var gulp = require("gulp"); var presetES2015 = require("@joepie91/gulp-preset-es2015"); var source = ["src/**/*.js"] gulp.task('babel', function() { return gulp.src(source) .pipe(presetES2015({ basePath: __dirname })) .pipe(gulp.dest("lib/")); }); gulp.task("watch", function () { gulp.watch(source, ["babel"]); }); gulp.task("default", ["babel", "watch"]);