gulpfile.babel.js

import gulp from "gulp";
import babel from "gulp-babel";
import copy from "gulp-copy";
import newer from "gulp-newer";
import del from "del";
import { spawn } from "child_process";

const lib = 'lib';

gulp.task('clean', () => del(['lib/']));

gulp.task('build', () => {
  return gulp.src('src/*.js')
    .pipe(newer(lib))
    .pipe(babel())
    .pipe(gulp.dest(lib));
});

gulp.task('copy-snapshots', () => {
  return gulp.src('src/*.snap')
    .pipe(newer(lib))
    .pipe(copy(lib, { prefix: 1 }));
});

gulp.task('build:test', ['build', 'copy-snapshots']);

gulp.task('watch', ['build'], () => {
  gulp.watch('src/*.js', ['build']);
});

gulp.task('default', ['watch']);