babel having trouble with import statement - node.js

Question

I have a project I'm doing with node in ES6 which was using babel-node to run. Now I'm trying to implement babel in a more production manner and have tried two attempts.
Webpack babel-loader with following configuration:
module.exports = {
entry: './src/cloud/main.js',
devtool: 'source-map',
output: {
path: './src/static/build',
filename: 'bundle.js'
},
module: {
loaders: [
{
test: /\.js$/,
exclude: /node_modules/,
loaders: [
'babel-loader?presets[]=es2015',
],
},
{
test: /\.css$/,
loaders: [
'style-loader',
'css-loader',
],
},
{
test: /\.html$/,
loaders: [
'raw-loader',
],
},
],
},
}
It started complaining about the import statement in main.js and to silence it I used ?presets[]=es2015 which I found in a similar question. Then the problem arrived in which it filtered to the import statements that went to node_modules with the following message:
ERROR in ./~/socket.io/lib/index.js
Module not found: Error: Cannot resolve module 'fs' in
My other approach was with the register hook like this:
require('babel-core/register')({
ignore: /node_modules/,
});
require('./main.js');
but it threw this message:
import express from 'express';
^^^^^^
SyntaxError: Unexpected reserved word
//main.js - simplified
import express from 'express'
const app = express()
const server = app.listen(port, () => {
console.log(`Listening at http://${server.address().address === '::' ? 'localhost' : server.address().address}:${server.address().port}`)
})

Answer 1

I don't think you need to exclude the node_modules in your loader config. However, you might want to let webpack know what to resolve. Try adding something like this:
resolve: {
root: path.join(__dirname),
fallback: path.join(__dirname, 'node_modules'),
modulesDirectories: ['node_modules'],
extensions: ['', '.json', '.js', '.jsx', '.scss', '.png', '.jpg', '.jpeg', '.gif']
},
The modulesDirectories key should keep webpack from running down every single require / import in your working directory.
Also, adding target to the top of your config should resolve issues with builtins like fs
target: 'node'

Answer 2

Ok I figured it out thanks to other answers and 4m1r' answer. I post the example code.
var path = require('path');
var fs = require('fs');
var nodeModules = {};
fs.readdirSync('node_modules')
.filter(function (x) {
return ['.bin'].indexOf(x) === -1;
})
.forEach(function (mod) {
nodeModules[mod] = 'commonjs ' + mod;
});
module.exports = {
name: 'server',
target: 'node',
context: path.join(__dirname, 'src', 'cloud'),
entry: {
server: './main.js'
},
output: {
path: path.join(__dirname),
filename: '[name].js'
},
externals: nodeModules,
module: {
loaders: [
{test: /\.js$/, exclude: /node_modules/, loaders: ['babel-loader?presets[]=es2015']}
]
},
resolve: {
root: path.join(__dirname),
fallback: path.join(__dirname, 'node_modules'),
modulesDirectories: ['node_modules'],
}
};
What was really important too was the externals key which prevented it fro leaking to the node_modules through requires and specifying for some reason ?presets[]=2015 in the babel-loader. I'm accepting 4m1r because it was what finally fixed the code.