bandolier-template/static/djenterator/command.js

// you may not need all of these but they come up a lot
import fs from "fs";
import assert from "assert";
import logging from '../lib/logging.js';
import glob from "fast-glob";
import path from "path";
import template from "lodash/template.js";

const log = logging.create(import.meta.url);

export const description = "Describe your command here."

// your command uses the npm package commander's options format
export const options = [
  ["--input <string>", "A string option with a default.", "default.json"],
  ["--min <number>", "A number option, no default."],
]

// example of a positional argument, it's the 1st argument to main
export const argument = ["source", "source directory"];

// put required options in the required variable
export const required = [
  ["--output <string>", "Save to file rather than stdout."],
]

// handy function for checking things are good and aborting
const check = (test, fail_message) => {
  if(!test) {
    log.error(fail_message);
    process.exit(1);
  }
}

/*
  + FOOTGUN: commander tries to be "fancy" and if you don't have
   an `arguments` setting for positional arguments then you
   have to change this to `(opts)` instead of `(arg, opts)`.
   The reason is if your command doesn't have an argument, then
   commander will call your main with only opts, and if it does
   then it calls your main with arg, and opts.  If you get weird
   errors and `opts` looks like a `Command` object then this is
   what happened.
 */
export const main = async (arg, opts) => {
  // if they give an numeric option this is how you can convert it
  // yes, this is annoying and commander should handle it but oh well
  if(opts.min !== undefined) {
    // commander doesn't do integer conversions sadly
    opts.min = parseInt(opts.min, 10);
    check(!isNaN(opts.min), "--min must be a number");
  }

  // it's easier to debug options with console
  console.log("OPTIONS", opts, "ARG", arg);

  // due to how async/await works it's just easier to manually exit with exit codes
  process.exit(0);
}