[fixed] Call all transition hooks on query changes

This commit fires transition hooks on all route handlers in the
hierarchy whenever the query changes, not just the leaf route.

This also fixes a regression in remix-run#499 that throws a TypeError when
there are not yet any routes in the router state (see remix-run#623).

Fixes remix-run#623

modules/__tests__/Router-test.js

@@ -2,6 +2,7 @@ var expect = require('expect');
 var React = require('react');
 var Router = require('../index');
 var Route = require('../components/Route');
+var RouteHandler = require('../components/RouteHandler');
 var TestLocation = require('../locations/TestLocation');
 var ScrollToTopBehavior = require('../behaviors/ScrollToTopBehavior');
 var getWindowScrollPosition = require('../utils/getWindowScrollPosition');
@@ -533,8 +534,22 @@ describe('Router', function () {
       });
     });
 
-    it('execute willTransition* callbacks when query changes', function (done) {
-      var fromCallbackExecuted = false;
+    it('executes transition hooks when only the query changes', function (done) {
+      var fromKnifeCalled = false;
+      var fromSpoonCalled = false;
+
+      var Knife = React.createClass({
+        statics: {
+          willTransitionFrom: function () {
+            fromKnifeCalled = true;
+          }
+        },
+
+        render: function () {
+          return <RouteHandler/>;
+        }
+      });
+
       var Spoon = React.createClass({
         statics: {
           willTransitionTo: function (transition, params, query) {
@@ -543,12 +558,13 @@ describe('Router', function () {
             }
 
             expect(query['filter']).toEqual('second');
-            expect(fromCallbackExecuted).toBe(true);
+            expect(fromKnifeCalled).toBe(true);
+            expect(fromSpoonCalled).toBe(true);
             done();
           },
 
           willTransitionFrom: function (transition, element) {
-            fromCallbackExecuted = true;
+            fromSpoonCalled = true;
           }
         },
 
@@ -558,7 +574,7 @@ describe('Router', function () {
       });
 
       var routes = (
-        <Route handler={Nested} path='/'>
+        <Route handler={Knife}>
           <Route name="spoon" handler={Spoon}/>
         </Route>
       );

modules/utils/createRouter.js

@@ -91,22 +91,32 @@ function createMatch(route, params) {
   return { routes: [ route ], params: params };
 }
 
-function hasMatch(routes, route, prevParams, nextParams) {
+function hasProperties(object, properties) {
+  for (var propertyName in properties)
+    if (properties.hasOwnProperty(propertyName) && object[propertyName] !== properties[propertyName])
+      return false;
+
+  return true;
+}
+
+function hasMatch(routes, route, prevParams, nextParams, prevQuery, nextQuery) {
   return routes.some(function (r) {
     if (r !== route)
       return false;
 
     var paramNames = route.paramNames;
     var paramName;
 
+    // Ensure that all params the route cares about did not change.
     for (var i = 0, len = paramNames.length; i < len; ++i) {
       paramName = paramNames[i];
 
       if (nextParams[paramName] !== prevParams[paramName])
         return false;
     }
 
-    return true;
+    // Ensure the query hasn't changed.
+    return hasProperties(prevQuery, nextQuery) && hasProperties(nextQuery, prevQuery);
   });
 }
 
@@ -335,6 +345,7 @@ function createRouter(options) {
 
         var prevRoutes = state.routes || [];
         var prevParams = state.params || {};
+        var prevQuery = state.query || {};
 
         var nextRoutes = match.routes || [];
         var nextParams = match.params || {};
@@ -343,27 +354,17 @@ function createRouter(options) {
         var fromRoutes, toRoutes;
         if (prevRoutes.length) {
           fromRoutes = prevRoutes.filter(function (route) {
-            return !hasMatch(nextRoutes, route, prevParams, nextParams);
+            return !hasMatch(nextRoutes, route, prevParams, nextParams, prevQuery, nextQuery);
           });
 
           toRoutes = nextRoutes.filter(function (route) {
-            return !hasMatch(prevRoutes, route, prevParams, nextParams);
+            return !hasMatch(prevRoutes, route, prevParams, nextParams, prevQuery, nextQuery);
           });
         } else {
           fromRoutes = [];
           toRoutes = nextRoutes;
         }
 
-        // If routes' hooks arrays are empty, then we transition to current route.
-        // But path is somehow still get changed.
-        // That could be only because of route query changes.
-        // Need to push current route to routes' hooks arrays.
-        if (!toRoutes.length && !fromRoutes.length) {
-          var currentRoute = state.routes[state.routes.length-1];
-          fromRoutes = [currentRoute];
-          toRoutes = [currentRoute];
-        }
-
         var transition = new Transition(path, this.replaceWith.bind(this, path));
         pendingTransition = transition;