https://gist.github.com/barraponto/d7b1ed410f5ec7ccb574e40fd21faf39

extract-text-middleware.js

const ExtractTextPlugin = require('extract-text-webpack-plugin');

module.exports = (neutrino, options) => {
  // Supports neutrino-preset-web and any other preset following this pattern.
  const styleRule = neutrino.config.module.rule('style');
  const styleTest = styleRule.get('test');
  const styleFallback = {
    loader: styleRule.use('style').get('loader'),
    options: styleRule.use('style').get('options') };
  const styleLoaders = Array.from(styleRule.uses.store.keys())
    .filter((key) => key !== 'style')
    .map((key) => styleRule.use(key))
    .map((use) => ({loader: use.get('loader'), options: use.get('options')}));

  const loaders = ExtractTextPlugin.extract({
    fallback: options.fallback || styleFallback|| 'style-loader',
    use: options.use || styleLoaders || 'css-loader',
  });

  styleRule.uses.clear();
  loaders.forEach(({loader, options}) => {
    styleRule.use(loader).loader(loader).options(options);
  });

  neutrino.config.plugin('extract')
    .use(ExtractTextPlugin, [options.filename || '[name].css']);
};

Just wanted to give you a shout out that this worked so well! I can convert .scss to .css with neutrino no problem.

Why not publish it?

@leesiongchan it is published here :)

@jaridmargolin @leesiongchan @timkelty @kirikintha can you help try the preset out?
just run yarn add github:barraponto/neutrino-preset-extractstyles to install from github