From 0c31bc44eaed1e45baa59eaefcad8ba2cee06e22 Mon Sep 17 00:00:00 2001
From: Brent Vatne <brentvatne@gmail.com>
Date: Mon, 12 Mar 2018 15:06:38 -0700
Subject: [PATCH] Make push, pop, and popToTop bubble like navigate (#3617)

---
 src/routers/StackRouter.js                | 22 ++-----
 src/routers/__tests__/StackRouter-test.js | 72 +++++++++++------------
 2 files changed, 39 insertions(+), 55 deletions(-)

diff --git a/src/routers/StackRouter.js b/src/routers/StackRouter.js
index 9d86ca53..56bcf320 100644
--- a/src/routers/StackRouter.js
+++ b/src/routers/StackRouter.js
@@ -259,12 +259,8 @@ export default (routeConfigs, stackConfig = {}) => {
         action.type === NavigationActions.PUSH &&
         childRouters[action.routeName] === undefined
       ) {
-        // If we've made it this far with a push action, we return the
-        // state with a new identity to prevent the action from bubbling
-        // back up.
-        return {
-          ...state,
-        };
+        // Return the state identity to bubble the action up
+        return state;
       }
 
       // Handle navigation to other child routers that are not yet pushed
@@ -313,11 +309,7 @@ export default (routeConfigs, stackConfig = {}) => {
 
         // If we're already at the top, then we return the state with a new
         // identity so that the action is handled by this router.
-        if (state.index === 0) {
-          return {
-            ...state,
-          };
-        } else {
+        if (state.index > 0) {
           return {
             ...state,
             isTransitioning: action.immediate !== true,
@@ -442,15 +434,9 @@ export default (routeConfigs, stackConfig = {}) => {
             index: backRouteIndex - 1,
             isTransitioning: immediate !== true,
           };
-        } else if (
-          backRouteIndex === 0 &&
-          action.type === NavigationActions.POP
-        ) {
-          return {
-            ...state,
-          };
         }
       }
+
       return state;
     },
 
diff --git a/src/routers/__tests__/StackRouter-test.js b/src/routers/__tests__/StackRouter-test.js
index 9fcc675f..245ab55d 100644
--- a/src/routers/__tests__/StackRouter-test.js
+++ b/src/routers/__tests__/StackRouter-test.js
@@ -366,38 +366,7 @@ describe('StackRouter', () => {
     expect(pushedState.routes[1].routes[1].routeName).toEqual('qux');
   });
 
-  test('pop does not bubble up', () => {
-    const ChildNavigator = () => <div />;
-    ChildNavigator.router = StackRouter({
-      Baz: { screen: () => <div /> },
-      Qux: { screen: () => <div /> },
-    });
-    const router = StackRouter({
-      Foo: { screen: () => <div /> },
-      Bar: { screen: ChildNavigator },
-    });
-
-    const state = router.getStateForAction({ type: NavigationActions.INIT });
-    const state2 = router.getStateForAction(
-      {
-        type: NavigationActions.NAVIGATE,
-        routeName: 'Bar',
-        key: 'StackRouterRoot',
-      },
-      state
-    );
-    const barKey = state2.routes[1].routes[0].key;
-    const state3 = router.getStateForAction(
-      {
-        type: NavigationActions.POP,
-      },
-      state2
-    );
-    expect(state3 && state3.index).toEqual(1);
-    expect(state3 && state3.routes[1].index).toEqual(0);
-  });
-
-  test('push does not bubble up', () => {
+  test('push bubbles up', () => {
     const ChildNavigator = () => <div />;
     ChildNavigator.router = StackRouter({
       Baz: { screen: () => <div /> },
@@ -424,11 +393,41 @@ describe('StackRouter', () => {
       },
       state2
     );
-    expect(state3 && state3.index).toEqual(1);
-    expect(state3 && state3.routes.length).toEqual(2);
+    expect(state3 && state3.index).toEqual(2);
+    expect(state3 && state3.routes.length).toEqual(3);
   });
 
-  test('popToTop does not bubble up', () => {
+  test('pop bubbles up', () => {
+    const ChildNavigator = () => <div />;
+    ChildNavigator.router = StackRouter({
+      Baz: { screen: () => <div /> },
+      Qux: { screen: () => <div /> },
+    });
+    const router = StackRouter({
+      Foo: { screen: () => <div /> },
+      Bar: { screen: ChildNavigator },
+    });
+
+    const state = router.getStateForAction({ type: NavigationActions.INIT });
+    const state2 = router.getStateForAction(
+      {
+        type: NavigationActions.NAVIGATE,
+        routeName: 'Bar',
+        key: 'StackRouterRoot',
+      },
+      state
+    );
+    const barKey = state2.routes[1].routes[0].key;
+    const state3 = router.getStateForAction(
+      {
+        type: NavigationActions.POP,
+      },
+      state2
+    );
+    expect(state3 && state3.index).toEqual(0);
+  });
+
+  test('popToTop bubbles up', () => {
     const ChildNavigator = () => <div />;
     ChildNavigator.router = StackRouter({
       Baz: { screen: () => <div /> },
@@ -453,8 +452,7 @@ describe('StackRouter', () => {
       },
       state2
     );
-    expect(state3 && state3.index).toEqual(1);
-    expect(state3 && state3.routes[1].index).toEqual(0);
+    expect(state3 && state3.index).toEqual(0);
   });
 
   test('popToTop targets StackRouter by key if specified', () => {