build

#!/usr/bin/env node

const async = require('async');
const path = require('path');
const yargs = require('yargs');
const ParseComments = require('parse-comments');
const showdown = require('showdown');
const fs = require('fs');
const glob = require('glob');
const _ = require('lodash');

const argv = yargs
  .option('allRules', {
    alias: 'a',
    default: false
  })
  .option('outputPath', {
    alias: 'o',
    default: __dirname + '/rules.json'
  })
  .argv;

const files = glob.sync(__dirname + '/src/rules/*.js');

const parseComments = new ParseComments();

const converter = new showdown.Converter();
showdown.setFlavor('github');

async.reduce(files, [], (rules, file, callback) => {

  fs.readFile(file, 'utf8', (err, data) => {
    if (err) return callback(err);

    const parsed = parseComments.parse(data)[0];

    // strip the opening comment and remove extra newlines
    const code = data.split('\n').slice(parsed.loc.end.line).join('\n').trim();

    const ruleTags = {};
    parsed.tags.forEach((tag) => ruleTags[tag.title] = tag.description);

    if (argv.allRules || ruleTags.gallery === 'true') {
      const ruleExample = parsed.examples.reduce((prev, curr) => "\n\n" + curr.description + "\n<pre><code>" + curr.value + "</code></pre>" + prev, "");
      const ruleDescription = converter.makeHtml(parsed.description + ruleExample);

      if (!ruleDescription) {
        return callback(new Error(`Blank description for ${file}`));
      }

      const rule = {
        id: path.basename(file).replace('.js', ''),
        title: ruleTags.title,
        overview: ruleTags.overview,
        categories: ruleTags.category ? ruleTags.category.split(',') : ['default'],
        description: ruleDescription,
        code
      };
      rules.push(rule);
    }

    return callback(null, rules);
  });
}, (err, rules) => {
  if (err) {
    console.log(err.stack);
    process.exit(1);
  }

  const expandedRules = _.chain(rules)
    .flatMap(rule => _.map(rule.categories, category => _.assign(_.clone(rule), { category })))
    .groupBy(r => r.category)
    .map((rules, category) => ({
      name: category,
      templates: _.map(rules, rule => _.omit(rule, 'category'))
    }))
    .value();

  console.log(`rules written to ${argv.outputPath}`);
  fs.writeFileSync(argv.outputPath, JSON.stringify(expandedRules, null, 2));
  process.exit(0);
});