模块无法在JSX解析，无法在webpack，babel配置中找到错误

Question

我已经多次检查了此设置的详细信息，它曾经很久没被唤醒过，现在出现了一个错误...

ERROR in ./src/index.js
Module parse failed: /Users/Jeff/javascript/testbuildwords/src/index.js Unexpected token (5:11)
You may need an appropriate loader to handle this file type.
| class MyComponent extends React.Component {
|   render() {
|     return <div>This is my component</div>;
|   }
| }

我觉得该错误一定在这些文件中，但是我仔细检查了一下，并将它们与其他文件进行了1​​000次比较，但我找不到该错误

webpack.config.js

const path = require("path");

module.exports = {
  entry: "./src/index.js",
  output: {
    path: path.resolve(__dirname, "build"),
    filename: "index.js",
    libraryTarget: "commonjs2"
  },
  module: {
    rules: [
      {
        test: /.js$/,
        include: path.resolve(__dirname, "src"),
        exclude: /(node_modules|bower_components|build)/,
        use: "babel-loader"
      },
      {
        test: /.css$/,
        use: ["style-loader", "css-loader"]
      },
      {
        test: /.(png|jpg|gif|eot|svg|ttf|woff|woff2)$/,
        use: [
          {
            loader: "file-loader",
            options: {}
          }
        ]
      }
    ]
  },
  externals: {
    react: "commonjs react"
  }
};

.babelrc

{
  "presets": ["env"],
  "plugins": [
    "transform-object-rest-spread",
    "transform-react-jsx",
    "transform-class-properties"
    ]
}

package.json

{
  "name": "testbuildwords",
  "version": "0.1.0",
  "main": "build/index.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1",
    "start": "webpack --watch",
    "build": "webpack"
  },
  "author": "",
  "license": "ISC",
  "description": "",
  "dependencies": {
    "css-loader": "^0.28.7",
    "file-loader": "^1.1.5",
    "prop-types": "^15.6.0",
    "react": "^16.0.0",
    "react-dom": "^16.0.0",
    "style-loader": "^0.19.0",
    "webpack": "^3.6.0"
  },
  "devDependencies": {
    "babel-cli": "^6.26.0",
    "babel-core": "^6.26.0",
    "babel-loader": "^7.1.2",
    "babel-plugin-transform-class-properties": "^6.24.1",
    "babel-plugin-transform-object-rest-spread": "^6.26.0",
    "babel-plugin-transform-react-jsx": "^6.24.1",
    "babel-preset-env": "^1.6.0",
    "eslint-plugin-class-property": "^1.0.6"
  }
}

./src/index.js

import React from "react";

class MyComponent extends React.Component {
  render() {
    return <div>This is my component</div>;
  }
}
export default MyComponent;

Answer 1

尝试添加babel react-preset 。

{
  "presets": ["env", "react"]
}

Answer 2

我认为Webpack无法隐式解析.jsx文件。 如果将应解析的扩展名添加到webpack.config.js文件中怎么办？：

resolve: {
  extensions: ['', '.js', '.jsx']
}

Answer 3

添加更多带有预设的规则来解析jsx扩展

test: /.jsx$/,
include: path.resolve(__dirname, "src"),
exclude: /(node_modules|bower_components|build)/,
use: {
    loader: 'babel-loader',
    options: {
      presets: ['es2015', 'react', 'babel-preset-stage-0']
    }
}

并在解决块中添加jsx条目，例如

resolve: {
   extensions: ['', '.jsx', '.js']
}

Answer 4

没有答案对我有帮助。 我最终将webpack而不是devDependencies添加到了dependencies ，因为在那里列出了webpack正在使用的其他大多数内容，之后该问题得到了解决。