chore: 🔧 move display list logging into service, refactor

DisplayDetective.CommandLineApp/Program.cs

@@ -17,18 +17,11 @@
     var services = context.GetHost().Services;
     var logger = services.GetRequiredService<ILogger<Program>>();
     var service = services.GetRequiredService<IDisplayListService>();
-    logger.LogInformation("🔍 Scanning displays");
-    var displays = service.GetDisplays();
-    logger.LogInformation("✨ Found {count} display(s)", displays.Count);
-    for (int i = 0; i < displays.Count; i++)
-    {
-        var display = displays[i];
-        logger.LogInformation("\n📺 Display {i}\n{display}", i + 1, display.ToMultilineString());
-    }
+    service.ListDisplays();
 });
 
 var monitorCmd = new Command("monitor");
-monitorCmd.SetHandler(async context =>
+monitorCmd.SetHandler(static async context =>
 {
     var token = context.GetCancellationToken();
     var services = context.GetHost().Services;
@@ -59,9 +52,9 @@
             {
                 services.Configure<EventLogSettings>(host.Configuration.GetSection("Logging:EventLog"));
             }
-            services.AddTransient((_) =>
+            services.AddTransient((provider) =>
             {
-                var factory = new DisplayListServiceFactory(OperatingSystem.IsWindows());
+                var factory = new DisplayListServiceFactory(provider, OperatingSystem.IsWindows());
                 return factory.Create();
             });
             services.AddTransient((_) =>

DisplayDetective.Library.Tests/Common/DisplayDetectiveServiceTests.cs

@@ -1,5 +1,4 @@
 using System.Diagnostics;
-using System.Reflection.Emit;
 
 using DisplayDetective.Library.Common;
 
@@ -26,16 +25,6 @@ private static IEnumerable<TheoryDataRow<string>> GetConfigFiles(string subDirec
 
     private static IConfiguration GoodConfiguration => GetGoodConfig("both-commands-with-args");
 
-    private static void VerifyLog<T>(Mock<ILogger<T>> loggerMock, LogLevel level, Times times) where T : class
-    {
-        loggerMock.Verify(m => m.Log(
-            level,
-            It.IsAny<EventId>(),
-            It.IsAny<It.IsAnyType>(),
-            It.IsAny<Exception>(),
-            It.IsAny<Func<It.IsAnyType, Exception?, string>>()), times);
-    }
-
     private const string DeviceID = "TestDeviceID";
     private static readonly IDisplay TestDisplay = Display.Create(DeviceID, "TestName", "TestManufacturer", "TestDescription");
 
@@ -102,8 +91,8 @@ public void RunAsync_Works_BothCommandAndArgs()
         runnerMock.Verify(m => m.Run("test2.exe", new string[] { "argZ" }, TestContext.Current.CancellationToken), Times.Once());
         runnerMock.VerifyNoOtherCalls();
 
-        VerifyLog(loggerMock, LogLevel.Error, Times.Never());
-        VerifyLog(loggerMock, LogLevel.Warning, Times.Never());
+        loggerMock.VerifyLog(LogLevel.Error, Times.Never());
+        loggerMock.VerifyLog(LogLevel.Warning, Times.Never());
     }
 
     [Fact]
@@ -130,8 +119,8 @@ public void RunAsync_Works_OnlyCreateCommandWithArgs()
         runnerMock.Verify(m => m.Run("test1.exe", new string[] { "argX", "argY" }, TestContext.Current.CancellationToken), Times.Once());
         runnerMock.VerifyNoOtherCalls();
 
-        VerifyLog(loggerMock, LogLevel.Error, Times.Never());
-        VerifyLog(loggerMock, LogLevel.Warning, Times.Never());
+        loggerMock.VerifyLog(LogLevel.Error, Times.Never());
+        loggerMock.VerifyLog(LogLevel.Warning, Times.Never());
     }
 
     [Fact]
@@ -162,8 +151,8 @@ public void RunAsync_AfterCancelling_NoMoreEventsFire()
 
         runnerMock.VerifyNoOtherCalls();
 
-        VerifyLog(loggerMock, LogLevel.Error, Times.Never());
-        VerifyLog(loggerMock, LogLevel.Warning, Times.Never());
+        loggerMock.VerifyLog(LogLevel.Error, Times.Never());
+        loggerMock.VerifyLog(LogLevel.Warning, Times.Never());
     }
 
     [Fact]

DisplayDetective.Library.Tests/Common/DisplayListServiceFactoryTests.cs

@@ -3,6 +3,8 @@
 using DisplayDetective.Library.Common;
 using DisplayDetective.Library.Windows;
 
+using Microsoft.Extensions.Logging;
+
 namespace DisplayDetective.Library.Tests.Windows;
 
 [Trait("Category", "Unit")]
@@ -12,19 +14,30 @@ public class DisplayListServiceFactoryTests
     [Fact]
     public void Create_OnWindows_Works()
     {
+        var provider = new Mock<IServiceProvider>();
+        provider.Setup(m => m.GetService(typeof(ILogger<WindowsDisplayListService>)))
+            .Returns(Mock.Of<ILogger<WindowsDisplayListService>>());
+
         bool isWindows = true;
-        var factory = new DisplayListServiceFactory(isWindows);
+
+        var factory = new DisplayListServiceFactory(provider.Object, isWindows);
         var service = factory.Create();
+
         Assert.NotNull(service);
         Assert.IsType<WindowsDisplayListService>(service);
+
+        provider.Verify(m => m.GetService(typeof(ILogger<WindowsDisplayListService>)), Times.Once());
+        provider.VerifyNoOtherCalls();
     }
 
     [UnsupportedOSPlatform("windows")]
     [Fact]
     public void Create_NotOnWindows_DoesNotWork()
     {
+        var provider = new Mock<IServiceProvider>();
         bool isWindows = false;
-        var factory = new DisplayListServiceFactory(isWindows);
-        Assert.Throws<PlatformNotSupportedException>(() => factory.Create());
+        var factory = new DisplayListServiceFactory(provider.Object, isWindows);
+        Assert.Throws<PlatformNotSupportedException>(factory.Create);
+        provider.VerifyNoOtherCalls();
     }
 }

DisplayDetective.Library.Tests/MockLoggerExtensions.cs

@@ -0,0 +1,30 @@
+using System.Text.RegularExpressions;
+
+using Microsoft.Extensions.Logging;
+
+public static class MockLoggerExtensions
+{
+    public static void VerifyLog<T>(this Mock<ILogger<T>> loggerMock, LogLevel level, Times times) where T : class
+    {
+        loggerMock.Verify(m => m.Log(
+            level,
+            It.IsAny<EventId>(),
+            It.IsAny<It.IsAnyType>(),
+            It.IsAny<Exception>(),
+            It.IsAny<Func<It.IsAnyType, Exception?, string>>()), times);
+    }
+
+    public static Mock<ILogger<T>> VerifyLogMatch<T>(this Mock<ILogger<T>> logger, LogLevel level, Times times, string pattern)
+    {
+        Func<object, Type, bool> test = (value, _) => value != null && Regex.IsMatch(value.ToString() ?? "", pattern);
+
+        logger.Verify(m => m.Log(
+            level,
+            It.IsAny<EventId>(),
+            It.Is<It.IsAnyType>((v, t) => test(v, t)),
+            It.IsAny<Exception>(),
+            It.IsAny<Func<It.IsAnyType, Exception?, string>>()), times);
+
+        return logger;
+    }
+}

DisplayDetective.Library.Tests/Windows/WindowsDisplayListServiceTests.cs

@@ -2,6 +2,8 @@
 
 using DisplayDetective.Library.Windows;
 
+using Microsoft.Extensions.Logging;
+
 namespace DisplayDetective.Library.Tests.Windows;
 
 [Trait("Category", "Acceptance")]
@@ -11,16 +13,13 @@ public class WindowsDisplayListServiceTests
     [Fact]
     public void GetDisplays_ReturnsNonEmptyList()
     {
-        var service = new WindowsDisplayListService();
-        var displays = service.GetDisplays();
-
-        Assert.NotNull(displays);
-        Assert.NotEmpty(displays);
+        var loggerMock = new Mock<ILogger<WindowsDisplayListService>>();
+        var service = new WindowsDisplayListService(loggerMock.Object);
+        service.ListDisplays();
 
-        var display = displays.First();
-        Assert.NotEmpty(display.DeviceID);
-        Assert.NotEmpty(display.Name);
-        Assert.NotEmpty(display.Manufacturer);
-        Assert.NotEmpty(display.Description);
+        loggerMock.VerifyLogMatch(LogLevel.Information, Times.Once(), @"(?i).+scanning");
+        loggerMock.VerifyLogMatch(LogLevel.Information, Times.Once(), @"(?i).+found \d+ display");
+        loggerMock.VerifyLogMatch(LogLevel.Information, Times.Once(), @"(?i).+display 1");
+        loggerMock.VerifyLog(LogLevel.Error, Times.Never());
     }
 }

DisplayDetective.Library/Common/DisplayListServiceFactory.cs

@@ -2,23 +2,29 @@
 
 using DisplayDetective.Library.Windows;
 
+using Microsoft.Extensions.DependencyInjection;
+using Microsoft.Extensions.Logging;
+
 namespace DisplayDetective.Library.Common;
 
 public sealed class DisplayListServiceFactory
 {
+    private readonly IServiceProvider _provider;
+
     [SupportedOSPlatformGuard("windows")]
     private readonly bool _isWindows;
 
-    public DisplayListServiceFactory(bool isWindows)
+    public DisplayListServiceFactory(IServiceProvider provider, bool isWindows)
     {
+        _provider = provider;
         _isWindows = isWindows;
     }
 
     public IDisplayListService Create()
     {
         if (_isWindows)
         {
-            return new WindowsDisplayListService();
+            return new WindowsDisplayListService(_provider.GetRequiredService<ILogger<WindowsDisplayListService>>());
         }
         throw new PlatformNotSupportedException();
     }

DisplayDetective.Library/Common/IDisplayListService.cs

@@ -2,5 +2,5 @@ namespace DisplayDetective.Library.Common;
 
 public interface IDisplayListService
 {
-    IList<IDisplay> GetDisplays();
+    void ListDisplays();
 }

DisplayDetective.Library/Windows/WindowsDisplayListService.cs

@@ -3,18 +3,34 @@
 
 using DisplayDetective.Library.Common;
 
+using Microsoft.Extensions.Logging;
+
 namespace DisplayDetective.Library.Windows;
 
 [SupportedOSPlatform("windows")]
-internal sealed class WindowsDisplayListService : IDisplayListService
+public sealed class WindowsDisplayListService : IDisplayListService
 {
     private static readonly ManagementScope Scope = new(ManagementPath.DefaultPath);
 
     private static readonly ObjectQuery Query = new("SELECT * FROM Win32_PnPEntity WHERE PNPClass = 'Monitor'");
 
-    public IList<IDisplay> GetDisplays()
+    private readonly ILogger<WindowsDisplayListService> _logger;
+
+    internal WindowsDisplayListService(ILogger<WindowsDisplayListService> logger)
+    {
+        _logger = logger;
+    }
+
+    public void ListDisplays()
     {
+        _logger.LogInformation("🔍 Scanning displays");
         using var searcher = new ManagementObjectSearcher(Scope, Query);
-        return [.. searcher.Get().Cast<ManagementObject>().Select(Display.Create)];
+        IList<IDisplay> displays = [.. searcher.Get().Cast<ManagementObject>().Select(Display.Create)];
+        _logger.LogInformation("✨ Found {count} display(s)", displays.Count);
+        for (int i = 0; i < displays.Count; i++)
+        {
+            var display = displays[i];
+            _logger.LogInformation("\n📺 Display {i}\n{display}", i + 1, display.ToMultilineString());
+        }
     }
 }

DisplayDetective.Library/Windows/WindowsDisplayMonitorService.cs

@@ -6,7 +6,7 @@
 namespace DisplayDetective.Library.Windows;
 
 [SupportedOSPlatform("windows")]
-internal sealed class WindowsDisplayMonitorService : IDisplayMonitorService
+public sealed class WindowsDisplayMonitorService : IDisplayMonitorService
 {
     public event EventHandler<IDisplay> OnDisplayCreated = delegate { };