add more tests

ChatBot.Tests/Services/SystemPromptServiceTests.cs

@@ -3,10 +3,9 @@ using ChatBot.Services;
 using ChatBot.Tests.TestUtilities;
 using FluentAssertions;
 using Microsoft.Extensions.Logging;
+using Microsoft.Extensions.Options;
 using Moq;
 
-namespace ChatBot.Tests.Services;
-
 public class SystemPromptServiceTests : UnitTestBase
 {
     private readonly Mock<ILogger<SystemPromptService>> _loggerMock;
@@ -52,4 +51,139 @@ public class SystemPromptServiceTests : UnitTestBase
         newPrompt.Should().NotBeNull();
         // Note: In a real scenario, we might mock the file system to test cache clearing
     }
+
+    [Fact]
+    public async Task GetSystemPromptAsync_ShouldReturnDefaultPrompt_WhenFileNotFound()
+    {
+        // Arrange
+        var aiSettings = new AISettings { SystemPromptPath = "nonexistent-file.txt" };
+        var aiSettingsMock = TestDataBuilder.Mocks.CreateOptionsMock(aiSettings);
+        var service = new SystemPromptService(_loggerMock.Object, aiSettingsMock.Object);
+
+        // Act
+        var result = await service.GetSystemPromptAsync();
+
+        // Assert
+        result.Should().Be(SystemPromptService.DefaultPrompt);
+        _loggerMock.Verify(
+            x =>
+                x.Log(
+                    LogLevel.Warning,
+                    It.IsAny<EventId>(),
+                    It.Is<It.IsAnyType>(
+                        (v, t) => v.ToString()!.Contains("System prompt file not found")
+                    ),
+                    It.IsAny<Exception>(),
+                    It.IsAny<Func<It.IsAnyType, Exception?, string>>()
+                ),
+            Times.Once
+        );
+    }
+
+    [Fact]
+    public async Task GetSystemPromptAsync_ShouldReturnDefaultPrompt_WhenFileReadFails()
+    {
+        // Arrange
+        var aiSettings = new AISettings
+        {
+            SystemPromptPath = "invalid-path-that-causes-exception.txt",
+        };
+        var aiSettingsMock = TestDataBuilder.Mocks.CreateOptionsMock(aiSettings);
+        var service = new SystemPromptService(_loggerMock.Object, aiSettingsMock.Object);
+
+        // Act
+        var result = await service.GetSystemPromptAsync();
+
+        // Assert
+        result.Should().Be(SystemPromptService.DefaultPrompt);
+        // The file doesn't exist, so it logs a warning, not an error
+        _loggerMock.Verify(
+            x =>
+                x.Log(
+                    LogLevel.Warning,
+                    It.IsAny<EventId>(),
+                    It.Is<It.IsAnyType>(
+                        (v, t) => v.ToString()!.Contains("System prompt file not found")
+                    ),
+                    It.IsAny<Exception>(),
+                    It.IsAny<Func<It.IsAnyType, Exception?, string>>()
+                ),
+            Times.Once
+        );
+    }
+
+    [Fact]
+    public async Task GetSystemPromptAsync_ShouldReturnDefaultPrompt_WhenPathIsNull()
+    {
+        // Arrange
+        var aiSettings = new AISettings { SystemPromptPath = null! };
+        var aiSettingsMock = TestDataBuilder.Mocks.CreateOptionsMock(aiSettings);
+        var service = new SystemPromptService(_loggerMock.Object, aiSettingsMock.Object);
+
+        // Act
+        var result = await service.GetSystemPromptAsync();
+
+        // Assert
+        result.Should().Be(SystemPromptService.DefaultPrompt);
+        _loggerMock.Verify(
+            x =>
+                x.Log(
+                    LogLevel.Error,
+                    It.IsAny<EventId>(),
+                    It.Is<It.IsAnyType>(
+                        (v, t) => v.ToString()!.Contains("Failed to load system prompt")
+                    ),
+                    It.IsAny<Exception>(),
+                    It.IsAny<Func<It.IsAnyType, Exception?, string>>()
+                ),
+            Times.Once
+        );
+    }
+
+    [Fact]
+    public async Task GetSystemPromptAsync_ShouldReturnDefaultPrompt_WhenPathIsEmpty()
+    {
+        // Arrange
+        var aiSettings = new AISettings { SystemPromptPath = string.Empty };
+        var aiSettingsMock = TestDataBuilder.Mocks.CreateOptionsMock(aiSettings);
+        var service = new SystemPromptService(_loggerMock.Object, aiSettingsMock.Object);
+
+        // Act
+        var result = await service.GetSystemPromptAsync();
+
+        // Assert
+        result.Should().Be(SystemPromptService.DefaultPrompt);
+        // Empty path results in file not found, so it logs a warning, not an error
+        _loggerMock.Verify(
+            x =>
+                x.Log(
+                    LogLevel.Warning,
+                    It.IsAny<EventId>(),
+                    It.Is<It.IsAnyType>(
+                        (v, t) => v.ToString()!.Contains("System prompt file not found")
+                    ),
+                    It.IsAny<Exception>(),
+                    It.IsAny<Func<It.IsAnyType, Exception?, string>>()
+                ),
+            Times.Once
+        );
+    }
+
+    [Fact]
+    public async Task ReloadPromptAsync_ShouldClearCacheAndReload()
+    {
+        // Arrange
+        var aiSettings = new AISettings { SystemPromptPath = "nonexistent-file.txt" };
+        var aiSettingsMock = TestDataBuilder.Mocks.CreateOptionsMock(aiSettings);
+        var service = new SystemPromptService(_loggerMock.Object, aiSettingsMock.Object);
+
+        // Act
+        await service.GetSystemPromptAsync(); // First call to cache default prompt
+        await service.ReloadPromptAsync(); // Reload should clear cache
+
+        // Assert
+        // The service should still return the default prompt after reload
+        var result = await service.GetSystemPromptAsync();
+        result.Should().Be(SystemPromptService.DefaultPrompt);
+    }
 }