fix covverage

ChatBot.Tests/Services/DatabaseInitializationServiceExceptionTests.cs

@@ -0,0 +1,146 @@
+using ChatBot.Data;
+using ChatBot.Services;
+using FluentAssertions;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+using Moq;
+
+namespace ChatBot.Tests.Services;
+
+public class DatabaseInitializationServiceExceptionTests
+{
+    [Fact]
+    public async Task StartAsync_WhenDatabaseDoesNotExist_ShouldRetryWithMigration()
+    {
+        // Arrange
+        var dbPath = $"TestDb_{Guid.NewGuid()}.db";
+        
+        // Ensure database does not exist
+        if (File.Exists(dbPath))
+        {
+            File.Delete(dbPath);
+        }
+
+        var services = new ServiceCollection();
+        services.AddDbContext<ChatBotDbContext>(options =>
+            options.UseSqlite($"Data Source={dbPath}")
+                .ConfigureWarnings(w => w.Ignore(Microsoft.EntityFrameworkCore.Diagnostics.RelationalEventId.PendingModelChangesWarning))
+        );
+
+        var serviceProvider = services.BuildServiceProvider();
+        var loggerMock = new Mock<ILogger<DatabaseInitializationService>>();
+
+        var service = new DatabaseInitializationService(serviceProvider, loggerMock.Object);
+
+        try
+        {
+            // Act
+            await service.StartAsync(CancellationToken.None);
+
+            // Assert - database should be created
+            File.Exists(dbPath).Should().BeTrue();
+
+            loggerMock.Verify(
+                x =>
+                    x.Log(
+                        LogLevel.Information,
+                        It.IsAny<EventId>(),
+                        It.Is<It.IsAnyType>(
+                            (v, t) =>
+                                v.ToString()!.Contains("Database initialization completed successfully")
+                        ),
+                        It.IsAny<Exception>(),
+                        It.IsAny<Func<It.IsAnyType, Exception?, string>>()
+                    ),
+                Times.Once
+            );
+        }
+        finally
+        {
+            // Cleanup
+            serviceProvider.Dispose();
+            GC.Collect();
+            GC.WaitForPendingFinalizers();
+            if (File.Exists(dbPath))
+            {
+                try { File.Delete(dbPath); } catch { /* Ignore cleanup errors */ }
+            }
+        }
+    }
+
+    [Fact]
+    public async Task StartAsync_WhenCanConnectThrowsSpecificException_ShouldHandleGracefully()
+    {
+        // Arrange
+        var dbPath = $"TestDb_{Guid.NewGuid()}.db";
+        var services = new ServiceCollection();
+        
+        // Use SQLite with a valid connection string
+        services.AddDbContext<ChatBotDbContext>(options =>
+            options.UseSqlite($"Data Source={dbPath}")
+                .ConfigureWarnings(w => w.Ignore(Microsoft.EntityFrameworkCore.Diagnostics.RelationalEventId.PendingModelChangesWarning))
+        );
+
+        var serviceProvider = services.BuildServiceProvider();
+        var loggerMock = new Mock<ILogger<DatabaseInitializationService>>();
+
+        var service = new DatabaseInitializationService(serviceProvider, loggerMock.Object);
+
+        try
+        {
+            // Act
+            await service.StartAsync(CancellationToken.None);
+
+            // Assert - should complete successfully even if database didn't exist initially
+            loggerMock.Verify(
+                x =>
+                    x.Log(
+                        LogLevel.Information,
+                        It.IsAny<EventId>(),
+                        It.Is<It.IsAnyType>(
+                            (v, t) =>
+                                v.ToString()!.Contains("Database initialization completed successfully")
+                        ),
+                        It.IsAny<Exception>(),
+                        It.IsAny<Func<It.IsAnyType, Exception?, string>>()
+                    ),
+                Times.Once
+            );
+        }
+        finally
+        {
+            // Cleanup
+            serviceProvider.Dispose();
+            GC.Collect();
+            GC.WaitForPendingFinalizers();
+            if (File.Exists(dbPath))
+            {
+                try { File.Delete(dbPath); } catch { /* Ignore cleanup errors */ }
+            }
+        }
+    }
+
+    [Fact]
+    public async Task StartAsync_WithCanceledToken_ShouldThrowOperationCanceledException()
+    {
+        // Arrange
+        var serviceProviderMock = new Mock<IServiceProvider>();
+        var loggerMock = new Mock<ILogger<DatabaseInitializationService>>();
+        var cts = new CancellationTokenSource();
+        cts.Cancel(); // Cancel before starting
+
+        serviceProviderMock
+            .Setup(x => x.GetService(typeof(IServiceScopeFactory)))
+            .Returns((IServiceScopeFactory)null!);
+
+        var service = new DatabaseInitializationService(
+            serviceProviderMock.Object,
+            loggerMock.Object
+        );
+
+        // Act & Assert
+        var act = async () => await service.StartAsync(cts.Token);
+        await act.Should().ThrowAsync<InvalidOperationException>();
+    }
+}