fix: flush CLI stdio before forced exit

src/cli-metadata.ts

@@ -1,5 +1,6 @@
 import { spawn } from 'node:child_process';
 import fs from 'node:fs/promises';
+import path from 'node:path';
 import type { ServerDefinition, ServerSource } from './config.js';
 
 export type CliArtifactKind = 'template' | 'bundle' | 'binary';
@@ -98,7 +99,8 @@ export async function readCliMetadata(artifactPath: string): Promise<CliArtifact
 
 async function readMetadataFromCli(artifactPath: string): Promise<CliArtifactMetadata> {
   return await new Promise<CliArtifactMetadata>((resolve, reject) => {
-    const child = spawn(artifactPath, ['__mcporter_inspect'], {
+    const inspectCommand = resolveMetadataInspectCommand(artifactPath);
+    const child = spawn(inspectCommand.command, inspectCommand.args, {
       stdio: ['ignore', 'pipe', 'pipe'],
     });
     let stdout = '';
@@ -139,6 +141,18 @@ async function readMetadataFromCli(artifactPath: string): Promise<CliArtifactMet
   });
 }
 
+function resolveMetadataInspectCommand(artifactPath: string): { readonly command: string; readonly args: string[] } {
+  if (process.platform === 'win32' && shouldRunArtifactWithNode(artifactPath)) {
+    return { command: process.execPath, args: [artifactPath, '__mcporter_inspect'] };
+  }
+  return { command: artifactPath, args: ['__mcporter_inspect'] };
+}
+
+function shouldRunArtifactWithNode(artifactPath: string): boolean {
+  const extension = path.extname(artifactPath).toLowerCase();
+  return extension === '' || extension === '.js' || extension === '.mjs' || extension === '.cjs' || extension === '.ts';
+}
+
 function isErrno(error: unknown, code: string): error is NodeJS.ErrnoException {
   return Boolean(error && typeof error === 'object' && (error as NodeJS.ErrnoException).code === code);
 }

tests/cli-metadata.test.ts

@@ -1,7 +1,7 @@
 import fs from 'node:fs/promises';
 import os from 'node:os';
 import path from 'node:path';
-import { describe, expect, it } from 'vitest';
+import { describe, expect, it, vi } from 'vitest';
 import { metadataPathForArtifact, readCliMetadata } from '../src/cli-metadata.js';
 
 describe('readCliMetadata', () => {
@@ -22,6 +22,28 @@ describe('readCliMetadata', () => {
       server: { name: 'embedded' },
     });
   });
+
+  it('reads embedded metadata from extensionless JavaScript artifacts on Windows', async () => {
+    const platformSpy = vi.spyOn(process, 'platform', 'get').mockReturnValue('win32');
+    try {
+      const tempDir = await fs.mkdtemp(path.join(os.tmpdir(), 'mcporter-metadata-win-'));
+      const artifact = path.join(tempDir, 'artifact');
+      const embedded = metadataPayload('embedded');
+      const sidecar = metadataPayload('sidecar');
+      await fs.writeFile(
+        artifact,
+        `#!/usr/bin/env node\nconsole.log(${JSON.stringify(JSON.stringify(embedded))});\n`,
+        'utf8'
+      );
+      await fs.writeFile(metadataPathForArtifact(artifact), JSON.stringify(sidecar), 'utf8');
+
+      await expect(readCliMetadata(artifact)).resolves.toMatchObject({
+        server: { name: 'embedded' },
+      });
+    } finally {
+      platformSpy.mockRestore();
+    }
+  });
 });
 
 function metadataPayload(name: string) {