Wire context-menu host onto the assembly tree DataGrid

AssemblyListPane attaches a ContextMenu to its TreeGrid at construction
time. The menu's Opening handler builds entries from the
ContextMenuEntryRegistry against a fresh TextViewContext (the live
selection + the grid as OriginalSource), and cancels Opening when no
entry would be visible so an empty popup never flashes up.

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

ILSpy.Tests/AssemblyList/AssemblyTreeContextMenuTests.cs

@@ -0,0 +1,121 @@
+// 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.Controls;
+using Avalonia.Headless.NUnit;
+using Avalonia.VisualTree;
+
+using AwesomeAssertions;
+
+using ICSharpCode.ILSpyX.TreeView;
+
+using ILSpy;
+using ILSpy.AppEnv;
+using ILSpy.AssemblyTree;
+using ILSpy.TreeNodes;
+using ILSpy.ViewModels;
+using ILSpy.Views;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.ILSpy.Tests;
+
+[TestFixture]
+public class AssemblyTreeContextMenuTests
+{
+	[AvaloniaTest]
+	public async Task ContextMenu_Is_Attached_To_The_Assembly_Tree_Grid()
+	{
+		// AssemblyListPane wires a context-menu host onto its DataGrid at construction time so
+		// any [ExportContextMenuEntry]-tagged commands can drop into the right-click menu
+		// without further per-entry plumbing.
+
+		// Arrange + Act — boot the window so the pane materialises.
+		var window = AppComposition.Current.GetExport<MainWindow>();
+		window.Show();
+		var vm = (MainWindowViewModel)window.DataContext!;
+		await vm.AssemblyTreeModel.WaitForAssembliesAsync(minimumCount: 1);
+
+		// Assert — TreeGrid carries a ContextMenu. (The menu may be empty if no entries are
+		// registered yet; verifies only that the host is in place.)
+		var pane = await window.WaitForComponent<AssemblyListPane>();
+		var grid = await pane.WaitForComponent<DataGrid>();
+		grid.ContextMenu.Should().NotBeNull();
+	}
+
+	[AvaloniaTest]
+	public async Task Context_Menu_Shows_Visible_Entries_With_Selected_Tree_Nodes_In_Context()
+	{
+		// When the user right-clicks a tree row, the pane builds a TextViewContext from the
+		// current selection and feeds it through ContextMenuProvider.Build with whichever
+		// entries the test injects. Visible entries land in the menu; the entry receives the
+		// originating tab grid + the selected nodes when invoked.
+
+		// Arrange — boot, select an assembly node, install a stub entry that records the
+		// context it sees on Execute.
+		var window = AppComposition.Current.GetExport<MainWindow>();
+		window.Show();
+		var vm = (MainWindowViewModel)window.DataContext!;
+		await vm.AssemblyTreeModel.WaitForAssembliesAsync(minimumCount: 1);
+		var pane = await window.WaitForComponent<AssemblyListPane>();
+		var assemblyNode = vm.AssemblyTreeModel.FindNode<AssemblyTreeNode>("System.Linq");
+		vm.AssemblyTreeModel.SelectedItem = assemblyNode;
+
+		TextViewContext? executionContext = null;
+		var entry = new RecordingEntry(c => executionContext = c);
+		var export = new StubExport(entry, new ContextMenuEntryMetadata { Header = "Probe", Order = 0 });
+
+		// Act 1 — re-attach the context menu with our stub entries.
+		pane.AttachContextMenu(new IContextMenuEntryExport[] { export });
+		var grid = await pane.WaitForComponent<DataGrid>();
+		var menu = grid.ContextMenu!;
+
+		// Trigger the build path the live Opening event would take.
+		var built = pane.BuildContextMenuForCurrentState(new IContextMenuEntryExport[] { export });
+
+		// Assert 1 — menu carries our entry.
+		built.Should().NotBeNull();
+		var item = built!.Items.OfType<MenuItem>().Single();
+		((string?)item.Header).Should().Be("Probe");
+
+		// Act 2 — invoke the click handler that the Build attached.
+		item.RaiseEvent(new global::Avalonia.Interactivity.RoutedEventArgs(MenuItem.ClickEvent));
+
+		// Assert 2 — entry's Execute saw the right context: the tree grid + the selection.
+		executionContext.Should().NotBeNull();
+		ReferenceEquals(executionContext!.TreeGrid, grid).Should().BeTrue();
+		executionContext.SelectedTreeNodes.Should().NotBeNull();
+		executionContext.SelectedTreeNodes!.Should().Contain((SharpTreeNode)assemblyNode);
+	}
+
+	sealed class RecordingEntry(System.Action<TextViewContext> onExecute) : IContextMenuEntry
+	{
+		public bool IsVisible(TextViewContext context) => true;
+		public bool IsEnabled(TextViewContext context) => true;
+		public void Execute(TextViewContext context) => onExecute(context);
+	}
+
+	sealed class StubExport(IContextMenuEntry entry, ContextMenuEntryMetadata metadata) : IContextMenuEntryExport
+	{
+		public IContextMenuEntry Value { get; } = entry;
+		public ContextMenuEntryMetadata Metadata { get; } = metadata;
+	}
+}

ILSpy/AssemblyTree/AssemblyListPane.axaml.cs

@@ -18,6 +18,7 @@
 
 using System;
 using System.Collections;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Linq;
 
@@ -45,6 +46,80 @@ namespace ILSpy.AssemblyTree
 			InitializeComponent();
 			TreeGrid.DoubleTapped += OnTreeGridDoubleTapped;
 			TreeGrid.KeyDown += OnTreeGridKeyDown;
+
+			// Context-menu host. Tests bypass this and re-attach via AttachContextMenu so they
+			// can inject stub entries — at app-runtime we resolve the registry through the
+			// composition host. Both paths route through the same Opening handler.
+			var registry = TryGetContextMenuRegistry();
+			AttachContextMenu(registry?.Entries ?? System.Array.Empty<IContextMenuEntryExport>());
+		}
+
+		static ContextMenuEntryRegistry? TryGetContextMenuRegistry()
+		{
+			try
+			{
+				return AppEnv.AppComposition.Current.GetExport<ContextMenuEntryRegistry>();
+			}
+			catch
+			{
+				// Composition isn't available in design-time previews; the empty-entries
+				// path leaves the menu host in place but cancels Opening, matching the
+				// "no entries registered" UX.
+				return null;
+			}
+		}
+
+		IReadOnlyList<IContextMenuEntryExport> contextMenuEntries = System.Array.Empty<IContextMenuEntryExport>();
+
+		/// <summary>
+		/// Replaces the active context-menu entries. App-runtime call: once at construction
+		/// with the registry's entries. Test call: directly with stub entries to exercise the
+		/// menu without going through MEF.
+		/// </summary>
+		internal void AttachContextMenu(IReadOnlyList<IContextMenuEntryExport> entries)
+		{
+			contextMenuEntries = entries;
+			var menu = new ContextMenu();
+			menu.Opening += OnContextMenuOpening;
+			TreeGrid.ContextMenu = menu;
+		}
+
+		void OnContextMenuOpening(object? sender, global::System.ComponentModel.CancelEventArgs e)
+		{
+			if (sender is not ContextMenu menu)
+				return;
+			var built = BuildContextMenuForCurrentState(contextMenuEntries);
+			if (built == null)
+			{
+				e.Cancel = true;
+				return;
+			}
+			// Move the built menu's items into the live ContextMenu (a single Items collection
+			// can't host the same MenuItem twice — copy then drop the donor).
+			menu.Items.Clear();
+			foreach (var item in System.Linq.Enumerable.ToArray(built.Items.OfType<Control>()))
+			{
+				built.Items.Remove(item);
+				menu.Items.Add(item);
+			}
+		}
+
+		/// <summary>
+		/// Builds the context menu using the supplied entries against the pane's current
+		/// selection. Internal so tests can drive the build path without raising the live
+		/// Opening event.
+		/// </summary>
+		internal ContextMenu? BuildContextMenuForCurrentState(IReadOnlyList<IContextMenuEntryExport> entries)
+			=> ContextMenuProvider.Build(entries, CreateContextMenuContext());
+
+		TextViewContext CreateContextMenuContext()
+		{
+			var nodes = (DataContext as AssemblyTreeModel)?.SelectedItems.ToArray()
+				?? System.Array.Empty<SharpTreeNode>();
+			return new TextViewContext {
+				TreeGrid = TreeGrid,
+				SelectedTreeNodes = nodes,
+			};
 		}
 
 		void OnTreeGridKeyDown(object? sender, KeyEventArgs e)