var gulp = require('gulp'); var sass = require('gulp-sass'); var autoprefixer = require('gulp-autoprefixer'); gulp.task('sass', function () { gulp.src('./**/*.scss') .pipe(sass()) .pipe(autoprefixer()) .pipe(gulp.dest('./css')); }); this.processing = new Promise(function (resolve, reject) { ^ ReferenceError: Promise is not defined at LazyResult.async (/Users/xxx/app/node_modules/postcss/lib/lazy-r