ilspycmd: add --member for single-member decompilation

Decompiling one method or property previously required decompiling its whole type and searching the output, which is wasteful for scripted and agent-driven use against large assemblies. The new -m|--member option accepts an XML documentation id string (the syntax of compiler-generated documentation files and of the UI's --navigateto option) or a metadata token in 0x06000005 form, resolves it against the main module (with a bounds check for tokens and distinct error messages for malformed ids, unknown members, and members of other modules), and prints just that member through the engine's single-member decompilation path. The tests seed a new ICSharpCode.ILSpyCmd.Tests project (part of the XPlat and Desktop solution filters and of the per-project CI test steps), driving the real Main in-process via InternalsVisibleTo, so future ilspycmd features have a dedicated home for CLI tests. Assisted-by: Claude:claude-fable-5:Claude Code
2 months ago · 74bc61b70f
9 changed files with 854 additions and 0 deletions
--- a/.github/workflows/build-ilspy.yml
+++ b/.github/workflows/build-ilspy.yml
@ -350,6 +350,13 @@ jobs:
				@@ -350,6 +350,13 @@ jobs:
        --no-build --report-trx
        --results-directory test-results

+    - name: Execute ilspycmd tests
+      run: >
+        dotnet test --project ICSharpCode.ILSpyCmd.Tests/ICSharpCode.ILSpyCmd.Tests.csproj
+        --configuration Release
+        --no-build --report-trx
+        --results-directory test-results
+
    - name: Execute BAML decompiler tests
      run: >
        dotnet test --project ILSpy.BamlDecompiler.Tests/ILSpy.BamlDecompiler.Tests.csproj
--- a/ICSharpCode.ILSpyCmd.Tests/ICSharpCode.ILSpyCmd.Tests.csproj
+++ b/ICSharpCode.ILSpyCmd.Tests/ICSharpCode.ILSpyCmd.Tests.csproj
@ -0,0 +1,27 @@
				@@ -0,0 +1,27 @@
+<?xml version="1.0" encoding="utf-8"?>
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>net11.0</TargetFramework>
+    <LangVersion>preview</LangVersion>
+
+    <IsPackable>false</IsPackable>
+
+    <GenerateTestingPlatformEntryPoint>true</GenerateTestingPlatformEntryPoint>
+    <StartupObject>ICSharpCode.ILSpyCmd.Tests.MicrosoftTestingPlatformEntryPoint</StartupObject>
+    <OutputType>Exe</OutputType>
+
+  </PropertyGroup>
+
+  <ItemGroup>
+    <PackageReference Include="NUnit" />
+    <PackageReference Include="NUnit3TestAdapter" />
+    <PackageReference Include="Microsoft.Testing.Extensions.TrxReport" />
+    <PackageReference Include="Microsoft.Testing.Extensions.VSTestBridge" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <ProjectReference Include="..\ICSharpCode.ILSpyCmd\ICSharpCode.ILSpyCmd.csproj" />
+  </ItemGroup>
+
+</Project>
--- a/ICSharpCode.ILSpyCmd.Tests/MemberOptionTests.cs
+++ b/ICSharpCode.ILSpyCmd.Tests/MemberOptionTests.cs
@ -0,0 +1,156 @@
				@@ -0,0 +1,156 @@
+// Copyright (c) 2026 Siegfried Pammer
+//
+// 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.IO;
+using System.Threading.Tasks;
+
+using NUnit.Framework;
+
+namespace ICSharpCode.ILSpyCmd.Tests
+{
+	[TestFixture]
+	public class ILSpyCmdMemberOptionTests
+	{
+		static readonly string testAssemblyPath = typeof(ILSpyCmdMemberOptionTests).Assembly.Location;
+
+		static async Task<(int ExitCode, string Output, string Error)> RunAsync(params string[] args)
+		{
+			var originalOut = Console.Out;
+			var originalError = Console.Error;
+			var stdout = new StringWriter();
+			var stderr = new StringWriter();
+			try
+			{
+				Console.SetOut(stdout);
+				Console.SetError(stderr);
+				int exitCode = await ILSpyCmdProgram.Main(args);
+				return (exitCode, stdout.ToString(), stderr.ToString());
+			}
+			finally
+			{
+				Console.SetOut(originalOut);
+				Console.SetError(originalError);
+			}
+		}
+
+		[Test]
+		public async Task MethodByDocumentationIdString()
+		{
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck",
+				"-m", "M:ICSharpCode.ILSpyCmd.Tests.MemberOptionSample.Add(System.Int32,System.Int32)");
+
+			Assert.That(result.ExitCode, Is.EqualTo(0), result.Error);
+			Assert.That(result.Output, Does.Contain("int Add(int a, int b)"));
+			Assert.That(result.Output, Does.Not.Contain("Unrelated"));
+		}
+
+		[Test]
+		public async Task PropertyByDocumentationIdString()
+		{
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck",
+				"-m", "P:ICSharpCode.ILSpyCmd.Tests.MemberOptionSample.Answer");
+
+			Assert.That(result.ExitCode, Is.EqualTo(0), result.Error);
+			Assert.That(result.Output, Does.Contain("Answer"));
+			Assert.That(result.Output, Does.Not.Contain("Add(int a, int b)"));
+		}
+
+		[Test]
+		public async Task MethodByMetadataToken()
+		{
+			int token = typeof(MemberOptionSample).GetMethod(nameof(MemberOptionSample.Add))!.MetadataToken;
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck", "-m", $"0x{token:x8}");
+
+			Assert.That(result.ExitCode, Is.EqualTo(0), result.Error);
+			Assert.That(result.Output, Does.Contain("int Add(int a, int b)"));
+		}
+
+		[Test]
+		public async Task UnknownMemberReportsError()
+		{
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck",
+				"-m", "M:ICSharpCode.ILSpyCmd.Tests.MemberOptionSample.DoesNotExist");
+
+			Assert.That(result.ExitCode, Is.EqualTo(ProgramExitCodes.EX_DATAERR));
+			Assert.That(result.Error, Does.Contain("DoesNotExist"));
+		}
+
+		[Test]
+		public async Task MalformedTokenReportsTokenSpecificError()
+		{
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck", "-m", "0xZZ000001");
+
+			Assert.That(result.ExitCode, Is.EqualTo(ProgramExitCodes.EX_DATAERR));
+			Assert.That(result.Error, Does.Contain("metadata token"));
+			Assert.That(result.Error, Does.Not.Contain("documentation id"));
+		}
+
+		[Test]
+		public async Task MemberOfAnotherModuleReportsDistinctError()
+		{
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck", "-m", "M:System.Object.ToString");
+
+			Assert.That(result.ExitCode, Is.EqualTo(ProgramExitCodes.EX_DATAERR));
+			Assert.That(result.Error, Does.Contain("defined in"));
+		}
+
+		[Test]
+		public async Task SurroundingWhitespaceIsIgnored()
+		{
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck",
+				"-m", " M:ICSharpCode.ILSpyCmd.Tests.MemberOptionSample.Add(System.Int32,System.Int32) ");
+
+			Assert.That(result.ExitCode, Is.EqualTo(0), result.Error);
+			Assert.That(result.Output, Does.Contain("int Add(int a, int b)"));
+		}
+
+		[Test]
+		public async Task OutOfRangeTokenReportsError()
+		{
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck", "-m", "0x06ffffff");
+
+			Assert.That(result.ExitCode, Is.EqualTo(ProgramExitCodes.EX_DATAERR));
+			Assert.That(result.Error, Does.Contain("0x06ffffff"));
+		}
+
+		[Test]
+		public async Task TypeAndMemberOptionsAreMutuallyExclusive()
+		{
+			var result = await RunAsync(testAssemblyPath, "--disable-updatecheck",
+				"-t", "ICSharpCode.ILSpyCmd.Tests.MemberOptionSample",
+				"-m", "P:ICSharpCode.ILSpyCmd.Tests.MemberOptionSample.Answer");
+
+			Assert.That(result.ExitCode, Is.EqualTo(ProgramExitCodes.EX_USAGE));
+		}
+	}
+
+	public class MemberOptionSample
+	{
+		public int Add(int a, int b)
+		{
+			return a + b;
+		}
+
+		public string Answer => "42";
+
+		public void Unrelated()
+		{
+		}
+	}
+}
--- a/ICSharpCode.ILSpyCmd.Tests/packages.lock.json
+++ b/ICSharpCode.ILSpyCmd.Tests/packages.lock.json
@ -0,0 +1,549 @@
				@@ -0,0 +1,549 @@
+{
+  "version": 2,
+  "dependencies": {
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+        "dependencies": {
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+          "Microsoft.Testing.Platform": "2.1.0"
+        }
+      },
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+          "Microsoft.Testing.Platform": "2.1.0"
+        }
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+      "NUnit": {
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+          "Microsoft.Extensions.Logging.Abstractions": "10.0.10",
+          "Microsoft.Extensions.Options": "10.0.10",
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+        "dependencies": {
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+        "dependencies": {
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+          "Microsoft.Extensions.Configuration.Binder": "10.0.10",
+          "Microsoft.Extensions.DependencyInjection.Abstractions": "10.0.10",
+          "Microsoft.Extensions.Options": "10.0.10",
+          "Microsoft.Extensions.Primitives": "10.0.10"
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+      },
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+        "dependencies": {
+          "Microsoft.ApplicationInsights": "2.23.0",
+          "Microsoft.Testing.Platform": "2.1.0"
+        }
+      },
+      "Microsoft.Testing.Extensions.TrxReport.Abstractions": {
+        "type": "Transitive",
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+        "dependencies": {
+          "Microsoft.Testing.Platform": "2.1.0"
+        }
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+      },
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+        "type": "Transitive",
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+        "dependencies": {
+          "Microsoft.Testing.Platform": "2.1.0"
+        }
+      },
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+        "type": "Transitive",
+        "resolved": "18.0.1",
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+        "dependencies": {
+          "System.Reflection.Metadata": "8.0.0"
+        }
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+        "type": "Transitive",
+        "resolved": "13.0.3",
+        "contentHash": "HrC5BXdl00IP9zeV+0Z848QWPAoCr9P3bDEZguI+gkLcBKAOxix/tLEAAHC+UvDNPv4a2d18lOReHMOagPa+zQ=="
+      },
+      "NuGet.Common": {
+        "type": "Transitive",
+        "resolved": "7.6.0",
+        "contentHash": "uyXLqkbbZmkMvdHOR23l1EHW2hRmULtzoG3Ocj84VpGptnNfkODVboHGJfDfcn9Gi9oUNDs8/VjL4FZcST6zVg==",
+        "dependencies": {
+          "NuGet.Frameworks": "7.6.0"
+        }
+      },
+      "NuGet.Configuration": {
+        "type": "Transitive",
+        "resolved": "7.6.0",
+        "contentHash": "+bNj+YneC5CNg1vR+WZjLAakscJlsi0KhADZUgIJPn4pwh8/jeCUMC5ik5cpET/i+QOplDy7aJVTGkpdfrlPww==",
+        "dependencies": {
+          "NuGet.Common": "7.6.0",
+          "System.Security.Cryptography.ProtectedData": "8.0.0"
+        }
+      },
+      "NuGet.Packaging": {
+        "type": "Transitive",
+        "resolved": "7.6.0",
+        "contentHash": "TDp+qHzRBy1zjwiJGCbfpdO0jMG5hH/bk7p1EABLKv9p5SIykDPGnbuYXm2iZO0QJ/H+hOI/vo5LfqM17Q+G0w==",
+        "dependencies": {
+          "Newtonsoft.Json": "13.0.3",
+          "NuGet.Configuration": "7.6.0",
+          "NuGet.Versioning": "7.6.0",
+          "System.Security.Cryptography.Pkcs": "8.0.1"
+        }
+      },
+      "NuGet.Versioning": {
+        "type": "Transitive",
+        "resolved": "7.6.0",
+        "contentHash": "TpZxfOoQBQk/0r/2uc1A1qNYIKHkJGgOrWP+ax3nsNAUN/1BOQMDrgmGADogSA4hOXH1ZJiyeYg4Ca+vUW0sEg=="
+      },
+      "System.Diagnostics.DiagnosticSource": {
+        "type": "Transitive",
+        "resolved": "5.0.0",
+        "contentHash": "tCQTzPsGZh/A9LhhA6zrqCRV4hOHsK90/G7q3Khxmn6tnB1PuNU0cRaKANP2AWcF9bn0zsuOoZOSrHuJk6oNBA=="
+      },
+      "System.Diagnostics.EventLog": {
+        "type": "Transitive",
+        "resolved": "10.0.10",
+        "contentHash": "OvGz3PrzuAI/Sj7LTcXcCe3FClRI1IyRMZjNONcZtFh+Ww7nAtSh4kh08r8KVe/xxkXJPjR0Y1jF7H+N42d4xQ=="
+      },
+      "System.Security.Cryptography.ProtectedData": {
+        "type": "Transitive",
+        "resolved": "8.0.0",
+        "contentHash": "+TUFINV2q2ifyXauQXRwy4CiBhqvDEDZeVJU7qfxya4aRYOKzVBpN+4acx25VcPB9ywUN6C0n8drWl110PhZEg=="
+      },
+      "icsharpcode.bamldecompiler": {
+        "type": "Project",
+        "dependencies": {
+          "ICSharpCode.Decompiler": "[8.0.0-noversion, )"
+        }
+      },
+      "icsharpcode.decompiler": {
+        "type": "Project",
+        "dependencies": {
+          "System.Collections.Immutable": "[9.0.0, )",
+          "System.Reflection.Metadata": "[9.0.0, )"
+        }
+      },
+      "icsharpcode.ilspyx": {
+        "type": "Project",
+        "dependencies": {
+          "ICSharpCode.Decompiler": "[8.0.0-noversion, )",
+          "K4os.Compression.LZ4": "[1.3.8, )",
+          "Mono.Cecil": "[0.11.6, )",
+          "System.Composition.AttributedModel": "[10.0.10, )",
+          "System.Reflection.Metadata": "[10.0.10, )",
+          "System.Runtime.CompilerServices.Unsafe": "[6.1.2, )"
+        }
+      },
+      "ilspycmd": {
+        "type": "Project",
+        "dependencies": {
+          "ICSharpCode.BamlDecompiler": "[10.0.0-noversion, )",
+          "ICSharpCode.Decompiler": "[8.0.0-noversion, )",
+          "ICSharpCode.ILSpyX": "[8.0.0-noversion, )",
+          "McMaster.Extensions.Hosting.CommandLine": "[5.1.0, )",
+          "Microsoft.Extensions.Hosting": "[10.0.10, )",
+          "NuGet.Protocol": "[7.6.0, )",
+          "System.Security.Cryptography.Pkcs": "[10.0.10, )"
+        }
+      },
+      "K4os.Compression.LZ4": {
+        "type": "CentralTransitive",
+        "requested": "[1.3.8, )",
+        "resolved": "1.3.8",
+        "contentHash": "LhwlPa7c1zs1OV2XadMtAWdImjLIsqFJPoRcIWAadSRn0Ri1DepK65UbWLPmt4riLqx2d40xjXRk0ogpqNtK7g=="
+      },
+      "McMaster.Extensions.CommandLineUtils": {
+        "type": "CentralTransitive",
+        "requested": "[5.1.0, )",
+        "resolved": "5.1.0",
+        "contentHash": "YceiKmxdsBrlkAJpmJ2N8XkLyAH01xLsm4VLfjNp5MvtAom2wflZtEBz3CLMQret6Z7jSh3oBO1ULF1Is0tNxA=="
+      },
+      "McMaster.Extensions.Hosting.CommandLine": {
+        "type": "CentralTransitive",
+        "requested": "[5.1.0, )",
+        "resolved": "5.1.0",
+        "contentHash": "XN6s/86/bP0PSsP5p2eX49ZKmWrURSNg7nvrG5vws3abm7Py1A4bv3x3Pdvg7FqR8mLgEE0gNTI1qDtlYQIQnw==",
+        "dependencies": {
+          "McMaster.Extensions.CommandLineUtils": "5.1.0",
+          "Microsoft.Extensions.Hosting.Abstractions": "10.0.5",
+          "Microsoft.Extensions.Logging.Abstractions": "10.0.5"
+        }
+      },
+      "Microsoft.Extensions.Configuration": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.10, )",
+        "resolved": "10.0.10",
+        "contentHash": "plJWK2zpWuuyxI8F8s2scx6Je7N1Ajjs6HvYUGKwRnDMWIVIz9FHwAkiT7ASgrvAOd10T0FPVlh9BzAJJME+jg==",
+        "dependencies": {
+          "Microsoft.Extensions.Configuration.Abstractions": "10.0.10",
+          "Microsoft.Extensions.Primitives": "10.0.10"
+        }
+      },
+      "Microsoft.Extensions.Configuration.Json": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.10, )",
+        "resolved": "10.0.10",
+        "contentHash": "uvJ6sHwjgrkMEJOgiC76G0mcZGXerwyyWkwX34EOjCbxKG6TCtfAoqDKAMsCvEBf9HxjlGQEgqsSMOGCmGBf+A==",
+        "dependencies": {
+          "Microsoft.Extensions.Configuration": "10.0.10",
+          "Microsoft.Extensions.Configuration.Abstractions": "10.0.10",
+          "Microsoft.Extensions.Configuration.FileExtensions": "10.0.10",
+          "Microsoft.Extensions.FileProviders.Abstractions": "10.0.10"
+        }
+      },
+      "Microsoft.Extensions.DependencyInjection.Abstractions": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.10, )",
+        "resolved": "10.0.10",
+        "contentHash": "z/2xXlFw2aLGjHyEm6E0tQ+In6VfzQzTrtArbQ2c0TQE16ZbyDCMGPvaUT9I0s8rgy9sRWlU2P9waW37qV04qA=="
+      },
+      "Microsoft.Extensions.Hosting": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.10, )",
+        "resolved": "10.0.10",
+        "contentHash": "tL9FkfV64GPUDSPvwrgyw42LVzsnVAnyrqJEuZVJbODgrQ3eL63zmzEcVWoCHzfgqUhWggzbgAyUCnz/zfI3Pg==",
+        "dependencies": {
+          "Microsoft.Extensions.Configuration": "10.0.10",
+          "Microsoft.Extensions.Configuration.Abstractions": "10.0.10",
+          "Microsoft.Extensions.Configuration.Binder": "10.0.10",
+          "Microsoft.Extensions.Configuration.CommandLine": "10.0.10",
+          "Microsoft.Extensions.Configuration.EnvironmentVariables": "10.0.10",
+          "Microsoft.Extensions.Configuration.FileExtensions": "10.0.10",
+          "Microsoft.Extensions.Configuration.Json": "10.0.10",
+          "Microsoft.Extensions.Configuration.UserSecrets": "10.0.10",
+          "Microsoft.Extensions.DependencyInjection": "10.0.10",
+          "Microsoft.Extensions.DependencyInjection.Abstractions": "10.0.10",
+          "Microsoft.Extensions.Diagnostics": "10.0.10",
+          "Microsoft.Extensions.FileProviders.Abstractions": "10.0.10",
+          "Microsoft.Extensions.FileProviders.Physical": "10.0.10",
+          "Microsoft.Extensions.Hosting.Abstractions": "10.0.10",
+          "Microsoft.Extensions.Logging": "10.0.10",
+          "Microsoft.Extensions.Logging.Abstractions": "10.0.10",
+          "Microsoft.Extensions.Logging.Configuration": "10.0.10",
+          "Microsoft.Extensions.Logging.Console": "10.0.10",
+          "Microsoft.Extensions.Logging.Debug": "10.0.10",
+          "Microsoft.Extensions.Logging.EventLog": "10.0.10",
+          "Microsoft.Extensions.Logging.EventSource": "10.0.10",
+          "Microsoft.Extensions.Options": "10.0.10"
+        }
+      },
+      "Mono.Cecil": {
+        "type": "CentralTransitive",
+        "requested": "[0.11.6, )",
+        "resolved": "0.11.6",
+        "contentHash": "f33RkDtZO8VlGXCtmQIviOtxgnUdym9xx/b1p9h91CRGOsJFxCFOFK1FDbVt1OCf1aWwYejUFa2MOQyFWTFjbA=="
+      },
+      "NuGet.Frameworks": {
+        "type": "CentralTransitive",
+        "requested": "[7.6.0, )",
+        "resolved": "7.6.0",
+        "contentHash": "rJ7QtKN45XzLXCrMATve6eFLiUyUGEkA1rFSb6U6Fw6laM4hEAcKOrcdbgWlcFUlCK2158qP1LF00hg/ivF3nw=="
+      },
+      "NuGet.Protocol": {
+        "type": "CentralTransitive",
+        "requested": "[7.6.0, )",
+        "resolved": "7.6.0",
+        "contentHash": "Ccb9dJG9hW0FdHFjXoHmhJBBJRYSCeSJArLdZjyZj6/FEAIKezLn75KFQNrTPE5UiAp4HVrjBizufZ/0IXhfKQ==",
+        "dependencies": {
+          "NuGet.Packaging": "7.6.0"
+        }
+      },
+      "System.Collections.Immutable": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.10, )",
+        "resolved": "10.0.10",
+        "contentHash": "Ih5zrydoDc1H5I0eNP6f4Lzw3cjsPMN4Nikd86kbyi66y0flkM9GfjVo62aUbcxeTbypzBCFAFQ+/6RF2jRORg=="
+      },
+      "System.Composition.AttributedModel": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.10, )",
+        "resolved": "10.0.10",
+        "contentHash": "alK+Ew7XBsxHgwmSmiZzg7x4sLpNIaQ3QVJUkJ/issHZY0L+RHceqO27pDp0J0sDnSf8g6yJNpDnWSKL5sAa/g=="
+      },
+      "System.Reflection.Metadata": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.10, )",
+        "resolved": "10.0.10",
+        "contentHash": "NZIS6/IUBh70nJfVvE577oDc81y5GfYRgjWssC8AGpSlVzSu5YfbHXEtHXyLeEY7gqqbAaASwJEP0Oy3Q54Jfw=="
+      },
+      "System.Runtime.CompilerServices.Unsafe": {
+        "type": "CentralTransitive",
+        "requested": "[6.1.2, )",
+        "resolved": "6.1.2",
+        "contentHash": "2hBr6zdbIBTDE3EhK7NSVNdX58uTK6iHW/P/Axmm9sl1xoGSLqDvMtpecn226TNwHByFokYwJmt/aQQNlO5CRw=="
+      },
+      "System.Security.Cryptography.Pkcs": {
+        "type": "CentralTransitive",
+        "requested": "[10.0.10, )",
+        "resolved": "10.0.10",
+        "contentHash": "KG8t5RHczdgB3IWvRndpI0nE1DSo7ikDYSDbITxfgRFyIvnYiKzuPjaZOsPnwFQ1aOGUl9sEulJul9wlHLEUoA=="
+      }
+    }
+  }
+}
--- a/ICSharpCode.ILSpyCmd/ICSharpCode.ILSpyCmd.csproj
+++ b/ICSharpCode.ILSpyCmd/ICSharpCode.ILSpyCmd.csproj
@ -71,4 +71,8 @@
				@@ -71,4 +71,8 @@
    </ReadLinesFromFile>
  </Target>

+  <ItemGroup>
+    <InternalsVisibleTo Include="ICSharpCode.ILSpyCmd.Tests" />
+  </ItemGroup>
+
 </Project>
--- a/ICSharpCode.ILSpyCmd/IlspyCmdProgram.cs
+++ b/ICSharpCode.ILSpyCmd/IlspyCmdProgram.cs
@ -23,7 +23,9 @@ using System.IO;
				@@ -23,7 +23,9 @@ using System.IO;
 using System.IO.Compression;
 using System.IO.MemoryMappedFiles;
 using System.Linq;
+using System.Globalization;
 using System.Reflection.Metadata;
+using System.Reflection.Metadata.Ecma335;
 using System.Reflection.PortableExecutable;
 using System.Threading;
 using System.Threading.Tasks;
@ -33,6 +35,7 @@ using ICSharpCode.Decompiler;
				@@ -33,6 +35,7 @@ using ICSharpCode.Decompiler;
 using ICSharpCode.Decompiler.CSharp;
 using ICSharpCode.Decompiler.CSharp.ProjectDecompiler;
 using ICSharpCode.Decompiler.DebugInfo;
+using ICSharpCode.Decompiler.Documentation;
 using ICSharpCode.Decompiler.Disassembler;
 using ICSharpCode.Decompiler.Metadata;
 using ICSharpCode.Decompiler.Solution;
@ -105,6 +108,9 @@ Examples:
				@@ -105,6 +108,9 @@ Examples:
 		[Option("-t|--type <type-name>", "The fully qualified name of the type to decompile.", CommandOptionType.SingleValue)]
 		public string TypeName { get; }

+		[Option("-m|--member <doc-id-or-token>", "The single member to decompile: an XML documentation id string (e.g. \"M:System.String.Concat(System.String,System.String)\", as also accepted by the UI's --navigateto option) or a metadata token (e.g. 0x06000005).", CommandOptionType.SingleValue)]
+		public string MemberIdString { get; }
+
 		[Option("-il|--ilcode", "Show IL code.", CommandOptionType.NoValue)]
 		public bool ShowILCodeFlag { get; }

@ -359,6 +365,12 @@ Examples:
				@@ -359,6 +365,12 @@ Examples:
 				}
 				else
 				{
+					if (MemberIdString != null && TypeName != null)
+					{
+						app.Error.WriteLine("The --type and --member options are mutually exclusive.");
+						return ProgramExitCodes.EX_USAGE;
+					}
+
 					if (outputDirectory != null)
 					{
 						string outputName = Path.GetFileNameWithoutExtension(fileName);
@ -366,6 +378,11 @@ Examples:
				@@ -366,6 +378,11 @@ Examples:
 							(string.IsNullOrEmpty(TypeName) ? outputName : TypeName) + ".decompiled.cs"));
 					}

+					if (MemberIdString != null)
+					{
+						return DecompileMember(fileName, output, MemberIdString);
+					}
+
 					return Decompile(fileName, output, TypeName);
 				}
 			}
@ -619,6 +636,84 @@ Examples:
				@@ -619,6 +636,84 @@ Examples:
 			return 0;
 		}

+		int DecompileMember(string assemblyFileName, TextWriter output, string idOrToken)
+		{
+			CSharpDecompiler decompiler = GetDecompiler(assemblyFileName);
+
+			if (!TryResolveMember(decompiler.TypeSystem, idOrToken, out EntityHandle handle, out string error))
+			{
+				Console.Error.WriteLine(error);
+				return ProgramExitCodes.EX_DATAERR;
+			}
+
+			output.Write(decompiler.DecompileAsString(handle));
+			return 0;
+		}
+
+		/// <summary>
+		/// Resolves a member reference supplied on the command line: either an XML
+		/// documentation id string ("M:...", "P:...", "F:...", "E:..." or "T:...") or a
+		/// metadata token in hexadecimal "0x06000005" form. Documentation id strings use
+		/// the same syntax as the compiler-generated documentation files and the UI's
+		/// --navigateto option.
+		/// </summary>
+		static bool TryResolveMember(IDecompilerTypeSystem typeSystem, string idOrToken, out EntityHandle handle, out string error)
+		{
+			handle = default;
+			error = null;
+			string trimmed = idOrToken.Trim();
+
+			if (trimmed.StartsWith("0x", StringComparison.OrdinalIgnoreCase))
+			{
+				if (!int.TryParse(trimmed.AsSpan(2), NumberStyles.HexNumber, CultureInfo.InvariantCulture, out int tokenValue))
+				{
+					error = $"'{trimmed}' is not a valid metadata token; expected a hexadecimal value like 0x06000005.";
+					return false;
+				}
+				var metadata = typeSystem.MainModule.MetadataFile.Metadata;
+				var candidate = MetadataTokens.EntityHandle(tokenValue);
+				int rowNumber = tokenValue & 0x00ffffff;
+				int rowCount = candidate.Kind switch {
+					HandleKind.TypeDefinition => metadata.TypeDefinitions.Count,
+					HandleKind.FieldDefinition => metadata.FieldDefinitions.Count,
+					HandleKind.MethodDefinition => metadata.MethodDefinitions.Count,
+					HandleKind.PropertyDefinition => metadata.PropertyDefinitions.Count,
+					HandleKind.EventDefinition => metadata.EventDefinitions.Count,
+					_ => 0,
+				};
+				if (rowNumber < 1 || rowNumber > rowCount)
+				{
+					error = $"Metadata token {trimmed} does not reference a type or member of this module.";
+					return false;
+				}
+				handle = candidate;
+				return true;
+			}
+
+			IEntity entity;
+			try
+			{
+				entity = IdStringProvider.FindEntity(trimmed, new SimpleTypeResolveContext(typeSystem.MainModule));
+			}
+			catch (ReflectionNameParseException ex)
+			{
+				error = $"'{trimmed}' is not a valid documentation id string: {ex.Message}";
+				return false;
+			}
+			if (entity == null || entity.MetadataToken.IsNil)
+			{
+				error = $"Member '{trimmed}' was not found in this module. Expected an XML documentation id string (e.g. \"M:System.String.Concat(System.String,System.String)\") or a metadata token (e.g. 0x06000005).";
+				return false;
+			}
+			if (entity.ParentModule != typeSystem.MainModule)
+			{
+				error = $"Member '{trimmed}' is defined in '{entity.ParentModule?.AssemblyName}', not in this module.";
+				return false;
+			}
+			handle = entity.MetadataToken;
+			return true;
+		}
+
 		/// <summary>
 		/// Resolves a type name supplied on the command line to a single type definition.
 		/// <para>
--- a/ILSpy.Desktop.slnf
+++ b/ILSpy.Desktop.slnf
@ -5,6 +5,7 @@
				@@ -5,6 +5,7 @@
 			"ICSharpCode.BamlDecompiler\\ICSharpCode.BamlDecompiler.csproj",
 			"ICSharpCode.Decompiler.TestRunner\\ICSharpCode.Decompiler.TestRunner.csproj",
 			"ICSharpCode.Decompiler.Tests\\ICSharpCode.Decompiler.Tests.csproj",
+			"ICSharpCode.ILSpyCmd.Tests\\ICSharpCode.ILSpyCmd.Tests.csproj",
 			"ICSharpCode.Decompiler\\ICSharpCode.Decompiler.csproj",
 			"ICSharpCode.ILSpyX\\ICSharpCode.ILSpyX.csproj",
 			"ILSpy.BamlDecompiler.Tests\\ILSpy.BamlDecompiler.Tests.csproj",
--- a/ILSpy.XPlat.slnf
+++ b/ILSpy.XPlat.slnf
@ -3,6 +3,7 @@
				@@ -3,6 +3,7 @@
 		"path": "ILSpy.sln",
 		"projects": [
 			"ICSharpCode.ILSpyCmd\\ICSharpCode.ILSpyCmd.csproj",
+			"ICSharpCode.ILSpyCmd.Tests\\ICSharpCode.ILSpyCmd.Tests.csproj",
 			"ICSharpCode.Decompiler.PowerShell\\ICSharpCode.Decompiler.PowerShell.csproj",
 			"ICSharpCode.Decompiler.TestRunner\\ICSharpCode.Decompiler.TestRunner.csproj",
 			"ICSharpCode.Decompiler.Tests\\ICSharpCode.Decompiler.Tests.csproj",
--- a/ILSpy.sln
+++ b/ILSpy.sln
@ -49,6 +49,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ILSpy.BamlDecompiler.Tests"
				@@ -49,6 +49,8 @@ Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ILSpy.BamlDecompiler.Tests"
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ILSpy.BamlDecompiler.Tests.Windows", "ILSpy.BamlDecompiler.Tests.Windows\ILSpy.BamlDecompiler.Tests.Windows.csproj", "{7A5C3CEF-0744-4643-BA1E-7AE6610FF269}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "ICSharpCode.ILSpyCmd.Tests", "ICSharpCode.ILSpyCmd.Tests\ICSharpCode.ILSpyCmd.Tests.csproj", "{042FE5F2-3C0A-4B99-A268-D1917CC67B47}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@ -239,6 +241,18 @@ Global
				@@ -239,6 +241,18 @@ Global
 		{7A5C3CEF-0744-4643-BA1E-7AE6610FF269}.Release|x64.Build.0 = Release|Any CPU
 		{7A5C3CEF-0744-4643-BA1E-7AE6610FF269}.Release|x86.ActiveCfg = Release|Any CPU
 		{7A5C3CEF-0744-4643-BA1E-7AE6610FF269}.Release|x86.Build.0 = Release|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Debug|x64.ActiveCfg = Debug|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Debug|x64.Build.0 = Debug|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Debug|x86.ActiveCfg = Debug|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Debug|x86.Build.0 = Debug|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Release|Any CPU.Build.0 = Release|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Release|x64.ActiveCfg = Release|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Release|x64.Build.0 = Release|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Release|x86.ActiveCfg = Release|Any CPU
+		{042FE5F2-3C0A-4B99-A268-D1917CC67B47}.Release|x86.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE