fix: flush process output before completion

src/terminal-manager.ts

@@ -336,9 +336,10 @@ export class TerminalManager {
         });
       }, timeoutMs);
 
-      childProcess.on('exit', (code: any) => {
+      childProcess.on('close', (code: any) => {
         if (childProcess.pid) {
-          // Store completed session before removing active session
+          // Store completed session only after stdio closes, so fast-exiting
+          // processes do not lose stdout/stderr that arrives after exit.
           this.completedSessions.set(childProcess.pid, {
             pid: childProcess.pid,
             outputLines: [...session.outputLines], // Copy line buffer
@@ -626,4 +627,4 @@ export class TerminalManager {
   }
 }
 
-export const terminalManager = new TerminalManager();
+export const terminalManager = new TerminalManager();

test/test-process-output-close.js

@@ -0,0 +1,79 @@
+import assert from 'assert';
+import fs from 'fs/promises';
+import os from 'os';
+import path from 'path';
+import { pathToFileURL } from 'url';
+
+import { terminalManager } from '../dist/terminal-manager.js';
+
+const TEST_DIR_PREFIX = path.join(os.tmpdir(), 'desktop-commander-process-output-close-');
+
+function quoteForShell(value) {
+  return `"${value.replace(/"/g, '\\"')}"`;
+}
+
+async function setup() {
+  const testDir = await fs.mkdtemp(TEST_DIR_PREFIX);
+  const scriptPath = path.join(testDir, 'fast-stderr.mjs');
+  try {
+    await fs.writeFile(
+      scriptPath,
+      [
+        "import fs from 'fs';",
+        "fs.writeSync(2, 'FAST_STDERR_START\\n');",
+        "fs.writeSync(2, 'x'.repeat(256 * 1024));",
+        "fs.writeSync(2, '\\nFAST_STDERR_END\\n');",
+        'process.exit(1);',
+      ].join('\n'),
+    );
+    return { testDir, scriptPath };
+  } catch (error) {
+    await fs.rm(testDir, { recursive: true, force: true });
+    throw error;
+  }
+}
+
+async function teardown(testDir) {
+  await fs.rm(testDir, { recursive: true, force: true });
+}
+
+async function testFastExitStderrIsFlushed(scriptPath) {
+  const command = `${quoteForShell(process.execPath)} ${quoteForShell(scriptPath)}`;
+  const result = await terminalManager.executeCommand(command, 2000);
+
+  assert.strictEqual(result.isBlocked, false, 'Fast-failing process should be marked complete');
+
+  const output = terminalManager.readOutputPaginated(result.pid, 0, 100);
+  assert(output, 'Completed process output should remain readable');
+
+  const text = output.lines.join('\n');
+  assert.strictEqual(output.exitCode, 1, 'Process exit code should be preserved');
+  assert(text.includes('FAST_STDERR_START'), 'stderr start marker should be captured');
+  assert(text.includes('FAST_STDERR_END'), 'stderr end marker should be captured after process exit');
+
+  console.log('✓ fast-exiting process stderr is flushed before completion');
+}
+
+export default async function runTests() {
+  let testDir;
+  try {
+    const fixture = await setup();
+    testDir = fixture.testDir;
+    await testFastExitStderrIsFlushed(fixture.scriptPath);
+    console.log('\n✅ process output close tests passed!');
+    return true;
+  } catch (error) {
+    console.error('❌ process output close test failed:', error instanceof Error ? error.message : String(error));
+    return false;
+  } finally {
+    if (testDir) {
+      await teardown(testDir);
+    }
+  }
+}
+
+if (process.argv[1] && import.meta.url === pathToFileURL(process.argv[1]).href) {
+  runTests().then((ok) => {
+    process.exit(ok ? 0 : 1);
+  });
+}