Development and Hot Module Reload Middleware for Koa2, in a single middleware module.
This module wraps and composes
webpack-dev-middleware and
webpack-hot-client
into a single middleware module, allowing for quick and concise implementation.
As an added bonus, it'll also use the installed webpack module from your project,
and the webpack.config.js file in the root of your project, automagically, should
you choose to let it. This negates the need for all of the repetitive setup and
config that you get with koa-webpack-middleware.
Using npm:
npm install koa-webpack --save-dev
koa-webpack is an evergreen module. 🌲 This module requires an Active LTS Node version (v8.0.0+ or v10.0.0+), and Webpack v4.0.0+.
constKoa=require('koa');constkoaWebpack=require('koa-webpack');constapp=newKoa();constoptions={..};constmiddleware=awaitkoaWebpack(options);app.use(middleware);Returns a Promise which resolves the server middleware containing the
following additional properties:
close(callback)(Function) - Closes both the instance ofwebpack-dev-middlewareandwebpack-hot-client. Accepts a singleFunctioncallback parameter that is executed when complete.hotClient(Object) - An instance ofwebpack-hot-client.devMiddleware(Object) - An instance ofwebpack-dev-middleware
The middleware accepts an options Object, which can contain options for the
webpack-dev-middleware and webpack-hot-client bundled with this module.
The following is a property reference for the Object:
Type: Objectoptional
Should you rather that the middleware use an instance of webpack that you've
already init'd [with webpack config], you can pass it to the middleware using
this option.
Example:
constwebpack=require('webpack');constconfig=require('./webpack.config.js');constkoaWebpack=require('koa-webpack');constcompiler=webpack(config);constmiddleware=awaitkoaWebpack({ compiler });app.use(middleware);Type: Object
Should you rather that the middleware use an instance of webpack configuration that you've already required/imported, you can pass it to the middleware using this option.
Example:
constkoaWebpack=require('koa-webpack');constconfig=require('./webpack.config.js');constmiddleware=awaitkoaWebpack({ config });app.use(middleware);Type: String
Allows you to specify the absolute path to the Webpack config file to be used.
Example:
constpath=require('path');constkoaWebpack=require('koa-webpack');// The Webpack config file would be at "./client/webpack.config.js".constmiddleware=awaitkoaWebpack({configPath: path.join(__dirname,'client','webpack.config.js')});app.use(middleware);Type: Object
The devMiddleware property should contain options for webpack-dev-middleware, a list of
which is available at webpack-dev-middleware.
Omitting this property will result in webpack-dev-middleware using its default
options.
Type: Object|Boolean
The hotClient property should contain options for webpack-hot-client, a list of
which is available at webpack-hot-client.
Omitting this property will result in webpack-hot-client using its default
options.
As of v3.0.1 setting this to false will completely disable webpack-hot-client
and all automatic Hot Module Replacement functionality.
When using koa-webpack with koa-compress,
you may experience issues with saving files and hot module reload. Please review
this issue
for more information and a workaround.
When serverSideRender is set to true in config.devMiddleware, webpackStats is
accessible from ctx.state.webpackStats.
app.use(async(ctx,next)=>{constassetsByChunkName=ctx.state.webpackStats.toJson().assetsByChunkName;// do something with assetsByChunkName})For more details please refer to: webpack-dev-middleware
When using with html-webpack-plugin, you can access dev-middleware in-memory filesystem to serve index.html file:
constmiddleware=awaitkoaWebpack({ config });app.use(middleware);app.use(async(ctx)=>{constfilename=path.resolve(webpackConfig.output.path,'index.html')ctx.response.type='html'ctx.response.body=middleware.devMiddleware.fileSystem.createReadStream(filename)});Please take a moment to read our contributing guidelines if you haven't yet done so.
This module started as a fork of
koa-webpack-middleware