watch p5, p5.js and p5.js-website repos and move a bunch of files around when changes are made

docwatch-website.js

/*
This script watches p5.js-sound/src for changes,
then moves the built library to p5.js to generate documentation,
then moves the documentation and p5.sound library files to the p5.js-website repo.

Assumes a directory structure like...
./docwatch-website.js
./p5.js/
./p5.js-sound/
./p5.js-website/

Usage:
- Run `node docwatch-website.js` in the root directory.
*/
 
const fs = require('fs');
const path = require('path');
const { spawn } = require('child_process');

// repo locations
const p5 = path.join(__dirname, './p5.js');
const p5Sound = path.join(__dirname, './p5.js-sound');
const p5Website = path.join(__dirname, './p5.js-website');

watchP5Sound();
serveWebsite();

// watch p5.sound for changes...
fs.watchFile(`${p5Sound}/lib/p5.sound.js`, function() {
  // once the compiled p5.js-sound has been moved to p5.js `addons`, generate documentation
  copyFile(`${p5Sound}/lib/p5.sound.js`, `${p5}/lib/addons/p5.sound.js`)
    .then(copyFile(`${p5Sound}lib/p5.sound.min.js`, `${p5}/src/assets/js/p5.sound.min.js`))
    .then(copyFile(`${p5Sound}lib/p5.sound.js`, `${p5Website}/src/assets/js/p5.sound.js`))
    .then(copyFile(`${p5Sound}lib/p5.sound.min.js`, `${p5Website}/src/assets/js/p5.sound.min.js`))
    .then(generateDocs)
    .then(copyFile(`${p5}/docs/reference/data.min.json`, `${p5Website}/dist/reference/data.min.json`))
    .then(copyFile(`${p5}/docs/reference/data.json`, `${p5Website}/dist/reference/data.json`))
    .then(function() {
      console.log('done!');
    })
    .catch(function(err) {
      console.error(err);
    });
});

function copyFile(oldLocation, newLocation) {
  const read = fs.createReadStream(oldLocation);
  const write = fs.createWriteStream(newLocation);
 
  return new Promise( function(resolve, reject) {
    read.on('error', reject);
    write.on('error', reject);
    write.on('finish', resolve);
    read.pipe(write);
  }).catch(function(err) {
    read.destroy();
    write.end();
    throw err;
  });
}

function generateDocs() {
  return new Promise(function(resolve, reject) {
    console.log('running grunt yui:docs');

    const gruntTask = spawn('grunt', ['yui:docs'], {
      cwd: p5
    });
    gruntTask.stdout.on('data', function(data) {
      console.log(`Generate Docs: ${data}`)
    });
    gruntTask.stderr.on('data', function(err) {
      console.error(`Generate Docs: ${err}`);
    });
    gruntTask.stdout.on('finish', function(code, signal) {
      if (!signal) {
        return resolve(code);
      } else {
        console.error('child process exited with ' +
          `code ${code} and signal ${signal}`);
        return reject(code);
      }
    });
  });
}

function watchP5Sound() {
  console.log('p5Sound: watching src for changes');

  const gruntTask = spawn('grunt', ['watch'], {
    cwd: p5Sound
  });
  gruntTask.stdout.on('data', function(data) {
    console.log(`p5Sound: ${data}`)
  });
  gruntTask.stderr.on('data', function(err) {
    console.error(`p5Sound: ${err}`);
  });
}

function serveWebsite() {
  console.log('serving p5 website');

  const gruntTask = spawn('grunt', ['server'], {
    cwd: p5Website
  });
  gruntTask.stdout.on('data', function(data) {
    console.log(`p5Website: ${data}`)
  });
  gruntTask.stderr.on('data', function(err) {
    console.error(`p5Website: ${err}`);
  });
}

console.log('watching files for changes', 'text-decoration: underline');