Javascript 如何解决 Gulp 上的这个缩小错误？
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How to solve this minification error on Gulp?
提问by StackOverflower
I'm getting below error running this command
运行此命令时出现以下错误
gulp.task('minify', function () {
return gulp
.src('public/app/js/myapp.bundle.js')
.pipe(uglify())
.pipe(gulp.dest('public/app/js/myapp.bundle.min.js'));
});
GulpUglifyError: unable to minify JavaScript Caused by: SyntaxError: Unexpected token: name (MenuItem) (line: 1628, col: 18, pos: 53569)
GulpUglifyError：无法缩小 JavaScript 导致：语法错误：意外标记：名称（MenuItem）（行：1628，列：18，位置：53569）
Code on that location is this
该位置的代码是这样的
setters: [],
execute: function () {
class MenuItem { // <-- line 1628
What's wrong?
怎么了？
回答by StriplingWarrior
UglifyJS does not currently supportEcmaScript 6 structures like classes.
UglifyJS目前不支持像 classes 这样的EcmaScript 6 结构。
You'll probably need to run your JavaScript through a transpiler step first, or find a minifier that knows what to do with ES6 code.
您可能需要首先通过转译器步骤运行您的 JavaScript，或者找到一个知道如何处理 ES6 代码的压缩器。
Update 2017-06-17
更新 2017-06-17
The branch of UglifyJS that is designed to work with ES6 is now published as uglify-eson npm.
设计用于 ES6 的 UglifyJS 分支现在uglify-es在 npm 上发布。
Update 2018-09-10
更新 2018-09-10
terseris the new uglify-es, uglify-esis no longer maintained.
terser是新的uglify-es，uglify-es不再维护。
If using gulpboth npmjs gulp-uglify-esand npmjs gulp-terserpackages support terser.
如果使用吞掉两npmjs一饮而尽，丑化-ES和npmjs一饮而尽，更简洁的包支持更简洁。
npm install gulp-terser --save-dev
const gulp = require('gulp');
const terser = require('gulp-terser');
function es(){
return gulp.src('./src/index.js')
.pipe(terser())
.pipe(gulp.dest('./build'))
}
gulp.task('default', es);
回答by Adam Reis
If you run into this problem and you havein fact a transpiler step like Babel, make sure that you include the proper Babel preset in you .babelrcfile. Otherwise Babel will simply leave your code as is.
如果您遇到这个问题，你有其实是一个transpiler一步通天塔一样，请确保您在您正确的巴贝尔预设.babelrc文件。否则 Babel 只会让你的代码保持原样。
E.g.
例如
{
"presets": ["es2015"]
}
