prettier-package-json/bin/prettier-package-json

#!/usr/bin/env node

const cmdline = require('commander');
const fs = require('fs-extra');
const path = require('path');
const prettier = require('../src');
const { version } = require('../package.json');
const defaults = require('../src/defaultOptions');
const glob = require('glob');

cmdline
    .version(version)
    .arguments('[PATH...]')
    .option('--write', 'Edit the files in-place. (Beware!)')
    .option('--tab-width <int>', `Specify the number of spaces per indentation-level. Defaults to ${defaults.tabWidth}.`, (value) => parseInt(value, 10), defaults.tabWidth)
    .option('--use-tabs', 'Indent lines with tabs instead of spaces.')
    .option('--expand-users', 'Expand author and contributors into objects.')
    .option('--key-order <items>', 'Sort order for keys in package.json', (val) => val.split(','), defaults.keyOrder)
    .option('-l, --list-different', 'Print filenames of files that are different from prettier-package-json formatting.')
    .parse(process.argv);

const globs = cmdline.args.length > 0 ? cmdline.args : [path.join(process.cwd(), 'package.json')];

const files = Promise.all(globs.map(globToPaths)).then((matches) => {
  return matches.reduce((state, match) => [...state, ...match], []);
});

if (cmdline.listDifferent) {
  files.then((paths) => {
    return Promise.all(paths.map((filepath) => check(filepath, cmdline)));
  }).then((details) => {
    details.forEach(({ filepath, isDifferent, error }) => {
      if (error) {
        console.error(error);
      } else if (isDifferent) {
        console.log(filepath);
      }
    });
  });
} else {
  files.then((paths) => {
    return Promise.all(paths.map((filepath) => format(filepath, cmdline)));
  }).then((details) => {
    details.forEach(({ filepath, json, error }) => {
      if (error) {
        console.error(error);
      } else {
        if (cmdline.write) {
          return fs.writeFile(filepath, json);
        } else {
          return console.log(json);
        }
      }
    });
  })
}

function globToPaths(arg) {
  return new Promise((resolve, reject) => {
    glob(arg, (err, files) => err ? reject(err) : resolve(files));
  });
}

function format(filepath, options) {
  return fs.pathExists(filepath).then((exists) => {
    if (exists) {
      return fs.readJson(filepath);
    } else {
      return Promise.reject(`${filepath} doesn't exist`);
    }
  }).then((json) => {
    return prettier.format(json, options);
  }).then((json) => {
    return { filepath, json };
  }).catch((error) => {
    return { filepath, error };
  });
}

function check(filepath, options) {
  return fs.pathExists(filepath).then((exists) => {
    if (exists) {
      return fs.readJson(filepath);
    } else {
      return Promise.reject(`${filepath} doesn't exist`);
    }
  }).then((json) => {
    return prettier.check(json, options);
  }).then((isSame) => {
    return { filepath, isDifferent: !isSame };
  }).catch((error) => {
    return { filepath, error };
  });
}