gulpfile.js
import gulp from 'gulp';import babel from 'gulp-babel'; const compile = (cb) => { gulp.src('server/**/*.js') .pipe(babel()) .pipe(gulp.dest('dist')); cb();}; const compileTest = (cb) => { gulp.src('__tests__/server/**/*.js') .pipe(babel()) .pipe(gulp.dest('dist/__tests__')); cb();}; exports.build = gulp.series(gulp.parallel(compile, compileTest));