class ActionDispatch::Journey::Formatter

def generate(name, options, path_parameters)
  original_options = options.dup
  path_params = options.delete(:path_params) || {}
  options = path_params.merge(options)
  constraints = path_parameters.merge(options)
  missing_keys = nil
  match_route(name, constraints) do |route|
    parameterized_parts = extract_parameterized_parts(route, options, path_parameters)
    # Skip this route unless a name has been provided or it is a
    # standard Rails route since we can't determine whether an options
    # hash passed to url_for matches a Rack application or a redirect.
    next unless name || route.dispatcher?
    missing_keys = missing_keys(route, parameterized_parts)
    next if missing_keys && !missing_keys.empty?
    params = options.delete_if do |key, _|
      # top-level params' normal behavior of generating query_params
      # should be preserved even if the same key is also a bind_param
      parameterized_parts.key?(key) || route.defaults.key?(key) ||
        (path_params.key?(key) && !original_options.key?(key))
    end
    defaults       = route.defaults
    required_parts = route.required_parts
    route.parts.reverse_each do |key|
      break if defaults[key].nil? && parameterized_parts[key].present?
      next if parameterized_parts[key].to_s != defaults[key].to_s
      break if required_parts.include?(key)
      parameterized_parts.delete(key)
    end
    return RouteWithParams.new(route, parameterized_parts, params)
  end
  unmatched_keys = (missing_keys || []) & constraints.keys
  missing_keys = (missing_keys || []) - unmatched_keys
  MissingRoute.new(constraints, missing_keys, unmatched_keys, routes, name)
end