From 618d92fd66cff8e2e6e067f561de188e17566e1d Mon Sep 17 00:00:00 2001
From: Om Singhal <wengsinghal@gmail.com>
Date: Fri, 16 Oct 2026 18:24:38 -0400
Subject: [PATCH] fix: list Node 24 processes in the attach picker on Linux

Node 24 names its main thread "MainThread", and on Linux ps reports that
name in the comm column, so the process picker filtered the process out.

procps also heads the comm column "COMMAND", so the parser split each line
at comm and never compared it with the command line. Split at the last
"COMMAND" header instead, and fall back to argv[0] when comm does not
appear in the command line.

Also use argv[0] when comm contains whitespace. Such a comm is a process
title, not a binary name: pm2 sets the title to "node <script>", and
searching for it would swallow the whole command line and hide the app.
---
 src/ui/processTree/darwinProcessTree.ts |  3 +-
 src/ui/processTree/posixProcessTree.ts  | 11 ++--
 src/ui/processTree/processTree.test.ts  | 73 +++++++++++++++++++++++++
 3 files changed, 80 insertions(+), 7 deletions(-)

diff --git a/src/ui/processTree/darwinProcessTree.ts b/src/ui/processTree/darwinProcessTree.ts
index 7c9690b39..f41b8b058 100644
--- a/src/ui/processTree/darwinProcessTree.ts
+++ b/src/ui/processTree/darwinProcessTree.ts
@@ -63,7 +63,8 @@ export class DarwinProcessTree extends BaseProcessTree {
     let commandOffset: number | void;
     return line => {
       if (!commandOffset) {
-        commandOffset = line.indexOf('COMMAND');
+        // procps on Linux also labels the comm column COMMAND, so use the last one.
+        commandOffset = line.lastIndexOf('COMMAND');
         return;
       }
 
diff --git a/src/ui/processTree/posixProcessTree.ts b/src/ui/processTree/posixProcessTree.ts
index ba536d851..99a4d401c 100644
--- a/src/ui/processTree/posixProcessTree.ts
+++ b/src/ui/processTree/posixProcessTree.ts
@@ -24,12 +24,11 @@ export class PosixProcessTree extends DarwinProcessTree {
         return;
       }
 
-      let pos = process.args.indexOf(process.command);
-      if (pos === -1) {
-        return process;
-      }
-
-      pos = pos + process.command.length;
+      // comm is the name of the main thread, which is not always the binary:
+      // Node 24 renames it to "MainThread", and a title with spaces (pm2 sets
+      // "node <script>") is not a binary name. Fall back to argv[0] then.
+      let pos = /\s/.test(process.command) ? -1 : process.args.indexOf(process.command);
+      pos = pos === -1 ? 0 : pos + process.command.length;
       while (pos < process.args.length) {
         if (process.args[pos] === ' ') {
           break;
diff --git a/src/ui/processTree/processTree.test.ts b/src/ui/processTree/processTree.test.ts
index 00c72662c..ee7497db0 100644
--- a/src/ui/processTree/processTree.test.ts
+++ b/src/ui/processTree/processTree.test.ts
@@ -3,6 +3,9 @@
  *--------------------------------------------------------*/
 
 import { expect } from 'chai';
+import { promises as fsPromises } from 'fs';
+import { LocalFsUtils } from '../../common/fsUtils';
+import { PosixProcessTree } from './posixProcessTree';
 import { analyseArguments } from './processTree';
 
 describe('process tree', () => {
@@ -36,4 +39,74 @@ describe('process tree', () => {
       });
     }
   });
+
+  describe('posix ps output', () => {
+    class TestPosixProcessTree extends PosixProcessTree {
+      public parse(lines: string[]) {
+        const parser = this.createParser();
+        return lines.map(parser).filter(p => !!p);
+      }
+    }
+
+    // procps labels both the comm and command columns COMMAND, right aligns
+    // the ids, and pads comm to the 30 columns that PosixProcessTree asks for.
+    const row = (pid: string, ppid: string, comm: string, command: string) =>
+      `${pid.padStart(7)} ${ppid.padStart(7)} ${comm.padEnd(30)} ${command}`;
+
+    const tt = [
+      {
+        name: 'node',
+        comm: 'node',
+        input: '/usr/bin/node /app/server.js',
+        command: '/usr/bin/node',
+        args: '/app/server.js',
+      },
+      {
+        name: 'node 24, whose main thread is named MainThread',
+        comm: 'MainThread',
+        input: 'node /app/server.js',
+        command: 'node',
+        args: '/app/server.js',
+      },
+      {
+        name: 'node 24 without arguments',
+        comm: 'MainThread',
+        input: 'node',
+        command: 'node',
+        args: '',
+      },
+      {
+        name: 'node 25, whose main thread is named node-MainThread',
+        comm: 'node-MainThread',
+        input: '/usr/local/bin/node /app/server.js',
+        command: '/usr/local/bin/node',
+        args: '/app/server.js',
+      },
+      {
+        name: 'a pm2 app, whose title is "node <script>"',
+        comm: 'node /home/me/a',
+        input: 'node /home/me/app/server.js',
+        command: 'node',
+        args: '/home/me/app/server.js',
+      },
+      {
+        name: 'a process that set its title',
+        comm: 'my-long-server-',
+        input: 'my-long-server-name',
+        command: 'my-long-server-name',
+        args: '',
+      },
+    ];
+
+    for (const t of tt) {
+      it(`should parse ${t.name}`, () => {
+        const tree = new TestPosixProcessTree(new LocalFsUtils(fsPromises));
+        const parsed = tree.parse([
+          row('PID', 'PPID', 'COMMAND', 'COMMAND'),
+          row('4242', '1', t.comm, t.input),
+        ]);
+        expect(parsed).to.deep.equal([{ pid: 4242, ppid: 1, command: t.command, args: t.args }]);
+      });
+    }
+  });
 });