Back button navigation fix 31238 (elastic#32372)

* initial fix for navigation issue + Spencer
* added navigation test for issue elastic#31238 
* added more validations to the navigate back test

src/legacy/ui/public/chrome/directives/kbn_chrome.js

@@ -20,6 +20,7 @@
 import React from 'react';
 import ReactDOM from 'react-dom';
 import $ from 'jquery';
+import url from 'url';
 
 import { uiModules } from '../../modules';
 import {
@@ -57,7 +58,7 @@ export function kbnChromeProvider(chrome, internals) {
         },
 
         controllerAs: 'chrome',
-        controller($scope, $rootScope, Private) {
+        controller($scope, $rootScope, Private, $location) {
           const getUnhashableStates = Private(getUnhashableStatesProvider);
           const subUrlRouteFilter = Private(SubUrlRouteFilterProvider);
 
@@ -73,6 +74,19 @@ export function kbnChromeProvider(chrome, internals) {
             }
           }
 
+          $rootScope.$on('$locationChangeStart', (e, newUrl) => {
+            // This handler fixes issue #31238 where browser back navigation
+            // fails due to angular 1.6 parsing url encoded params wrong.
+            const absUrlHash = url.parse($location.absUrl()).hash;
+            const decodedAbsUrlHash = decodeURIComponent(absUrlHash);
+            const hash = url.parse(newUrl).hash;
+            const decodedHash = decodeURIComponent(hash);
+            if (absUrlHash !== hash && decodedHash === decodedAbsUrlHash) {
+              // replace the urlencoded hash with the version that angular sees.
+              $location.url(absUrlHash).replace();
+            }
+
+          });
           $rootScope.$on('$routeChangeSuccess', onRouteChange);
           $rootScope.$on('$routeUpdate', onRouteChange);
           updateSubUrls(); // initialize sub urls

test/functional/apps/home/_navigation.js

@@ -0,0 +1,74 @@
+/*
+ * Licensed to Elasticsearch B.V. under one or more contributor
+ * license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright
+ * ownership. Elasticsearch B.V. licenses this file to you under
+ * the Apache License, Version 2.0 (the "License"); you may
+ * not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *    http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing,
+ * software distributed under the License is distributed on an
+ * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+ * KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations
+ * under the License.
+ */
+
+import expect from 'expect.js';
+
+
+export default function ({ getService, getPageObjects }) {
+  const browser = getService('browser');
+  const PageObjects = getPageObjects(['dashboard', 'common', 'home', 'timePicker']);
+  const appsMenu = getService('appsMenu');
+  const kibanaServer = getService('kibanaServer');
+  const fromTime = '2015-09-19 06:31:44.000';
+  const toTime = '2015-09-23 18:31:44.000';
+
+  describe('Kibana browser back navigation should work', function describeIndexTests() {
+
+    before(async () => {
+      await PageObjects.dashboard.initTests();
+      await kibanaServer.uiSettings.disableToastAutohide();
+      await browser.refresh();
+    });
+
+    it('detect navigate back issues', async ()=> {
+      let currUrl;
+      // Detects bug described in issue #31238 - where back navigation would get stuck to URL encoding handling in Angular.
+      // Navigate to home app
+      await PageObjects.common.navigateToApp('home');
+      const homeUrl = await browser.getCurrentUrl();
+
+      // Navigate to discover app
+      await appsMenu.clickLink('Discover');
+      const discoverUrl = await browser.getCurrentUrl();
+      await PageObjects.timePicker.setAbsoluteRange(fromTime, toTime);
+      const modifiedTimeDiscoverUrl = await browser.getCurrentUrl();
+
+      // Navigate to dashboard app
+      await appsMenu.clickLink('Dashboard');
+
+      // Navigating back to discover
+      await browser.goBack();
+      currUrl = await browser.getCurrentUrl();
+      expect(currUrl).to.be(modifiedTimeDiscoverUrl);
+
+      // Navigating back from time settings
+      await browser.goBack(); // undo time settings
+      await browser.goBack(); // undo automatically set config, should it be in the history stack? (separate issue!)
+      currUrl = await browser.getCurrentUrl();
+      // Discover view also keeps adds some default arguments into the _a URL parameter, so we can only check that the url starts the same.
+      expect(currUrl.startsWith(discoverUrl)).to.be(true);
+
+      // Navigate back home
+      await browser.goBack();
+      currUrl = await browser.getCurrentUrl();
+      expect(currUrl).to.be(homeUrl);
+    });
+  });
+
+}

test/functional/apps/home/index.js

@@ -27,6 +27,7 @@ export default function ({ getService, loadTestFile }) {
       return browser.setWindowSize(1200, 800);
     });
 
+    loadTestFile(require.resolve('./_navigation'));
     loadTestFile(require.resolve('./_home'));
     loadTestFile(require.resolve('./_add_data'));
     loadTestFile(require.resolve('./_sample_data'));