Convert annotations to dataframes (#31400)

* Stop using transformation to tables

* Update datasource.ts to parse from dataframes

* Add test on transformToDataframe func

* Remove parseResponse and do the work inside parseToAnnotations method

* Name the dataframe after the RefID

* Small fix when mapping to annotation

* Add tests in annotation_query_test.go class

* Small fix in loop iteration

* Change for loop signature

pkg/tsdb/cloudmonitoring/annotation_query_test.go

@@ -10,18 +10,51 @@ import (
 )
 
 func TestCloudMonitoringExecutor_parseToAnnotations(t *testing.T) {
-	data, err := loadTestFile("./test-data/2-series-response-no-agg.json")
+	d, err := loadTestFile("./test-data/2-series-response-no-agg.json")
 	require.NoError(t, err)
-	require.Len(t, data.TimeSeries, 3)
+	require.Len(t, d.TimeSeries, 3)
 
 	res := &tsdb.QueryResult{Meta: simplejson.New(), RefId: "annotationQuery"}
 	query := &cloudMonitoringTimeSeriesFilter{}
 
-	err = query.parseToAnnotations(res, data, "atitle {{metric.label.instance_name}} {{metric.value}}", "atext {{resource.label.zone}}", "atag")
+	err = query.parseToAnnotations(res, d, "atitle {{metric.label.instance_name}} {{metric.value}}", "atext {{resource.label.zone}}", "atag")
 	require.NoError(t, err)
 
-	require.Len(t, res.Tables, 1)
-	require.Len(t, res.Tables[0].Rows, 9)
-	assert.Equal(t, "atitle collector-asia-east-1 9.856650", res.Tables[0].Rows[0][1])
-	assert.Equal(t, "atext asia-east1-a", res.Tables[0].Rows[0][3])
+	decoded, _ := res.Dataframes.Decoded()
+	require.Len(t, decoded, 3)
+	assert.Equal(t, "title", decoded[0].Fields[1].Name)
+	assert.Equal(t, "tags", decoded[0].Fields[2].Name)
+	assert.Equal(t, "text", decoded[0].Fields[3].Name)
+}
+
+func TestCloudMonitoringExecutor_parseToAnnotations_emptyTimeSeries(t *testing.T) {
+	res := &tsdb.QueryResult{Meta: simplejson.New(), RefId: "annotationQuery"}
+	query := &cloudMonitoringTimeSeriesFilter{}
+
+	response := cloudMonitoringResponse{
+		TimeSeries: []timeSeries{},
+	}
+
+	err := query.parseToAnnotations(res, response, "atitle", "atext", "atag")
+	require.NoError(t, err)
+
+	decoded, _ := res.Dataframes.Decoded()
+	require.Len(t, decoded, 0)
+}
+
+func TestCloudMonitoringExecutor_parseToAnnotations_noPointsInSeries(t *testing.T) {
+	res := &tsdb.QueryResult{Meta: simplejson.New(), RefId: "annotationQuery"}
+	query := &cloudMonitoringTimeSeriesFilter{}
+
+	response := cloudMonitoringResponse{
+		TimeSeries: []timeSeries{
+			{Points: nil},
+		},
+	}
+
+	err := query.parseToAnnotations(res, response, "atitle", "atext", "atag")
+	require.NoError(t, err)
+
+	decoded, _ := res.Dataframes.Decoded()
+	require.Len(t, decoded, 0)
 }