HMR (Hot-Module Replacement)

This is only one example, but there are many others that can easily trip people up. Luckily, there are a lot of loaders out there (some of which are mentioned below) that will make hot module replacement much easier. HMR with Stylesheets. Hot Module Replacement with CSS is actually fairly straightforward with the help of the style-loader. This loader uses module.hot.accept behind the scenes to patch <style> tags when CSS dependencies are updated.