describe('TabRouter', () => {
     });
   });
 
+  test('Handles the SetParams action', () => {
+    const router = TabRouter({
+      Foo: {
+        screen: () => <div />,
+      },
+      Bar: {
+        screen: () => <div />,
+      },
+    });
+    const state2 = router.getStateForAction({
+      type: NavigationActions.SET_PARAMS,
+      params: { name: 'Qux' },
+      key: 'Foo',
+    });
+    expect(state2 && state2.routes[0].params).toEqual({ name: 'Qux' });
+  });
+
   test('getStateForAction returns null when navigating to same tab', () => {
     const router = TabRouter({ Foo: BareLeafRouteConfig, Bar: BareLeafRouteConfig }, { initialRouteName: 'Bar' });
     const state = router.getStateForAction({ type: NavigationActions.INIT });