event bus

internal/pkg/eventbus/manager_test.go

@@ -0,0 +1,68 @@
+package eventbus
+
+import (
+	"reflect"
+	"sync"
+	"testing"
+)
+
+func TestGetReturnsSameBusForSameType(t *testing.T) {
+	resetManagerForTest(t)
+
+	first := Get[UserCreated]()
+	second := Get[UserCreated]()
+
+	if first != second {
+		t.Fatalf("expected same bus instance for same event type")
+	}
+}
+
+func TestGetReturnsDifferentBusForDifferentTypes(t *testing.T) {
+	resetManagerForTest(t)
+
+	userBus := Get[UserCreated]()
+	orderBus := Get[OrderCreated]()
+
+	if userBus == any(orderBus) {
+		t.Fatalf("expected different bus instances for different event types")
+	}
+}
+
+func TestGetCreatesOnlyOneBusUnderConcurrency(t *testing.T) {
+	resetManagerForTest(t)
+
+	const workers = 32
+
+	results := make(chan *Bus[UserCreated], workers)
+	var wg sync.WaitGroup
+
+	for range workers {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			results <- Get[UserCreated]()
+		}()
+	}
+
+	wg.Wait()
+	close(results)
+
+	var first *Bus[UserCreated]
+	for bus := range results {
+		if first == nil {
+			first = bus
+			continue
+		}
+		if bus != first {
+			t.Fatalf("expected same bus instance for concurrent access")
+		}
+	}
+}
+
+func resetManagerForTest(t *testing.T) {
+	t.Helper()
+
+	mu.Lock()
+	buss = make(map[reflect.Type]any)
+	mu.Unlock()
+}