text: const gulp = require('gulp');
  const babel = require('gulp-babel');
  const mocha = require('gulp-mocha');
  const gutil = require('gulp-util');
  
  gulp.task('default', function() {
    gulp.watch(['lib/**', 'test/**'], ['mocha']);
  });
  
  gulp.task('babel', function() {
    return gulp.src(['lib/*.js'])
                    .pipe(babel({
                      presets: ['env']
                    }))
                    .pipe(gulp.dest('dist'))
                    .on('error', gutil.log);
  });
  
  gulp.task('mocha', ['babel'], function() {
    return gulp.src(['test/*.js'], { read: false })
                    .pipe(mocha({
                      reporter: 'list' 
                    }))
                    .on('error', gutil.log);
  });