fix metrics tests (#4146)

Signed-off-by: Joshua Kim <20001595+joshua-kim@users.noreply.github.com>

Author: joshua-kim

.golangci.yml

@@ -36,7 +36,6 @@ linters:
     - bodyclose
     - copyloopvar
     - depguard
-    - dupword
     - errcheck
     - errorlint
     - forbidigo

api/metrics/label_gatherer_test.go

@@ -4,11 +4,12 @@
 package metrics
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/testutil"
 	"github.com/stretchr/testify/require"
-	"google.golang.org/protobuf/proto"
 
 	dto "github.com/prometheus/client_model/go"
 )
@@ -23,68 +24,24 @@ func TestLabelGatherer_Gather(t *testing.T) {
 		customLabelValueB = "b"
 	)
 	tests := []struct {
-		name            string
-		labelName       string
-		expectedMetrics []*dto.Metric
-		expectErr       bool
+		name        string
+		labelName   string
+		wantMetrics string
+		expectErr   bool
 	}{
 		{
 			name:      "no overlap",
 			labelName: customLabelName,
-			expectedMetrics: []*dto.Metric{
-				{
-					Label: []*dto.LabelPair{
-						{
-							Name:  proto.String(labelName),
-							Value: proto.String(labelValueB),
-						},
-						{
-							Name:  proto.String(customLabelName),
-							Value: proto.String(customLabelValueB),
-						},
-					},
-					Counter: &dto.Counter{
-						Value: proto.Float64(1),
-					},
-				},
-				{
-					Label: []*dto.LabelPair{
-						{
-							Name:  proto.String(labelName),
-							Value: proto.String(labelValueA),
-						},
-						{
-							Name:  proto.String(customLabelName),
-							Value: proto.String(customLabelValueA),
-						},
-					},
-					Counter: &dto.Counter{
-						Value: proto.Float64(0),
-					},
-				},
-			},
-			expectErr: false,
+			wantMetrics: `
+# HELP counter help
+# TYPE counter counter
+counter{smith="morty",tag="b"} 1
+counter{smith="rick",tag="a"} 0
+`,
 		},
 		{
 			name:      "has overlap",
 			labelName: labelName,
-			expectedMetrics: []*dto.Metric{
-				{
-					Label: []*dto.LabelPair{
-						{
-							Name:  proto.String(labelName),
-							Value: proto.String(labelValueB),
-						},
-						{
-							Name:  proto.String(customLabelName),
-							Value: proto.String(customLabelValueB),
-						},
-					},
-					Counter: &dto.Counter{
-						Value: proto.Float64(1),
-					},
-				},
-			},
 			expectErr: true,
 		},
 	}
@@ -117,23 +74,17 @@ func TestLabelGatherer_Gather(t *testing.T) {
 				require.NoError(registerB.Register(counterB))
 			}
 
-			metrics, err := gatherer.Gather()
 			if test.expectErr {
-				require.Error(err) //nolint:forbidigo // the error is not exported
+				require.Error(testutil.GatherAndCompare( //nolint:forbidigo // the error is not exported
+					gatherer,
+					strings.NewReader(test.wantMetrics),
+				))
 			} else {
-				require.NoError(err)
+				require.NoError(testutil.GatherAndCompare(
+					gatherer,
+					strings.NewReader(test.wantMetrics),
+				))
 			}
-			require.Equal(
-				[]*dto.MetricFamily{
-					{
-						Name:   proto.String(counterOpts.Name),
-						Help:   proto.String(counterOpts.Help),
-						Type:   dto.MetricType_COUNTER.Enum(),
-						Metric: test.expectedMetrics,
-					},
-				},
-				metrics,
-			)
 		})
 	}
 }

api/metrics/prefix_gatherer_test.go

@@ -4,11 +4,12 @@
 package metrics
 
 import (
+	"strings"
 	"testing"
 
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/testutil"
 	"github.com/stretchr/testify/require"
-	"google.golang.org/protobuf/proto"
 
 	dto "github.com/prometheus/client_model/go"
 )
@@ -34,39 +35,20 @@ func TestPrefixGatherer_Gather(t *testing.T) {
 		require.NoError(registerB.Register(counterB))
 	}
 
-	metrics, err := gatherer.Gather()
-	require.NoError(err)
-	require.Equal(
-		[]*dto.MetricFamily{
-			{
-				Name: proto.String("a_counter"),
-				Help: proto.String(counterOpts.Help),
-				Type: dto.MetricType_COUNTER.Enum(),
-				Metric: []*dto.Metric{
-					{
-						Label: []*dto.LabelPair{},
-						Counter: &dto.Counter{
-							Value: proto.Float64(0),
-						},
-					},
-				},
-			},
-			{
-				Name: proto.String("b_counter"),
-				Help: proto.String(counterOpts.Help),
-				Type: dto.MetricType_COUNTER.Enum(),
-				Metric: []*dto.Metric{
-					{
-						Label: []*dto.LabelPair{},
-						Counter: &dto.Counter{
-							Value: proto.Float64(1),
-						},
-					},
-				},
-			},
-		},
-		metrics,
-	)
+	wantMetrics := `
+# HELP a_counter help
+# TYPE a_counter counter
+a_counter 0
+
+# HELP b_counter help
+# TYPE b_counter counter
+b_counter 1
+`
+
+	require.NoError(testutil.GatherAndCompare(
+		gatherer,
+		strings.NewReader(wantMetrics),
+	))
 }
 
 func TestPrefixGatherer_Register(t *testing.T) {