From f0db09efbdce6c776e53c14f456a04f2faaf4144 Mon Sep 17 00:00:00 2001
From: Emmanuel T Odeke <emmanuel@orijtech.com>
Date: Wed, 12 May 2021 03:00:17 -0700
Subject: [PATCH] receiver/prometheus: add metricFamily.isCumulative +
 equivalence tests

---
 .../internal/otlp_metricfamily_test.go        | 99 +++++++++++++++++++
 .../internal/otlp_metricsbuilder_test.go      |  2 +-
 2 files changed, 100 insertions(+), 1 deletion(-)
 create mode 100644 receiver/prometheusreceiver/internal/otlp_metricfamily_test.go

diff --git a/receiver/prometheusreceiver/internal/otlp_metricfamily_test.go b/receiver/prometheusreceiver/internal/otlp_metricfamily_test.go
new file mode 100644
index 00000000000..6f8cc98136e
--- /dev/null
+++ b/receiver/prometheusreceiver/internal/otlp_metricfamily_test.go
@@ -0,0 +1,99 @@
+// Copyright The OpenTelemetry Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//       http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package internal
+
+import (
+	"testing"
+
+	"github.com/prometheus/prometheus/pkg/labels"
+	"github.com/prometheus/prometheus/pkg/textparse"
+	"github.com/prometheus/prometheus/scrape"
+	"github.com/stretchr/testify/assert"
+)
+
+type byLookupMetadataCache map[string]scrape.MetricMetadata
+
+func (bmc byLookupMetadataCache) Metadata(familyName string) (scrape.MetricMetadata, bool) {
+	lookup, ok := bmc[familyName]
+	return lookup, ok
+}
+
+func (bmc byLookupMetadataCache) SharedLabels() labels.Labels {
+	return nil
+}
+
+func TestIsCumulativeEquivalence(t *testing.T) {
+	mc := byLookupMetadataCache{
+		"counter": scrape.MetricMetadata{
+			Metric: "cr",
+			Type:   textparse.MetricTypeCounter,
+			Help:   "This is some help",
+			Unit:   "By",
+		},
+		"gauge": scrape.MetricMetadata{
+			Metric: "ge",
+			Type:   textparse.MetricTypeGauge,
+			Help:   "This is some help",
+			Unit:   "1",
+		},
+		"gaugehistogram": scrape.MetricMetadata{
+			Metric: "gh",
+			Type:   textparse.MetricTypeGaugeHistogram,
+			Help:   "This is some help",
+			Unit:   "?",
+		},
+		"histogram": scrape.MetricMetadata{
+			Metric: "hg",
+			Type:   textparse.MetricTypeHistogram,
+			Help:   "This is some help",
+			Unit:   "ms",
+		},
+		"summary": scrape.MetricMetadata{
+			Metric: "s",
+			Type:   textparse.MetricTypeSummary,
+			Help:   "This is some help",
+			Unit:   "?",
+		},
+		"unknown": scrape.MetricMetadata{
+			Metric: "u",
+			Type:   textparse.MetricTypeUnknown,
+			Help:   "This is some help",
+			Unit:   "?",
+		},
+	}
+
+	tests := []struct {
+		name string
+		want bool
+	}{
+		{name: "counter", want: true},
+		{name: "gauge", want: false},
+		{name: "histogram", want: true},
+		{name: "gaugehistogram", want: false},
+		{name: "does not exist", want: false},
+		{name: "unknown", want: false},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			mf := newMetricFamily(tt.name, mc).(*metricFamily)
+			mfp := newMetricFamilyPdata(tt.name, mc).(*metricFamilyPdata)
+			assert.Equal(t, mf.isCumulativeType(), mfp.isCumulativeTypePdata(), "mismatch in isCumulative")
+			assert.Equal(t, mf.isCumulativeType(), tt.want, "isCumulative does not match for regular metricFamily")
+			assert.Equal(t, mfp.isCumulativeTypePdata(), tt.want, "isCumulative does not match for pdata metricFamily")
+		})
+	}
+}
diff --git a/receiver/prometheusreceiver/internal/otlp_metricsbuilder_test.go b/receiver/prometheusreceiver/internal/otlp_metricsbuilder_test.go
index 1637b936469..dc97c757190 100644
--- a/receiver/prometheusreceiver/internal/otlp_metricsbuilder_test.go
+++ b/receiver/prometheusreceiver/internal/otlp_metricsbuilder_test.go
@@ -80,7 +80,7 @@ func TestGetBoundaryEquivalence(t *testing.T) {
 			},
 			wantErr: "QuantileLabel is empty",
 		},
-                {
+		{
 			name:   "other data types without matches",
 			mtype:  metricspb.MetricDescriptor_GAUGE_DOUBLE,
 			pmtype: pdata.MetricDataTypeDoubleGauge,