v0.11.0 harden persistence and prepare game replays

internal/server/service/waiter_test.go

@@ -0,0 +1,81 @@
+package service
+
+import (
+	"context"
+	"sync"
+	"testing"
+	"time"
+
+	"chess/internal/server/core"
+)
+
+func TestWaitRegistryDeliversNotificationToCallerAndRemovesWaiter(t *testing.T) {
+	registry := NewWaitRegistry()
+	notify := registry.RegisterWait("game-1", 0, context.Background())
+
+	registry.NotifyGame("game-1", 1, core.StateOngoing)
+	select {
+	case <-notify:
+	case <-time.After(time.Second):
+		t.Fatal("game update was consumed before reaching the caller")
+	}
+	select {
+	case _, ok := <-notify:
+		if ok {
+			t.Fatal("completed notification channel returned another value")
+		}
+	default:
+		t.Fatal("completed notification channel was not closed")
+	}
+
+	registry.mu.RLock()
+	remaining := len(registry.waiters["game-1"])
+	registry.mu.RUnlock()
+	if remaining != 0 {
+		t.Fatalf("completed waiter remains registered: %d", remaining)
+	}
+	if err := registry.Shutdown(time.Second); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestWaitRegistryCompletionAndShutdownAreConcurrentAndIdempotent(t *testing.T) {
+	registry := NewWaitRegistry()
+	ctx, cancel := context.WithCancel(context.Background())
+	notify := registry.RegisterWait("game-1", 0, ctx)
+
+	var callers sync.WaitGroup
+	callers.Add(3)
+	go func() {
+		defer callers.Done()
+		registry.NotifyGame("game-1", 1, core.StateOngoing)
+	}()
+	go func() {
+		defer callers.Done()
+		registry.RemoveGame("game-1")
+	}()
+	go func() {
+		defer callers.Done()
+		cancel()
+	}()
+	callers.Wait()
+
+	select {
+	case <-notify:
+	case <-time.After(time.Second):
+		t.Fatal("concurrent completion did not notify caller")
+	}
+	if err := registry.Shutdown(time.Second); err != nil {
+		t.Fatal(err)
+	}
+	if err := registry.Shutdown(time.Second); err != nil {
+		t.Fatalf("second shutdown failed: %v", err)
+	}
+
+	afterShutdown := registry.RegisterWait("game-2", 0, context.Background())
+	select {
+	case <-afterShutdown:
+	default:
+		t.Fatal("registration after shutdown did not return a closed signal")
+	}
+}