Use Plug helpers to parse variables from routes

Author: mbuhot

lib/open_api_spex/operation.ex

@@ -60,29 +60,33 @@ defmodule OpenApiSpex.Operation do
   """
   @spec from_route(PathItem.route) :: {:ok, t} | {:error, String.t()}
   def from_route(route) do
-    operation = from_plug(route.plug, route.opts)
-    check_all_path_params_declared(operation, route.path)
+    operation = from_plug(route.plug, Map.get(route, :opts, []))
+
+    case route do
+      %{path: path} -> check_all_path_params_declared(operation, path)
+      _ -> {:ok, operation}
+    end
   end
 
   defp check_all_path_params_declared(operation, route_path) do
-    pattern = ~r/{(.*?)}/
-    expected_path_params =
-      pattern
-      |> Regex.scan(route_path)
-      |> Enum.map(fn [_match, param] -> param end)
+    {expected_path_params, _} = Plug.Router.Utils.build_path_match(route_path)
 
     actual_path_params =
       operation.parameters
-      |> Enum.filter(& &1.in == :path)
-      |> Enum.map(& &1.name |> to_string)
+      |> Enum.filter(&(&1.in == :path))
+      |> Enum.map(& &1.name)
 
     missing_params = expected_path_params -- actual_path_params
+
     case missing_params do
-      [] -> {:ok, operation}
+      [] ->
+        {:ok, operation}
+
       _ ->
         message =
           "Operation for route: #{inspect(route_path)} " <>
-          "did not declare path parameters: #{inspect(missing_params)}"
+            "did not declare path parameters: #{inspect(missing_params)}"
+
         {:error, message}
     end
   end

lib/open_api_spex/paths.ex

@@ -19,8 +19,7 @@ defmodule OpenApiSpex.Paths do
   @spec from_router(module) :: {:ok, t} | {:error, String.t()}
   def from_router(router) do
     router.__routes__()
-    |> Enum.map(fn route -> %{route | path: open_api_path(route.path)} end)
-    |> Enum.group_by(fn route -> route.path end)
+    |> Enum.group_by(fn route -> open_api_path(route.path) end)
     |> Enum.map(fn {path, routes} -> {path, PathItem.from_routes(routes)} end)
     |> Enum.reduce_while(%{}, fn
       {_path, {:error, reason}}, _acc -> {:halt, {:error, reason}}

test/operation_test.exs

@@ -5,12 +5,12 @@ defmodule OpenApiSpex.OperationTest do
 
   describe "Operation.from_route" do
     test "succeeds when all path params present" do
-      route = %{plug: UserController, opts: :show, path: "/users/{id}"}
+      route = %{plug: UserController, opts: :show, path: "/users/:id"}
       assert Operation.from_route(route) == {:ok, UserController.show_operation()}
     end
 
     test "Fails on missing path params" do
-      path = "/teams/{missing_team_id_param}/users/{id}"
+      path = "/teams/:missing_team_id_param/users/:id"
       route = %{plug: UserController, opts: :show, path: path}
       assert {:error, message} = Operation.from_route(route)
       assert message =~ "missing_team_id_param"