Question

我的webpack.config.js文件中包含以下内容：

const webpack = require('webpack');
const path = require('path');

const config = {
  context: path.resolve(__dirname, 'src'),
  entry: './app.js',
  output: {
    path: path.resolve(__dirname, 'dist'),
    filename: 'bundle.js'
  },
  module: {
    rules: [
      {
        test: /\.css$/,
        exclude: path.resolve(__dirname, 'node_modules'),
        use: [ 'style-loader', 'css-loader' ]
      },
      {
        test: /\.js$/,
        exclude: path.resolve(__dirname, 'node_modules'),
        use: [{
          loader: 'babel-loader',
          options: {
            presets: [
              ['es2015']
            ]
          }
        }]
      }
    ]
  }
};

module.exports = config;

当我运行webpack时，我收到以下错误：

ERROR in (webpack)/~/buffer/index.js
Module build failed: Error: Couldn't find preset "es2015" relative to directory "/home/echessa/node/node-v6.9.1-linux-x64/lib/node_modules/webpack/node_modules/buffer"
    at /home/echessa/Documents/DEV/demo-project/node_modules/babel-core/lib/transformation/file/options/option-manager.js:293:19
    at Array.map (native)
    at OptionManager.resolvePresets (/home/echessa/Documents/DEV/demo-project/node_modules/babel-core/lib/transformation/file/options/option-manager.js:275:20)
    at OptionManager.mergePresets (/home/echessa/Documents/DEV/demo-project/node_modules/babel-core/lib/transformation/file/options/option-manager.js:264:10)
    at OptionManager.mergeOptions (/home/echessa/Documents/DEV/demo-project/node_modules/babel-core/lib/transformation/file/options/option-manager.js:249:14)
    at OptionManager.init (/home/echessa/Documents/DEV/demo-project/node_modules/babel-core/lib/transformation/file/options/option-manager.js:368:12)
    at File.initOptions (/home/echessa/Documents/DEV/demo-project/node_modules/babel-core/lib/transformation/file/index.js:212:65)
    at new File (/home/echessa/Documents/DEV/demo-project/node_modules/babel-core/lib/transformation/file/index.js:135:24)
    at Pipeline.transform (/home/echessa/Documents/DEV/demo-project/node_modules/babel-core/lib/transformation/pipeline.js:46:16)
    at transpile (/home/echessa/Documents/DEV/demo-project/node_modules/babel-loader/lib/index.js:48:20)
    at Object.module.exports (/home/echessa/Documents/DEV/demo-project/node_modules/babel-loader/lib/index.js:163:20)
 @ ../~/css-loader/lib/css-base.js 1:0-117
 @ ../~/css-loader!./main.css
 @ ./main.css
 @ ./app.js

我正在使用Webpack版本2.3.2。

以下是我使用的开发依赖项：

"devDependencies": {
  "babel-core": "^6.24.0",
  "babel-loader": "^7.0.0-beta.1",
  "babel-preset-es2015": "^6.24.0",
  "css-loader": "^0.27.3",
  "style-loader": "^0.16.1"
}

对于babel-loader，我使用测试版，因为建议将7.x版用于Webpack 2.以下内容来自Github repo：

webpack 1.x | babel-loader＆lt; = 6.x

webpack 2.x | babel-loader＆gt; = 7.x（推荐）（^ 6.2.10也可以，但有弃用警告）

版本7.0.0还没有出来，所以我正在使用测试版。我尝试过使用6.2.10，但我仍然遇到同样的错误。

当我只使用其中一条规则时，webpack构建成功。例如。当我只有js规则（并删除CSS文件）时，它可以工作。

module: {
  rules: [
    {
      test: /\.js$/,
      exclude: path.resolve(__dirname, 'node_modules'),
      use: [{
        loader: 'babel-loader',
        options: {
          presets: [
            ['es2015']
          ]
        }
      }]
    }
  ]
}

或者当我只有CSS规则（并删除任何ES6代码）时，它可以工作。

module: {
  rules: [
    {
      test: /\.css$/,
      exclude: path.resolve(__dirname, 'node_modules'),
      use: [ 'style-loader', 'css-loader' ]
    }
  ]
}

什么可能？这可能是babel-loader的问题，还是我的配置文件结构不正确？

Answer 1

我找到了一个有效的解决方案。如果我将以下内容从webpack.config.js文件移到.babelrc文件，那么webpack运行正常。

{
  "presets": ["es2015"]
}

我不确定为什么配置文件中的预设不起作用。我在网上看过的任何Webpack 2指南都在配置文件中。无论如何，我认为我应该在这里留下这个解决方案以防其他人被卡住。

加载程序在Webpack 2中失败。它们单独工作，但在配置文件中包含两者时失败

1 个答案: