app exec alias support

dotnet/CLI.md

@@ -166,6 +166,10 @@ Before launching the server or writing the archive, `mcpb pack` now validates th
 
 If any of these files are missing, packing fails immediately with an error like `Missing icon file: icon.png`. This happens before dynamic capability discovery so you get fast feedback on manifest inaccuracies.
 
+On Windows, `.exe` entry points or path-like commands can be satisfied by [App Execution Aliases](https://learn.microsoft.com/windows/apps/desktop/modernize/desktop-to-uwp-extensions). When a referenced `.exe` is not present under your extension directory, the CLI automatically checks `%LOCALAPPDATA%\Microsoft\WindowsApps` (the folder where aliases surface). To point discovery/validation at custom alias locations—or to simulate aliases in CI—set `MCPB_WINDOWS_APP_ALIAS_DIRS` to a path-separated list of directories.
+
+When discovery launches your server it resolves the executable using the same logic, so an alias that passes validation is the exact binary that will be executed.
+
 Commands (e.g. `node`, `python`) that are not path-like are not validated—they are treated as executables resolved by the environment.
 
 Examples:

dotnet/mcpb.Tests/CliPackFileValidationTests.cs

@@ -1,20 +1,28 @@
-using System.Text.Json;
-using Xunit;
+using System;
 using System.IO;
+using System.Text.Json;
 using Mcpb.Json;
+using Xunit;
 
 namespace Mcpb.Tests;
 
 public class CliPackFileValidationTests
 {
     private string CreateTempDir()
     {
-        var dir = Path.Combine(Path.GetTempPath(), "mcpb_cli_pack_files_" + Guid.NewGuid().ToString("N"));
+        var dir = Path.Combine(
+            Path.GetTempPath(),
+            "mcpb_cli_pack_files_" + Guid.NewGuid().ToString("N")
+        );
         Directory.CreateDirectory(dir);
         Directory.CreateDirectory(Path.Combine(dir, "server"));
         return dir;
     }
-    private (int exitCode, string stdout, string stderr) InvokeCli(string workingDir, params string[] args)
+
+    private (int exitCode, string stdout, string stderr) InvokeCli(
+        string workingDir,
+        params string[] args
+    )
     {
         var root = Mcpb.Commands.CliRoot.Build();
         var prev = Directory.GetCurrentDirectory();
@@ -26,23 +34,31 @@ private string CreateTempDir()
             var code = CommandRunner.Invoke(root, args, swOut, swErr);
             return (code, swOut.ToString(), swErr.ToString());
         }
-        finally { Directory.SetCurrentDirectory(prev); }
+        finally
+        {
+            Directory.SetCurrentDirectory(prev);
+        }
     }
 
-    private Mcpb.Core.McpbManifest BaseManifest() => new Mcpb.Core.McpbManifest
-    {
-        Name = "demo",
-        Description = "desc",
-        Author = new Mcpb.Core.McpbManifestAuthor { Name = "A" },
-        Icon = "icon.png",
-        Screenshots = new List<string> { "shots/s1.png" },
-        Server = new Mcpb.Core.McpbManifestServer
+    private Mcpb.Core.McpbManifest BaseManifest() =>
+        new Mcpb.Core.McpbManifest
         {
-            Type = "node",
-            EntryPoint = "server/index.js",
-            McpConfig = new Mcpb.Core.McpServerConfigWithOverrides { Command = "node", Args = new List<string> { "${__dirname}/server/index.js" } }
-        }
-    };
+            Name = "demo",
+            Description = "desc",
+            Author = new Mcpb.Core.McpbManifestAuthor { Name = "A" },
+            Icon = "icon.png",
+            Screenshots = new List<string> { "shots/s1.png" },
+            Server = new Mcpb.Core.McpbManifestServer
+            {
+                Type = "node",
+                EntryPoint = "server/index.js",
+                McpConfig = new Mcpb.Core.McpServerConfigWithOverrides
+                {
+                    Command = "node",
+                    Args = new List<string> { "${__dirname}/server/index.js" },
+                },
+            },
+        };
 
     [Fact]
     public void Pack_MissingIcon_Fails()
@@ -52,7 +68,10 @@ public void Pack_MissingIcon_Fails()
         Directory.CreateDirectory(Path.Combine(dir, "shots"));
         File.WriteAllText(Path.Combine(dir, "shots", "s1.png"), "fake");
         var manifest = BaseManifest();
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, _, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.NotEqual(0, code);
         Assert.Contains("Missing icon file", stderr);
@@ -66,7 +85,10 @@ public void Pack_MissingEntryPoint_Fails()
         Directory.CreateDirectory(Path.Combine(dir, "shots"));
         File.WriteAllText(Path.Combine(dir, "shots", "s1.png"), "fake");
         var manifest = BaseManifest();
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, _, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.NotEqual(0, code);
         Assert.Contains("Missing entry_point file", stderr);
@@ -79,7 +101,10 @@ public void Pack_MissingScreenshot_Fails()
         File.WriteAllText(Path.Combine(dir, "icon.png"), "fake");
         File.WriteAllText(Path.Combine(dir, "server", "index.js"), "// js");
         var manifest = BaseManifest();
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, _, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.NotEqual(0, code);
         Assert.Contains("Missing screenshot file", stderr);
@@ -96,12 +121,103 @@ public void Pack_PathLikeCommandMissing_Fails()
         var manifest = BaseManifest();
         // Make command path-like to trigger validation
         manifest.Server.McpConfig.Command = "${__dirname}/server/missing.js";
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, _, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.NotEqual(0, code);
         Assert.Contains("Missing server.command file", stderr);
     }
 
+    [Fact]
+    public void Pack_CommandWindowsAlias_Succeeds()
+    {
+        var aliasDir = Path.Combine(
+            Path.GetTempPath(),
+            "mcpb_windows_alias_" + Guid.NewGuid().ToString("N")
+        );
+        Directory.CreateDirectory(aliasDir);
+        var aliasName = "alias-command.exe";
+        File.WriteAllText(Path.Combine(aliasDir, aliasName), "alias");
+        var previousAliases = Environment.GetEnvironmentVariable("MCPB_WINDOWS_APP_ALIAS_DIRS");
+        Environment.SetEnvironmentVariable("MCPB_WINDOWS_APP_ALIAS_DIRS", aliasDir);
+        try
+        {
+            var dir = CreateTempDir();
+            File.WriteAllText(Path.Combine(dir, "icon.png"), "fake");
+            File.WriteAllText(Path.Combine(dir, "server", "index.js"), "// js");
+            Directory.CreateDirectory(Path.Combine(dir, "shots"));
+            File.WriteAllText(Path.Combine(dir, "shots", "s1.png"), "fake");
+            var manifest = BaseManifest();
+            manifest.Server.McpConfig.Command = aliasName;
+            File.WriteAllText(
+                Path.Combine(dir, "manifest.json"),
+                JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+            );
+            var (code, stdout, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
+            Assert.Equal(0, code);
+            Assert.Contains("demo@", stdout);
+            Assert.DoesNotContain("Missing server.command", stderr);
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable("MCPB_WINDOWS_APP_ALIAS_DIRS", previousAliases);
+            try
+            {
+                Directory.Delete(aliasDir, true);
+            }
+            catch
+            {
+                // Ignore cleanup failures in tests
+            }
+        }
+    }
+
+    [Fact]
+    public void Pack_EntryPointWindowsAlias_Succeeds()
+    {
+        var aliasDir = Path.Combine(
+            Path.GetTempPath(),
+            "mcpb_windows_alias_" + Guid.NewGuid().ToString("N")
+        );
+        Directory.CreateDirectory(aliasDir);
+        var aliasName = "alias-entry.exe";
+        File.WriteAllText(Path.Combine(aliasDir, aliasName), "alias");
+        var previousAliases = Environment.GetEnvironmentVariable("MCPB_WINDOWS_APP_ALIAS_DIRS");
+        Environment.SetEnvironmentVariable("MCPB_WINDOWS_APP_ALIAS_DIRS", aliasDir);
+        try
+        {
+            var dir = CreateTempDir();
+            File.WriteAllText(Path.Combine(dir, "icon.png"), "fake");
+            File.WriteAllText(Path.Combine(dir, "server", "index.js"), "// js");
+            Directory.CreateDirectory(Path.Combine(dir, "shots"));
+            File.WriteAllText(Path.Combine(dir, "shots", "s1.png"), "fake");
+            var manifest = BaseManifest();
+            manifest.Server.EntryPoint = aliasName;
+            File.WriteAllText(
+                Path.Combine(dir, "manifest.json"),
+                JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+            );
+            var (code, stdout, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
+            Assert.Equal(0, code);
+            Assert.Contains("demo@", stdout);
+            Assert.DoesNotContain("Missing entry_point", stderr);
+        }
+        finally
+        {
+            Environment.SetEnvironmentVariable("MCPB_WINDOWS_APP_ALIAS_DIRS", previousAliases);
+            try
+            {
+                Directory.Delete(aliasDir, true);
+            }
+            catch
+            {
+                // Ignore cleanup failures in tests
+            }
+        }
+    }
+
     [Fact]
     public void Pack_AllFilesPresent_Succeeds()
     {
@@ -112,7 +228,10 @@ public void Pack_AllFilesPresent_Succeeds()
         File.WriteAllText(Path.Combine(dir, "shots", "s1.png"), "fake");
         var manifest = BaseManifest();
         // Ensure command not path-like (node) so validation doesn't require it to exist as file
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, stdout, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.Equal(0, code);
         Assert.Contains("demo@", stdout);
@@ -129,9 +248,12 @@ public void Pack_MissingIconsFile_Fails()
         manifest.ManifestVersion = "0.3";
         manifest.Icons = new List<Mcpb.Core.McpbManifestIcon>
         {
-            new() { Src = "icon-16.png", Size = "16x16" }
+            new() { Src = "icon-16.png", Size = "16x16" },
         };
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, _, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.NotEqual(0, code);
         Assert.Contains("Missing icons[0] file", stderr);
@@ -149,9 +271,12 @@ public void Pack_IconsFilePresent_Succeeds()
         manifest.Screenshots = null; // Remove screenshots requirement for this test
         manifest.Icons = new List<Mcpb.Core.McpbManifestIcon>
         {
-            new() { Src = "icon-16.png", Size = "16x16" }
+            new() { Src = "icon-16.png", Size = "16x16" },
         };
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, stdout, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.True(code == 0, $"Pack failed with code {code}. Stderr: {stderr}");
         Assert.Contains("demo@", stdout);
@@ -168,9 +293,12 @@ public void Pack_MissingLocalizationResources_Fails()
         manifest.Localization = new Mcpb.Core.McpbManifestLocalization
         {
             Resources = "locales/${locale}/messages.json",
-            DefaultLocale = "en-US"
+            DefaultLocale = "en-US",
         };
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, _, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.NotEqual(0, code);
         Assert.Contains("Missing localization resources", stderr);
@@ -190,9 +318,12 @@ public void Pack_LocalizationResourcesPresent_Succeeds()
         manifest.Localization = new Mcpb.Core.McpbManifestLocalization
         {
             Resources = "locales/${locale}/messages.json",
-            DefaultLocale = "en-US"
+            DefaultLocale = "en-US",
         };
-        File.WriteAllText(Path.Combine(dir, "manifest.json"), JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions));
+        File.WriteAllText(
+            Path.Combine(dir, "manifest.json"),
+            JsonSerializer.Serialize(manifest, McpbJsonContext.WriteOptions)
+        );
         var (code, stdout, stderr) = InvokeCli(dir, "pack", dir, "--no-discover");
         Assert.True(code == 0, $"Pack failed with code {code}. Stderr: {stderr}");
         Assert.Contains("demo@", stdout);