Require buy-in before cash-out

Author: lorenblue

PokerBank.Domain/PokerGame.cs

@@ -79,6 +79,11 @@ private Result<GameEntry> AddEntry(Guid playerId, Money amount, GameEntryType ty
             return Result.Fail<GameEntry>(PokerGameErrors.InvalidAmount());
         }
 
+        if (type == GameEntryType.CashOut && !HasBuyIn(playerId))
+        {
+            return Result.Fail<GameEntry>(PokerGameErrors.PlayerHasNoBuyIns());
+        }
+
         if (type == GameEntryType.CashOut && TotalCashOuts + amount > TotalBuyIns)
         {
             return Result.Fail<GameEntry>(PokerGameErrors.CashOutsExceedBuyIns());
@@ -92,6 +97,11 @@ private Result<GameEntry> AddEntry(Guid playerId, Money amount, GameEntryType ty
 
     private bool IsClosed() => Status == GameStatus.Closed;
 
+    private bool HasBuyIn(Guid playerId)
+    {
+        return _entries.Any(entry => entry.PlayerId == playerId && entry.Type == GameEntryType.BuyIn);
+    }
+
     private Money SumEntries(GameEntryType type)
     {
         return _entries

PokerBank.Domain/PokerGameErrorCode.cs

@@ -6,5 +6,6 @@ public enum PokerGameErrorCode
     InvalidAmount = 2,
     GameClosed = 3,
     CashOutsExceedBuyIns = 4,
-    BuyInsMustEqualCashOuts = 5
+    BuyInsMustEqualCashOuts = 5,
+    PlayerHasNoBuyIns = 6
 }

PokerBank.Domain/PokerGameErrors.cs

@@ -18,6 +18,10 @@ public static class PokerGameErrors
         PokerGameErrorCode.CashOutsExceedBuyIns,
         "Cash-outs cannot exceed total buy-ins.");
 
+    public static PokerGameError PlayerHasNoBuyIns() => new(
+        PokerGameErrorCode.PlayerHasNoBuyIns,
+        "Player must have a buy-in before cashing out.");
+
     public static PokerGameError BuyInsMustEqualCashOuts() => new(
         PokerGameErrorCode.BuyInsMustEqualCashOuts,
         "Cannot close a game until total buy-ins equal total cash-outs.");

PokerBank.Tests/Domain/PokerGameTests.cs

@@ -100,6 +100,23 @@ public void AddCashOut_Fails_WhenTotalCashOutsWouldExceedTotalBuyIns()
         Assert.DoesNotContain(game.Entries, entry => entry.Type == GameEntryType.CashOut);
     }
 
+    [Fact]
+    public void AddCashOut_Fails_WhenPlayerHasNoBuyIns()
+    {
+        var game = PokerGame.Create();
+        var playerWithBuyIn = Guid.NewGuid();
+        var playerWithoutBuyIn = Guid.NewGuid();
+
+        Assert.True(game.AddBuyIn(playerWithBuyIn, new Money(100m)).IsSuccess);
+
+        var result = game.AddCashOut(playerWithoutBuyIn, new Money(50m));
+
+        Assert.True(result.IsFailed);
+        var error = Assert.Single(result.Errors.OfType<PokerGameError>());
+        Assert.Equal(PokerGameErrorCode.PlayerHasNoBuyIns, error.Code);
+        Assert.DoesNotContain(game.Entries, entry => entry.Type == GameEntryType.CashOut);
+    }
+
     [Fact]
     public void ClosedGame_CannotBeModified()
     {

PokerBank.Tests/Features/Games/GamesApiTests.cs

@@ -386,6 +386,28 @@ public async Task AddCashOut_ReturnsNotFound_WhenPlayerDoesNotExist()
         Assert.Equal(HttpStatusCode.NotFound, response.StatusCode);
     }
 
+    [Fact]
+    public async Task AddCashOut_ReturnsConflict_WhenPlayerHasNotBoughtIn()
+    {
+        using var client = factory.CreateHttpsClient();
+
+        var game = await CreateGame(client);
+        var playerWithBuyIn = await CreatePlayer(client, "Lorenzo");
+        var playerWithoutBuyIn = await CreatePlayer(client, "Maya");
+        await AddBuyIn(client, game.Id, playerWithBuyIn.Id, 100m);
+
+        var response = await client.PostAsJsonAsync(
+            $"/games/{game.Id}/cash-outs",
+            new { PlayerId = playerWithoutBuyIn.Id, Amount = 50m });
+
+        Assert.Equal(HttpStatusCode.Conflict, response.StatusCode);
+
+        var error = await response.Content.ReadFromJsonAsync<ErrorResponse>();
+
+        Assert.NotNull(error);
+        Assert.Equal("Player must have a buy-in before cashing out.", error.Error);
+    }
+
     [Theory]
     [InlineData(0)]
     [InlineData(-10)]
@@ -636,6 +658,8 @@ private sealed record GameDetailsResponse(
 
     private sealed record PlayerResponse(Guid Id, string Name, bool IsActive);
 
+    private sealed record ErrorResponse(string Error);
+
     private sealed record GameEntryDetailsResponse(
         Guid Id,
         Guid PlayerId,