我正在尝试在本地运行我的 server.js 文件，但每次我尝试“node server.js”时都会得到:
SyntaxError: Unexpected Identifier for "import React from react
我只是想看看在访问我的数据库的函数中是否收到 console.log("connected") 消息。
我已经尝试将“transform-es2015-modules-amd”添加到 Babel 部分的 package.json 文件中的插件中。我已经尝试了 Stack Overflow 帖子中提供的几乎所有其他与我的类似的解决方案。
package.json
{
"dependencies": {
"atob": "^2.1.2",
"axios": "^0.19.0",
"babel-loader": "^8.0.0-beta.6",
"babel-upgrade": "^1.0.1",
"btoa": "^1.2.1",
"concurrently": "^5.0.0",
"cors": "^2.8.5",
"express": "^4.17.1",
"mysql": "^2.17.1",
"node-fetch": "^2.6.0",
"react": "^16.11.0",
"react-dom": "^16.11.0",
"react-redux": "^7.1.1",
"react-router": "^5.1.2",
"react-router-dom": "^5.1.2",
"redux": "^4.0.4",
"request": "^2.88.0",
"serialize-javascript": "^2.1.0"
},
"devDependencies": {
"@babel/cli": "^7.6.4",
"@babel/core": "^7.6.4",
"@babel/node": "^7.6.3",
"@babel/preset-env": "^7.6.3",
"@babel/preset-react": "^7.6.3",
"@types/node": "^12.11.2",
"babel-loader": "^8.0.6",
"babel-preset-es2015": "^6.24.1",
"babel-preset-react": "^6.24.1",
"css-loader": "^3.2.0",
"nodemon": "^1.19.4",
"style-loader": "^1.0.0",
"webpack": "^4.41.2",
"webpack-cli": "^3.3.9",
"webpack-dev-server": "^3.9.0",
"webpack-node-externals": "^1.7.2"
},
"babel": {
"presets": [
"@babel/preset-react",
"@babel/preset-env"
]
"plugins": [
"transform-es2015-modules-amd"
]
}
}
服务器.js
import React from 'react';
import { StaticRouter } from 'react-router-dom';
import { Provider as ReduxProvider } from "react-redux";
import App from '../client/src/App.js';
import { renderToString } from "react-dom/server";
import createStore, { initialize, fetchCharacters } from './store.js';
var path = require("path");
var express = require("express");
var serialize = require("serialize-javascript");
var db = require('./db');
const PORT = process.env.HTTP_PORT || 4001;
const app = express();
app.use('/static', express.static(path.join(__dirname, 'public')));
console.log(__dirname);
app.get('/*', function(req, res) {
const context = {};
const store = createStore();
store.dispatch(initialize());
Promise.all([store.dispatch(fetchCharacters())]).then(() => {
const component = (
<ReduxProvider store={store}>
<StaticRouter location={req.url} context={context}>
<App/>
</StaticRouter>
</ReduxProvider>
);
const ss_react = renderToString(component);
const ss_state = store.getState();
res.writeHead( 200, { "Content-Type": "text/html" });
res.end(htmlTemplate(component, ss_state));
});
});
function htmlTemplate(component, ss_state) {
return `
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<title>React SSR</title>
</head>
`;
}
app.listen(PORT, () => {
console.log(`server listening at port ${PORT}. `);
});
webpack.config.js
const webpack = require('webpack')
const nodeExternals = require('webpack-node-externals')
const path = require('path')
const js = {
test: /\.m?(js|jsx)$/,
exclude: /(node_modules|bower_components)/,
use: {
loader: 'babel-loader'
}
}
const css = {
test: /\.css$/,
use: [
"style-loader",
{
loader: "css-loader",
options: {
modules: true
}
}
]
}
const serverConfig = {
mode: 'development',
target: 'node',
node: {
__dirname: false
},
externals: [nodeExternals()],
entry: {
'index.js': path.resolve(__dirname, 'server/server.js')
},
module: {
rules: [js]
},
output: {
path: path.resolve(__dirname, 'dist'),
filename: '[name]'
}
}
const clientConfig = {
mode: 'development',
target: 'web',
entry: {
'index.js': path.resolve(__dirname, 'client/src/index.js')
},
module: {
rules: [js, css]
},
optimization: {
splitChunks: {
chunks: 'all'
}
},
output: {
path: path.resolve(__dirname, 'dist/public'),
filename: '[name]'
}
}
module.exports = [serverConfig, clientConfig]
最佳答案
Node 不理解 React JSX。这就是 Webpack 的用途 - 它使用 Babel 将代码转换为普通 JavaScript。
看起来您已将 webpack-dev-server 作为开发依赖项，因此应该已经安装了它(如果您已完成 npm install)。确保 package.json scripts 字段中有类似的内容:
"scripts": {
"start:dev": "webpack-dev-server --config webpack.config.js"
},
然后在控制台中运行 npm run start:dev。
关于javascript - 语法错误: Import React from 'react' Unexpected identifier，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/58774177/