Decompile-in-new-tab context-menu entry

[ExportContextMenuEntry(Header = "DecompileToNewPanel")] sitting in the
Analyze category — opens a fresh DecompilerTabPageModel, asks the dock
workspace to put it next to the existing tab, and assigns the selected
tree-node(s) as its CurrentNodes (which fires the decompile pipeline the
same way a regular selection change does).

Assisted-by: Claude:claude-opus-4-7:Claude Code

ILSpy.Tests/ContextMenus/DecompileInNewViewTests.cs

@@ -0,0 +1,138 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System.Linq;
+using System.Threading.Tasks;
+
+using Avalonia.Headless.NUnit;
+
+using AwesomeAssertions;
+
+using ICSharpCode.ILSpy.Properties;
+using ICSharpCode.ILSpyX.TreeView;
+
+using ILSpy;
+using ILSpy.AppEnv;
+using ILSpy.Docking;
+using ILSpy.TextView;
+using ILSpy.TreeNodes;
+using ILSpy.ViewModels;
+using ILSpy.Views;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.ILSpy.Tests;
+
+[TestFixture]
+public class DecompileInNewViewTests
+{
+	[AvaloniaTest]
+	public async Task DecompileInNewView_Entry_Is_Registered()
+	{
+		// "Decompile in new tab" is a context-menu entry sitting alongside Remove on every
+		// node that decompiles. Verifies the [ExportContextMenuEntry] is discovered.
+
+		// Arrange — boot.
+		var window = AppComposition.Current.GetExport<MainWindow>();
+		window.Show();
+		var registry = AppComposition.Current.GetExport<ContextMenuEntryRegistry>();
+
+		// Assert — registry contains an entry whose header is the DecompileToNewPanel resource.
+		registry.Entries.Should().Contain(
+			e => e.Metadata.Header == nameof(Resources.DecompileToNewPanel));
+	}
+
+	[AvaloniaTest]
+	public async Task DecompileInNewView_Is_Visible_When_Selection_Has_ILSpyTreeNodes()
+	{
+		// IsVisible: any non-empty selection of ILSpyTreeNodes makes the entry surface — the
+		// action runs against whatever the user picked.
+
+		// Arrange — boot, locate the registered entry.
+		var window = AppComposition.Current.GetExport<MainWindow>();
+		window.Show();
+		var vm = (MainWindowViewModel)window.DataContext!;
+		// wait for assemblies to load
+		await vm.AssemblyTreeModel.WaitForAssembliesAsync(minimumCount: 1);
+		var registry = AppComposition.Current.GetExport<ContextMenuEntryRegistry>();
+		var entry = registry.Entries
+			.Single(e => e.Metadata.Header == nameof(Resources.DecompileToNewPanel))
+			.Value;
+
+		var asm = vm.AssemblyTreeModel.FindNode<AssemblyTreeNode>("System.Linq");
+
+		// Assert — visible with a tree node, hidden with no selection.
+		entry.IsVisible(new TextViewContext { SelectedTreeNodes = new[] { (SharpTreeNode)asm } })
+			.Should().BeTrue();
+		entry.IsVisible(new TextViewContext { SelectedTreeNodes = null })
+			.Should().BeFalse();
+		entry.IsVisible(new TextViewContext { SelectedTreeNodes = System.Array.Empty<SharpTreeNode>() })
+			.Should().BeFalse();
+	}
+
+	[AvaloniaTest]
+	public async Task DecompileInNewView_Execute_Opens_A_New_Tab_With_The_Selected_Nodes_Decompiled()
+	{
+		// Execute opens a fresh document tab in the dock workspace, populated with the
+		// decompilation of the supplied nodes — without disturbing the currently-active tab.
+
+		// Arrange — boot, decompile a method into the existing tab so we have a "current"
+		// document to compare against.
+		var window = AppComposition.Current.GetExport<MainWindow>();
+		window.Show();
+		var vm = (MainWindowViewModel)window.DataContext!;
+		// wait for assemblies to load
+		await vm.AssemblyTreeModel.WaitForAssembliesAsync(minimumCount: 3);
+		var typeNode = vm.AssemblyTreeModel.FindNode<TypeTreeNode>(
+			"System.Linq", "System.Linq", "System.Linq.Enumerable");
+		// expand typeNode
+		typeNode.IsExpanded = true;
+		var firstMethod = typeNode.Children.OfType<MethodTreeNode>()
+			.Single(m => m.MethodDefinition.Name == "AsEnumerable");
+		var secondMethod = typeNode.Children.OfType<MethodTreeNode>()
+			.First(m => m.MethodDefinition.Name == "Empty");
+		// select firstMethod
+		vm.AssemblyTreeModel.SelectNode(firstMethod);
+		// wait for decompile to finish
+		var firstTab = await vm.DockWorkspace.WaitForDecompiledTextAsync();
+
+		var registry = AppComposition.Current.GetExport<ContextMenuEntryRegistry>();
+		var entry = registry.Entries
+			.Single(e => e.Metadata.Header == nameof(Resources.DecompileToNewPanel))
+			.Value;
+
+		var documents = ((ILSpyDockFactory)vm.DockWorkspace.Factory).Documents!;
+		var initialCount = documents.VisibleDockables?.Count ?? 0;
+
+		// Act — invoke Execute with the second method as the selection.
+		entry.Execute(new TextViewContext {
+			SelectedTreeNodes = new[] { (SharpTreeNode)secondMethod },
+		});
+
+		// Assert — a new tab landed and now decompiles "Empty"; the original tab still
+		// shows AsEnumerable.
+		await Waiters.WaitForAsync(
+			() => (documents.VisibleDockables?.Count ?? 0) > initialCount);
+		// wait for decompile to finish
+		var newTab = await vm.DockWorkspace.WaitForDecompiledTextAsync();
+		ReferenceEquals(newTab, firstTab).Should().BeFalse(
+			"a fresh decompiler tab must be created instead of reusing the existing one");
+		newTab.Text.Should().Contain("Empty");
+		firstTab.Text.Should().Contain("AsEnumerable");
+	}
+}

ILSpy/Commands/DecompileInNewViewCommand.cs

@@ -0,0 +1,74 @@
+// Copyright (c) 2026 AlphaSierraPapa for the SharpDevelop Team
+//
+// Permission is hereby granted, free of charge, to any person obtaining a copy of this
+// software and associated documentation files (the "Software"), to deal in the Software
+// without restriction, including without limitation the rights to use, copy, modify, merge,
+// publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons
+// to whom the Software is furnished to do so, subject to the following conditions:
+//
+// The above copyright notice and this permission notice shall be included in all copies or
+// substantial portions of the Software.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
+// INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+// PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE
+// FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
+// OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+// DEALINGS IN THE SOFTWARE.
+
+using System.Composition;
+using System.Linq;
+
+using ICSharpCode.ILSpy.Properties;
+
+using ILSpy.Docking;
+using ILSpy.Languages;
+using ILSpy.TextView;
+using ILSpy.TreeNodes;
+
+namespace ILSpy.Commands
+{
+	/// <summary>
+	/// Right-click → "Decompile to new tab" — opens a fresh document tab and decompiles the
+	/// selected tree node(s) into it without disturbing the existing tab. Useful for
+	/// side-by-side comparison or to keep your bookmarked code visible while exploring
+	/// somewhere else.
+	/// </summary>
+	[ExportContextMenuEntry(
+		Header = nameof(Resources.DecompileToNewPanel),
+		Category = nameof(Resources.Analyze),
+		Order = 90)]
+	[Shared]
+	internal sealed class DecompileInNewViewCommand : IContextMenuEntry
+	{
+		readonly DockWorkspace dockWorkspace;
+		readonly LanguageService languageService;
+
+		[ImportingConstructor]
+		public DecompileInNewViewCommand(DockWorkspace dockWorkspace, LanguageService languageService)
+		{
+			this.dockWorkspace = dockWorkspace;
+			this.languageService = languageService;
+		}
+
+		public bool IsVisible(TextViewContext context)
+			=> SelectedNodes(context).Any();
+
+		public bool IsEnabled(TextViewContext context)
+			=> SelectedNodes(context).Any();
+
+		public void Execute(TextViewContext context)
+		{
+			var nodes = SelectedNodes(context).ToArray();
+			if (nodes.Length == 0)
+				return;
+			var tab = new DecompilerTabPageModel { Language = languageService.CurrentLanguage };
+			dockWorkspace.OpenNewTab(tab);
+			tab.CurrentNodes = nodes;
+		}
+
+		static System.Collections.Generic.IEnumerable<ILSpyTreeNode> SelectedNodes(TextViewContext context)
+			=> context.SelectedTreeNodes?.OfType<ILSpyTreeNode>()
+				?? System.Linq.Enumerable.Empty<ILSpyTreeNode>();
+	}
+}