[Screenshot Mode] Prevent newsfeed plugin from fetching items (#101256)

* - updated newsfeed to depend on low-level screenshotmode plugin
- added new NeverFetch driver that will never resolve to true
  for new fetch requests
- added plugin-level test for expected behaviour

* added screenshotmode contract to start!

* address pr feedback

* removed old test and updated test description

* update use of jest.fn to tidy up code

* simplify jest tests and remove unnecessary async

Co-authored-by: Kibana Machine <42973632+kibanamachine@users.noreply.github.com>

src/plugins/newsfeed/kibana.json

@@ -2,5 +2,6 @@
   "id": "newsfeed",
   "version": "kibana",
   "server": true,
-  "ui": true
+  "ui": true,
+  "requiredPlugins": ["screenshotMode"]
 }

src/plugins/newsfeed/public/lib/api.test.mocks.ts

@@ -8,6 +8,7 @@
 
 import { storageMock } from './storage.mock';
 import { driverMock } from './driver.mock';
+import { NeverFetchNewsfeedApiDriver } from './never_fetch_driver';
 
 export const storageInstanceMock = storageMock.create();
 jest.doMock('./storage', () => ({
@@ -18,3 +19,7 @@ export const driverInstanceMock = driverMock.create();
 jest.doMock('./driver', () => ({
   NewsfeedApiDriver: jest.fn().mockImplementation(() => driverInstanceMock),
 }));
+
+jest.doMock('./never_fetch_driver', () => ({
+  NeverFetchNewsfeedApiDriver: jest.fn(() => new NeverFetchNewsfeedApiDriver()),
+}));

src/plugins/newsfeed/public/lib/api.test.ts

@@ -7,12 +7,16 @@
  */
 
 import { driverInstanceMock, storageInstanceMock } from './api.test.mocks';
+
 import moment from 'moment';
 import { getApi } from './api';
 import { TestScheduler } from 'rxjs/testing';
 import { FetchResult, NewsfeedPluginBrowserConfig } from '../types';
 import { take } from 'rxjs/operators';
 
+import { NewsfeedApiDriver as MockNewsfeedApiDriver } from './driver';
+import { NeverFetchNewsfeedApiDriver as MockNeverFetchNewsfeedApiDriver } from './never_fetch_driver';
+
 const kibanaVersion = '8.0.0';
 const newsfeedId = 'test';
 
@@ -46,6 +50,8 @@ describe('getApi', () => {
   afterEach(() => {
     storageInstanceMock.isAnyUnread$.mockReset();
     driverInstanceMock.fetchNewsfeedItems.mockReset();
+    (MockNewsfeedApiDriver as jest.Mock).mockClear();
+    (MockNeverFetchNewsfeedApiDriver as jest.Mock).mockClear();
   });
 
   it('merges the newsfeed and unread observables', () => {
@@ -60,7 +66,7 @@ describe('getApi', () => {
           a: createFetchResult({ feedItems: ['item' as any] }),
         })
       );
-      const api = getApi(createConfig(1000), kibanaVersion, newsfeedId);
+      const api = getApi(createConfig(1000), kibanaVersion, newsfeedId, false);
 
       expectObservable(api.fetchResults$.pipe(take(1))).toBe('(a|)', {
         a: createFetchResult({
@@ -83,7 +89,7 @@ describe('getApi', () => {
           a: createFetchResult({ feedItems: ['item' as any] }),
         })
       );
-      const api = getApi(createConfig(2), kibanaVersion, newsfeedId);
+      const api = getApi(createConfig(2), kibanaVersion, newsfeedId, false);
 
       expectObservable(api.fetchResults$.pipe(take(2))).toBe('a-(b|)', {
         a: createFetchResult({
@@ -111,7 +117,7 @@ describe('getApi', () => {
           a: createFetchResult({}),
         })
       );
-      const api = getApi(createConfig(10), kibanaVersion, newsfeedId);
+      const api = getApi(createConfig(10), kibanaVersion, newsfeedId, false);
 
       expectObservable(api.fetchResults$.pipe(take(2))).toBe('a--(b|)', {
         a: createFetchResult({
@@ -123,4 +129,16 @@ describe('getApi', () => {
       });
     });
   });
+
+  it('uses the news feed API driver if in not screenshot mode', () => {
+    getApi(createConfig(10), kibanaVersion, newsfeedId, false);
+    expect(MockNewsfeedApiDriver).toHaveBeenCalled();
+    expect(MockNeverFetchNewsfeedApiDriver).not.toHaveBeenCalled();
+  });
+
+  it('uses the never fetch news feed API driver if in not screenshot mode', () => {
+    getApi(createConfig(10), kibanaVersion, newsfeedId, true);
+    expect(MockNewsfeedApiDriver).not.toHaveBeenCalled();
+    expect(MockNeverFetchNewsfeedApiDriver).toHaveBeenCalled();
+  });
 });

src/plugins/newsfeed/public/lib/api.ts

@@ -11,6 +11,7 @@ import { map, catchError, filter, mergeMap, tap } from 'rxjs/operators';
 import { i18n } from '@kbn/i18n';
 import { FetchResult, NewsfeedPluginBrowserConfig } from '../types';
 import { NewsfeedApiDriver } from './driver';
+import { NeverFetchNewsfeedApiDriver } from './never_fetch_driver';
 import { NewsfeedStorage } from './storage';
 
 export enum NewsfeedApiEndpoint {
@@ -40,13 +41,23 @@ export interface NewsfeedApi {
 export function getApi(
   config: NewsfeedPluginBrowserConfig,
   kibanaVersion: string,
-  newsfeedId: string
+  newsfeedId: string,
+  isScreenshotMode: boolean
 ): NewsfeedApi {
-  const userLanguage = i18n.getLocale();
-  const fetchInterval = config.fetchInterval.asMilliseconds();
-  const mainInterval = config.mainInterval.asMilliseconds();
   const storage = new NewsfeedStorage(newsfeedId);
-  const driver = new NewsfeedApiDriver(kibanaVersion, userLanguage, fetchInterval, storage);
+  const mainInterval = config.mainInterval.asMilliseconds();
+
+  const createNewsfeedApiDriver = () => {
+    if (isScreenshotMode) {
+      return new NeverFetchNewsfeedApiDriver();
+    }
+
+    const userLanguage = i18n.getLocale();
+    const fetchInterval = config.fetchInterval.asMilliseconds();
+    return new NewsfeedApiDriver(kibanaVersion, userLanguage, fetchInterval, storage);
+  };
+
+  const driver = createNewsfeedApiDriver();
 
   const results$ = timer(0, mainInterval).pipe(
     filter(() => driver.shouldFetch()),

src/plugins/newsfeed/public/lib/driver.ts

@@ -10,6 +10,7 @@ import moment from 'moment';
 import * as Rx from 'rxjs';
 import { NEWSFEED_DEFAULT_SERVICE_BASE_URL } from '../../common/constants';
 import { ApiItem, FetchResult, NewsfeedPluginBrowserConfig } from '../types';
+import { INewsfeedApiDriver } from './types';
 import { convertItems } from './convert_items';
 import type { NewsfeedStorage } from './storage';
 
@@ -19,7 +20,7 @@ interface NewsfeedResponse {
   items: ApiItem[];
 }
 
-export class NewsfeedApiDriver {
+export class NewsfeedApiDriver implements INewsfeedApiDriver {
   private readonly kibanaVersion: string;
   private readonly loadedTime = moment().utc(); // the date is compared to time in UTC format coming from the service
 

src/plugins/newsfeed/public/lib/never_fetch_driver.ts

@@ -0,0 +1,25 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import type { Observable } from 'rxjs';
+import { FetchResult } from '../types';
+import { INewsfeedApiDriver } from './types';
+
+/**
+ * NewsfeedApiDriver variant that never fetches results. This is useful for instances where Kibana is started
+ * without any user interaction like when generating a PDF or PNG report.
+ */
+export class NeverFetchNewsfeedApiDriver implements INewsfeedApiDriver {
+  shouldFetch(): boolean {
+    return false;
+  }
+
+  fetchNewsfeedItems(): Observable<FetchResult> {
+    throw new Error('Not implemented!');
+  }
+}

src/plugins/newsfeed/public/lib/types.ts

@@ -0,0 +1,19 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import type { Observable } from 'rxjs';
+import type { FetchResult, NewsfeedPluginBrowserConfig } from '../types';
+
+export interface INewsfeedApiDriver {
+  /**
+   * Check whether newsfeed items should be (re-)fetched
+   */
+  shouldFetch(): boolean;
+
+  fetchNewsfeedItems(config: NewsfeedPluginBrowserConfig['service']): Observable<FetchResult>;
+}

src/plugins/newsfeed/public/plugin.test.ts

@@ -0,0 +1,76 @@
+/*
+ * Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+ * or more contributor license agreements. Licensed under the Elastic License
+ * 2.0 and the Server Side Public License, v 1; you may not use this file except
+ * in compliance with, at your election, the Elastic License 2.0 or the Server
+ * Side Public License, v 1.
+ */
+
+import { take } from 'rxjs/operators';
+import { coreMock } from '../../../core/public/mocks';
+import { NewsfeedPublicPlugin } from './plugin';
+import { NewsfeedApiEndpoint } from './lib/api';
+
+describe('Newsfeed plugin', () => {
+  let plugin: NewsfeedPublicPlugin;
+
+  beforeAll(() => {
+    jest.useFakeTimers();
+  });
+
+  afterAll(() => {
+    jest.useRealTimers();
+  });
+
+  beforeEach(() => {
+    plugin = new NewsfeedPublicPlugin(coreMock.createPluginInitializerContext());
+  });
+
+  describe('#start', () => {
+    beforeEach(() => {
+      plugin.setup(coreMock.createSetup());
+    });
+
+    beforeEach(() => {
+      /**
+       * We assume for these tests that the newsfeed stream exposed by start will fetch newsfeed items
+       * on the first tick for new subscribers
+       */
+      jest.spyOn(window, 'fetch');
+    });
+
+    afterEach(() => {
+      jest.clearAllMocks();
+    });
+
+    describe('base case', () => {
+      it('makes fetch requests', () => {
+        const startContract = plugin.start(coreMock.createStart(), {
+          screenshotMode: { isScreenshotMode: () => false },
+        });
+        const sub = startContract
+          .createNewsFeed$(NewsfeedApiEndpoint.KIBANA) // Any endpoint will do
+          .pipe(take(1))
+          .subscribe(() => {});
+        jest.runOnlyPendingTimers();
+        expect(window.fetch).toHaveBeenCalled();
+        sub.unsubscribe();
+      });
+    });
+
+    describe('when in screenshot mode', () => {
+      it('makes no fetch requests in screenshot mode', () => {
+        const startContract = plugin.start(coreMock.createStart(), {
+          screenshotMode: { isScreenshotMode: () => true },
+        });
+        const sub = startContract
+          .createNewsFeed$(NewsfeedApiEndpoint.KIBANA) // Any endpoint will do
+          .pipe(take(1))
+          .subscribe(() => {});
+        jest.runOnlyPendingTimers();
+        expect(window.fetch).not.toHaveBeenCalled();
+        sub.unsubscribe();
+      });
+    });
+  });
+});

src/plugins/newsfeed/public/plugin.tsx

@@ -13,7 +13,7 @@ import React from 'react';
 import moment from 'moment';
 import { I18nProvider } from '@kbn/i18n/react';
 import { PluginInitializerContext, CoreSetup, CoreStart, Plugin } from 'src/core/public';
-import { NewsfeedPluginBrowserConfig } from './types';
+import { NewsfeedPluginBrowserConfig, NewsfeedPluginStartDependencies } from './types';
 import { NewsfeedNavButton } from './components/newsfeed_header_nav_button';
 import { getApi, NewsfeedApi, NewsfeedApiEndpoint } from './lib/api';
 
@@ -41,8 +41,10 @@ export class NewsfeedPublicPlugin
     return {};
   }
 
-  public start(core: CoreStart) {
-    const api = this.createNewsfeedApi(this.config, NewsfeedApiEndpoint.KIBANA);
+  public start(core: CoreStart, { screenshotMode }: NewsfeedPluginStartDependencies) {
+    const isScreenshotMode = screenshotMode.isScreenshotMode();
+
+    const api = this.createNewsfeedApi(this.config, NewsfeedApiEndpoint.KIBANA, isScreenshotMode);
     core.chrome.navControls.registerRight({
       order: 1000,
       mount: (target) => this.mount(api, target),
@@ -56,7 +58,7 @@ export class NewsfeedPublicPlugin
             pathTemplate: `/${endpoint}/v{VERSION}.json`,
           },
         });
-        const { fetchResults$ } = this.createNewsfeedApi(config, endpoint);
+        const { fetchResults$ } = this.createNewsfeedApi(config, endpoint, isScreenshotMode);
         return fetchResults$;
       },
     };
@@ -68,9 +70,10 @@ export class NewsfeedPublicPlugin
 
   private createNewsfeedApi(
     config: NewsfeedPluginBrowserConfig,
-    newsfeedId: NewsfeedApiEndpoint
+    newsfeedId: NewsfeedApiEndpoint,
+    isScreenshotMode: boolean
   ): NewsfeedApi {
-    const api = getApi(config, this.kibanaVersion, newsfeedId);
+    const api = getApi(config, this.kibanaVersion, newsfeedId, isScreenshotMode);
     return {
       markAsRead: api.markAsRead,
       fetchResults$: api.fetchResults$.pipe(

src/plugins/newsfeed/public/types.ts

@@ -7,6 +7,10 @@
  */
 
 import { Duration, Moment } from 'moment';
+import type { ScreenshotModePluginStart } from 'src/plugins/screenshot_mode/public';
+export interface NewsfeedPluginStartDependencies {
+  screenshotMode: ScreenshotModePluginStart;
+}
 
 // Ideally, we may want to obtain the type from the configSchema and exposeToBrowser keys...
 export interface NewsfeedPluginBrowserConfig {

src/plugins/newsfeed/tsconfig.json

@@ -7,13 +7,9 @@
     "declaration": true,
     "declarationMap": true
   },
-  "include": [
-    "public/**/*",
-    "server/**/*",
-    "common/*",
-    "../../../typings/**/*"
-  ],
+  "include": ["public/**/*", "server/**/*", "common/*", "../../../typings/**/*"],
   "references": [
-    { "path": "../../core/tsconfig.json" }
+    { "path": "../../core/tsconfig.json" },
+    { "path": "../screenshot_mode/tsconfig.json" }
   ]
 }

src/plugins/screenshot_mode/public/index.ts

@@ -18,4 +18,4 @@ export {
   KBN_SCREENSHOT_MODE_ENABLED_KEY,
 } from '../common';
 
-export { ScreenshotModePluginSetup } from './types';
+export { ScreenshotModePluginSetup, ScreenshotModePluginStart } from './types';

src/plugins/screenshot_mode/public/plugin.test.ts

@@ -21,7 +21,7 @@ describe('Screenshot mode public', () => {
     setScreenshotModeDisabled();
   });
 
-  describe('setup contract', () => {
+  describe('public contract', () => {
     it('detects screenshot mode "true"', () => {
       setScreenshotModeEnabled();
       const screenshotMode = plugin.setup(coreMock.createSetup());
@@ -34,10 +34,4 @@ describe('Screenshot mode public', () => {
       expect(screenshotMode.isScreenshotMode()).toBe(false);
     });
   });
-
-  describe('start contract', () => {
-    it('returns nothing', () => {
-      expect(plugin.start(coreMock.createStart())).toBe(undefined);
-    });
-  });
 });

src/plugins/screenshot_mode/public/plugin.ts

@@ -8,18 +8,22 @@
 
 import { CoreSetup, CoreStart, Plugin } from '../../../core/public';
 
-import { ScreenshotModePluginSetup } from './types';
+import { ScreenshotModePluginSetup, ScreenshotModePluginStart } from './types';
 
 import { getScreenshotMode } from '../common';
 
 export class ScreenshotModePlugin implements Plugin<ScreenshotModePluginSetup> {
+  private publicContract = Object.freeze({
+    isScreenshotMode: () => getScreenshotMode() === true,
+  });
+
   public setup(core: CoreSetup): ScreenshotModePluginSetup {
-    return {
-      isScreenshotMode: () => getScreenshotMode() === true,
-    };
+    return this.publicContract;
   }
 
-  public start(core: CoreStart) {}
+  public start(core: CoreStart): ScreenshotModePluginStart {
+    return this.publicContract;
+  }
 
   public stop() {}
 }

src/plugins/screenshot_mode/public/types.ts

@@ -15,3 +15,4 @@ export interface IScreenshotModeService {
 }
 
 export type ScreenshotModePluginSetup = IScreenshotModeService;
+export type ScreenshotModePluginStart = IScreenshotModeService;