[URL UPDATE] Change '/app/enterprise_search/app_search' to '/app/app_…

…search'

- This needs to be done because App Search and Workplace search *have* to be registered as separate plugins to have 2 distinct nav links
- Currently Kibana doesn't support nested app names (see: elastic#59190) but potentially will in the future

- To support this change, we need to update applications/index.tsx to NOT handle '/app/enterprise_search' level routing, but instead accept an async imported app component (e.g. AppSearch, WorkplaceSearch).
- AppSearch should now treat its router as root '/' instead of '/app_search'

- (Addl) Per Josh Dover's recommendation, switch to `<Router history={params.history}>` from `<BrowserRouter basename={params.appBasePath}>` since they're deprecating appBasePath

x-pack/plugins/enterprise_search/public/applications/app_search/index.test.tsx

@@ -16,7 +16,7 @@ import { EngineOverview } from './components/engine_overview';
 import { AppSearch } from './';
 
 describe('App Search Routes', () => {
-  describe('/app_search', () => {
+  describe('/', () => {
     it('redirects to Setup Guide when enterpriseSearchUrl is not set', () => {
       useContext.mockImplementationOnce(() => ({ enterpriseSearchUrl: '' }));
       const wrapper = shallow(<AppSearch />);
@@ -34,7 +34,7 @@ describe('App Search Routes', () => {
     });
   });
 
-  describe('/app_search/setup_guide', () => {
+  describe('/setup_guide', () => {
     it('renders', () => {
       const wrapper = shallow(<AppSearch />);
 

x-pack/plugins/enterprise_search/public/applications/app_search/index.tsx

@@ -17,10 +17,10 @@ export const AppSearch: React.FC<> = () => {
 
   return (
     <>
-      <Route exact path="/app_search">
-        {!enterpriseSearchUrl ? <Redirect to="/app_search/setup_guide" /> : <EngineOverview />}
+      <Route exact path="/">
+        {!enterpriseSearchUrl ? <Redirect to="/setup_guide" /> : <EngineOverview />}
       </Route>
-      <Route path="/app_search/setup_guide">
+      <Route path="/setup_guide">
         <SetupGuide />
       </Route>
     </>

x-pack/plugins/enterprise_search/public/applications/index.test.tsx

@@ -0,0 +1,40 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License;
+ * you may not use this file except in compliance with the Elastic License.
+ */
+
+import React from 'react';
+
+import { coreMock } from 'src/core/public/mocks';
+import { licensingMock } from '../../../licensing/public/mocks';
+
+import { renderApp } from './';
+import { AppSearch } from './app_search';
+
+describe('renderApp', () => {
+  const params = coreMock.createAppMountParamters();
+  const core = coreMock.createStart();
+  const config = {};
+  const plugins = {
+    licensing: licensingMock.createSetup(),
+  };
+
+  beforeEach(() => {
+    jest.clearAllMocks();
+  });
+
+  it('mounts and unmounts UI', () => {
+    const MockApp: React.FC = () => <div className="hello-world">Hello world!</div>;
+
+    const unmount = renderApp(MockApp, core, params, config, plugins);
+    expect(params.element.querySelector('.hello-world')).not.toBeNull();
+    unmount();
+    expect(params.element.innerHTML).toEqual('');
+  });
+
+  it('renders AppSearch', () => {
+    renderApp(AppSearch, core, params, config, plugins);
+    expect(params.element.querySelector('.setup-guide')).not.toBeNull();
+  });
+});

x-pack/plugins/enterprise_search/public/applications/index.tsx

@@ -6,16 +6,14 @@
 
 import React from 'react';
 import ReactDOM from 'react-dom';
-import { BrowserRouter, Route, Redirect } from 'react-router-dom';
+import { Router, Route, Redirect } from 'react-router-dom';
 
 import { CoreStart, AppMountParams, HttpHandler } from 'src/core/public';
 import { ClientConfigType, PluginsSetup } from '../plugin';
 import { TSetBreadcrumbs } from './shared/kibana_breadcrumbs';
 import { ILicense } from '../../../../licensing/public';
 import { LicenseProvider } from './shared/licensing';
 
-import { AppSearch } from './app_search';
-
 export interface IKibanaContext {
   enterpriseSearchUrl?: string;
   http(): HttpHandler;
@@ -25,7 +23,14 @@ export interface IKibanaContext {
 
 export const KibanaContext = React.createContext();
 
+/**
+ * This file serves as a reusable wrapper to share Kibana-level context and other helpers
+ * between various Enterprise Search plugins (e.g. AppSearch, WorkplaceSearch, ES landing page)
+ * which should be imported and passed in as the first param in plugin.ts.
+ */
+
 export const renderApp = (
+  App: React.Element,
   core: CoreStart,
   params: AppMountParams,
   config: ClientConfigType,
@@ -41,16 +46,9 @@ export const renderApp = (
       }}
     >
       <LicenseProvider>
-        <BrowserRouter basename={params.appBasePath}>
-          <Route exact path="/">
-            {/* This will eventually contain an Enterprise Search landing page,
-            and we'll also actually have a /workplace_search route */}
-            <Redirect to="/app_search" />
-          </Route>
-          <Route path="/app_search">
-            <AppSearch />
-          </Route>
-        </BrowserRouter>
+        <Router history={params.history}>
+          <App />
+        </Router>
       </LicenseProvider>
     </KibanaContext.Provider>,
     params.element

x-pack/plugins/enterprise_search/public/plugin.ts

@@ -40,29 +40,32 @@ export class EnterpriseSearchPlugin implements Plugin {
     const config = this.config;
 
     core.application.register({
-      id: 'enterprise_search',
-      title: 'App Search', // TODO: This will eventually be 'Enterprise Search' once there's more than just App Search in here
+      id: 'app_search',
+      title: 'App Search',
+      // appRoute: '/app/enterprise_search/app_search', // TODO: Switch to this once https://github.com/elastic/kibana/issues/59190 is in
       category: DEFAULT_APP_CATEGORIES.enterpriseSearch,
       mount: async (params: AppMountParameters) => {
         const [coreStart] = await core.getStartServices();
 
         const { renderApp } = await import('./applications');
+        const { AppSearch } = await import('./applications/app_search');
 
-        return renderApp(coreStart, params, config, plugins);
+        return renderApp(AppSearch, coreStart, params, config, plugins);
       },
     });
+    // TODO: Workplace Search will need to register its own plugin.
 
     plugins.home.featureCatalogue.register({
       id: 'app_search',
       title: 'App Search',
       icon: AppSearchLogo,
       description:
         'Leverage dashboards, analytics, and APIs for advanced application search made simple.',
-      path: '/app/enterprise_search/app_search',
+      path: '/app/app_search', // TODO: Switch to '/app/enterprise_search/app_search' once https://github.com/elastic/kibana/issues/59190 is in
       category: FeatureCatalogueCategory.DATA,
       showOnHomePage: true,
     });
-    // TODO: Workplace Search will likely also register its own feature catalogue section/card.
+    // TODO: Workplace Search will need to register its own feature catalogue section/card.
   }
 
   public start(core: CoreStart) {}