Add code coverage for toolstrip (#11773)

* Add code coverage for toolstrip

* Update src/System.Windows.Forms/tests/UnitTests/System/Windows/Forms/ToolStripTests.cs

Co-authored-by: Loni Tra <[email protected]>

---------

Co-authored-by: Loni Tra <[email protected]>

Author: Zheng-Li01

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

@@ -7304,6 +7304,96 @@ public void ToolStrip_GetNextItem_ItemsBackwardExpected(ToolStripLayoutStyle too
         Assert.False(toolStrip.IsHandleCreated);
     }
 
+    [WinFormsTheory]
+    [InlineData(10, 10)]
+    [InlineData(0, 0)]
+    [InlineData(-10, -10)]
+    public void ToolStrip_GetChildAtPoint_WithoutSkipValue_Invoke_ReturnsExpected(int x, int y)
+    {
+        using ToolStrip toolStrip = new();
+        var child = toolStrip.GetChildAtPoint(new Point(x, y));
+
+        child.Should().BeNull();
+    }
+
+    [WinFormsTheory]
+    [InlineData(GetChildAtPointSkip.None)]
+    [InlineData(GetChildAtPointSkip.Disabled)]
+    [InlineData(GetChildAtPointSkip.Invisible)]
+    [InlineData(GetChildAtPointSkip.Transparent)]
+    public void ToolStrip_GetChildAtPoint_WithSkipValue_Invoke_ReturnsExpected(GetChildAtPointSkip skipValue)
+    {
+        using ToolStrip toolStrip = new();
+        var child = toolStrip.GetChildAtPoint(new Point(10, 10), skipValue);
+
+        child.Should().BeNull();
+    }
+
+    [WinFormsFact]
+    public void ToolStrip_ResetMinimumSize_Invoke_Success()
+    {
+        using ToolStrip toolStrip = new();
+        Size oldSize = toolStrip.MinimumSize;
+
+        toolStrip.ResetMinimumSize();
+
+        oldSize.Should().NotBe(toolStrip.MinimumSize);
+        toolStrip.MinimumSize.Should().Be(new Size(-1, -1));
+    }
+
+    [WinFormsFact]
+    public void ToolStrip_ResetGripMargin_SetsGripMarginToDefault()
+    {
+        using ToolStrip toolStrip = new();
+        var defaultMargin = toolStrip.Grip.DefaultMargin;
+        toolStrip.GripMargin = new Padding(10, 10, 10, 10);
+
+        toolStrip.TestAccessor().Dynamic.ResetGripMargin();
+
+        toolStrip.GripMargin.Should().Be(defaultMargin);
+    }
+
+    [WinFormsFact]
+    public void ToolStrip_SetAutoScrollMargin_Invoke_Success()
+    {
+        using var toolStrip = new ToolStrip() { AutoScrollMargin = new Size(10, 20) };
+
+        toolStrip.AutoScrollMargin.Should().Be(new Size(10, 20));
+    }
+
+    [WinFormsFact]
+    public void ToolStrip_ShouldSerializeLayoutStyle_Invoke_ReturnsExpected()
+    {
+        using ToolStrip toolStrip = new();
+        toolStrip.ShouldSerializeLayoutStyle().Should().BeFalse();
+
+        toolStrip.LayoutStyle = ToolStripLayoutStyle.Flow;
+        toolStrip.ShouldSerializeLayoutStyle().Should().BeTrue();
+
+        toolStrip.LayoutStyle = ToolStripLayoutStyle.HorizontalStackWithOverflow;
+        toolStrip.ShouldSerializeLayoutStyle().Should().BeTrue();
+
+        toolStrip.LayoutStyle = ToolStripLayoutStyle.VerticalStackWithOverflow;
+        toolStrip.ShouldSerializeLayoutStyle().Should().BeTrue();
+
+        toolStrip.LayoutStyle = ToolStripLayoutStyle.Table;
+        toolStrip.ShouldSerializeLayoutStyle().Should().BeTrue();
+
+        toolStrip.LayoutStyle = ToolStripLayoutStyle.StackWithOverflow;
+        toolStrip.ShouldSerializeLayoutStyle().Should().BeFalse();
+    }
+
+    [WinFormsFact]
+    public void ToolStrip_ShouldSerializeGripMargin_Invoke_ReturnsExpected()
+    {
+        using ToolStrip toolStrip = new() { GripMargin = new Padding(1) };
+        ((bool)toolStrip.TestAccessor().Dynamic.ShouldSerializeGripMargin()).Should().BeTrue();
+
+        var defaultGripMargin = (Padding)toolStrip.TestAccessor().Dynamic.DefaultGripMargin;
+        toolStrip.GripMargin = defaultGripMargin;
+        ((bool)toolStrip.TestAccessor().Dynamic.ShouldSerializeGripMargin()).Should().BeFalse();
+    }
+
     private class SubAxHost : AxHost
     {
         public SubAxHost(string clsid) : base(clsid)