Commander.js: Have in-house support in-order to recommend matching commands

Created on 11 Aug 2019 · 15Comments · Source: tj/commander.js

yargs comes shipped with a recommendCommands() method as part of the public API. It would be great if commander.js would have it as well :clap:

program
  .name('sample')
  .usage('<command>)
  .version(version)
  .recommendCommands();

program
  .command('init')
  .action(() => {});

program
  .command('create');
  .action(() => {});

sample creat

Unknown command creat.
Did you mean create?

enhancement

Source

jamesgeorge007

👀1

Most helpful comment

Only for me, I think it's not necessary. People can realize it by

program.command("*").action(cmd => {
  suggestCommand(cmd);
});

And we can find a npm package named didyoumean to customzie suggestCommand(cmd) easily.

I'm not familiar with yargs, it seems that it doesn't have an api to match regex cmd like '*' so it has recommendCommands() to handle this. But commander do.

oGsLP on 14 Aug 2019

👍2

All 15 comments

Only for me, I think it's not necessary. People can realize it by

program.command("*").action(cmd => {
  suggestCommand(cmd);
});

And we can find a npm package named didyoumean to customzie suggestCommand(cmd) easily.

I'm not familiar with yargs, it seems that it doesn't have an api to match regex cmd like '*' so it has recommendCommands() to handle this. But commander do.

oGsLP on 14 Aug 2019

👍2

I do not think it likely I would accept a PR for this currently, as we still have some improvements to make in whether Commander warns about unrecognised commands in the first place. (So not "in-house support".)

I am interested in how a user might add possible matches, and currently that would be in their own code or in an add-on package. Also interested in how popular an idea this is, so feel free to leave this issue open even if you decide not to investigate yourself.

My limited knowledge (not researched) is most computer programs use the Levenshtein distance algorithm. I was casually looking at didyoumean and didyoumean2 in weekend. (Using these as examples rather than recommendations.)

(Both roll-your-own solutions and didyoumean also suggested by @oGsLP, thanks for comment )

shadowspawn on 14 Aug 2019

I came across an implementation in comments: https://github.com/tj/commander.js/issues/432#issuecomment-175785162

shadowspawn on 18 Aug 2019

👍1

@shadowspawn what about documenting how to achieve it with didyoumean.
I would happily submit a PR :+1:

jamesgeorge007 on 27 Sep 2019

Same feedback as building it in, I do not think it likely I would accept a PR for this currently. If the code is not huge, you could simply add it as a comment here though.

shadowspawn on 28 Sep 2019

A typical implementaion would be:-

const didYouMean = require('didyoumean');

const suggestCommands = cmd => {
  const availableCommands = program.commands.map(c => c._name);

  const suggestion = didYouMean(cmd, availableCommands);
  if (suggestion) {
    console.log(`Did you mean ${suggestion}?`));
  }
};

program.arguments('<command>').action(cmd => {
  program.outputHelp();
  console.log(`Unknown command ${cmd}.`));
  console.log();
  suggestCommands(cmd);
});

jamesgeorge007 on 29 Sep 2019

I have opened a PR to use didYouMean in the README as the example for an unrecognised command #1176

shadowspawn on 7 Feb 2020

https://github.com/tj/commander.js/pull/1176/files#r376756601