Graphite: Handle invalid annotations (#32437)

* Handle invalid annotations

* Add a test for handling invalid tags response

* Unify test descriptions

public/app/plugins/datasource/graphite/datasource.test.ts

@@ -233,15 +233,14 @@ describe('graphiteDatasource', () => {
         },
       ];
 
-      beforeEach(() => {
+      beforeEach(async () => {
         fetchMock.mockImplementation((options: any) => {
           return of(createFetchResponse(response));
         });
 
-        ctx.ds.annotationQuery(options).then((data: any) => {
+        await ctx.ds.annotationQuery(options).then((data: any) => {
           results = data;
         });
-        // ctx.$rootScope.$apply();
       });
 
       it('should parse the tags string into an array', () => {
@@ -251,6 +250,16 @@ describe('graphiteDatasource', () => {
         expect(results[0].tags[1]).toEqual('tag2');
       });
     });
+
+    it('and tags response is invalid', async () => {
+      fetchMock.mockImplementation((options: any) => {
+        return of(createFetchResponse('zzzzzzz'));
+      });
+      await ctx.ds.annotationQuery(options).then((data: any) => {
+        results = data;
+      });
+      expect(results).toEqual([]);
+    });
   });
 
   describe('when fetching Graphite function descriptions', () => {

public/app/plugins/datasource/graphite/datasource.ts

@@ -261,6 +261,10 @@ export class GraphiteDatasource extends DataSourceApi<GraphiteQuery, GraphiteOpt
       const tags = this.templateSrv.replace(options.annotation.tags);
       return this.events({ range: options.range, tags: tags }).then((results: any) => {
         const list = [];
+        if (!_.isArray(results.data)) {
+          console.error(`Unable to get annotations from ${results.url}.`);
+          return [];
+        }
         for (let i = 0; i < results.data.length; i++) {
           const e = results.data[i];