Export several selected assemblies as a Visual Studio solution

The single-assembly project save was already wired, but selecting
multiple assemblies and choosing Save Code only ever saved one of
them: SolutionWriter had never been ported, so there was no path that
emitted a .sln with one decompiled project per assembly.

Port SolutionWriter UI-agnostically and route both Save Code surfaces
(the context-menu entry and the Ctrl+S command) through a shared
SolutionExport helper that recognises a multi-assembly selection,
prompts for the .sln path, runs the export behind the tab's cancellable
progress UI, and reports the result into the active decompiler tab
(matching how the other long-running commands surface their output).
Unlike the prior app, the project-export path writes the .csproj to
disk itself and only returns a breadcrumb through the text output, so
each project's on-disk file is located after decompiling rather than
captured from the output stream.

Assisted-by: Claude:claude-opus-4-8:Claude Code

ILSpy.Tests/ContextMenus/SaveCodeSolutionContextMenuTests.cs

@@ -0,0 +1,100 @@
+// 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.TextView;
+using ILSpy.TreeNodes;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.ILSpy.Tests;
+
+/// <summary>
+/// Visibility/enablement rules for "Save Code": a single node always qualifies (its own
+/// <c>Save</c> override decides the format), several valid assemblies qualify (the solution
+/// export path), and any other multi-selection does not.
+/// </summary>
+[TestFixture]
+public class SaveCodeSolutionContextMenuTests
+{
+	static IContextMenuEntry Entry()
+		=> AppComposition.Current.GetExport<ContextMenuEntryRegistry>().GetEntry(nameof(Resources._SaveCode));
+
+	static TextViewContext Context(params SharpTreeNode[] nodes)
+		=> new() { SelectedTreeNodes = nodes };
+
+	[AvaloniaTest]
+	public async Task Single_Node_Is_Visible()
+	{
+		var (_, vm) = await TestHarness.BootAsync(3);
+		var assembly = vm.AssemblyTreeModel.FindNode<AssemblyTreeNode>("System.Linq");
+		Assert.That(assembly, Is.Not.Null);
+
+		var entry = Entry();
+		entry.IsVisible(Context(assembly!)).Should().BeTrue("a single node delegates to its own Save override");
+		entry.IsEnabled(Context(assembly!)).Should().BeTrue();
+	}
+
+	[AvaloniaTest]
+	public async Task Multiple_Valid_Assemblies_Are_Visible()
+	{
+		var (_, vm) = await TestHarness.BootAsync(3);
+		var assemblies = vm.AssemblyTreeModel.AssemblyList!.GetAssemblies()
+			.Where(a => a.IsLoadedAsValidAssembly)
+			.GroupBy(a => a.ShortName).Select(g => g.First())
+			.Take(2)
+			.Select(a => (SharpTreeNode)new AssemblyTreeNode(a))
+			.ToArray();
+		assemblies.Should().HaveCount(2);
+
+		Entry().IsVisible(Context(assemblies)).Should().BeTrue(
+			"several valid assemblies offer the solution export path");
+	}
+
+	[AvaloniaTest]
+	public async Task Mixed_Multi_Selection_Is_Hidden()
+	{
+		var (_, vm) = await TestHarness.BootAsync(3);
+		var assembly = vm.AssemblyTreeModel.FindNode<AssemblyTreeNode>("System.Linq");
+		var type = vm.AssemblyTreeModel.FindNode<TypeTreeNode>(
+			"System.Linq", "System.Linq", "System.Linq.Enumerable");
+		Assert.That(assembly, Is.Not.Null);
+		Assert.That(type, Is.Not.Null);
+
+		Entry().IsVisible(Context(assembly!, type!)).Should().BeFalse(
+			"a mixed assembly + type selection has no well-defined Save Code action");
+	}
+
+	[AvaloniaTest]
+	public async Task Empty_Selection_Is_Hidden()
+	{
+		await TestHarness.BootAsync(1);
+		Entry().IsVisible(Context()).Should().BeFalse();
+	}
+}

ILSpy.Tests/Languages/SolutionExportTests.cs

@@ -0,0 +1,126 @@
+// 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.IO;
+using System.Linq;
+using System.Threading.Tasks;
+
+using Avalonia.Headless.NUnit;
+
+using AwesomeAssertions;
+
+using ILSpy.AppEnv;
+using ILSpy.Languages;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.ILSpy.Tests.Languages;
+
+/// <summary>
+/// End-to-end smoke test of the multi-assembly solution (.sln) export path that backs the
+/// "Save Code" entry when several assemblies are selected. Drives
+/// <see cref="global::ILSpy.SolutionWriter.CreateSolutionAsync"/> directly (no file picker)
+/// and asserts a solution file plus one project per assembly is produced.
+/// </summary>
+[TestFixture]
+public class SolutionExportTests
+{
+	[AvaloniaTest]
+	public async Task CreateSolution_Writes_Sln_And_Per_Assembly_Projects()
+	{
+		var (_, vm) = await TestHarness.BootAsync(3);
+
+		// CoreLib is too big for a smoke test; the Uri and System.Linq reference assemblies
+		// the headless fixture seeds are both manageable full-project decompiles.
+		var assemblies = vm.AssemblyTreeModel.AssemblyList!.GetAssemblies()
+			.Where(a => a.IsLoadedAsValidAssembly && a.ShortName != TreeNavigation.CoreLibName)
+			.GroupBy(a => a.ShortName).Select(g => g.First())
+			.Take(2).ToList();
+		assemblies.Should().HaveCountGreaterThanOrEqualTo(2, "a solution needs at least two distinct assemblies");
+
+		foreach (var a in assemblies)
+			await a.GetLoadResultAsync();
+
+		var language = AppComposition.Current.GetExport<LanguageService>()
+			.Languages.OfType<CSharpLanguage>().First();
+
+		var tempDir = Path.Combine(Path.GetTempPath(), "ILSpySln_" + System.Guid.NewGuid().ToString("N"));
+		Directory.CreateDirectory(tempDir);
+		var slnPath = Path.Combine(tempDir, "Solution.sln");
+		try
+		{
+			var result = await global::ILSpy.SolutionWriter.CreateSolutionAsync(slnPath, language, assemblies);
+
+			result.Success.Should().BeTrue(
+				"the solution export should succeed for valid assemblies. Status:\n" + result.StatusText);
+			File.Exists(slnPath).Should().BeTrue("the .sln file must be written to the chosen path");
+
+			foreach (var a in assemblies)
+			{
+				var projectDir = Path.Combine(tempDir, a.ShortName);
+				Directory.EnumerateFiles(projectDir, "*.csproj").Should().HaveCount(1,
+					$"each assembly gets its own subdirectory with one project file ({a.ShortName})");
+				Directory.EnumerateFiles(projectDir, "*.cs", SearchOption.AllDirectories).Should().NotBeEmpty(
+					$"the decompiled project for {a.ShortName} must contain at least one source file");
+			}
+
+			result.StatusText.Should().Contain("Created the Visual Studio Solution file",
+				"a successful run reports the solution-written breadcrumb");
+		}
+		finally
+		{
+			try
+			{ Directory.Delete(tempDir, recursive: true); }
+			catch { /* best-effort cleanup */ }
+		}
+	}
+
+	[AvaloniaTest]
+	public async Task CreateSolution_Aborts_On_Duplicate_Assembly_Names()
+	{
+		var (_, vm) = await TestHarness.BootAsync(3);
+
+		var assembly = vm.AssemblyTreeModel.AssemblyList!.GetAssemblies()
+			.First(a => a.IsLoadedAsValidAssembly && a.ShortName != TreeNavigation.CoreLibName);
+		await assembly.GetLoadResultAsync();
+
+		var language = AppComposition.Current.GetExport<LanguageService>()
+			.Languages.OfType<CSharpLanguage>().First();
+
+		var tempDir = Path.Combine(Path.GetTempPath(), "ILSpySlnDup_" + System.Guid.NewGuid().ToString("N"));
+		Directory.CreateDirectory(tempDir);
+		var slnPath = Path.Combine(tempDir, "Solution.sln");
+		try
+		{
+			// The same assembly twice collides on ShortName: the writer must refuse rather than
+			// clobber one project directory with another.
+			var result = await global::ILSpy.SolutionWriter.CreateSolutionAsync(
+				slnPath, language, new[] { assembly, assembly });
+
+			result.Success.Should().BeFalse("duplicate assembly names cannot produce a valid solution");
+			result.StatusText.Should().Contain("Duplicate assembly names");
+			File.Exists(slnPath).Should().BeFalse("no solution file is written when the export aborts");
+		}
+		finally
+		{
+			try
+			{ Directory.Delete(tempDir, recursive: true); }
+			catch { /* best-effort cleanup */ }
+		}
+	}
+}

ILSpy/Commands/FileCommands.cs

@@ -202,13 +202,22 @@ namespace ILSpy.Commands
 	[method: ImportingConstructor]
 	internal sealed class SaveCommand(
 		AssemblyTreeModel assemblyTreeModel,
-		LanguageService languageService) : SimpleCommand
+		LanguageService languageService,
+		DockWorkspace dockWorkspace) : SimpleCommand
 	{
 		public override bool CanExecute(object? parameter)
 			=> assemblyTreeModel.SelectedItem is ILSpyTreeNode;
 
 		public override async void Execute(object? parameter)
 		{
+			// Several selected assemblies export a Visual Studio solution (one project each),
+			// matching the Save Code context-menu entry.
+			if (SolutionExport.TryGetAssemblies(assemblyTreeModel.SelectedItems, out var assemblies))
+			{
+				await SolutionExport.PromptAndExportAsync(assemblies, languageService.CurrentLanguage, dockWorkspace);
+				return;
+			}
+
 			if (assemblyTreeModel.SelectedItem is not ILSpyTreeNode node)
 				return;
 			// Resource nodes (and any future override) handle their own save format and dialog;

ILSpy/Commands/SaveCodeContextMenuEntry.cs

@@ -17,40 +17,71 @@
 // DEALINGS IN THE SOFTWARE.
 
 using System.Composition;
+using System.Linq;
 
 using ICSharpCode.ILSpy.Properties;
 using ICSharpCode.ILSpyX.TreeView;
 
+using ILSpy.Docking;
+using ILSpy.Languages;
 using ILSpy.TreeNodes;
 
 namespace ILSpy.Commands
 {
 	/// <summary>
-	/// Right-click → "Save Code". Delegates to the selected node's
-	/// <see cref="ILSpyTreeNode.Save"/> override so the context-menu entry and File →
-	/// Save Code take exactly the same path: <c>AssemblyTreeNode</c> drives project /
-	/// single-file selection, <c>ResourceTreeNode</c> writes raw bytes, every other
-	/// node falls through to the generic single-file decompile in the existing
-	/// <c>FileCommands.SaveCommand</c>.
+	/// Right-click → "Save Code". Mirrors the WPF entry's two modes:
+	/// <list type="bullet">
+	/// <item>A single node delegates to its <see cref="ILSpyTreeNode.Save"/> override —
+	/// <c>AssemblyTreeNode</c> drives project / single-file selection, <c>ResourceTreeNode</c>
+	/// writes raw bytes, every other node falls through to the generic single-file decompile.</item>
+	/// <item>Several selected assemblies export a Visual Studio solution (one decompiled project
+	/// each) via <see cref="SolutionWriter"/>.</item>
+	/// </list>
 	/// </summary>
 	[ExportContextMenuEntry(Header = nameof(Resources._SaveCode), Category = nameof(Resources.Save), Icon = "Images/Save", Order = 300)]
 	[Shared]
 	public sealed class SaveCodeContextMenuEntry : IContextMenuEntry
 	{
-		public bool IsVisible(TextViewContext context) => GetTarget(context) != null;
+		readonly LanguageService languageService;
+		readonly DockWorkspace dockWorkspace;
 
-		public bool IsEnabled(TextViewContext context) => GetTarget(context) != null;
+		[ImportingConstructor]
+		public SaveCodeContextMenuEntry(LanguageService languageService, DockWorkspace dockWorkspace)
+		{
+			this.languageService = languageService;
+			this.dockWorkspace = dockWorkspace;
+		}
+
+		public bool IsVisible(TextViewContext context) => CanExecute(context.SelectedTreeNodes);
+
+		public bool IsEnabled(TextViewContext context) => CanExecute(context.SelectedTreeNodes);
 
 		public void Execute(TextViewContext context)
 		{
-			GetTarget(context)?.Save();
+			var nodes = context.SelectedTreeNodes;
+			if (nodes is not { Length: > 0 })
+				return;
+
+			if (SolutionExport.TryGetAssemblies(nodes, out var assemblies))
+			{
+				_ = SolutionExport.PromptAndExportAsync(assemblies, languageService.CurrentLanguage, dockWorkspace);
+				return;
+			}
+
+			if (nodes.Length == 1)
+				(nodes[0] as ILSpyTreeNode)?.Save();
 		}
 
-		static ILSpyTreeNode? GetTarget(TextViewContext context)
+		// Visible when exactly one ILSpyTreeNode is selected (the single-node save path), or when
+		// several valid assemblies are selected (the solution-export path). Mixed or other
+		// multi-selections have no well-defined "save code" meaning.
+		static bool CanExecute(SharpTreeNode[]? selectedNodes)
 		{
-			if (context.SelectedTreeNodes is not { Length: 1 } nodes)
-				return null;
-			return nodes[0] as ILSpyTreeNode;
+			if (selectedNodes is not { Length: > 0 })
+				return false;
+			if (selectedNodes.Length == 1)
+				return selectedNodes[0] is ILSpyTreeNode;
+			return SolutionExport.TryGetAssemblies(selectedNodes, out _);
 		}
 	}
 }

ILSpy/Commands/SolutionExport.cs

@@ -0,0 +1,115 @@
+// 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;
+using System.Collections.Generic;
+using System.Diagnostics;
+using System.IO;
+using System.Linq;
+using System.Threading.Tasks;
+
+using ICSharpCode.ILSpy.Properties;
+using ICSharpCode.ILSpyX;
+using ICSharpCode.ILSpyX.TreeView;
+
+using ILSpy.Docking;
+using ILSpy.Languages;
+using ILSpy.TextView;
+using ILSpy.TreeNodes;
+
+namespace ILSpy.Commands
+{
+	/// <summary>
+	/// The shared "export several assemblies as a Visual Studio solution" flow behind both the
+	/// File &rarr; Save Code command and the Save Code context-menu entry: it recognises a
+	/// solution-eligible selection, prompts for the <c>.sln</c> path, runs
+	/// <see cref="SolutionWriter"/> behind the tab's cancellable progress UI, and surfaces the
+	/// status report in the active decompiler tab.
+	/// </summary>
+	internal static class SolutionExport
+	{
+		/// <summary>
+		/// True when <paramref name="nodes"/> is several assembly nodes that all loaded as valid
+		/// assemblies — the only selection shape that maps onto a multi-project solution.
+		/// </summary>
+		public static bool TryGetAssemblies(IReadOnlyList<SharpTreeNode>? nodes, out List<LoadedAssembly> assemblies)
+		{
+			assemblies = new List<LoadedAssembly>();
+			if (nodes is not { Count: > 1 })
+				return false;
+			if (!nodes.All(n => n is AssemblyTreeNode { LoadedAssembly.IsLoadedAsValidAssembly: true }))
+				return false;
+			assemblies = nodes.OfType<AssemblyTreeNode>().Select(n => n.LoadedAssembly).ToList();
+			return true;
+		}
+
+		/// <summary>
+		/// Prompts for a target <c>.sln</c> file and exports <paramref name="assemblies"/> into it,
+		/// one decompiled project each. The status report lands in the active decompiler tab, where
+		/// the user is already looking. Does nothing if the user cancels the picker.
+		/// </summary>
+		public static async Task PromptAndExportAsync(IReadOnlyList<LoadedAssembly> assemblies,
+			Language language, DockWorkspace dockWorkspace)
+		{
+			var path = await FilePickers.SaveAsync(
+				Resources.VisualStudioSolutionFileSlnAllFiles, "Solution.sln", Resources._SaveCode)
+				.ConfigureAwait(true);
+			if (string.IsNullOrEmpty(path))
+				return;
+
+			try
+			{
+				var output = await dockWorkspace.RunWithCancellation(async token => {
+					var result = await SolutionWriter.CreateSolutionAsync(path, language, assemblies, token)
+						.ConfigureAwait(false);
+					var o = new AvaloniaEditTextOutput { Title = Resources._SaveCode };
+					o.Write(result.StatusText);
+					o.WriteLine();
+					if (result.Success && Path.GetDirectoryName(path) is { Length: > 0 } directory)
+					{
+						o.AddButton(null, Resources.OpenExplorer, (_, _) => OpenFolder(directory));
+						o.WriteLine();
+					}
+					return o;
+				}, "Exporting solution");
+				dockWorkspace.ShowText(output);
+			}
+			catch (OperationCanceledException)
+			{
+				// User cancelled — leave the previous tab content visible.
+			}
+		}
+
+		static void OpenFolder(string path)
+		{
+			try
+			{
+				if (OperatingSystem.IsWindows())
+					Process.Start(new ProcessStartInfo("explorer.exe", $"\"{path}\"") { UseShellExecute = false });
+				else if (OperatingSystem.IsMacOS())
+					Process.Start(new ProcessStartInfo("open", $"\"{path}\"") { UseShellExecute = false });
+				else
+					Process.Start(new ProcessStartInfo("xdg-open", path) { UseShellExecute = false });
+			}
+			catch
+			{
+				// Best-effort.
+			}
+		}
+	}
+}

ILSpy/SolutionWriter.cs

@@ -0,0 +1,243 @@
+// Copyright (c) 2011 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;
+using System.Collections.Concurrent;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading;
+using System.Threading.Tasks;
+
+using ICSharpCode.Decompiler;
+using ICSharpCode.Decompiler.Solution;
+using ICSharpCode.ILSpyX;
+
+using ILSpy.Languages;
+
+namespace ILSpy
+{
+	/// <summary>
+	/// The outcome of a <see cref="SolutionWriter.CreateSolutionAsync"/> run: whether a complete
+	/// solution was produced and the human-readable status report (the same breadcrumb the WPF
+	/// version printed into the decompiler text view).
+	/// </summary>
+	public sealed record SolutionExportResult(bool Success, string StatusText);
+
+	/// <summary>
+	/// Creates a Visual Studio solution containing one decompiled project per assembly. The
+	/// solution directory must be empty or non-existent. UI-agnostic: callers supply an explicit
+	/// target path (the "Save Code" entry picks it via a file dialog) and surface
+	/// <see cref="SolutionExportResult.StatusText"/> however they like.
+	/// </summary>
+	internal sealed class SolutionWriter
+	{
+		/// <summary>
+		/// Decompiles every assembly in <paramref name="assemblies"/> into its own project under the
+		/// directory of <paramref name="solutionFilePath"/> and writes the solution file itself.
+		/// </summary>
+		/// <exception cref="ArgumentException">Thrown when <paramref name="solutionFilePath"/> is null
+		/// or whitespace.</exception>
+		/// <exception cref="ArgumentNullException">Thrown when <paramref name="language"/> or
+		/// <paramref name="assemblies"/> is null.</exception>
+		public static Task<SolutionExportResult> CreateSolutionAsync(string solutionFilePath,
+			Language language, IReadOnlyList<LoadedAssembly> assemblies,
+			CancellationToken cancellationToken = default)
+		{
+			if (string.IsNullOrWhiteSpace(solutionFilePath))
+				throw new ArgumentException("The solution file path cannot be null or empty.", nameof(solutionFilePath));
+			ArgumentNullException.ThrowIfNull(language);
+			ArgumentNullException.ThrowIfNull(assemblies);
+
+			return new SolutionWriter(solutionFilePath).CreateSolutionAsync(assemblies, language, cancellationToken);
+		}
+
+		readonly string solutionFilePath;
+		readonly string solutionDirectory;
+		readonly ConcurrentBag<ProjectItem> projects;
+		readonly ConcurrentBag<string> statusOutput;
+
+		SolutionWriter(string solutionFilePath)
+		{
+			this.solutionFilePath = solutionFilePath;
+			solutionDirectory = Path.GetDirectoryName(solutionFilePath)!;
+			statusOutput = new ConcurrentBag<string>();
+			projects = new ConcurrentBag<ProjectItem>();
+		}
+
+		async Task<SolutionExportResult> CreateSolutionAsync(IReadOnlyList<LoadedAssembly> allAssemblies,
+			Language language, CancellationToken ct)
+		{
+			var report = new StringBuilder();
+
+			// Two assemblies that share a short name would decompile into the same project directory;
+			// refuse rather than have one clobber the other.
+			var assembliesByShortName = allAssemblies.GroupBy(a => a.ShortName).ToDictionary(g => g.Key, g => g.ToList());
+			bool first = true;
+			bool abort = false;
+			foreach (var (_, assemblies) in assembliesByShortName)
+			{
+				if (assemblies.Count == 1)
+					continue;
+				if (first)
+				{
+					report.AppendLine("Duplicate assembly names selected, cannot generate a solution:");
+					abort = true;
+					first = false;
+				}
+				report.AppendLine("- " + assemblies[0].Text + " conflicts with "
+					+ string.Join(", ", assemblies.Skip(1).Select(a => a.Text)));
+			}
+
+			if (abort)
+				return new SolutionExportResult(false, report.ToString());
+
+			try
+			{
+				// An explicit enumerable partitioner avoids Parallel.ForEach's list special-casing,
+				// whose static partitioning is inefficient when assemblies decompile at different speeds.
+				await Task.Run(() => System.Threading.Tasks.Parallel.ForEach(Partitioner.Create(allAssemblies),
+					new ParallelOptions { MaxDegreeOfParallelism = Environment.ProcessorCount, CancellationToken = ct },
+					item => WriteProject(item, language, solutionDirectory, ct)))
+					.ConfigureAwait(false);
+
+				if (projects.Count == 0)
+				{
+					report.AppendLine();
+					report.AppendLine("Solution could not be created, because none of the selected assemblies could be decompiled into a project.");
+					return new SolutionExportResult(false, report.ToString());
+				}
+
+				await Task.Run(() => SolutionCreator.WriteSolutionFile(solutionFilePath, projects.ToList()), ct)
+					.ConfigureAwait(false);
+			}
+			catch (AggregateException ae)
+			{
+				if (ae.Flatten().InnerExceptions.All(e => e is OperationCanceledException))
+				{
+					report.AppendLine();
+					report.AppendLine("Generation was cancelled.");
+					return new SolutionExportResult(false, report.ToString());
+				}
+
+				report.AppendLine();
+				report.AppendLine("Failed to generate the Visual Studio Solution. Errors:");
+				ae.Handle(e => {
+					report.AppendLine(e.Message);
+					return true;
+				});
+				return new SolutionExportResult(false, report.ToString());
+			}
+			catch (OperationCanceledException)
+			{
+				report.AppendLine();
+				report.AppendLine("Generation was cancelled.");
+				return new SolutionExportResult(false, report.ToString());
+			}
+
+			foreach (var item in statusOutput)
+				report.AppendLine(item);
+
+			// statusOutput only collects per-assembly failures; an empty bag means every project built.
+			if (statusOutput.Count != 0)
+				return new SolutionExportResult(false, report.ToString());
+
+			report.AppendLine("Successfully decompiled the following assemblies into Visual Studio projects:");
+			foreach (var n in allAssemblies)
+				report.AppendLine(n.Text.ToString());
+			report.AppendLine();
+			if (allAssemblies.Count == projects.Count)
+				report.AppendLine("Created the Visual Studio Solution file.");
+
+			return new SolutionExportResult(true, report.ToString());
+		}
+
+		void WriteProject(LoadedAssembly loadedAssembly, Language language, string targetDirectory, CancellationToken ct)
+		{
+			targetDirectory = Path.Combine(targetDirectory, loadedAssembly.ShortName);
+
+			if (language.ProjectFileExtension == null)
+			{
+				statusOutput.Add("-------------");
+				statusOutput.Add($"Language '{language.Name}' does not support exporting assemblies as projects!");
+				return;
+			}
+
+			if (File.Exists(targetDirectory))
+			{
+				statusOutput.Add("-------------");
+				statusOutput.Add($"Failed to create a directory '{targetDirectory}':{Environment.NewLine}A file with the same name already exists!");
+				return;
+			}
+
+			if (!Directory.Exists(targetDirectory))
+			{
+				try
+				{
+					Directory.CreateDirectory(targetDirectory);
+				}
+				catch (Exception e)
+				{
+					statusOutput.Add("-------------");
+					statusOutput.Add($"Failed to create a directory '{targetDirectory}':{Environment.NewLine}{e}");
+					return;
+				}
+			}
+
+			try
+			{
+				var options = new DecompilationOptions {
+					FullDecompilation = true,
+					EscapeInvalidIdentifiers = true,
+					CancellationToken = ct,
+					SaveAsProjectDirectory = targetDirectory,
+				};
+
+				// The project-export path writes the .csproj into SaveAsProjectDirectory itself; the
+				// ITextOutput only receives a "Project written to ..." breadcrumb, which we discard here.
+				var projectInfo = language.DecompileAssembly(loadedAssembly, new PlainTextOutput(new StringWriter()), options);
+				if (projectInfo != null)
+				{
+					// SolutionCreator.FixAllProjectReferences parses each project file off disk, so the
+					// ProjectItem must point at the .csproj the decompiler actually produced (its name is
+					// derived from the module name, not necessarily the assembly short name).
+					var projectFileName = Directory.EnumerateFiles(targetDirectory, "*" + language.ProjectFileExtension).FirstOrDefault()
+						?? Path.Combine(targetDirectory, loadedAssembly.ShortName + language.ProjectFileExtension);
+					projects.Add(new ProjectItem(projectFileName, projectInfo.PlatformName, projectInfo.Guid, projectInfo.TypeGuid));
+				}
+			}
+			catch (NotSupportedException e)
+			{
+				statusOutput.Add("-------------");
+				statusOutput.Add($"Failed to decompile the assembly '{loadedAssembly.FileName}':{Environment.NewLine}{e.Message}");
+			}
+			catch (PathTooLongException e)
+			{
+				statusOutput.Add("-------------");
+				statusOutput.Add(string.Format(ICSharpCode.ILSpy.Properties.Resources.ProjectExportPathTooLong, loadedAssembly.FileName)
+					+ Environment.NewLine + Environment.NewLine + e.ToString());
+			}
+			catch (Exception e) when (e is not OperationCanceledException)
+			{
+				statusOutput.Add("-------------");
+				statusOutput.Add($"Failed to decompile the assembly '{loadedAssembly.FileName}':{Environment.NewLine}{e}");
+			}
+		}
+	}
+}