gulpfile.babel.js

import gulp from 'gulp';
import gulpLoadPlugins from 'gulp-load-plugins';
import path from 'path';

const plugins = gulpLoadPlugins();

const paths = {
  js: ['./**/*.js', '!dist/**', '!node_modules/**', '!coverage/**'],
  nonJs: ['./package.json', './.gitignore', './.env'],
  tests: './server/tests/*.js',
};

// Clean up dist and coverage directory
gulp.task('clean', (done) => {
  let deleteSync;
  import('del')
    .then((mod) => {
      deleteSync = mod.deleteSync;
      deleteSync(
        ['dist/**', 'dist/.*', 'coverage/**', '!dist', '!coverage'],
      );
    })
    .catch((e) => { console.log(e.message); });
  return done();
});

// Copy non-js files to dist
gulp.task('copy', () => gulp.src(paths.nonJs)
  .pipe(plugins.newer('dist'))
  .pipe(gulp.dest('dist')));

// Compile ES6 to ES5 and copy to dist
gulp.task('babel', () => gulp.src([...paths.js, '!gulpfile.babel.js'], { base: '.' })
  .pipe(plugins.newer('dist'))
  .pipe(plugins.sourcemaps.init())
  .pipe(plugins.babel())
  .pipe(plugins.sourcemaps.write('.', {
    includeContent: false,
    sourceRoot(file) {
      return path.relative(file.path, __dirname);
    },
  }))
  .pipe(gulp.dest('dist')));

// Start server with restart on file changes
gulp.task('nodemon', gulp.series('copy', 'babel', (done) => {
  plugins.nodemon({
    script: path.join('dist', 'index.js'),
    ext: 'js',
    ignore: ['node_modules/**/*.js', 'dist/**/*.js'],
    tasks: ['copy', 'babel'],
  });
  done();
}));

// gulp serve for development
gulp.task('serve', gulp.series('clean', 'nodemon'));

// default task: clean dist, compile js files and copy non-js files.
gulp.task('default', gulp.series('clean', 'copy', 'babel'));