gulpfile.js

import childProcess from 'child_process';
import gulp from 'gulp';
import log from 'fancy-log';
import { rollup, watch } from 'rollup';
import { deleteAsync } from 'del';

const DIST = 'dist';

async function loadConfig() {
  const { default: rollupConfig } = await import('./rollup.config.js');
  return rollupConfig;
}

export function clean() {
  return deleteAsync([DIST]);
}

function copy() {
  return gulp.src('src/public/**').pipe(gulp.dest(DIST));
}

async function buildJs() {
  const rollupConfig = await loadConfig();
  return Promise.all(
    rollupConfig.map(async (config) => {
      const bundle = await rollup(config);
      await bundle.write(config.output);
    })
  );
}

async function watchJs() {
  const rollupConfig = await loadConfig();
  const watcher = watch(rollupConfig);
  return new Promise((resolve, reject) => {
    watcher.on('event', (e) => {
      if (e.code === 'ERROR') {
        console.error();
        console.error(`${e.error}`);
        console.error();
        reject(e);
      } else if (e.code === 'BUNDLE_END') {
        log(`Compilation success after ${e.duration}ms`);
        resolve();
      }
    });
  });
}

let loaded = false;
function serveDemo() {
  if (loaded) return;
  loaded = true;
  childProcess.spawn(
    'node',
    ['.', 'serve', '--cwd', 'demo', '-p', process.env.PORT || 4000],
    {
      stdio: 'inherit',
    }
  );
}

function wrapError(handle) {
  const wrapped = () =>
    handle().catch((err) => {
      log(err.toString());
    });
  wrapped.displayName = handle.name;
  return wrapped;
}

export const build = gulp.series([copy, buildJs]);
export const dev = gulp.series([copy, watchJs]);
export const demo = gulp.series([dev, serveDemo]);