[data views] add getDefaultDataView method (#113891)

* add new method to data views api

* add tests

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

src/plugins/data_views/common/data_views/data_views.test.ts

@@ -50,9 +50,15 @@ describe('IndexPatterns', () => {
   let indexPatterns: DataViewsService;
   let savedObjectsClient: SavedObjectsClientCommon;
   let SOClientGetDelay = 0;
+  const uiSettings = {
+    get: () => Promise.resolve(false),
+    getAll: () => {},
+    set: () => () => {},
+    remove: jest.fn(),
+  } as any as UiSettingsCommon;
+  const indexPatternObj = { id: 'id', version: 'a', attributes: { title: 'title' } };
 
   beforeEach(() => {
-    const indexPatternObj = { id: 'id', version: 'a', attributes: { title: 'title' } };
     savedObjectsClient = {} as SavedObjectsClientCommon;
     savedObjectsClient.find = jest.fn(
       () => Promise.resolve([indexPatternObj]) as Promise<Array<SavedObject<any>>>
@@ -86,10 +92,7 @@ describe('IndexPatterns', () => {
       });
 
     indexPatterns = new DataViewsService({
-      uiSettings: {
-        get: () => Promise.resolve(false),
-        getAll: () => {},
-      } as any as UiSettingsCommon,
+      uiSettings,
       savedObjectsClient: savedObjectsClient as unknown as SavedObjectsClientCommon,
       apiClient: createFieldsFetcher(),
       fieldFormats,
@@ -274,4 +277,49 @@ describe('IndexPatterns', () => {
     // successful subsequent request
     expect(async () => await indexPatterns.get(id)).toBeDefined();
   });
+
+  describe('getDefaultDataView', () => {
+    test('gets default data view', async () => {
+      indexPatterns.clearCache();
+      jest.clearAllMocks();
+
+      expect(await indexPatterns.getDefaultDataView()).toBeInstanceOf(DataView);
+      // make sure we're not pulling from cache
+      expect(savedObjectsClient.get).toBeCalledTimes(1);
+      expect(savedObjectsClient.find).toBeCalledTimes(1);
+    });
+
+    test('returns undefined if no data views exist', async () => {
+      savedObjectsClient.find = jest.fn(
+        () => Promise.resolve([]) as Promise<Array<SavedObject<any>>>
+      );
+      savedObjectsClient.get = jest.fn(() => Promise.resolve(undefined) as Promise<any>);
+      indexPatterns.clearCache();
+      expect(await indexPatterns.getDefaultDataView()).toBeUndefined();
+    });
+
+    test("default doesn't exist, grabs another data view", async () => {
+      indexPatterns.clearCache();
+      jest.clearAllMocks();
+      uiSettings.get = jest.fn().mockResolvedValue(['bar']);
+
+      savedObjectsClient.find = jest.fn(
+        () => Promise.resolve([indexPatternObj]) as Promise<Array<SavedObject<any>>>
+      );
+
+      savedObjectsClient.get = jest.fn().mockResolvedValue({
+        id: 'bar',
+        version: 'foo',
+        attributes: {
+          title: 'something',
+        },
+      });
+
+      expect(await indexPatterns.getDefaultDataView()).toBeInstanceOf(DataView);
+      // make sure we're not pulling from cache
+      expect(savedObjectsClient.get).toBeCalledTimes(1);
+      expect(savedObjectsClient.find).toBeCalledTimes(1);
+      expect(uiSettings.remove).toBeCalledTimes(1);
+    });
+  });
 });

src/plugins/data_views/common/data_views/data_views.ts

@@ -79,6 +79,10 @@ export class DataViewsService {
   private onError: OnError;
   private dataViewCache: ReturnType<typeof createDataViewCache>;
 
+  /**
+   * @deprecated Use `getDefaultDataView` instead (when loading data view) and handle
+   *             'no data view' case in api consumer code - no more auto redirect
+   */
   ensureDefaultDataView: EnsureDefaultDataView;
 
   constructor({
@@ -681,6 +685,33 @@ export class DataViewsService {
     this.dataViewCache.clear(indexPatternId);
     return this.savedObjectsClient.delete(DATA_VIEW_SAVED_OBJECT_TYPE, indexPatternId);
   }
+
+  /**
+   * Returns the default data view as an object. If no default is found, or it is missing
+   * another data view is selected as default and returned.
+   * @returns default data view
+   */
+
+  async getDefaultDataView() {
+    const patterns = await this.getIds();
+    let defaultId = await this.config.get('defaultIndex');
+    let defined = !!defaultId;
+    const exists = patterns.includes(defaultId);
+
+    if (defined && !exists) {
+      await this.config.remove('defaultIndex');
+      defaultId = defined = false;
+    }
+
+    if (patterns.length >= 1 && (await this.hasUserDataView().catch(() => true))) {
+      defaultId = patterns[0];
+      await this.config.set('defaultIndex', defaultId);
+    }
+
+    if (defaultId) {
+      return this.get(defaultId);
+    }
+  }
 }
 
 /**