Javascript Gulp concat插件错误

我在一个大文件中使用gulp for concat我的插件（bootstrap、jquery等），这是我的代码：

const gulp = require('gulp');
const csso = require('gulp-csso');
const concat = require('gulp-concat');
const babel = require('gulp-babel');
const uglify = require('gulp-uglify');

gulp.task('build', function() {

gulp.src(["./bower_components/bootstrap/dist/css/bootstrap.min.css", 
         "./bower_components/ekko-lightbox/dist/ekko-lightbox.css",
         "./bower_components/owl.carousel/dist/assets/owl.carousel.min.css",
         "./bower_components/owl.carousel/dist/assets/owl.theme.default.css",
         "./client/css/core.css",
         "./client/css/responsive.css"])
.pipe(csso())
.pipe(concat("main.css"))
.pipe(gulp.dest("./build"));

gulp.src(["./bower_components/jquery/dist/jquery.js",
          "./bower_components/bootstrap/dist/js/bootstrap.bundle.js",
          "./bower_components/ekko-lightbox/dist/ekko-lightbox.min.js",
          "./bower_components/lazysizes/lazysizes.min.js",
          "./bower_components/owl.carousel/dist/owl.carousel.min.js",
          "./bower_components/moment/min/moment.min.js",
          "./bower_components/moment/min/locales.min.js",
          "./client/js/script.js" ])    
.pipe(babel({
        presets: ['es2015']
    }))
.pipe(uglify())
.pipe(concat("main.js"))
.pipe(gulp.dest('./build'));

});

一切都很好。但当我在项目中包含此脚本时，console会抛出我的错误：

uncaughttypeerror:cannotsetproperty'bootstrap'of undefined

。 我在没有

es2015

或

uglify

的情况下尝试了concat，但此错误（或其他错误，如

未定义时刻

）仍然存在。我做错了什么？好的，我明白了

npm install --save-dev babel-plugin-proposal-object-rest-spread
npm install --save-dev babel-plugin-transform-object-rest-spread

然后是烟斗

.pipe(babel({
    presets: [['env', {
        loose: true,
        modules: false,
        exclude: ['transform-es2015-typeof-symbol']
    }]],
    plugins: ['transform-es2015-modules-strip', 'transform-object-rest-spread']
}))

它是有效的