Webpack bundle imports with an # - node.js

Question

I am trying to bundle a Node Express server built with TypeScript using Webpack.
Compiling/Transpiling into one JavaScript file server.js works well, but the file does not seem to have all necessary imports included. If the file is in dist/server.js and there are still Node modules in node_modules/..., then starting the server using node dist/server.js works well. But if I copy the server.js to any other location without also copying the Node modules, and then start it, it does not find classes imported with an #.
Possible error:
mysystem:Desktop myuser$ node server.js
internal/modules/cjs/loader.js:582
throw err;
^
Error: Cannot find module '#overnightjs/core'
at Function.Module._resolveFilename (internal/modules/cjs/loader.js:580:15)
at Function.Module._load (internal/modules/cjs/loader.js:506:25)
at Module.require (internal/modules/cjs/loader.js:636:17)
at require (internal/modules/cjs/helpers.js:20:18)
at Object.<anonymous> (/Users/myuser/Desktop/server.js:1:1422)
at a (/Users/myuser/Desktop/server.js:1:172)
at Object.<anonymous> (/Users/myuser/Desktop/server.js:1:6473)
at a (/Users/myuser/Desktop/server.js:1:172)
at Object.<anonymous> (/Users/myuser/Desktop/server.js:1:6233)
at a (/Users/myuser/Desktop/server.js:1:172)
I think that I might have something missing in my Webpack configuration file, which is:
const path = require('path');
const nodeExternals = require('webpack-node-externals');
const { CleanWebpackPlugin } = require('clean-webpack-plugin');
module.exports = {
entry: "./src/start.ts",
output: {
filename: "server.js",
path: path.resolve(__dirname, "dist")
},
node: {
// Need this when working with express, otherwise the build fails
__dirname: false, // if you don't put this is, __dirname
__filename: false, // and __filename return blank or /
fs: 'empty',
},
resolve: {
alias: {},
// Add '.ts', and '.tsx' as resolvable exteensions.
extensions: [".ts", ".tsx", ".js", ".json"]
},
externals: [nodeExternals()], // Need this to avoid error when working with Express
module: {
rules: [
// All files with a '.ts' or '.tsx' extension will be handled by 'awesome-typescript-loader'.
{ test: /\.tsx?$/, loader: "awesome-typescript-loader" },
// All output '.js' files will have any sourcemaps re-processed by 'source-map-loader'.
{ enforce: "pre", test: /\.js$/, loader: "source-map-loader" }
]
},
plugins: [
new CleanWebpackPlugin({
cleanAfterEveryBuildPatterns: ['dist']
})
]
};
The versions I use:
Node (v10.13.0)
yarn (1.7.0)
Express (4.17.1)
TypeScript (3.7.4)
Webpack (4.41.4)
Webpack-CLI (3.3.10)
How can I also add imports starting with an # into the bundle in Webpack?

Answer 1

It is make sense, Your externals config tells webpack not to bundle node_modules into the bundle but require them at run time.
This means that if you are not copying node_modules to the new location, it will try to require it, and will fail.
Usually it is best practice not to bundle node_modules whenever you are creating a node bundle.
You have 2 choices:
Remove externals config - will increase bundle size cause it will contain all the node_modules that your app is using.
Installing a fresh node_modules on you new location, if this location is a production env, you can use npm install --production which will install only the dependencies without devDependencies.

Answer 2

Don't bundle modules when transpiling TypeScript. Standard practice is two download modules wherever you've deployed you server. Make sure to use the production flag if you're all done developing. npm i --production