test: add unit tests for Blackjack and TicTacToe

- Add xUnit test projects for both games
- Implement game flow tests for Blackjack
- Implement game flow tests for TicTacToe
- Rename namespaces and projects to follow `Game.*` convention
- Add documentation for testing games

Game.Blackjack.Tests/Game.Blackjack.Tests.csproj

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <RootNamespace>Game.Blackjack.Tests</RootNamespace>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="FluentAssertions" Version="6.12.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageReference Include="xunit" Version="2.9.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Game.Blackjack\Blackjack.csproj" />
+  </ItemGroup>
+
+</Project>

Game.Blackjack.Tests/GameFlowTests.cs

@@ -0,0 +1,247 @@
+using FluentAssertions;
+using Game.Blackjack;
+using OECS;
+using Xunit;
+
+namespace Game.Blackjack.Tests;
+
+public class GameFlowTests
+{
+    [Fact]
+    public void NewGame_StartsInBettingPhase()
+    {
+        var (world, _) = SetupGame();
+
+        var state = world.ReadSingleton<GameState>();
+        state.Phase.Should().Be(GamePhase.Betting);
+        state.Chips.Should().Be(100);
+        state.RoundNumber.Should().Be(1);
+    }
+
+    [Fact]
+    public void PlaceBet_AdvancesToDealing()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group.RunLogical();
+
+        var state = world.ReadSingleton<GameState>();
+        state.Phase.Should().Be(GamePhase.PlayerTurn); // Dealing → PlayerTurn happens automatically
+        state.CurrentBet.Should().Be(10);
+        state.Chips.Should().Be(90);
+    }
+
+    [Fact]
+    public void PlaceBet_RejectsInsufficientChips()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 200 });
+        group.RunLogical();
+
+        var state = world.ReadSingleton<GameState>();
+        state.Phase.Should().Be(GamePhase.Betting); // Should not advance
+        state.Chips.Should().Be(100);
+    }
+
+    [Fact]
+    public void PlaceBet_RejectsZeroOrNegative()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 0 });
+        group.RunLogical();
+        world.ReadSingleton<GameState>().Phase.Should().Be(GamePhase.Betting);
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = -5 });
+        group.RunLogical();
+        world.ReadSingleton<GameState>().Phase.Should().Be(GamePhase.Betting);
+    }
+
+    [Fact]
+    public void Dealing_CreatesDeckAndHands()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group.RunLogical();
+
+        // Should have a deck entity.
+        var deckEntity = FindEntity<Deck>(world);
+        deckEntity.Should().NotBe(Entity.Null);
+
+        // Should have player and dealer hand entities.
+        var playerHand = FindEntity<PlayerHand>(world);
+        playerHand.Should().NotBe(Entity.Null);
+
+        var dealerHand = FindEntity<DealerHand>(world);
+        dealerHand.Should().NotBe(Entity.Null);
+    }
+
+    [Fact]
+    public void Dealing_DealsTwoCardsToEach()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group.RunLogical();
+
+        var playerHand = FindEntity<PlayerHand>(world);
+        var dealerHand = FindEntity<DealerHand>(world);
+
+        CountCardsInHand(world, playerHand).Should().Be(2);
+        CountCardsInHand(world, dealerHand).Should().Be(2);
+    }
+
+    [Fact]
+    public void Hit_DrawsOneCard()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group.RunLogical();
+
+        var playerHand = FindEntity<PlayerHand>(world);
+        var before = CountCardsInHand(world, playerHand);
+
+        world.Commands.Enqueue(new HitCommand());
+        group.RunLogical();
+
+        var after = CountCardsInHand(world, playerHand);
+        after.Should().Be(before + 1);
+    }
+
+    [Fact]
+    public void Stand_AdvancesToDealerTurn()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group.RunLogical();
+
+        world.Commands.Enqueue(new StandCommand());
+        group.RunLogical();
+
+        var state = world.ReadSingleton<GameState>();
+        state.Phase.Should().Be(GamePhase.RoundOver);
+    }
+
+    [Fact]
+    public void NewRound_ResetsPhase()
+    {
+        var (world, group) = SetupGame();
+
+        // Play a round.
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group.RunLogical();
+        world.Commands.Enqueue(new StandCommand());
+        group.RunLogical();
+
+        // Start new round.
+        world.Commands.Enqueue(new NewRoundCommand());
+        group.RunLogical();
+
+        var state = world.ReadSingleton<GameState>();
+        state.Phase.Should().Be(GamePhase.Betting);
+        state.Result.Should().Be(RoundResult.None);
+    }
+
+    [Fact]
+    public void DeterministicSeed_ProducesSameDeal()
+    {
+        var (world1, group1) = SetupGame(seed: 42);
+        world1.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group1.RunLogical();
+        var cards1 = GetAllCards(world1);
+
+        var (world2, group2) = SetupGame(seed: 42);
+        world2.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group2.RunLogical();
+        var cards2 = GetAllCards(world2);
+
+        cards1.Should().Equal(cards2);
+    }
+
+    [Fact]
+    public void PlayerBust_LosesBet()
+    {
+        // Use a seed that produces a bust-prone hand, then hit repeatedly.
+        var (world, group) = SetupGame(seed: 12345);
+
+        world.Commands.Enqueue(new PlaceBetCommand { Amount = 10 });
+        group.RunLogical();
+
+        var chipsBefore = world.ReadSingleton<GameState>().Chips;
+
+        // Hit until bust or stand.
+        while (world.ReadSingleton<GameState>().Phase == GamePhase.PlayerTurn)
+        {
+            world.Commands.Enqueue(new HitCommand());
+            group.RunLogical();
+        }
+
+        // Game should have resolved.
+        var state = world.ReadSingleton<GameState>();
+        state.Phase.Should().Be(GamePhase.RoundOver);
+    }
+
+    // ── Helpers ───────────────────────────────────────────────────────
+
+    private static (World, SystemGroup) 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 = 100,
+            CurrentBet = 0,
+            RoundNumber = 1,
+            Seed = seed
+        });
+        world.PostChanges();
+
+        return (world, group);
+    }
+
+    private static Entity FindEntity<T>(World world) where T : struct
+    {
+        using var iter = world.Select<T>();
+        while (iter.MoveNext())
+        {
+            if (iter.CurrentEntity != World.SingletonEntity)
+                return iter.CurrentEntity;
+        }
+        return Entity.Null;
+    }
+
+    private static int CountCardsInHand(World world, Entity handEntity)
+    {
+        // Holds relationship: Source = card entity, Target = hand entity.
+        // GetSources returns all card entities that have a Holds pointing to handEntity.
+        return world.GetSources<Holds>(handEntity).Count;
+    }
+
+    private static List<(Suit, Rank)> GetAllCards(World world)
+    {
+        var cards = new List<(Suit, Rank)>();
+        var query = world.Query().With<Card>().Build();
+        world.ForEach(query, (Entity e, ref Card card) =>
+        {
+            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;
+    }
+}

Game.Blackjack/Blackjack.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <RootNamespace>Blackjack</RootNamespace>
+    <RootNamespace>Game.Blackjack</RootNamespace>
   </PropertyGroup>
 
   <ItemGroup>

Game.Blackjack/Commands/HitCommand.cs

@@ -1,7 +1,7 @@
 using MessagePack;
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Player hits: draws one card from the deck to the player's hand.

Game.Blackjack/Commands/NewRoundCommand.cs

@@ -1,7 +1,7 @@
 using MessagePack;
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Starts a new round after the previous one ended.

Game.Blackjack/Commands/PlaceBetCommand.cs

@@ -1,7 +1,7 @@
 using MessagePack;
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Places a bet and advances the game to the dealing phase.

Game.Blackjack/Commands/StandCommand.cs

@@ -1,7 +1,7 @@
 using MessagePack;
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Player stands: advance to the dealer's turn.

Game.Blackjack/Components/Card.cs

@@ -1,6 +1,6 @@
 using MessagePack;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// A playing card with a suit and rank.

Game.Blackjack/Components/DealerHand.cs

@@ -1,6 +1,6 @@
 using MessagePack;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Tag component marking the dealer's hand entity.

Game.Blackjack/Components/Deck.cs

@@ -1,6 +1,6 @@
 using MessagePack;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Tag component marking the deck entity.

Game.Blackjack/Components/Holds.cs

@@ -1,7 +1,7 @@
 using MessagePack;
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Relationship from a hand entity to a card entity,

Game.Blackjack/Components/InDeck.cs

@@ -1,7 +1,7 @@
 using MessagePack;
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Relationship from a card entity to the deck entity,

Game.Blackjack/Components/PlayerHand.cs

@@ -1,6 +1,6 @@
 using MessagePack;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Tag component marking the player's hand entity.

Game.Blackjack/Components/Rank.cs

@@ -1,4 +1,4 @@
-namespace Blackjack;
+namespace Game.Blackjack;
 
 public enum Rank : byte
 {

Game.Blackjack/Components/Suit.cs

@@ -1,4 +1,4 @@
-namespace Blackjack;
+namespace Game.Blackjack;
 
 public enum Suit : byte
 {

Game.Blackjack/Mulberry32.cs

@@ -1,4 +1,4 @@
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Mulberry32 PRNG — a fast, high-quality 32-bit random number generator.

Game.Blackjack/Singletons/GamePhase.cs

@@ -1,4 +1,4 @@
-namespace Blackjack;
+namespace Game.Blackjack;
 
 public enum GamePhase : byte
 {

Game.Blackjack/Singletons/GameState.cs

@@ -1,6 +1,6 @@
 using MessagePack;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Global game state stored on the singleton entity.

Game.Blackjack/Singletons/RoundResult.cs

@@ -1,4 +1,4 @@
-namespace Blackjack;
+namespace Game.Blackjack;
 
 public enum RoundResult : byte
 {

Game.Blackjack/Systems/DealSystem.cs

@@ -1,6 +1,6 @@
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Deals initial two cards to player and dealer when entering the dealing phase.

Game.Blackjack/Systems/DealerSystem.cs

@@ -1,6 +1,6 @@
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Dealer draws cards until reaching 17 or higher,

Game.Blackjack/Systems/DeckSetupSystem.cs

@@ -1,6 +1,6 @@
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Creates the deck (52 cards + deck/hand entities) and shuffles

Game.Blackjack/Systems/HandUtil.cs

@@ -1,6 +1,6 @@
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Helper to calculate the blackjack value of a hand.

Game.Blackjack/Systems/PlayerBustCheckSystem.cs

@@ -1,6 +1,6 @@
 using OECS;
 
-namespace Blackjack;
+namespace Game.Blackjack;
 
 /// <summary>
 /// Evaluates the player's hand total after each hit.

Game.TicTacToe.Tests/Game.TicTacToe.Tests.csproj

@@ -0,0 +1,24 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <RootNamespace>Game.TicTacToe.Tests</RootNamespace>
+    <IsPackable>false</IsPackable>
+    <IsTestProject>true</IsTestProject>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="FluentAssertions" Version="6.12.1" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.11.1" />
+    <PackageReference Include="xunit" Version="2.9.2" />
+    <PackageReference Include="xunit.runner.visualstudio" Version="2.8.2">
+      <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+      <PrivateAssets>all</PrivateAssets>
+    </PackageReference>
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\Game.TicTacToe\TicTacToe.csproj" />
+  </ItemGroup>
+
+</Project>

Game.TicTacToe.Tests/GameFlowTests.cs

@@ -0,0 +1,213 @@
+using FluentAssertions;
+using Game.TicTacToe;
+using OECS;
+using Xunit;
+
+namespace Game.TicTacToe.Tests;
+
+public class GameFlowTests
+{
+    [Fact]
+    public void NewGame_HasEmptyBoard()
+    {
+        var (world, _) = SetupGame();
+
+        var query = world.Query().With<Cell>().Without<Mark>().Build();
+        var emptyCount = 0;
+        world.ForEach(query, (Entity e, ref Cell cell) => emptyCount++);
+
+        emptyCount.Should().Be(9);
+    }
+
+    [Fact]
+    public void PlaceMark_ClaimsCell()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceMarkCommand { Row = 0, Col = 0 });
+        group.RunLogical();
+
+        var query = world.Query().With<Cell>().With<Mark>().Build();
+        var markedCount = 0;
+        world.ForEach(query, (Entity e, ref Cell cell, ref Mark mark) =>
+        {
+            markedCount++;
+            cell.Row.Should().Be(0);
+            cell.Col.Should().Be(0);
+            mark.Player.Should().Be(Player.X);
+        });
+
+        markedCount.Should().Be(1);
+    }
+
+    [Fact]
+    public void PlaceMark_TogglesPlayer()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceMarkCommand { Row = 0, Col = 0 }); // X
+        group.RunLogical();
+        world.ReadSingleton<GameState>().CurrentPlayer.Should().Be(Player.O);
+
+        world.Commands.Enqueue(new PlaceMarkCommand { Row = 1, Col = 0 }); // O
+        group.RunLogical();
+        world.ReadSingleton<GameState>().CurrentPlayer.Should().Be(Player.X);
+    }
+
+    [Fact]
+    public void PlaceMark_CannotOverwriteClaimedCell()
+    {
+        var (world, group) = SetupGame();
+
+        world.Commands.Enqueue(new PlaceMarkCommand { Row = 0, Col = 0 }); // X
+        group.RunLogical();
+        world.Commands.Enqueue(new PlaceMarkCommand { Row = 0, Col = 0 }); // O tries same cell
+        group.RunLogical();
+
+        // Only one mark should exist at (0,0), and it should still be X.
+        var query = world.Query().With<Cell>().With<Mark>().Build();
+        var marks = new List<(int Row, int Col, Player Player)>();
+        world.ForEach(query, (Entity e, ref Cell cell, ref Mark mark) =>
+        {
+            marks.Add((cell.Row, cell.Col, mark.Player));
+        });
+
+        marks.Should().ContainSingle()
+            .Which.Should().Be((0, 0, Player.X));
+    }
+
+    [Fact]
+    public void XWins_Row()
+    {
+        var (world, group) = SetupGame();
+
+        // X: (0,0), O: (1,0), X: (0,1), O: (1,1), X: (0,2) → X wins row 0
+        PlayMoves(world, group, (0, 0), (1, 0), (0, 1), (1, 1), (0, 2));
+
+        world.ReadSingleton<GameState>().Status.Should().Be(GameStatus.XWon);
+    }
+
+    [Fact]
+    public void OWins_Column()
+    {
+        var (world, group) = SetupGame();
+
+        // X: (0,0), O: (1,0), X: (0,1), O: (1,1), X: (2,2), O: (1,2) → O wins col 0
+        PlayMoves(world, group, (0, 0), (1, 0), (0, 1), (1, 1), (2, 2), (1, 2));
+
+        world.ReadSingleton<GameState>().Status.Should().Be(GameStatus.OWon);
+    }
+
+    [Fact]
+    public void XWins_Diagonal()
+    {
+        var (world, group) = SetupGame();
+
+        // X: (0,0), O: (1,0), X: (1,1), O: (1,2), X: (2,2) → X wins diagonal
+        PlayMoves(world, group, (0, 0), (1, 0), (1, 1), (1, 2), (2, 2));
+
+        world.ReadSingleton<GameState>().Status.Should().Be(GameStatus.XWon);
+    }
+
+    [Fact]
+    public void Draw_AllCellsFilled()
+    {
+        var (world, group) = SetupGame();
+
+        // Fill all 9 cells without a winner.
+        // X: (0,0) (0,2) (1,0) (2,1) (2,2)
+        // O: (0,1) (1,1) (1,2) (2,0)
+        PlayMoves(world, group,
+            (0, 0), (0, 1), (0, 2),
+            (1, 1), (1, 0), (1, 2),
+            (2, 1), (2, 0), (2, 2));
+
+        world.ReadSingleton<GameState>().Status.Should().Be(GameStatus.Draw);
+    }
+
+    [Fact]
+    public void MovesAfterGameOver_AreIgnored()
+    {
+        var (world, group) = SetupGame();
+
+        // X wins.
+        PlayMoves(world, group, (0, 0), (1, 0), (0, 1), (1, 1), (0, 2));
+
+        world.ReadSingleton<GameState>().Status.Should().Be(GameStatus.XWon);
+
+        // Try to place another mark — should be ignored.
+        var moveCountBefore = world.ReadSingleton<GameState>().MoveCount;
+        world.Commands.Enqueue(new PlaceMarkCommand { Row = 2, Col = 2 });
+        group.RunLogical();
+
+        world.ReadSingleton<GameState>().MoveCount.Should().Be(moveCountBefore);
+    }
+
+    [Fact]
+    public void SaveLoad_RoundTrips()
+    {
+        var (world, group) = SetupGame();
+
+        // Play a few moves.
+        world.Commands.Enqueue(new PlaceMarkCommand { Row = 0, Col = 0 });
+        group.RunLogical();
+        world.Commands.Enqueue(new PlaceMarkCommand { Row = 1, Col = 0 });
+        group.RunLogical();
+
+        // Save.
+        using var stream = new MemoryStream();
+        WorldSerializer.Save(world, stream);
+        stream.Position = 0;
+
+        // Load into a new world.
+        var world2 = new World();
+        WorldSerializer.Load(world2, stream);
+
+        // Verify state.
+        var state = world2.ReadSingleton<GameState>();
+        state.CurrentPlayer.Should().Be(Player.X);
+        state.MoveCount.Should().Be(2);
+
+        var query = world2.Query().With<Cell>().With<Mark>().Build();
+        var marks = new List<(int Row, int Col, Player Player)>();
+        world2.ForEach(query, (Entity e, ref Cell cell, ref Mark mark) =>
+        {
+            marks.Add((cell.Row, cell.Col, mark.Player));
+        });
+
+        marks.Should().BeEquivalentTo([(0, 0, Player.X), (1, 0, Player.O)]);
+    }
+
+    // ── Helpers ───────────────────────────────────────────────────────
+
+    private static (World, SystemGroup) SetupGame()
+    {
+        var world = new World();
+        var group = new SystemGroup(world);
+        group.Add(new WinCheckSystem());
+
+        // Create the 9 cells.
+        for (int r = 0; r < 3; r++)
+            for (int c = 0; c < 3; c++)
+                world.AddComponent(world.CreateEntity(), new Cell { Row = r, Col = c });
+
+        world.SetSingleton(new GameState
+        {
+            CurrentPlayer = Player.X,
+            Status = GameStatus.Playing,
+            MoveCount = 0
+        });
+        world.PostChanges();
+
+        return (world, group);
+    }
+
+    private static void PlayMoves(World world, SystemGroup group, params (int Row, int Col)[] moves)
+    {
+        foreach (var (row, col) in moves)
+        {
+            world.Commands.Enqueue(new PlaceMarkCommand { Row = row, Col = col });
+            group.RunLogical();
+        }
+    }
+}

Game.TicTacToe/Commands/PlaceMarkCommand.cs

@@ -1,7 +1,7 @@
 using MessagePack;
 using OECS;
 
-namespace TicTacToe;
+namespace Game.TicTacToe;
 
 /// <summary>
 /// Places the current player's mark on the cell at (Row, Col).

Game.TicTacToe/Components/Cell.cs

@@ -1,6 +1,6 @@
 using MessagePack;
 
-namespace TicTacToe;
+namespace Game.TicTacToe;
 
 /// <summary>
 /// Identifies a board position. One entity per cell.

Game.TicTacToe/Components/Mark.cs

@@ -1,6 +1,6 @@
 using MessagePack;
 
-namespace TicTacToe;
+namespace Game.TicTacToe;
 
 /// <summary>
 /// A mark placed on a cell by a player.

Game.TicTacToe/Components/Player.cs

@@ -1,4 +1,4 @@
-namespace TicTacToe;
+namespace Game.TicTacToe;
 
 public enum Player : byte
 {

Game.TicTacToe/CsvLoader.cs

@@ -1,6 +1,6 @@
 using OECS;
 
-namespace TicTacToe;
+namespace Game.TicTacToe;
 
 /// <summary>
 /// Minimal CSV loader that creates entities from a CSV file.

Game.TicTacToe/Singletons/GameState.cs

@@ -1,6 +1,6 @@
 using MessagePack;
 
-namespace TicTacToe;
+namespace Game.TicTacToe;
 
 /// <summary>
 /// Global game state stored on the singleton entity.

Game.TicTacToe/Singletons/GameStatus.cs

@@ -1,4 +1,4 @@
-namespace TicTacToe;
+namespace Game.TicTacToe;
 
 public enum GameStatus : byte
 {

Game.TicTacToe/Systems/WinCheckSystem.cs

@@ -1,6 +1,6 @@
 using OECS;
 
-namespace TicTacToe;
+namespace Game.TicTacToe;
 
 /// <summary>
 /// After each move, checks whether the game has been won or drawn.

Game.TicTacToe/TicTacToe.csproj

@@ -2,7 +2,7 @@
 
   <PropertyGroup>
     <OutputType>Library</OutputType>
-    <RootNamespace>TicTacToe</RootNamespace>
+    <RootNamespace>Game.TicTacToe</RootNamespace>
   </PropertyGroup>
 
   <ItemGroup>

OECS.sln

@@ -8,9 +8,13 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "OECS.SourceGen", "OECS.Sour
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "OECS.Tests", "OECS.Tests\OECS.Tests.csproj", "{B2C3D4E5-F6A7-8901-BCDE-F12345678901}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Blackjack", "Blackjack\Blackjack.csproj", "{85631EDE-F984-4DA6-8EE9-0715AF1204E6}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Game.Blackjack", "Game.Blackjack\Blackjack.csproj", "{85631EDE-F984-4DA6-8EE9-0715AF1204E6}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "TicTacToe", "TicTacToe\TicTacToe.csproj", "{D4E5F6A7-B8C9-0123-DEF4-567890ABCDEF}"
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Game.TicTacToe", "Game.TicTacToe\TicTacToe.csproj", "{D4E5F6A7-B8C9-0123-DEF4-567890ABCDEF}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Game.Blackjack.Tests", "Game.Blackjack.Tests\Game.Blackjack.Tests.csproj", "{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Game.TicTacToe.Tests", "Game.TicTacToe.Tests\Game.TicTacToe.Tests.csproj", "{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -82,6 +86,31 @@ Global
 		{D4E5F6A7-B8C9-0123-DEF4-567890ABCDEF}.Release|x64.Build.0 = Release|Any CPU
 		{D4E5F6A7-B8C9-0123-DEF4-567890ABCDEF}.Release|x86.ActiveCfg = Release|Any CPU
 		{D4E5F6A7-B8C9-0123-DEF4-567890ABCDEF}.Release|x86.Build.0 = Release|Any CPU
+	EndGlobalSection
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Debug|Any CPU.Build.0 = Debug|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Debug|x64.ActiveCfg = Debug|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Debug|x64.Build.0 = Debug|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Debug|x86.ActiveCfg = Debug|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Debug|x86.Build.0 = Debug|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Release|Any CPU.ActiveCfg = Release|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Release|Any CPU.Build.0 = Release|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Release|x64.ActiveCfg = Release|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Release|x64.Build.0 = Release|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Release|x86.ActiveCfg = Release|Any CPU
+			{E5F6A7B8-C9D0-1234-EF56-7890ABCDEF01}.Release|x86.Build.0 = Release|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Debug|Any CPU.Build.0 = Debug|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Debug|x64.ActiveCfg = Debug|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Debug|x64.Build.0 = Debug|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Debug|x86.ActiveCfg = Debug|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Debug|x86.Build.0 = Debug|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Release|Any CPU.ActiveCfg = Release|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Release|Any CPU.Build.0 = Release|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Release|x64.ActiveCfg = Release|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Release|x64.Build.0 = Release|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Release|x86.ActiveCfg = Release|Any CPU
+			{F6A7B8C9-D0E1-2345-F678-90ABCDEF0123}.Release|x86.Build.0 = Release|Any CPU
 		EndGlobalSection
 		GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE

docs/testing-games.md

@@ -0,0 +1,7 @@
+# Testing games
+
+1. Games are dlls. Use a standalone test project to test a game.
+2. Create baseline game snapshots in textual format.
+3. Create baseline logs via the r3 observable api.
+4. Read the snapshot/logs manually to identify issues.
+5. Make sure serialization roundtrip works.