add test of Elixir cumulative explicit histogram

Author: tsloughter

test/otel_metric_tests.exs

@@ -3,6 +3,7 @@ defmodule OtelMetricTests do
 
   require OpenTelemetryAPIExperimental.Counter, as: Counter
   require OpenTelemetryAPIExperimental.UpDownCounter, as: UpDownCounter
+  require OpenTelemetryAPIExperimental.Histogram, as: Histogram
 
   require Record
   @fields Record.extract(:metric, from_lib: "opentelemetry_experimental/include/otel_metrics.hrl")
@@ -16,6 +17,9 @@ defmodule OtelMetricTests do
   @fields Record.extract(:sum, from_lib: "opentelemetry_experimental/include/otel_metrics.hrl")
   Record.defrecordp(:sum, @fields)
 
+  @fields Record.extract(:histogram, from_lib: "opentelemetry_experimental/include/otel_metrics.hrl")
+  Record.defrecordp(:histogram, @fields)
+
   setup do
     Application.load(:opentelemetry_experimental)
     Application.load(:opentelemetry)
@@ -34,7 +38,7 @@ defmodule OtelMetricTests do
             observable_counter: :temporality_cumulative,
             updown_counter: :temporality_delta,
             observable_updowncounter: :temporality_cumulative,
-            histogram: :temporality_delta,
+            histogram: :temporality_cumulative,
             observable_gauge: :temporality_cumulative
           }
         }
@@ -97,4 +101,32 @@ defmodule OtelMetricTests do
                       data: sum(datapoints: [datapoint(value: 9)])
                     )}
   end
+
+  test "create Histogram with macros" do
+    Histogram.create(:histogram_a, %{unit: "1", description: "some histogram_a"})
+    Histogram.record(:histogram_a, 1)
+
+    :otel_meter_server.force_flush()
+
+    assert_receive {:metric,
+                    metric(
+                      name: :histogram_a,
+                      data: histogram(aggregation_temporality: :temporality_cumulative,
+                        datapoints: [{:histogram_datapoint, %{}, _, _, 1, 1, [0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+                                      [0.0, 5.0, 10.0, 25.0, 50.0, 75.0, 100.0, 250.0, 500.0, 750.0, 1000.0, 2500.0, 5000.0, 7500.0, 10000.0], [], 0, 1, 1}])
+                    )}
+
+    Histogram.record(:histogram_a, 10)
+
+    :otel_meter_server.force_flush()
+
+    assert_receive {:metric,
+                    metric(
+                      name: :histogram_a,
+                      data: histogram(aggregation_temporality: :temporality_cumulative,
+                        datapoints: [{:histogram_datapoint, %{}, _, _, 2, 11, [0, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0],
+                                      [0.0, 5.0, 10.0, 25.0, 50.0, 75.0, 100.0, 250.0, 500.0, 750.0, 1000.0, 2500.0, 5000.0, 7500.0, 10000.0], [], 0, 1, 10}])
+                    )}
+  end
+
 end