function has_correct_case(file, assets) {
	if (file === assets) return true;

	const parent = path.dirname(file);

	if (fs.readdirSync(parent).includes(path.basename(file))) {
		return has_correct_case(parent, assets);
	}

	return false;
}
Determine if a file is being requested with the correct case,
to ensure consistent behaviour between dev and prod and across
operating systems. Note that we can't use realpath here,
because we don't want to follow symlinks
@param {string} file
@param {string} assets
@returns {boolean}