The convention for React components is to use pascal case (FooBar.js). We could detect files using JSX and enforce pascal case and ignore the chosen case, but it's also common to have an index.js, routes.js or app-routes.js that has JSX in them, but are not components. So my proposal would be to add an option that, when enabled, would enforce either pascalCase (FooBar.js) or kebabCase (app-routes.js) for files with JSX. I think it would be safe to have it on by default. The option could be called react (Suggestions for a better option name welcome!).