gulpfile.js

const yargs = require('yargs/yargs')
const { hideBin } = require('yargs/helpers')
const argv = yargs(hideBin(process.argv)).argv;
const { exec } = require('child_process');

const fs = require('fs-extra');
const gulp = require('gulp');
const concat = require('gulp-concat');
const terser = require('gulp-terser');
const mergeStreams = require('merge-stream');
const cleanCSS = require('gulp-clean-css');
const axios = require('axios').default;
const assets = fs.readJsonSync('./src/asset-map.json');

let compileLocation = 'assets/compiled';

async function fetchSpecRefs(){
  return Promise.all([
    axios.get('https://ghcdn.rawgit.org/tobie/specref/master/refs/ietf.json'),
    axios.get('https://ghcdn.rawgit.org/tobie/specref/master/refs/w3c.json'),
    axios.get('https://ghcdn.rawgit.org/tobie/specref/master/refs/whatwg.json')
  ]).then(async results => {
    let json = Object.assign(results[0].data, results[1].data, results[2].data);
    return fs.outputFile(compileLocation + '/refs.json', JSON.stringify(json));
  }).catch(e => console.log(e));
}

async function compileAssets(){
  await fs.ensureDir(compileLocation);
  return new Promise(resolve => {
    mergeStreams(
      gulp.src(assets.head.css)
        .pipe(cleanCSS())
        .pipe(concat('head.css'))
        .pipe(gulp.dest(compileLocation)),
      gulp.src(assets.head.js)
        .pipe(terser())
        .pipe(concat('head.js'))
        .pipe(gulp.dest(compileLocation)),
      gulp.src(assets.body.js)
        .pipe(terser())
        .pipe(concat('body.js'))
        .pipe(gulp.dest(compileLocation))
    ).on('finish', function() {
      resolve();
    })
  });
}

function runCommand(cmd){
  return new Promise((resolve, reject) => {
    exec(cmd, {}, error => error ? reject() : resolve());
  });
}

async function bumpVersion(){
  return runCommand(`npm version --no-git-tag-version ${ argv.v || 'patch' }`);
}

async function renderSpecs(){
  return runCommand('npm run render');
}

gulp.task('render', renderSpecs);

gulp.task('refs', fetchSpecRefs);

gulp.task('compile', compileAssets);

gulp.task('bump', bumpVersion);

gulp.task('publish', gulp.series(gulp.parallel(compileAssets, bumpVersion), renderSpecs));

gulp.task('watch', () => gulp.watch([
  'assets/**/*',
  '!assets/compiled/*'
], gulp.parallel('compile')));