test: add TestHelpers for blackjack tests

Game.Blackjack.Tests/TestHelpers.cs

@@ -0,0 +1,131 @@
+using Game.Blackjack;
+using OECS;
+using System.Text;
+
+namespace Game.Blackjack.Tests;
+
+internal static class TestHelpers
+{
+    private const int StartingChips = 100;
+
+    /// <summary>
+    /// Creates a fresh Blackjack world with systems registered and GameState singleton initialized.
+    /// </summary>
+    public static (World World, SystemGroup Group) SetupGame(uint seed = 42)
+    {
+        var world = new World();
+        var group = new SystemGroup(world);
+        group.Add(new DeckSetupSystem());
+        group.Add(new DealSystem());
+        group.Add(new PlayerBustCheckSystem());
+        group.Add(new DealerSystem());
+
+        world.SetSingleton(new GameState
+        {
+            Phase = GamePhase.Betting,
+            Result = RoundResult.None,
+            Chips = StartingChips,
+            CurrentBet = 0,
+            RoundNumber = 1,
+            Seed = seed
+        });
+        world.PostChanges();
+
+        return (world, group);
+    }
+
+    /// <summary>
+    /// Returns a human-readable textual snapshot of the world state.
+    /// </summary>
+    public static string SnapshotWorld(World world)
+    {
+        var sb = new StringBuilder();
+        var state = world.ReadSingleton<GameState>();
+        sb.AppendLine($"Phase: {state.Phase}");
+        sb.AppendLine($"Chips: {state.Chips}");
+        sb.AppendLine($"Bet: {state.CurrentBet}");
+        sb.AppendLine($"Round: {state.RoundNumber}");
+        sb.AppendLine($"Result: {state.Result}");
+        sb.AppendLine($"Seed: {state.Seed}");
+
+        var deckEntity = FindEntity<Deck>(world);
+        if (deckEntity != Entity.Null)
+        {
+            var cardsInDeck = world.GetSources<InDeck>(deckEntity).ToList();
+            sb.AppendLine($"Cards in deck: {cardsInDeck.Count}");
+        }
+
+        var playerHand = FindEntity<PlayerHand>(world);
+        if (playerHand != Entity.Null)
+        {
+            var cards = world.GetSources<Holds>(playerHand).ToList();
+            sb.AppendLine($"Player hand: {cards.Count} cards");
+            foreach (var cardEntity in cards)
+            {
+                var card = world.ReadComponent<Card>(cardEntity);
+                sb.AppendLine($"  {card.Rank} of {card.Suit}");
+            }
+        }
+
+        var dealerHand = FindEntity<DealerHand>(world);
+        if (dealerHand != Entity.Null)
+        {
+            var cards = world.GetSources<Holds>(dealerHand).ToList();
+            sb.AppendLine($"Dealer hand: {cards.Count} cards");
+            foreach (var cardEntity in cards)
+            {
+                var card = world.ReadComponent<Card>(cardEntity);
+                sb.AppendLine($"  {card.Rank} of {card.Suit}");
+            }
+        }
+
+        int entityCount = 0;
+        using (var iter = world.Select<Card>())
+        {
+            while (iter.MoveNext()) entityCount++;
+        }
+        sb.AppendLine($"Card entities: {entityCount}");
+
+        return sb.ToString().TrimEnd();
+    }
+
+    public static Entity FindEntity<T>(World world) where T : struct
+    {
+        return world.FindEntity<T>();
+    }
+
+    public static int CountCardsInHand(World world, Entity handEntity)
+    {
+        return world.GetSources<Holds>(handEntity).Count;
+    }
+
+    public static List<string> GetHandCards(World world, Entity hand)
+    {
+        var cards = new List<string>();
+        foreach (var cardEntity in world.GetSources<Holds>(hand))
+        {
+            var card = world.ReadComponent<Card>(cardEntity);
+            cards.Add($"{card.Rank} of {card.Suit}");
+        }
+        return cards;
+    }
+
+    public static List<(Suit, Rank)> GetAllCards(World world)
+    {
+        var cards = new List<(Suit, Rank)>();
+        using (var iter = world.Select<Card>())
+        {
+            while (iter.MoveNext())
+            {
+                var card = iter.Val1;
+                cards.Add((card.Suit, card.Rank));
+            }
+        }
+        cards.Sort((a, b) =>
+        {
+            int cmp = a.Item1.CompareTo(b.Item1);
+            return cmp != 0 ? cmp : a.Item2.CompareTo(b.Item2);
+        });
+        return cards;
+    }
+}