copilot/scripts/format

#!/usr/bin/env node

const { config } = require('../package.json');
const { exists } = require('mz/fs');
const sgf = require('staged-git-files');
const forceArray = require('force-array');
const awaitify = require('apr-awaitify');
const asyncFilter = require('apr-filter');
const execa = require('execa');
const globby = require('globby');
const main = require('apr-main');
const argv = require('yargs').argv;
const path = require('path');
const fs = require('fs');

const getStaged = awaitify(sgf);

const ROOT = path.join(__dirname, '../');
const SCRIPTS = path.resolve(__dirname);

const optOut = forceArray(config['fmt-opt-out']).map(pkg =>
  path.join(ROOT, `packages/${pkg}`)
);

const statuses = ['Added', 'Modified'];

const filter = (files = []) =>
  files
    .filter(file => !/node_modules/.test(file))
    .map(file => path.resolve(ROOT, file))
    .filter(file => !optOut.some(pkg => file.indexOf(pkg) === 0));

const run = async (files = []) => {
  const filteredFiles = filter(files);

  if (!filteredFiles.length) {
    return;
  }

  const cp = execa(
    'prettier',
    ['--write', '--single-quote'].concat(filter(files))
  );

  cp.stdout.pipe(process.stdout);
  cp.stderr.pipe(process.stderr);

  return cp;
};

const all = async () => {
  const files = await globby(['packages/**/*.js', 'scripts/*'], {
    cwd: path.join(__dirname, '..')
  });

  return run(files);
};

const staged = async () => {
  const files = (await getStaged())
    .filter(({ status }) => statuses.indexOf(status) >= 0)
    .map(({ filename }) => filename)
    .map(filename => path.resolve(ROOT, filename))
    .filter(
      filename => /\.js$/.test(filename) || filename.indexOf(SCRIPTS) === 0
    );

  const existing = await asyncFilter(files, exists);

  if (!existing.length) {
    return;
  }

  return run(existing);
};

main(argv._.length ? run(argv._) : argv.staged ? staged() : all());