Add coverage for ToolStripContainer_ToolStripContainerTypedContro… (dotnet#13527)

* Add ode coverage for ToolStripContainer_ToolStripContainerTypedControlCollection

* Handle feedback!

* Updated!

Author: MelonWang1

src/test/unit/System.Windows.Forms/System/Windows/Forms/ToolStripContainer.ToolStripContainerTypedControlCollectionTests.cs

@@ -0,0 +1,139 @@
+// Licensed to the .NET Foundation under one or more agreements.
+// The .NET Foundation licenses this file to you under the MIT license.
+
+namespace System.Windows.Forms.Tests;
+
+public class ToolStripContainer_ToolStripContainerTypedControlCollectionTests
+{
+    private static ToolStripContainer.ToolStripContainerTypedControlCollection CreateCollection(bool isReadOnly) =>
+        new(new ToolStripContainer(), isReadOnly);
+
+    [WinFormsFact]
+    public void Add_NullValue_DoesNothing()
+    {
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = CreateCollection(isReadOnly: false);
+
+        collection.Add(null);
+
+        collection.Cast<Control>().Should().BeEmpty();
+    }
+
+    [WinFormsFact]
+    public void Add_WhenReadOnly_ThrowsNotSupportedException()
+    {
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = CreateCollection(isReadOnly: true);
+        using ToolStripPanel panel = new();
+
+        Action act = () => collection.Add(panel);
+
+        act.Should().Throw<NotSupportedException>();
+    }
+
+    [WinFormsFact]
+    public void Add_InvalidType_ThrowsArgumentException()
+    {
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = CreateCollection(isReadOnly: false);
+        using Button button = new();
+
+        Action act = () => collection.Add(button);
+
+        act.Should().Throw<ArgumentException>();
+    }
+
+    [WinFormsTheory]
+    [InlineData(typeof(ToolStripPanel))]
+    [InlineData(typeof(ToolStripContentPanel))]
+    public void Add_ValidType_AddsSuccessfully(Type type)
+    {
+        using Form form = new();
+        using ToolStripContainer container = new();
+        form.Controls.Add(container);
+
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = new(container, isReadOnly: false);
+
+        Control control = (Control)Activator.CreateInstance(type)!;
+
+        collection.Add(control);
+
+        collection.Cast<Control>().Should().Contain(control);
+
+        collection.Remove(control);
+        control.Dispose();
+    }
+
+    [WinFormsTheory]
+    [InlineData(typeof(ToolStripPanel))]
+    [InlineData(typeof(ToolStripContentPanel))]
+    public void Remove_WhenReadOnly_ThrowsNotSupportedException(Type type)
+    {
+        using ToolStripContainer container = new();
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = new(container, isReadOnly: true);
+        using Control control = (Control)Activator.CreateInstance(type)!;
+        container.ContentPanel.Controls.Add(control);
+
+        Action act = () => collection.Remove(control);
+
+        act.Should().Throw<NotSupportedException>();
+    }
+
+    [WinFormsFact]
+    public void Remove_Panel_WhenNotReadOnly_RemovesPanel()
+    {
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = CreateCollection(isReadOnly: false);
+        using ToolStripPanel panel = new();
+        collection.Add(panel);
+
+        collection.Remove(panel);
+
+        collection.Cast<Control>().Should().NotContain(panel);
+    }
+
+    [WinFormsFact]
+    public void Remove_NonPanelOrContentPanel_DoesNotThrow()
+    {
+        using ToolStripContainer container = new();
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = new(container, isReadOnly: false);
+        using Button button = new();
+        container.ContentPanel.Controls.Add(button);
+
+        Action act = () => collection.Remove(button);
+
+        act.Should().NotThrow();
+        collection.Cast<Control>().Should().NotContain(button);
+    }
+
+    [WinFormsTheory]
+    [InlineData(typeof(ToolStripPanel))]
+    [InlineData(typeof(ToolStripContentPanel))]
+    public void SetChildIndexInternal_WhenReadOnly_ThrowsNotSupportedException(Type type)
+    {
+        using ToolStripContainer container = new();
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = new(container, isReadOnly: true);
+        using Control control = (Control)Activator.CreateInstance(type)!;
+        container.ContentPanel.Controls.Add(control);
+
+        Action act = () => collection.SetChildIndexInternal(control, 0);
+
+        act.Should().Throw<NotSupportedException>();
+    }
+
+    [WinFormsFact]
+    public void SetChildIndexInternal_Panel_WhenNotReadOnly_CallsBase()
+    {
+        using Form form = new();
+        using ToolStripContainer container = new();
+        form.Controls.Add(container);
+
+        ToolStripContainer.ToolStripContainerTypedControlCollection collection = new(container, isReadOnly: false);
+
+        ToolStripPanel panel = new();
+        collection.Add(panel);
+
+        collection.SetChildIndexInternal(panel, 0);
+
+        collection.GetChildIndex(panel).Should().Be(0);
+
+        collection.Remove(panel);
+        panel.Dispose();
+    }
+}