feat(metrics): introduce Tracker interface

Signed-off-by: lvlcn-t <75443136+lvlcn-t@users.noreply.github.com>

metrics/metrics.go

@@ -32,6 +32,12 @@ type Collector interface {
 	GetRegistry() *prometheus.Registry
 }
 
+// Tracker is the interface that wraps the basic methods of the OpenTelemetry tracer and Prometheus collector.
+type Tracker interface {
+	Tracer
+	Collector
+}
+
 // manager implements the Tracer and Collector interfaces
 // It is used to initialize the OpenTelemetry manager and Prometheus collectors
 type manager struct {
@@ -45,7 +51,7 @@ type manager struct {
 
 // New creates a new metrics instance with the given configuration.
 // This instance can be used to initialize the OpenTelemetry metrics and Prometheus collectors.
-func New(config Config) *manager {
+func New(config Config) Tracker {
 	registry := prometheus.NewRegistry()
 
 	registry.MustRegister(

metrics/metrics_test.go

@@ -43,9 +43,7 @@ func TestNew(t *testing.T) {
 	)
 
 	t.Run("Register a collector", func(t *testing.T) {
-		testMetrics.registry.MustRegister(
-			testGauge,
-		)
+		testMetrics.GetRegistry().MustRegister(testGauge)
 	})
 }
 
@@ -123,7 +121,7 @@ func TestTracer_Initialize_Shutdown(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			m := New(tt.config)
+			m := New(tt.config).(*manager)
 			if _, ok := tt.wantErr.(*ErrAlreadyInitialized); ok {
 				m.tracer = sdktrace.NewTracerProvider()
 			}