Add test for translation with flag

Signed-off-by: Carrie Edwards <edwrdscarrie@gmail.com>

storage/remote/otlptranslator/prometheusremotewrite/metrics_to_prw_test.go

@@ -94,6 +94,51 @@ func TestFromMetrics(t *testing.T) {
 		})
 	}
 
+	for _, convertHistogramsToNHCB := range []bool{false, true} {
+		t.Run(fmt.Sprintf("successful/convertHistogramsToNHCB=%v", convertHistogramsToNHCB), func(t *testing.T) {
+			request := pmetricotlp.NewExportRequest()
+			rm := request.Metrics().ResourceMetrics().AppendEmpty()
+			generateAttributes(rm.Resource().Attributes(), "resource", 10)
+
+			metrics := rm.ScopeMetrics().AppendEmpty().Metrics()
+			ts := pcommon.NewTimestampFromTime(time.Now())
+
+			m := metrics.AppendEmpty()
+			m.SetEmptyHistogram()
+			m.SetName("histogram-1")
+			m.Histogram().SetAggregationTemporality(pmetric.AggregationTemporalityCumulative)
+			h := m.Histogram().DataPoints().AppendEmpty()
+			h.SetTimestamp(ts)
+
+			h.SetCount(15)
+			h.SetSum(155)
+
+			generateAttributes(h.Attributes(), "series", 1)
+
+			converter := NewPrometheusConverter()
+			annots, err := converter.FromMetrics(
+				context.Background(),
+				request.Metrics(),
+				Settings{ConvertHistogramsToNHCB: convertHistogramsToNHCB},
+			)
+			require.NoError(t, err)
+			require.Empty(t, annots)
+
+			series := converter.TimeSeries()
+
+			if convertHistogramsToNHCB {
+				require.Len(t, series[0].Histograms, 1)
+				require.Len(t, series[0].Samples, 0)
+			} else {
+				require.Len(t, series, 3)
+				for i := range series {
+					require.Len(t, series[i].Samples, 1)
+					require.Nil(t, series[i].Histograms)
+				}
+			}
+		})
+	}
+
 	t.Run("context cancellation", func(t *testing.T) {
 		converter := NewPrometheusConverter()
 		ctx, cancel := context.WithCancel(context.Background())