Please export `utils/formatCmd` to make patching the log function less hacky.

[jessekrubin]

Why does the log function default to writing to stderr?

Using a custom log function isn't hard, but my ezpz version just involved me copy-pasta-ing your formatCmd function.

IMO the formatCmd function (as well as most of the things in utils) should be exported publicly.

Is there a recommended way of piping a process' stderr to stderr, BUT piping/writing everything else to stdout?

Thanks!

PS: I really do want to know the rational behind pumping all the process related stuff to stderr. (not trying to be a nuni)

[antonmedv]

I don't what to export all utils, as this is internal things and I want them to change without introducing breaking changes.

But for formatCmd probably we can export it somehow. Please, show an example of your log function.

PS: I really do want to know the rational behind pumping all the process related stuff to stderr.

Stderr usually used for debugging purposes. And stdout for data passing. Consider zx script.js | some-cmd.

[jessekrubin]

@antonmedv My log function (which is p similar to your/zx's log function is below.

It seems weird to me that stderr is the default destination for most outputs. Personally I would almost want just errors from my processes to go to stderr.

Any which way zx is still very good.

export function log(entry) {
  switch (entry.kind) {
    case 'cmd':
      if (!entry.verbose) return;
      process.stdout.write(`\n>$ ${entry.cmd}\n`);
      break;
    case 'stdout':
      if (!entry.verbose) return;
      process.stdout.write(entry.data);
      break;
    case 'stderr':
      if (!entry.verbose) return;
      process.stderr.write(entry.data);
      break;
    case 'cd':
      if (!$.verbose) return;
      process.stdout.write('$ ' + chalk.greenBright('cd') + ` ${entry.dir}\n`);
      break;
    case 'fetch':
      if (!$.verbose) return;
      const init = entry.init ? ' ' + inspect(entry.init) : '';
      process.stdout.write(
        '$ ' + chalk.greenBright('fetch') + ` ${entry.url}${init}\n`,
      );
      break;
    case 'retry':
      if (!$.verbose) return;
      process.stdout.write(entry.error + '\n');
  }
}

$.log = log;

[antonmedv]

One of the reasons is what output of zx script will change if —quiet flag is passed.

So to make sure some cmd are used to pront data should use:

await $’cmd’.pipe(process.stdout)