Update the helpers to sort labels alpabetically.

It will help to avoid the flaky tests and duplicated metrics.

As a bonus - added tests and benchmarks for monitoring package.

monitoring/helpers.go

@@ -3,6 +3,7 @@ package libpack_monitoring
 import (
 	"fmt"
 	"os"
+	"sort"
 	"strings"
 	"unicode"
 
@@ -10,37 +11,53 @@ import (
 )
 
 func (ms *MetricsSetup) get_metrics_name(name string, labels map[string]string) (complete_name string) {
-	if labels == nil {
+	const unknownPodName = "unknown"
-		labels = make(map[string]string)
-	}
-
-	// Adding default labels
-	labels["microservice"] = libpack_config.PKG_NAME
-	if podName, err := os.Hostname(); err == nil {
-		labels["pod"] = podName
-	} else {
-		labels["pod"] = "unknown"
-	}
-
 	var sb strings.Builder
+
+	// Prepare default labels without initializing a new map
+	podName := unknownPodName
+	if hn, err := os.Hostname(); err == nil {
+		podName = hn
+	}
+	if labels == nil {
+		labels = map[string]string{
+			"microservice": libpack_config.PKG_NAME,
+			"pod":          podName,
+		}
+	} else {
+		if _, exists := labels["microservice"]; !exists {
+			labels["microservice"] = libpack_config.PKG_NAME
+		}
+		if _, exists := labels["pod"]; !exists {
+			labels["pod"] = podName
+		}
+	}
+
+	// Prefix handling
 	if ms.metrics_prefix != "" {
 		sb.WriteString(ms.metrics_prefix)
 		sb.WriteString("_")
 	}
 	sb.WriteString(name)
 
+	// Append labels if any
 	if len(labels) > 0 {
 		sb.WriteString("{")
-		first := true
+
-		for k, v := range labels {
+		keys := make([]string, 0, len(labels))
-			if !first {
+		for k := range labels {
+			keys = append(keys, k)
+		}
+		sort.Strings(keys)
+
+		for i, k := range keys {
+			if i > 0 {
 				sb.WriteString(",")
 			}
 			sb.WriteString(k)
 			sb.WriteString("=\"")
-			sb.WriteString(v)
+			sb.WriteString(labels[k])
 			sb.WriteString("\"")
-			first = false
 		}
 		sb.WriteString("}")
 	}
@@ -82,9 +99,31 @@ func validate_metrics_name(name string) error {
 }
 
 func compile_metrics_with_labels(name string, labels map[string]string) string {
-	metric_name := name
+	var totalLength int
+	totalLength += len(name)
 	for k, v := range labels {
-		metric_name += "_" + k + "_" + v
+		totalLength += len(k) + len(v) + 2
 	}
-	return metric_name
+
+	var sb strings.Builder
+	sb.Grow(totalLength + 1)
+
+	sb.WriteString(name)
+
+	// Collect keys and sort them
+	keys := make([]string, 0, len(labels))
+	for k := range labels {
+		keys = append(keys, k)
+	}
+	sort.Strings(keys)
+
+	// Append sorted key-value pairs to the builder
+	for _, k := range keys {
+		sb.WriteString("_")
+		sb.WriteString(k)
+		sb.WriteString("_")
+		sb.WriteString(labels[k])
+	}
+
+	return sb.String()
 }

monitoring/helpers_bench_test.go

@@ -0,0 +1,44 @@
+package libpack_monitoring
+
+import (
+	"testing"
+
+	libpack_config "github.com/lukaszraczylo/graphql-monitoring-proxy/config"
+)
+
+func BenchmarkGetMetricsName(b *testing.B) {
+	// Setup environment
+	libpack_config.PKG_NAME = "test_service"
+
+	ms := &MetricsSetup{metrics_prefix: "test_prefix"}
+
+	labels := map[string]string{
+		"env":    "production",
+		"region": "us-west-2",
+	}
+
+	// Run the benchmark
+	for n := 0; n < b.N; n++ {
+		ms.get_metrics_name("request_count", labels)
+	}
+}
+
+func BenchmarkCompileMetricsWithLabels(b *testing.B) {
+	labels := map[string]string{
+		"env":    "production",
+		"region": "us-west-2",
+		"app":    "api-server",
+	}
+
+	for n := 0; n < b.N; n++ {
+		compile_metrics_with_labels("request_count", labels)
+	}
+}
+
+func BenchmarkValidateMetricsName(b *testing.B) {
+	input := "valid metric name with special chars @#! and underscores__"
+
+	for n := 0; n < b.N; n++ {
+		validate_metrics_name(input)
+	}
+}

monitoring/helpers_test.go

@@ -0,0 +1,143 @@
+package libpack_monitoring
+
+import (
+	"os"
+	"testing"
+
+	libpack_config "github.com/lukaszraczylo/graphql-monitoring-proxy/config"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestGetMetricsName(t *testing.T) {
+	ms := &MetricsSetup{metrics_prefix: "prefix"}
+	libpack_config.PKG_NAME = "example_microservice"
+
+	tests := []struct {
+		name           string
+		metricName     string
+		labels         map[string]string
+		expectedOutput string
+	}{
+		{
+			name:           "No labels",
+			metricName:     "test_metric",
+			labels:         nil,
+			expectedOutput: "prefix_test_metric{microservice=\"example_microservice\",pod=\"" + getPodName() + "\"}",
+		},
+		{
+			name:       "With labels",
+			metricName: "test_metric",
+			labels: map[string]string{
+				"label1": "value1",
+				"label2": "value2",
+			},
+			expectedOutput: "prefix_test_metric{label1=\"value1\",label2=\"value2\",microservice=\"example_microservice\",pod=\"" + getPodName() + "\"}",
+		},
+		{
+			name:       "Alphabetical order labels",
+			metricName: "test_metric",
+			labels: map[string]string{
+				"label2": "value2",
+				"label1": "value1",
+			},
+			expectedOutput: "prefix_test_metric{label1=\"value1\",label2=\"value2\",microservice=\"example_microservice\",pod=\"" + getPodName() + "\"}",
+		},
+		{
+			name:           "Empty metric name",
+			metricName:     "",
+			labels:         nil,
+			expectedOutput: "prefix_{microservice=\"example_microservice\",pod=\"" + getPodName() + "\"}",
+		},
+		{
+			name:           "Empty labels map",
+			metricName:     "test_metric",
+			labels:         map[string]string{},
+			expectedOutput: "prefix_test_metric{microservice=\"example_microservice\",pod=\"" + getPodName() + "\"}",
+		},
+		{
+			name:       "Single label",
+			metricName: "test_metric",
+			labels: map[string]string{
+				"label1": "value1",
+			},
+			expectedOutput: "prefix_test_metric{label1=\"value1\",microservice=\"example_microservice\",pod=\"" + getPodName() + "\"}",
+		},
+		{
+			name:       "Multiple labels with special characters",
+			metricName: "test_metric",
+			labels: map[string]string{
+				"label-2": "value-2",
+				"label_1": "value_1",
+			},
+			expectedOutput: "prefix_test_metric{label-2=\"value-2\",label_1=\"value_1\",microservice=\"example_microservice\",pod=\"" + getPodName() + "\"}",
+		},
+		{
+			name:       "Prefix only",
+			metricName: "",
+			labels: map[string]string{
+				"label1": "value1",
+			},
+			expectedOutput: "prefix_{label1=\"value1\",microservice=\"example_microservice\",pod=\"" + getPodName() + "\"}",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := ms.get_metrics_name(tt.metricName, tt.labels)
+			assert.Equal(t, tt.expectedOutput, result)
+		})
+	}
+}
+
+func TestCompileMetricsWithLabels(t *testing.T) {
+	tests := []struct {
+		name   string
+		labels map[string]string
+		want   string
+	}{
+		{"request_count", map[string]string{"env": "production", "region": "us-west-2"}, "request_count_env_production_region_us-west-2"},
+		{"metric_name", map[string]string{}, "metric_name"},
+		{"metric_name", nil, "metric_name"},
+		{"metric_name", map[string]string{"key1": "value1"}, "metric_name_key1_value1"},
+		{"metric_name", map[string]string{"k": "v", "key2": "value2"}, "metric_name_k_v_key2_value2"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := compile_metrics_with_labels(tt.name, tt.labels); got != tt.want {
+				t.Errorf("compile_metrics_with_labels() = %v, want %v", got, tt.want)
+			}
+		})
+	}
+}
+
+func TestValidateMetricsName(t *testing.T) {
+	tests := []struct {
+		name    string
+		input   string
+		wantErr bool
+	}{
+		{"Valid name", "valid_metric_name", false},
+		{"Name with spaces", "valid metric name", true},
+		{"Name with special chars", "valid@metric#name!", true},
+		{"Name with leading underscore", "_valid_metric_name", true},
+		{"Name with trailing underscore", "valid_metric_name_", true},
+		{"Name with consecutive underscores", "valid__metric__name", true},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := validate_metrics_name(tt.input); (err != nil) != tt.wantErr {
+				t.Errorf("validate_metrics_name() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}
+
+func getPodName() string {
+	podName, err := os.Hostname()
+	if err != nil {
+		return "unknown"
+	}
+	return podName
+}