TypeError: Cannot read property 'trim' of undefined

[ljubic]

I wanted to check this library out, but after using the example code you provided I am getting the following error:
TypeError: Cannot read property 'trim' of undefined

I have node v10 installed and using it on MacOS Mojave.

[sindresorhus]

Are you running the latest v10 version? If not I would try upgrading to the latest first.

[ljubic]

Yes, I have v10.12.0 installed.

[sindresorhus]

Hmm, it must be failing at

ps-list/index.js

Line 36 in 45a45d8

const val = line.slice(pid.length + 1).trim();

Can you add console.log(stdout); on line 32 and share the output?

[ljubic]

I already tried that, and stdout is undefined.

[ljubic]

However, when I log the definition of stdout on line before it I get printed processes list:

console.log(await execFile('ps', [flags, `pid,${cmd}`], {maxBuffer: TEN_MEGABYTES}));

but for some reason is the:

{stdout} = await execFile('ps', [flags, `pid,${cmd}`], {maxBuffer: TEN_MEGABYTES});

undefined.

[ljubic]

I tested with removing brackets around stdout and now it works:

const stdout = await execFile('ps', [flags, `pid,${cmd}`], {maxBuffer: TEN_MEGABYTES});

[ljubic]

@sindresorhus Can I make the pull request for this? Want to make my first open source contribution. Can you just test it on Windows so I can know whether the corresponding windows function should be changed as well? Looking at previous commits, I would assume yes :)

[sindresorhus]

Are you sure you're actually running the correct version? Try console logging process.versions.

From Node.js docs:

If this method is invoked as its util.promisify()ed version, it returns a Promise for an Object with stdout and stderr properties. In case of an error (including any error resulting in an exit code other than 0), a rejected promise is returned, with the same error object given in the callback, but with an additional two properties stdout and stderr. - https://nodejs.org/dist/latest-v10.x/docs/api/child_process.html#child_process_child_process_execfile_file_args_options_callback

[ljubic]

Executing

  const { execFile } = require('child_process');
      const child = execFile('node', ['--version'], (error, stdout, stderr) => {
        if (error) {
          throw error;
        }
        console.log("version", stdout);
      });

gives the same node version v10.12.0 .

[ljubic]

const util = require('util');
const execFile = util.promisify(require('child_process').execFile);
async function getVersion() {
  const { stdout } = await execFile('node', ['--version']);
  console.log(stdout);
}
getVersion();

stdout in this one is undefined.

[sindresorhus]

Definitely something weird with your Node.js version as the above example runs fine for me on v10.12.0.

[ljubic]

I am using this boilerplate for electron app:
https://github.com/electron-react-boilerplate/electron-react-boilerplate

Could there in project settings be some defined option to use other node version? I see in travis.yml file that they specified node_js version 9, but I am not sure whether that have influence on it.

[sindresorhus]

So when you run the snippet, you run it in Electron and not pure Node.js? If so, it could be an Electron bug.

[ljubic]

Yes, in Electron. I put that piece of code in main function.

[ljubic]

@sindresorhus could the problem be that this boilerplate is using Electron 2.0.6? Electron 2.0.0 uses Node 8.6 and in Version they switch to v10.2.0.

[sindresorhus]

Could be, yes.

[ljubic]

@sindresorhus is there any way to check whether the process has opened (not active) window? I am also using your active-win package, but need to get list of opened windows :)

[sindresorhus]

Maybe https://github.com/sentialx/node-window-manager