Prometheus: Refactor exemplar sampler (#60278)

pkg/tsdb/prometheus/querydata/exemplar/sampler_stddev_test.go

@@ -0,0 +1,27 @@
+package exemplar_test
+
+import (
+	"testing"
+	"time"
+
+	"github.com/grafana/grafana-plugin-sdk-go/experimental"
+	"github.com/grafana/grafana/pkg/tsdb/prometheus/models"
+	"github.com/grafana/grafana/pkg/tsdb/prometheus/querydata/exemplar"
+)
+
+func TestStdDevSampler(t *testing.T) {
+	sampler := exemplar.NewStandardDeviationSampler().(*exemplar.StandardDeviationSampler)
+	t.Run("standard deviation sampler", func(t *testing.T) {
+		tr := models.TimeRange{
+			Start: time.Unix(0, 0),
+			End:   time.Unix(100000, 0),
+		}
+		ex := generateTestExemplars(tr)
+		sampler.SetStep(600 * time.Second)
+		for i := 0; i < len(ex); i++ {
+			sampler.Add(ex[i])
+		}
+		framer := exemplar.NewFramer(sampler, exemplar.NewLabelTracker())
+		experimental.CheckGoldenJSONFramer(t, "testdata", "stddev_sampler", framer, update)
+	})
+}