Add check if Region is an empty string

Author: Chellybean

modules/GameLiftAllocator/Project/GameLiftAllocator.cs

@@ -43,7 +43,8 @@ public class GameLiftAllocator(IGameApiClient gameApiClient, IGameLiftFactory ga
     public async Task<AllocateResponse> Allocate(IExecutionContext context, AllocateRequest request)
     {
         // Determine AWS region from match properties or use default
-        var region = request.MatchmakingResults.MatchProperties.GetValueOrDefault("Region")?.ToString() ?? DefaultAwsRegion;
+        var regionValue = request.MatchmakingResults.MatchProperties.GetValueOrDefault("Region")?.ToString();
+        var region = string.IsNullOrEmpty(regionValue) ? DefaultAwsRegion : regionValue;
 
         // maxPlayers is only available in match properties when using Cloud Code hosting 
         // It is not present when using Multiplay hosting with Cloud Code override

tests/AllocatorTests/GameLiftAllocatorTests.cs

@@ -55,6 +55,29 @@ public async Task TestThatGameLiftCanAllocate()
         Assert.That(allocation.AllocationData["placementId"], Is.EqualTo("placementId"));
     }
 
+    [Test]
+    public async Task TestThatGameLiftDefaultsRegionWhenEmptyString()
+    {
+        _gameLiftMock.Reset();
+        _gameLiftMock.Setup(g => g.StartGameSessionPlacementAsync(It.IsAny<StartGameSessionPlacementRequest>(), CancellationToken.None))
+            .ReturnsAsync(new StartGameSessionPlacementResponse
+            {
+                GameSessionPlacement = new GameSessionPlacement
+                {
+                    PlacementId = "placementId",
+                }
+            });
+        
+        var allocation = await _allocator.Allocate(_executionContextMock.Object, new AllocateRequest("1234",
+            new MatchmakingResults(null, "matchId", "poolId", "poolName", "queueName", new
+            Dictionary<string, object>{
+                {"Region", ""},
+            })));
+        
+        Assert.That(allocation.AllocationData, Is.Not.Null);
+        Assert.That(allocation.AllocationData["awsRegion"], Is.EqualTo("eu-west-2"));
+    }
+
     [Test]
     public async Task TestThatGameLiftCanAllocateToRegions()
     {