In a previous post, I went over my process trying to develop a PostCSS plugin to make updating custom CSS for Google AMP easier. That plugin seems to be working okay (yay!) but since it’s not integrated into my Webpack build, there’s still a lot of manual work to be done and room for human error. 

So the next step was clearly to jump into learning Webpack plugins. I needed a plugin that could watch for CSS files created using the MiniCssExtractPlugin, filter out all the unnecessary styles, and create a new file just for AMP. The results are on GitHub. 

My build process is pretty simple so it’s very likely there are options or interactions I haven’t thought of. If you end up using it and notice any problems, let me know!