fix issues

ChatBot.Tests/Services/HistoryCompressionServiceTests.cs

@@ -173,9 +173,7 @@ public class HistoryCompressionServiceTests : UnitTestBase
         );
     }
 
-    private static IAsyncEnumerable<OllamaSharp.Models.Chat.ChatResponseStream> ThrowAsyncEnumerable(
-        Exception exception
-    )
+    private static ThrowingAsyncEnumerable ThrowAsyncEnumerable(Exception exception)
     {
         return new ThrowingAsyncEnumerable(exception);
     }

ChatBot.Tests/Services/ModelServiceTests.cs

@@ -37,10 +37,24 @@ public class ModelServiceTests : UnitTestBase
     public async Task InitializeAsync_ShouldLogModelInformation()
     {
         // Act
-        await _modelService.InitializeAsync();
+        var act = async () => await _modelService.InitializeAsync();
 
         // Assert
-        // The method should complete without throwing exceptions
-        // In a real test, we might verify logging calls
+        await act.Should()
+            .NotThrowAsync("InitializeAsync should complete without throwing exceptions");
+
+        // Verify that logging was called (at least once for model information)
+        _loggerMock.Verify(
+            x =>
+                x.Log(
+                    LogLevel.Information,
+                    It.IsAny<EventId>(),
+                    It.Is<It.IsAnyType>((v, t) => v.ToString()!.Contains("model")),
+                    It.IsAny<Exception>(),
+                    It.IsAny<Func<It.IsAnyType, Exception?, string>>()
+                ),
+            Times.AtLeastOnce,
+            "Should log model information"
+        );
     }
 }

ChatBot.Tests/TestUtilities/TestDataBuilder.cs

@@ -156,16 +156,16 @@ public static class TestDataBuilder
                 .Returns<long, string, string>(
                     (chatId, chatType, chatTitle) =>
                     {
-                        if (!sessions.ContainsKey(chatId))
+                        if (!sessions.TryGetValue(chatId, out var session))
                         {
-                            var session = TestDataBuilder.ChatSessions.CreateBasicSession(
+                            session = TestDataBuilder.ChatSessions.CreateBasicSession(
                                 chatId,
                                 chatType
                             );
                             session.ChatTitle = chatTitle;
                             sessions[chatId] = session;
                         }
-                        return sessions[chatId];
+                        return session;
                     }
                 );