javascript - babel-loader 没有转译并且没有错误

Question

为什么我的 babel-loader 没有转译？我添加了:let x = 'LOL';控制台.log(x);到我的 src/main.js。它不会输出任何错误并创建输出文件。但它不会将 es6 语法转换为 es5。

这是我的 src/main.js

var css = require('./styles.scss');

console.log('hello planet!');

let x = 'LOL';
console.log(x);

我的输出文件 dist/bundle.min.js 看起来像这样(let isnt 变成 var):

/******/ (function(modules) { // webpackBootstrap
/******/    // The module cache
/******/    var installedModules = {};
/******/
/******/    // The require function
/******/    function __webpack_require__(moduleId) {
/******/
/******/        // Check if module is in cache
/******/        if(installedModules[moduleId]) {
/******/            return installedModules[moduleId].exports;
/******/        }
/******/        // Create a new module (and put it into the cache)
/******/        var module = installedModules[moduleId] = {
/******/            i: moduleId,
/******/            l: false,
/******/            exports: {}
/******/        };
/******/
/******/        // Execute the module function
/******/        modules[moduleId].call(module.exports, module, module.exports, __webpack_require__);
/******/
/******/        // Flag the module as loaded
/******/        module.l = true;
/******/
/******/        // Return the exports of the module
/******/        return module.exports;
/******/    }
/******/
/******/
/******/    // expose the modules object (__webpack_modules__)
/******/    __webpack_require__.m = modules;
/******/
/******/    // expose the module cache
/******/    __webpack_require__.c = installedModules;
/******/
/******/    // identity function for calling harmony imports with the correct context
/******/    __webpack_require__.i = function(value) { return value; };
/******/
/******/    // define getter function for harmony exports
/******/    __webpack_require__.d = function(exports, name, getter) {
/******/        if(!__webpack_require__.o(exports, name)) {
/******/            Object.defineProperty(exports, name, {
/******/                configurable: false,
/******/                enumerable: true,
/******/                get: getter
/******/            });
/******/        }
/******/    };
/******/
/******/    // getDefaultExport function for compatibility with non-harmony modules
/******/    __webpack_require__.n = function(module) {
/******/        var getter = module && module.__esModule ?
/******/            function getDefault() { return module['default']; } :
/******/            function getModuleExports() { return module; };
/******/        __webpack_require__.d(getter, 'a', getter);
/******/        return getter;
/******/    };
/******/
/******/    // Object.prototype.hasOwnProperty.call
/******/    __webpack_require__.o = function(object, property) { return Object.prototype.hasOwnProperty.call(object, property); };
/******/
/******/    // __webpack_public_path__
/******/    __webpack_require__.p = "";
/******/
/******/    // Load entry module and return exports
/******/    return __webpack_require__(__webpack_require__.s = 1);
/******/ })
/************************************************************************/
/******/ ([
/* 0 */
/***/ (function(module, exports) {

// removed by extract-text-webpack-plugin

/***/ }),
/* 1 */
/***/ (function(module, exports, __webpack_require__) {

var css = __webpack_require__(0);

console.log('hello planet!');

let x = 'LOL';
console.log(x);

/***/ })
/******/ ]);

我的 webpack.config.js:

var path = require('path');
var HtmlWebpackPlugin = require('html-webpack-plugin');
const ExtractTextPlugin = require("extract-text-webpack-plugin");

module.exports = {
    entry: './src/main.js',
    output: {
        path: path.resolve(__dirname, 'dist'),
        filename: 'bundle.min.js'
    },
    module: {
        rules: [{
            test: /\.js$/,
            exclude: /(node_modules|bower_components)/,
            use: {
                loader: 'babel-loader',
                options: {
                    presets: ['env']
                }
            },
            test: /\.scss$/,
            use: ExtractTextPlugin.extract({
                fallback: 'style-loader',
                use: ['css-loader', 'sass-loader'],
                publicPath: "/dist"
            })
        }]
    },
    devServer: {
        contentBase: path.join(__dirname, "dist"),
        compress: true,
        stats: "errors-only"
    },
    plugins: [
        new HtmlWebpackPlugin({
            title: 'Custom template',
            // minify: {
            //       collapseWhitespace: true
            // },
            hash: true,
            // filename: './../index.html',
            template: './src/template.html',
        }),
        new ExtractTextPlugin({
            filename: "style.css",
            disable: false,
            allChunks: true
        })
    ]
}

我的package.json:

{
  "name": "pack3",
  "version": "1.0.0",
  "description": "",
  "main": "index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "dev": "webpack-dev-server --open",
    "dev-old": "webpack -d --watch",
    "prod": "webpack",
    "clean": "rimraf ./dist/*"
  },
  "keywords": [],
  "author": "",
  "license": "ISC",
  "devDependencies": {
    "babel-core": "^6.24.1",
    "babel-loader": "^7.0.0",
    "babel-preset-env": "^1.4.0",
    "css-loader": "^0.28.0",
    "extract-text-webpack-plugin": "^2.1.0",
    "html-webpack-plugin": "^2.28.0",
    "node-sass": "^4.5.2",
    "react": "^15.5.4",
    "react-dom": "^15.5.4",
    "rimraf": "^2.6.1",
    "sass-loader": "^6.0.3",
    "style-loader": "^0.16.1",
    "webpack": "^2.4.1",
    "webpack-dev-server": "^2.4.4"
  }
}

Answer 1

您的规则数组仅包含一条规则，其中您使用了 test 和 use 属性两次。生成的对象仅包含最后看到的定义的值，因此您只有一个 .scss 规则。您希望数组中有两个不同的对象，其中每个对象都是不同的规则。

module: {
    rules: [
        {
            test: /\.js$/,
            exclude: /(node_modules|bower_components)/,
            use: {
                loader: 'babel-loader',
                options: {
                    presets: ['env']
                }
            }
        },
        {
            test: /\.scss$/,
            use: ExtractTextPlugin.extract({
                fallback: 'style-loader',
                use: ['css-loader', 'sass-loader'],
                publicPath: "/dist"
            })
        }
    ]
},