本文翻译自:babel-loader jsx SyntaxError: Unexpected token [duplicate]
This question already has an answer here: 这个问题已经在这里有了答案:
I'm a beginner in React + Webpack. 我是React + Webpack的初学者。
I found a weird error in my hello world web app. 我在Hello World Web应用程序中发现了一个奇怪的错误。
I'm using babel-loader in webpack to help me convert jsx into js, but it seems like babel can't understand jsx syntax. 我在webpack中使用babel-loader来帮助我将jsx转换为js,但是babel似乎无法理解jsx语法。
Here are my dependencies: 这是我的依赖项:
"devDependencies": {
"babel-core": "^6.0.14",
"babel-loader": "^6.0.0",
"webpack": "^1.12.2",
"webpack-dev-server": "^1.12.1"
},
"dependencies": {
"react": "^0.14.1"
}
Here is my webpack.config.js
这是我的webpack.config.js
var path = require('path');
module.exports = {
entry: ['webpack/hot/dev-server',path.resolve(__dirname, 'app/main.js')],
output: {
path: path.resolve(__dirname, 'build'),
filename: 'bundle.js'
},
module: {
loaders: [
{ test: /\.js$/, exclude: /node_modules/, loader: "babel-loader"}
]
}
};
Here is my app/main.js
这是我的app/main.js
var React = require("react");
React.render(hello world
,document.getElementById("app"));
And this is the error message 这是错误消息
ERROR in ./app/main.js
Module build failed: SyntaxError: ~/**/app/main.js: Unexpected token (2:13)
1 | var React = require("react");
> 2 | React.render(hello world
,document.getElementById("app"));
| ^
at Parser.pp.raise (~/**/node_modules/babylon/lib/parser/location.js:24:13)
Thanks for you guys. 谢谢你们
参考:https://stackoom.com/question/2GOaC/babel-loader-jsx-SyntaxError-意外令牌-重复
Add "babel-preset-react" 添加“ babel-preset-react”
npm install babel-preset-react
and add "presets" option to babel-loader in your webpack.config.js 并在webpack.config.js中向babel-loader添加“预设”选项
(or you can add it to your .babelrc or package.js: http://babeljs.io/docs/usage/babelrc/ ) (或者您可以将其添加到您的.babelrc或package.js: http ://babeljs.io/docs/usage/babelrc/)
Here is an example webpack.config.js: 这是一个webpack.config.js示例:
{
test: /\.jsx?$/, // Match both .js and .jsx files
exclude: /node_modules/,
loader: "babel",
query:
{
presets:['react']
}
}
Recently Babel 6 was released and there was a major change: https://babeljs.io/blog/2015/10/29/6.0.0 最近发布了Babel 6,并进行了重大更改: https : //babeljs.io/blog/2015/10/29/6.0.0
If you are using react 0.14, you should use ReactDOM.render()
(from require('react-dom')
) instead of React.render()
: https://facebook.github.io/react/blog/#changelog 如果您使用ReactDOM.render()
0.14,则应该使用ReactDOM.render()
(来自require('react-dom')
)而不是React.render()
: https : React.render()
UPDATE 2018 更新2018
Rule.query has already been deprecated in favour of Rule.options. 不推荐使用Rule.query,而使用Rule.options。 Usage in webpack 4 is as follows: webpack 4中的用法如下:
npm install babel-loader babel-preset-react
Then in your webpack configuration (as an entry in the module.rules array in the module.exports object) 然后在您的webpack配置中(作为module.exports对象中module.rules数组中的条目)
{
test: /\.jsx?$/,
exclude: /node_modules/,
use: [
{
loader: 'babel-loader',
options: {
presets: ['react']
}
}
],
}
Since the answer above still leaves some people in the dark, here's what a complete webpack.config.js might look like: 由于上面的答案仍然使某些人望而却步,因此完整的webpack.config.js可能如下所示:
var path = require('path'); var config = { entry: path.resolve(__dirname, 'app/main.js'), output: { path: path.resolve(__dirname, 'build'), filename: 'bundle.js' }, module: { loaders: [{ test: /\\.jsx?$/, loader: 'babel', query: { presets:['es2015', 'react'] } }] }, }; module.exports = config;
I ran into a similar issue when migrating from babel 5 to babel 6. 从babel 5迁移到babel 6时,我遇到了类似的问题。
I was just running babel to compile the src to lib folder babel src --out-dir lib
我只是在运行babel将src编译为lib文件夹babel src --out-dir lib
I will share my setup for babel 6: 我将分享Babel 6的设置:
Ensure you have the following babel 6 devDependencies installed 确保您已安装以下babel 6 devDependencies
"babel-core": "^6.7.6",
"babel-loader": "^6.2.4",
"babel-preset-es2015": "^6.6.0",
"babel-preset-react": "^6.5.0",
"babel-preset-stage-0": "^6.5.0"
Add your .babelrc file to the project: 将.babelrc文件添加到项目中:
{
"presets": ["es2015", "stage-0", "react"]
}
The following way has helped me (includes react-hot, babel loaders and es2015, react presets): 以下方法对我有所帮助(包括react-hot,babel装载程序和es2015,react预设):
loaders: [
{
test: /\.jsx?$/,
exclude: /node_modules/,
loaders: ['react-hot', 'babel?presets[]=es2015&presets[]=react']
}
]
You can find a really good boilerplate made by Henrik Joreteg (ampersandjs) here: https://github.com/HenrikJoreteg/hjs-webpack 您可以在这里找到由Henrik Joreteg(&sandjs)制作的非常好的样板: https : //github.com/HenrikJoreteg/hjs-webpack
Then in your webpack.config.js
然后在您的webpack.config.js
var getConfig = require('hjs-webpack')
module.exports = getConfig({
in: 'src/index.js',
out: 'public',
clearBeforeBuild: true,
https: process.argv.indexOf('--https') !== -1
})