MemoryFileSystemError

const SERVER = require("./www/server.bundle").default;
const express = require("express");
const webpack = require('webpack');
const webpackDevMiddleware = require('webpack-dev-middleware');
const webpackHotMiddleware = require('webpack-hot-middleware');
// const webpackHotServerMiddleware = require('webpack-hot-server-middleware');
const app = express();
const PORT = 3000;
const compiler = webpack(require('./build/webpack/prod.js'));
app.use(webpackDevMiddleware(compiler));
app.use(webpackHotMiddleware(compiler.compilers.find(compiler => compiler.name === 'client')));
// app.use(webpackHotServerMiddleware(compiler));
app.use(SERVER);
app.listen(PORT, console.log.bind("listening at http://localhost:" + PORT));

If I uncomment the lines (webpackHotServerMiddleware itself) above, my build errors

/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack-dev-middleware/node_modules/memory-fs/lib/MemoryFileSystem.js:112
			throw new MemoryFileSystemError(errors.code.EISDIR, _path);
         ^
Error
    at MemoryFileSystem.readFileSync (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack-dev-middleware/node_modules/memory-fs/lib/MemoryFileSystem.js:112:10)
    at MultiCompiler.multiCompiler.plugin.multiStats (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack-hot-server-middleware/src/index.js:119:33)
    at MultiCompiler.applyPlugins (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/tapable/lib/Tapable.js:25:14)
    at MultiCompiler.<anonymous> (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/MultiCompiler.js:76:10)
    at Compiler.applyPlugins (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/tapable/lib/Tapable.js:25:14)
    at Watching._done (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/Compiler.js:93:17)
    at /home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/Compiler.js:76:18
    at Compiler.emitRecords (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/Compiler.js:350:37)
    at /home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/Compiler.js:59:19
    at /home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/Compiler.js:343:11
    at next (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/tapable/lib/Tapable.js:118:11)
    at Compiler.<anonymous> (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/performance/SizeLimitsPlugin.js:115:3)
    at Compiler.applyPluginsAsyncSeries1 (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/tapable/lib/Tapable.js:122:13)
    at Compiler.afterEmit (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/Compiler.js:340:8)
    at Compiler.<anonymous> (/home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/lib/Compiler.js:335:14)
    at /home/cescoferraro/code/go/src/github.com/cescoferraro/spotify/node_modules/webpack/node_modules/async/dist/async.js:356:16

[cescoferraro]

@richardsarrott That’s what I am doing. I just created the express chunk to see if could bundle everything with webpack to get cool syntax, but you are right. It’s not worth it.

[cescoferraro]

I ended up doing

const env = process.env.NODE_ENV || 'development';
entry: {
	server: [env === "production" ? "./src/server" : "./src/middleware"]
},

So with NODE_ENV=production I endup with a single server bundle with all the dependencies. Its especially good for docker, because instead of doing

FROM  mhart/alpine-node:6
RUN npm init -y
RUN npm i express morgan
WORKDIR /srv/spotify
ADD src/hot.js /srv/spotify/hot.js
ADD www/ /srv/spotify/www
CMD ["node","hot.js"]

I can

FROM  mhart/alpine-node:base-6
WORKDIR /srv/spotify
ADD www/ /srv/spotify/www
CMD ["node","www/server.bundle.js"]

For this the client/middleware/server.tsx files live inside the src dir while I keep a hot.js file on my root. Not having hmr logic inside the app source code makes sense for me.