[dev tools] Hide app link when there are no tools (#9489)

* [dev tools] Hide app link when there are no tools

* [dev tools] Add tests for setting app as hidden

src/core_plugins/kibana/index.js

@@ -74,6 +74,7 @@ module.exports = function (kibana) {
           description: 'compose visualizations for much win',
           icon: 'plugins/kibana/assets/dashboard.svg',
         }, {
+          id: 'kibana:dev_tools',
           title: 'Dev Tools',
           order: 9001,
           url: '/app/kibana#/dev_tools',

src/core_plugins/kibana/public/dev_tools/lib/__tests__/hide_empty_tools.js

@@ -0,0 +1,44 @@
+import ngMock from 'ng_mock';
+import expect from 'expect.js';
+import sinon from 'sinon';
+
+import chrome from 'ui/chrome';
+import { hideEmptyDevTools } from '../hide_empty_tools';
+
+describe('hide dev tools', function () {
+  let Private;
+  let navlinks;
+
+  function PrivateWithoutTools() {
+    return [];
+  }
+
+  function PrivateWithTools() {
+    return ['tool1', 'tool2'];
+  }
+
+  function isHidden() {
+    return !!chrome.getNavLinkById('kibana:dev_tools').hidden;
+  }
+
+  beforeEach(function () {
+    navlinks = {};
+    sinon.stub(chrome, 'getNavLinkById',function () {
+      return navlinks;
+    });
+  });
+
+  it('should hide the app if there are no dev tools', function () {
+    hideEmptyDevTools(PrivateWithTools);
+    expect(isHidden()).to.be(false);
+  });
+
+  it('should not hide the app if there are tools', function () {
+    hideEmptyDevTools(PrivateWithoutTools);
+    expect(isHidden()).to.be(true);
+  });
+
+  afterEach(function () {
+    chrome.getNavLinkById.restore();
+  });
+});

src/core_plugins/kibana/public/dev_tools/lib/hide_empty_tools.js

@@ -0,0 +1,10 @@
+import chrome from 'ui/chrome';
+import DevToolsRegistryProvider from 'ui/registry/dev_tools';
+
+export function hideEmptyDevTools(Private) {
+  const hasTools = !!Private(DevToolsRegistryProvider).length;
+  if (!hasTools) {
+    const navLink = chrome.getNavLinkById('kibana:dev_tools');
+    navLink.hidden = true;
+  }
+}

src/core_plugins/kibana/public/kibana.js

@@ -20,6 +20,7 @@ import 'ui/agg_types';
 import 'ui/timepicker';
 import Notifier from 'ui/notify/notifier';
 import 'leaflet';
+import { hideEmptyDevTools } from './dev_tools/lib/hide_empty_tools';
 
 routes.enable();
 
@@ -49,3 +50,4 @@ chrome
 });
 
 modules.get('kibana').run(Notifier.pullMessageFromUrl);
+modules.get('kibana').run(hideEmptyDevTools);