我如何同时运行两个任务

Question

我尝试同时编译公共和管理员的sass，我面对gulp文件的一些麻烦，也许有人可以弄清楚我错在哪里。

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

// Static Server + watching scss/html files
gulp.task('serve', ['sass'], function() {

    browserSync.init({
        notify: false,
        proxy: 'http://localhost/management_system/Job'
    });

    gulp.watch("scss/public/*.scss", ['sass']);
    gulp.watch("scss/admin/*.scss", ['sass']);
    gulp.watch('application/**/*.php').on('change', browserSync.reload);

});

// Compile sass into CSS & auto-inject into browsers for public
gulp.task('sass', function() {
    return gulp.src("scss/public/*.scss")
        .pipe(sass())
        .pipe(gulp.dest("assets/public/css"))
        .pipe(browserSync.stream());
});


// Compile sass into CSS & auto-inject into browsers for admin
gulp.task('sass', function() {
    return gulp.src("scss/admin/*.scss")
        .pipe(sass())
        .pipe(gulp.dest("assets/admin/css"))
        .pipe(browserSync.stream());
});

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