Remove test interop from System.Drawing (dotnet#10799)

Remove some hand spun interop from System.Drawing tests.  Also:

- Unskip RS4 related issue tests (seem to all work fine now)
- Only create the directory for FileCleanupTestBase on demand
- Cache the installed printer names for tests

Co-authored-by: Loni Tra <lonitra@microsoft.com>

src/Common/tests/TestUtilities/FileCleanupTestBase.cs

@@ -5,22 +5,27 @@ namespace System;
 
 public abstract class FileCleanupTestBase : IDisposable
 {
-    public readonly string TestDirectory;
+    private string? _testDirectory;
 
-    protected FileCleanupTestBase()
+    public string TestDirectory
     {
-        TestDirectory = Path.Combine(Path.GetTempPath(), GetUniqueName());
-        Directory.CreateDirectory(TestDirectory);
-    }
+        get
+        {
+            if (_testDirectory is null)
+            {
+                _testDirectory = Path.Combine(Path.GetTempPath(), GetUniqueName());
+                Directory.CreateDirectory(_testDirectory);
+            }
 
-    ~FileCleanupTestBase()
-    {
-        Dispose(false);
+            return _testDirectory;
+        }
     }
 
+    ~FileCleanupTestBase() => Dispose(disposing: false);
+
     public void Dispose()
     {
-        Dispose(true);
+        Dispose(disposing: true);
         GC.SuppressFinalize(this);
     }
 

src/System.Drawing.Common/tests/Helpers.cs

@@ -2,23 +2,24 @@
 // The .NET Foundation licenses this file to you under the MIT license.
 
 using System.Drawing.Printing;
-using System.Runtime.InteropServices;
 using System.Text;
+using Windows.Win32;
+using Windows.Win32.Foundation;
+using Windows.Win32.Graphics.Gdi;
 using Xunit.Sdk;
 
 namespace System.Drawing;
 
-public static class Helpers
+public unsafe static class Helpers
 {
-    public const string AnyInstalledPrinters = $"{nameof(Helpers)}.{nameof(IsAnyInstalledPrinters)}";
-    public const string WindowsRS3OrEarlier = $"{nameof(Helpers)}.{nameof(IsWindowsRS3OrEarlier)}";
+    // This MUST come before s_anyInstalledPrinters. Caching for performance in tests.
+    public static IReadOnlyList<string> InstalledPrinters { get; } = PrinterSettings.InstalledPrinters;
 
-    public static bool IsWindowsRS3OrEarlier => !PlatformDetection.IsWindows10Version1803OrGreater;
+    private static bool s_anyInstalledPrinters = InstalledPrinters.Count > 0;
 
-    public static bool IsAnyInstalledPrinters()
-    {
-        return PrinterSettings.InstalledPrinters.Count > 0;
-    }
+    public const string AnyInstalledPrinters = $"{nameof(Helpers)}.{nameof(AreAnyPrintersInstalled)}";
+
+    public static bool AreAnyPrintersInstalled() => s_anyInstalledPrinters;
 
     public static string GetTestBitmapPath(string fileName) => GetTestPath("bitmaps", fileName);
     public static string GetTestFontPath(string fileName) => GetTestPath("fonts", fileName);
@@ -83,84 +84,31 @@ private static void PrintColor(StringBuilder stringBuilder, Color color)
 
     public static Color EmptyColor => Color.FromArgb(0, 0, 0, 0);
 
-    private static Rectangle GetRectangle(RECT rect)
-    {
-        return new Rectangle(rect.Left, rect.Top, rect.Right - rect.Left, rect.Bottom - rect.Top);
-    }
-
-    private const int MONITOR_DEFAULTTOPRIMARY = 1;
-
-    [DllImport("libgdiplus", ExactSpelling = true)]
-    internal static extern string GetLibgdiplusVersion();
-
-    [DllImport("user32.dll", SetLastError = true)]
-    private static extern IntPtr MonitorFromWindow(IntPtr hWnd, int dwFlags);
-
-    [DllImport("user32.dll", SetLastError = true)]
-    private static extern int GetMonitorInfo(IntPtr hMonitor, ref MONITORINFO monitorInfo);
-
-    [DllImport("user32.dll", SetLastError = true)]
-    internal static extern IntPtr GetForegroundWindow();
-
-    [DllImport("user32.dll", ExactSpelling = true, SetLastError = true)]
-    internal static extern int GetGuiResources(IntPtr hProcess, uint flags);
-
-    [DllImport("user32.dll", SetLastError = true)]
-    internal static extern IntPtr GetDC(IntPtr hWnd);
+    internal static Rectangle GetWindowDCRect(HDC hdc) => GetHWndRect(PInvokeCore.WindowFromDC(hdc));
 
-    [DllImport("user32.dll", SetLastError = true)]
-    internal static extern IntPtr GetWindowDC(IntPtr hWnd);
-
-    public static Rectangle GetWindowDCRect(IntPtr hdc) => GetHWndRect(WindowFromDC(hdc));
-
-    public static Rectangle GetHWndRect(IntPtr hWnd)
+    internal static Rectangle GetHWndRect(HWND hwnd)
     {
-        if (hWnd == IntPtr.Zero)
+        if (hwnd.IsNull)
         {
-            return GetMonitorRectForWindow(hWnd);
+            return GetMonitorRectForWindow(hwnd);
         }
 
-        RECT rect = new();
-        GetClientRect(hWnd, ref rect);
-
-        return GetRectangle(rect);
+        PInvokeCore.GetClientRect(hwnd, out RECT rect);
+        return rect;
     }
 
-    private static Rectangle GetMonitorRectForWindow(IntPtr hWnd)
+    private static Rectangle GetMonitorRectForWindow(HWND hwnd)
     {
-        IntPtr hMonitor = MonitorFromWindow(hWnd, MONITOR_DEFAULTTOPRIMARY);
-        Assert.NotEqual(IntPtr.Zero, hMonitor);
-
-        MONITORINFO info = new();
-        info.cbSize = Marshal.SizeOf(info);
-        int result = GetMonitorInfo(hMonitor, ref info);
-        Assert.NotEqual(0, result);
-
-        return GetRectangle(info.rcMonitor);
-    }
+        HMONITOR hmonitor = PInvokeCore.MonitorFromWindow(hwnd, MONITOR_FROM_FLAGS.MONITOR_DEFAULTTOPRIMARY);
+        hmonitor.Value.Should().NotBe(0);
 
-    [DllImport("user32.dll", SetLastError = true)]
-    private static extern int GetClientRect(IntPtr hWnd, ref RECT lpRect);
-
-    [DllImport("user32.dll", SetLastError = true)]
-    private static extern IntPtr WindowFromDC(IntPtr hdc);
-
-    [StructLayout(LayoutKind.Sequential)]
-    private struct MONITORINFO
-    {
-        public int cbSize;
-        public RECT rcMonitor;
-        public RECT rcWork;
-        public int dwFlags;
-    }
+        MONITORINFO info = new()
+        {
+            cbSize = (uint)sizeof(MONITORINFO)
+        };
 
-    [StructLayout(LayoutKind.Sequential)]
-    private struct RECT
-    {
-        public int Left;
-        public int Top;
-        public int Right;
-        public int Bottom;
+        PInvokeCore.GetMonitorInfo(hmonitor, ref info).Should().Be(BOOL.TRUE);
+        return info.rcMonitor;
     }
 
     public static void VerifyBitmapNotBlank(Bitmap bmp)

src/System.Drawing.Common/tests/System/Drawing/GdiPlusHandlesTests.cs

@@ -3,6 +3,10 @@
 
 using System.Runtime.InteropServices;
 using Microsoft.DotNet.RemoteExecutor;
+using Windows.Win32;
+using Windows.Win32.Foundation;
+using Windows.Win32.Graphics.Gdi;
+using Windows.Win32.System.Threading;
 using Xunit.Sdk;
 
 namespace System.Drawing.Tests;
@@ -16,32 +20,32 @@ public static void GraphicsDrawIconDoesNotLeakHandles()
     {
         RemoteExecutor.Invoke(() =>
         {
-            const int handleTreshold = 1;
+            const int HandleThreshold = 1;
             using Bitmap bmp = new(100, 100);
             using Icon ico = new(Helpers.GetTestBitmapPath("16x16_one_entry_4bit.ico"));
 
-            IntPtr hdc = Helpers.GetDC(Helpers.GetForegroundWindow());
+            using GetDcScope hdc = new(PInvokeCore.GetForegroundWindow());
             using Graphics graphicsFromHdc = Graphics.FromHdc(hdc);
 
             using Process currentProcess = Process.GetCurrentProcess();
-            IntPtr processHandle = currentProcess.Handle;
+            HANDLE processHandle = new(currentProcess.Handle);
 
-            int initialHandles = Helpers.GetGuiResources(processHandle, 0);
+            uint initialHandles = PInvokeCore.GetGuiResources(processHandle, GET_GUI_RESOURCES_FLAGS.GR_GDIOBJECTS);
             ValidateNoWin32Error(initialHandles);
 
             for (int i = 0; i < 5000; i++)
             {
                 graphicsFromHdc.DrawIcon(ico, 100, 100);
             }
 
-            int finalHandles = Helpers.GetGuiResources(processHandle, 0);
+            uint finalHandles = PInvokeCore.GetGuiResources(processHandle, GET_GUI_RESOURCES_FLAGS.GR_GDIOBJECTS);
             ValidateNoWin32Error(finalHandles);
 
-            Assert.InRange(finalHandles, initialHandles - handleTreshold, initialHandles + handleTreshold);
+            Assert.InRange(finalHandles, initialHandles - HandleThreshold, initialHandles + HandleThreshold);
         }).Dispose();
     }
 
-    private static void ValidateNoWin32Error(int handleCount)
+    private static void ValidateNoWin32Error(uint handleCount)
     {
         if (handleCount == 0)
         {

src/System.Drawing.Common/tests/System/Drawing/GraphicsTests.cs

@@ -5,6 +5,9 @@
 using System.Drawing.Drawing2D;
 using System.Drawing.Imaging;
 using System.Drawing.Text;
+using Windows.Win32;
+using Windows.Win32.Foundation;
+using Windows.Win32.Graphics.Gdi;
 
 namespace System.Drawing.Tests;
 
@@ -74,42 +77,28 @@ public void GetHdc_Disposed_ThrowsObjectDisposedException()
         AssertExtensions.Throws<ArgumentException>(null, () => graphics.GetHdc());
     }
 
-    public static IEnumerable<object[]> FromHdc_TestData()
-    {
-        yield return new object[] { Helpers.GetDC(IntPtr.Zero) };
-        yield return new object[] { Helpers.GetWindowDC(IntPtr.Zero) };
-
-        // Likely the source of #51097- grabbing whatever the current foreground window is is not a great idea.
-        // Whatever that window is it could disappear at any time and what it's clipping info would be pretty
-        // random.
-        // https://github.com/dotnet/winforms/issues/8829
-
-        // IntPtr foregroundWindow = Helpers.GetForegroundWindow();
-        // yield return new object[] { Helpers.GetDC(foregroundWindow) };
-    }
-
-    [Theory]
-    [MemberData(nameof(FromHdc_TestData))]
-    public void FromHdc_ValidHdc_ReturnsExpected(IntPtr hdc)
+    [Fact]
+    public void FromHdc_ValidHdc_ReturnsExpected()
     {
+        using var hdc = GetDcScope.ScreenDC;
         using Graphics graphics = Graphics.FromHdc(hdc);
         Rectangle expected = Helpers.GetWindowDCRect(hdc);
         VerifyGraphics(graphics, expected);
     }
 
-    [Theory]
-    [MemberData(nameof(FromHdc_TestData))]
-    public void FromHdc_ValidHdcWithContext_ReturnsExpected(IntPtr hdc)
+    [Fact]
+    public void FromHdc_ValidHdcWithContext_ReturnsExpected()
     {
+        using var hdc = GetDcScope.ScreenDC;
         using Graphics graphics = Graphics.FromHdc(hdc, IntPtr.Zero);
         Rectangle expected = Helpers.GetWindowDCRect(hdc);
         VerifyGraphics(graphics, expected);
     }
 
-    [Theory]
-    [MemberData(nameof(FromHdc_TestData))]
-    public void FromHdcInternal_GetDC_ReturnsExpected(IntPtr hdc)
+    [Fact]
+    public void FromHdcInternal_GetDC_ReturnsExpected()
     {
+        using var hdc = GetDcScope.ScreenDC;
         using Graphics graphics = Graphics.FromHdcInternal(hdc);
         Rectangle expected = Helpers.GetWindowDCRect(hdc);
         VerifyGraphics(graphics, expected);
@@ -217,25 +206,25 @@ public void ReleaseHdc_Disposed_ThrowsObjectDisposedException()
 
     public static IEnumerable<object[]> Hwnd_TestData()
     {
-        yield return new object[] { IntPtr.Zero };
-        yield return new object[] { Helpers.GetForegroundWindow() };
+        yield return new object[] { (nint)0 };
+        yield return new object[] { (nint)PInvokeCore.GetForegroundWindow() };
     }
 
     [Theory]
     [MemberData(nameof(Hwnd_TestData))]
-    public void FromHwnd_ValidHwnd_ReturnsExpected(IntPtr hWnd)
+    public void FromHwnd_ValidHwnd_ReturnsExpected(nint hwnd)
     {
-        using Graphics graphics = Graphics.FromHwnd(hWnd);
-        Rectangle expected = Helpers.GetHWndRect(hWnd);
+        using Graphics graphics = Graphics.FromHwnd(hwnd);
+        Rectangle expected = Helpers.GetHWndRect((HWND)hwnd);
         VerifyGraphics(graphics, expected);
     }
 
     [Theory]
     [MemberData(nameof(Hwnd_TestData))]
-    public void FromHwndInternal_ValidHwnd_ReturnsExpected(IntPtr hWnd)
+    public void FromHwndInternal_ValidHwnd_ReturnsExpected(nint hwnd)
     {
-        using Graphics graphics = Graphics.FromHwnd(hWnd);
-        Rectangle expected = Helpers.GetHWndRect(hWnd);
+        using Graphics graphics = Graphics.FromHwnd(hwnd);
+        Rectangle expected = Helpers.GetHWndRect((HWND)hwnd);
         VerifyGraphics(graphics, expected);
     }
 

src/System.Drawing.Common/tests/System/Drawing/Printing/PageSettingsTests.cs

@@ -31,7 +31,7 @@ namespace System.Drawing.Printing.Tests;
 
 public class PageSettingsTests
 {
-    [ConditionalFact(Helpers.AnyInstalledPrinters, Helpers.WindowsRS3OrEarlier)] // RS4 failures: https://github.com/dotnet/winforms/issues/8816
+    [ConditionalFact(Helpers.AnyInstalledPrinters)]
     public void Clone_Success()
     {
         PageSettings ps = new();