我是 Node JS 的新手。我正在使用 webpack-hot-middleware 创建一个带有热重载的后端 API 服务器。我尝试使用 webpack-dev-middleware 将服务器脚本(index.js)加载到内存并执行该 javascrip t 文件。
这是我的代码:链接
我发现我的代码可以成功地进行热重载,但是我无法加载服务器脚本(index.js)并启动我的 API 服务器。由于某些原因,我想使用 webpack-dev-middleware 而不是 webpack 开发服务器。
这是我的文件结构:
├── package.json.
├── build
| ├── devserver.js
| └── webpack.devserver.config.js
├── server
| └── index.js (code of the API server)
└── dist
我找到了大量关于如何在呈现 HTML 的前端或后端服务器上执行此操作的教程,但我需要启动我的 index.js。
所以,我的问题是如何加载从 webpack-dev-middleware 生成的 js 文件并启动该 js 文件。
以下是我尝试的:
const path = require('path');
const express = require('express');
const webpack = require('webpack');
const webpackMiddleware = require('webpack-dev-middleware');
const webpackHotMiddleware = require('webpack-hot-middleware');
const webpackConfig = require('./webpack.devserver.config');
var StreamCache = require('stream-cache');
var fs = require('fs');
const compiler = webpack(webpackConfig);
const app = express();
const hotMiddleware = webpackHotMiddleware(compiler);
const middleware = webpackMiddleware(compiler, {
publicPath: "",
contentBase: 'server',
stats: {
colors: true,
hash: false,
timings: true,
chunks: false,
chunkModules: false,
modules: false
}
});
app.use(middleware);
app.use(hotMiddleware);
middleware.waitUntilValid(() => {
//Then, what should I do??????
console.log(middleware.fileSystem.readFileSync(path.join(__dirname, '../dist/backend.js')));
})
在 webpack.devserver.config.js 中:
var fs = require('fs');
var path = require('path');
var webpack = require('webpack');
var nodeModules = {};
fs.readdirSync('node_modules')
.filter(function (x) {
return ['.bin'].indexOf(x) === -1;
})
.forEach(function (mod) {
nodeModules[mod] = 'commonjs ' + mod;
});
module.exports = {
devtool: 'eval-source-map',
entry: [
'webpack/hot/signal.js',
'./server/index.js'
],
target: 'node',
output: {
path: path.resolve(__dirname, '../dist'),
filename: 'backend.js',
publicPath: ''
},
plugins: [
new webpack.optimize.OccurrenceOrderPlugin(),
new webpack.HotModuleReplacementPlugin(),
new webpack.NoEmitOnErrorsPlugin(),
new webpack.DefinePlugin({
})
],
recordsPath: path.resolve(__dirname, '../dist/a.json'),
resolveLoader: {
moduleExtensions: ['-loader']
},
externals: nodeModules,
watch: true,
module: {
rules: [{
test: /\.js$/,
loader: 'babel-loader'
},
{
test: /\.es6$/,
loaders: ['babel-loader']
},
{
test: /\.json?$/,
loader: 'json'
}
]
}
};
结果:在 index.js 上更改某些内容后,代码似乎已成功重新加载,但是当我访问 /api/hi API 时看不到更改。
webpack building...
webpack built 4f5191c370239429fae8 in 378ms
Version: webpack 3.10.0
Time: 378ms
Asset Size Chunks Chunk Names
backend.js 47 kB 0 [emitted] main
webpack: Compiled successfully.
webpack: Compiling...
webpack building...
webpack built 59489ea86a2ccf081fa6 in 30ms
Version: webpack 3.10.0
Time: 30ms
Asset Size Chunks Chunk Names
backend.js 47.1 kB 0 [emitted] main
0.4f5191c370239429fae8.hot-update.js 1.84 kB 0 [emitted] main
4f5191c370239429fae8.hot-update.json 43 bytes [emitted]
webpack: Compiled successfully.