gulpfile.js
var gulp = require('gulp');
var babel = require('gulp-babel');
var paths = {
src: 'src/**/*.js',
dest: 'dist',
test: 'test/**/*.js'
};
gulp.task('watch', function() {
return gulp.watch(paths.src, ['build']);
});
gulp.task('build', function () {
return gulp.src(paths.src)
.pipe(babel())
.pipe(gulp.dest(paths.dest));
});
gulp.task('dev', gulp.series(['watch', 'build']));