The code that does this for server-rendered js is in https://github.com/ReactTraining/react-router/blob/master/mo.... There's code to convert URL patterns to regular expressions in https://github.com/ReactTraining/react-router/blob/master/mo..., although that seems to work only for a single pattern and not all. Presumably you should find a way to convert all patterns to a single regex somewhere in the codebase and could use that to check the request in go.