获取：SyntaxError：缺少 ) 参数列表后，但无法找出 gulpfile.js 出了什么问题

您好，我在使用以下 gulp 文件启动“gulp default”时遇到错误。我无法弄清楚该文件出了什么问题。

var gulp = require('gulp');
var sass = require('gulp-sass');
var sourcemaps = require('gulp-sourcemaps');
var autoprefixer = require('gulp-autoprefixer');
var browserSync = require('browser-sync').create();

var input = './scss/**/*.scss';
var output = './css';

gulp.task('sass', function() {
  return gulp.src(input)
    .pipe(sourcemaps.init())
    .pipe(sass(errLogToConsole: true, outputStyle: 'compressed'))
    .pipe(autoprefixer(browsers: ['last 2 versions', '> 5%', 'Firefox ESR']))
    .pipe(sourcemaps.write())
    .pipe(gulp.dest(output))
    .pipe(browserSync.stream());
});

// Watch files for change and set Browser Sync
gulp.task('watch', function() {
  // BrowserSync settings
  browserSync.init({
    proxy: "mydomain.loc",
    files: "./css/styles.css"
  });

  // Scss file watcher
  gulp.watch(input, ['sass'])
    .on('change', function(event) {
      console.log('File' + event.path + ' was ' + event.type + ', running tasks...')
    });
});

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

我已经重新安装了节点，但所有软件包都无法解决问题。

试图改变这一点。它直接在另一行给出相同的错误：

/Users/hmook/Documents/Development/lvdb/gulpfile.js:14
    .pipe(autoprefixer(browsers: ['last 2 versions', '> 5%', 'Firefox ESR']))
                       ^^^^^^^^

SyntaxError: missing ) after argument list
    at createScript (vm.js:80:10)
    at Object.runInThisContext (vm.js:139:10)
    at Module._compile (module.js:599:28)
    at Object.Module._extensions..js (module.js:646:10)
    at Module.load (module.js:554:32)
    at tryModuleLoad (module.js:497:12)
    at Function.Module._load (module.js:489:3)
    at Module.require (module.js:579:17)
    at require (internal/module.js:11:18)
    at Liftoff.handleArguments (/usr/local/lib/node_modules/gulp/bin/gulp.js:116:3)