add the feature for observability

pkg/metrics/runtime_test.go

@@ -0,0 +1,91 @@
+package metrics
+
+import (
+	"context"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestInitRuntimeMetrics(t *testing.T) {
+	tests := []struct {
+		name      string
+		enabled   bool
+		wantError bool
+	}{
+		{
+			name:      "metrics enabled",
+			enabled:   true,
+			wantError: false,
+		},
+		{
+			name:      "metrics disabled",
+			enabled:   false,
+			wantError: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			// Setup: Initialize metrics with enabled state
+			cfg := Config{
+				Enabled:      tt.enabled,
+				ExporterType: ExporterPrometheus,
+				ServiceName:  "test-service",
+			}
+			err := InitMetrics(cfg)
+			require.NoError(t, err)
+
+			// Test InitRuntimeMetrics
+			err = InitRuntimeMetrics()
+			if tt.wantError {
+				assert.Error(t, err)
+			} else {
+				assert.NoError(t, err)
+			}
+
+			// Cleanup
+			Shutdown(context.Background())
+		})
+	}
+}
+
+func TestInitRuntimeMetrics_MultipleCalls(t *testing.T) {
+	// Setup
+	cfg := Config{
+		Enabled:      true,
+		ExporterType: ExporterPrometheus,
+		ServiceName:  "test-service",
+	}
+	err := InitMetrics(cfg)
+	require.NoError(t, err)
+	defer Shutdown(context.Background())
+
+	// Test: Multiple calls should not cause errors
+	err = InitRuntimeMetrics()
+	require.NoError(t, err)
+
+	// Note: Second call might fail if runtime.Start is already called,
+	// but that's expected behavior
+	err = InitRuntimeMetrics()
+	// We don't assert on error here as it depends on internal state
+	_ = err
+}
+
+func TestInitRuntimeMetrics_WhenDisabled(t *testing.T) {
+	// Setup: Metrics disabled
+	cfg := Config{
+		Enabled:      false,
+		ExporterType: ExporterPrometheus,
+		ServiceName:  "test-service",
+	}
+	err := InitMetrics(cfg)
+	require.NoError(t, err)
+	defer Shutdown(context.Background())
+
+	// Test: Should return nil without error when disabled
+	err = InitRuntimeMetrics()
+	assert.NoError(t, err)
+}
+