From 9ff483a554bc8e51602526918b52d534209a08a6 Mon Sep 17 00:00:00 2001
From: "satyajit.happy" <satyajit.happy@gmail.com>
Date: Mon, 29 Jul 2019 00:59:11 +0200
Subject: [PATCH] fix: adjust index when route names are changed

---
 example/StackNavigator.tsx                |  7 ++++++-
 example/TabNavigator.tsx                  | 19 +++++++++++--------
 src/__tests__/__fixtures__/MockRouter.tsx |  7 ++++++-
 src/__tests__/index.test.tsx              |  2 +-
 4 files changed, 24 insertions(+), 11 deletions(-)

diff --git a/example/StackNavigator.tsx b/example/StackNavigator.tsx
index bc5dac85..9916fe70 100644
--- a/example/StackNavigator.tsx
+++ b/example/StackNavigator.tsx
@@ -107,10 +107,15 @@ function StackRouter(options: DefaultRouterOptions) {
     },
 
     getStateForRouteNamesChange(state, { routeNames }) {
+      const routes = state.routes.filter(route =>
+        routeNames.includes(route.name)
+      );
+
       return {
         ...state,
         routeNames,
-        routes: state.routes.filter(route => routeNames.includes(route.name)),
+        routes,
+        index: Math.min(state.index, routes.length - 1),
       };
     },
 
diff --git a/example/TabNavigator.tsx b/example/TabNavigator.tsx
index 226a0545..eb6105db 100644
--- a/example/TabNavigator.tsx
+++ b/example/TabNavigator.tsx
@@ -91,17 +91,20 @@ function TabRouter(options: DefaultRouterOptions) {
     },
 
     getStateForRouteNamesChange(state, { routeNames, routeParamList }) {
+      const routes = routeNames.map(
+        name =>
+          state.routes.find(r => r.name === name) || {
+            name,
+            key: `${name}-${shortid()}`,
+            params: routeParamList[name],
+          }
+      );
+
       return {
         ...state,
         routeNames,
-        routes: routeNames.map(
-          name =>
-            state.routes.find(r => r.name === name) || {
-              name,
-              key: `${name}-${shortid()}`,
-              params: routeParamList[name],
-            }
-        ),
+        routes,
+        index: Math.min(state.index, routes.length - 1),
       };
     },
 
diff --git a/src/__tests__/__fixtures__/MockRouter.tsx b/src/__tests__/__fixtures__/MockRouter.tsx
index 37bb56d7..68a5a164 100644
--- a/src/__tests__/__fixtures__/MockRouter.tsx
+++ b/src/__tests__/__fixtures__/MockRouter.tsx
@@ -46,10 +46,15 @@ export default function MockRouter(options: DefaultRouterOptions) {
     },
 
     getStateForRouteNamesChange(state, { routeNames }) {
+      const routes = state.routes.filter(route =>
+        routeNames.includes(route.name)
+      );
+
       return {
         ...state,
         routeNames,
-        routes: state.routes.filter(route => routeNames.includes(route.name)),
+        routes,
+        index: Math.min(state.index, routes.length - 1),
       };
     },
 
diff --git a/src/__tests__/index.test.tsx b/src/__tests__/index.test.tsx
index ce851b46..3e6634f1 100644
--- a/src/__tests__/index.test.tsx
+++ b/src/__tests__/index.test.tsx
@@ -494,7 +494,7 @@ it('handles change in route names', () => {
   );
 
   expect(onStateChange).toBeCalledWith({
-    index: 1,
+    index: 0,
     key: '0',
     routeNames: ['foo', 'baz', 'qux'],
     routes: [{ key: 'foo', name: 'foo' }],