Add code coverage for buttons

src/System.Windows.Forms.Primitives/tests/TestUtilities/Metafiles/EmfValidateHelper.cs

@@ -0,0 +1,33 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Reflection;
+using System.Text;
+using System.Windows.Forms.Metafiles;
+
+namespace System.Windows.Forms.misc.Tests;
+
+public class EmfValidateHelper
+{
+    /// <summary>
+    ///  Helps immensely with debugging metafile tests.
+    /// </summary>
+    /// <param name="emf">The EmfScope instance to extract log information from.</param>
+    /// <param name="methodName">The name of the calling method. Use <see cref="MethodBase.GetCurrentMethod()"/> and property <see cref="MemberInfo.Name"/>.</param>
+    /// <param name="parameters">Optional parameters to include in the log information.</param>
+    internal void LogEmfValidateToFile(EmfScope emf, string methodName, params object[] parameters)
+    {
+        ArgumentNullException.ThrowIfNull(emf, nameof(emf));
+
+        string timestamp = DateTime.Now.ToString("yyyy/MM/dd HH:mm");
+
+        StringBuilder sb = new();
+        sb.Append($"# {timestamp}. Parameters: ");
+        sb.AppendJoin(", ", parameters);
+        sb.AppendLine("\r\n\r\n```c");
+        sb.AppendLine($"{emf.RecordsToString()}```\r\n");
+
+        File.AppendAllText(@$"c:\temp\{methodName}.md", sb.ToString());
+    }
+}
+

src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/AbstractButtonBaseTests.cs

@@ -0,0 +1,95 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+using System.Drawing;
+
+namespace System.Windows.Forms.Tests;
+
+public abstract class AbstractButtonBaseTests
+{
+    protected abstract ButtonBase CreateButton();
+
+    protected void ButtonBase_FlatStyle_ValidFlatButtonBorder(int borderSize)
+    {
+        using var control = CreateButton();
+        control.FlatStyle = FlatStyle.Flat;
+
+        control.Invoking(y => y.FlatAppearance.BorderColor = Color.Transparent)
+            .Should().Throw<NotSupportedException>();
+
+        if (borderSize < 0)
+        {
+            control.Invoking(y => y.FlatAppearance.BorderSize = borderSize)
+                .Should().Throw<ArgumentOutOfRangeException>();
+        }
+        else
+        {
+            control.FlatAppearance.BorderSize = borderSize;
+            control.FlatAppearance.BorderSize.Should().Be(borderSize);
+        }
+    }
+
+    protected void ButtonBase_FlatStyle_ProperFlatButtonColor(int red, int green, int blue)
+    {
+        Color expectedColor = Color.FromArgb(red, green, blue);
+
+        using var control = CreateButton();
+        control.FlatStyle = FlatStyle.Flat;
+        control.BackColor = expectedColor;
+
+        control.FlatAppearance.CheckedBackColor = expectedColor;
+        control.FlatAppearance.BorderColor = expectedColor;
+
+        control.BackColor.Should().Be(expectedColor);
+        control.FlatAppearance.BorderColor.Should().Be(expectedColor);
+        control.FlatAppearance.CheckedBackColor.Should().Be(expectedColor);
+    }
+
+    protected virtual void ButtonBase_OverChangeRectangle_Get(Appearance appearance, FlatStyle flatStyle)
+    {
+        using dynamic control = CreateButton();
+
+        if (control is null)
+        {
+            return;
+        }
+
+        control.Appearance = appearance;
+        control.FlatStyle = flatStyle;
+
+        Rectangle overChangeRectangle;
+
+        // ButtonBase.Adapter prohibits this
+        if (appearance == Appearance.Normal
+            && (flatStyle != FlatStyle.Standard
+                && flatStyle != FlatStyle.Popup
+                && flatStyle != FlatStyle.Flat))
+        {
+            // Compiler requires casting lambda expression to delegate or expression
+            // before using it as a dynamically dispatched operation
+            Action act = () => overChangeRectangle = control.OverChangeRectangle;
+            act.Should().Throw<Exception>();
+
+            return;
+        }
+
+        overChangeRectangle = control.OverChangeRectangle;
+
+        if (control.FlatStyle == FlatStyle.Standard)
+        {
+            overChangeRectangle.Should().Be(new Rectangle(-1, -1, 1, 1));
+        }
+
+        if (control.Appearance == Appearance.Button)
+        {
+            if (control.FlatStyle != FlatStyle.Standard)
+            {
+                overChangeRectangle.Should().Be(control.ClientRectangle);
+            }
+        }
+        else if (control.FlatStyle != FlatStyle.Standard)
+        {
+            overChangeRectangle.Should().Be(control.Adapter.CommonLayout().Layout().CheckBounds);
+        }
+    }
+}

src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ButtonBaseTests.cs

@@ -12,7 +12,7 @@
 
 namespace System.Windows.Forms.Tests;
 
-public class ButtonBaseTests
+public class ButtonBaseTests : AbstractButtonBaseTests
 {
     [WinFormsFact]
     public void ButtonBase_Ctor_Default()
@@ -9335,7 +9335,7 @@ private class SubButtonBase : ButtonBase
         public new bool GetStyle(ControlStyles flag) => base.GetStyle(flag);
 
         public new bool GetTopLevel() => base.GetTopLevel();
-        
+
         public new void OnClick(EventArgs e) => base.OnClick(e);
 
         public new void OnEnabledChanged(EventArgs e) => base.OnEnabledChanged(e);
@@ -9376,4 +9376,6 @@ private class SubButtonBase : ButtonBase
 
         public new void WndProc(ref Message m) => base.WndProc(ref m);
     }
+
+    protected override ButtonBase CreateButton() => new Button();
 }

src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ButtonRenderingTests.cs

@@ -6,12 +6,12 @@
 
 namespace System.Windows.Forms.Tests;
 
-public class ButtonRenderingTests
+public class ButtonRenderingTests : AbstractButtonBaseTests
 {
     [WinFormsFact]
     public unsafe void CaptureButton()
     {
-        using Button button = new();
+        using Button button = (Button)CreateButton();
         using EmfScope emf = new();
         button.PrintToMetafile(emf);
 
@@ -33,7 +33,7 @@ public unsafe void Button_VisualStyles_off_Default_LineDrawing()
             return;
         }
 
-        using Button button = new();
+        using Button button = (Button)CreateButton();
         using EmfScope emf = new();
         DeviceContextState state = new(emf);
         Rectangle bounds = button.Bounds;
@@ -77,7 +77,7 @@ public unsafe void Button_VisualStyles_on_Default_LineDrawing()
             return;
         }
 
-        using Button button = new();
+        using Button button = (Button)CreateButton();
         using EmfScope emf = new();
         DeviceContextState state = new(emf);
         Rectangle bounds = button.Bounds;
@@ -117,7 +117,8 @@ public unsafe void Button_VisualStyles_off_Default_WithText_LineDrawing()
             return;
         }
 
-        using Button button = new() { Text = "Hello" };
+        using Button button = (Button)CreateButton();
+        button.Text = "Hello";
         using EmfScope emf = new();
         DeviceContextState state = new(emf);
         Rectangle bounds = button.Bounds;
@@ -162,7 +163,8 @@ public unsafe void Button_VisualStyles_on_Default_WithText_LineDrawing()
             return;
         }
 
-        using Button button = new() { Text = "Hello" };
+        using Button button = (Button)CreateButton();
+        button.Text = "Hello";
         using EmfScope emf = new();
         DeviceContextState state = new(emf);
         Rectangle bounds = button.Bounds;
@@ -210,7 +212,7 @@ public unsafe void Button_VisualStyles_on_Default_WithText_LineDrawing()
     public unsafe void CaptureButtonOnForm()
     {
         using Form form = new();
-        using Button button = new();
+        using Button button = (Button)CreateButton();
         form.Controls.Add(button);
 
         using EmfScope emf = new();
@@ -222,11 +224,9 @@ public unsafe void CaptureButtonOnForm()
     [WinFormsFact]
     public unsafe void Button_FlatStyle_WithText_Rectangle()
     {
-        using Button button = new()
-        {
-            Text = "Flat Style",
-            FlatStyle = FlatStyle.Flat,
-        };
+        using Button button = (Button)CreateButton();
+        button.Text = "Flat Style";
+        button.FlatStyle = FlatStyle.Flat;
 
         using EmfScope emf = new();
         DeviceContextState state = new(emf);
@@ -245,4 +245,6 @@ public unsafe void Button_FlatStyle_WithText_Rectangle()
                 State.BrushStyle(BRUSH_STYLE.BS_NULL),       // Regressed in https://github.com/dotnet/winforms/pull/3667
                 State.Rop2(R2_MODE.R2_COPYPEN)));
     }
+
+    protected override ButtonBase CreateButton() => new Button();
 }

src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ButtonTests.cs

@@ -13,7 +13,7 @@
 
 namespace System.Windows.Forms.Tests;
 
-public class ButtonTests
+public class ButtonTests : AbstractButtonBaseTests
 {
     [WinFormsFact]
     public void Button_Ctor_Default()
@@ -3578,6 +3578,17 @@ public static IEnumerable<object[]> WndProc_ReflectCommandWithoutHandle_TestData
         yield return new object[] { FlatStyle.System, PARAM.FromLowHigh(123, 456), (IntPtr)250, 0 };
     }
 
+    [WinFormsFact]
+    public void ButtonBase_Click_RaisesEvent()
+    {
+        using var button = (SubButton)CreateButton();
+        bool clickEventRaised = false;
+        button.Click += (sender, e) => clickEventRaised = true;
+        button.PerformClick();
+
+        clickEventRaised.Should().BeTrue();
+    }
+
     [WinFormsTheory]
     [MemberData(nameof(WndProc_ReflectCommandWithoutHandle_TestData))]
     public void Button_WndProc_InvokeReflectCommandWithoutHandle_Success(FlatStyle flatStyle, IntPtr wParam, IntPtr expectedResult, int expectedCallCount)
@@ -3649,6 +3660,20 @@ public void Button_WndProc_InvokeReflectCommandWithHandle_Success(FlatStyle flat
         Assert.Equal(0, createdCallCount);
     }
 
+    [WinFormsTheory]
+    [InlineData(-1)]
+    [InlineData(0)]
+    [InlineData(1)]
+    public void Button_Flat_ValidBorder(int borderSize) => base.ButtonBase_FlatStyle_ValidFlatButtonBorder(borderSize);
+
+    [WinFormsTheory]
+    [InlineData(255, 0, 0)]
+    [InlineData(0, 255, 0)]
+    [InlineData(0, 0, 255)]
+    public void Button_Flat_ProperColor(int red, int green, int blue) => base.ButtonBase_FlatStyle_ProperFlatButtonColor(red, green, blue);
+
+    protected override ButtonBase CreateButton() => new SubButton();
+
     private class SubButton : Button
     {
         public new bool CanEnableIme => base.CanEnableIme;