From c0a8d719ef23d433731d80d136465bbcdb71923f Mon Sep 17 00:00:00 2001
From: Nikola Begedin <begedinnikola@gmail.com>
Date: Mon, 18 Sep 2017 15:02:56 +0200
Subject: [PATCH] Rewrote api helpers to use string ids, which is what our
 ember client sends

This reveals a bug in the comment controller, which is now fixed.
---
 .../controllers/comment_controller.ex         |  1 +
 lib/code_corps_web/plugs/ids_to_integers.ex   | 10 ++++--
 test/support/json_api_helpers.ex              | 32 +++++++++----------
 3 files changed, 24 insertions(+), 19 deletions(-)

diff --git a/lib/code_corps_web/controllers/comment_controller.ex b/lib/code_corps_web/controllers/comment_controller.ex
index bc5103919..9e4384208 100644
--- a/lib/code_corps_web/controllers/comment_controller.ex
+++ b/lib/code_corps_web/controllers/comment_controller.ex
@@ -5,6 +5,7 @@ defmodule CodeCorpsWeb.CommentController do
 
   action_fallback CodeCorpsWeb.FallbackController
   plug CodeCorpsWeb.Plug.DataToAttributes
+  plug CodeCorpsWeb.Plug.IdsToIntegers
 
   @spec index(Conn.t, map) :: Conn.t
   def index(%Conn{} = conn, %{} = params) do
diff --git a/lib/code_corps_web/plugs/ids_to_integers.ex b/lib/code_corps_web/plugs/ids_to_integers.ex
index 191844e10..9b78eaf56 100644
--- a/lib/code_corps_web/plugs/ids_to_integers.ex
+++ b/lib/code_corps_web/plugs/ids_to_integers.ex
@@ -1,7 +1,11 @@
 defmodule CodeCorpsWeb.Plug.IdsToIntegers do
   @moduledoc ~S"""
-  Converts id values (primary or relationships) in a conn params map into
-  integers, if applicable.
+  Converts `id` values in a `conn` parameters map into integers, if applicable.
+
+  The JSON API specification expects `id` values in resource objects to be
+  strings.
+
+  See http://jsonapi.org/format/#document-resource-object-identification
   """
 
   alias Plug.Conn
@@ -22,7 +26,7 @@ defmodule CodeCorpsWeb.Plug.IdsToIntegers do
 
   @spec convert_key_value(tuple) :: tuple
   defp convert_key_value({key, value}) do
-    case key |> convert?() do
+    case convert?(key) do
       true -> {key, value |> ensure_integer()}
       false -> {key, value}
     end
diff --git a/test/support/json_api_helpers.ex b/test/support/json_api_helpers.ex
index 0f28dc1ed..41946cbc8 100644
--- a/test/support/json_api_helpers.ex
+++ b/test/support/json_api_helpers.ex
@@ -3,14 +3,19 @@ defmodule CodeCorps.JsonAPIHelpers do
     with attributes <- build_attributes(attrs),
          relationships <- build_relationships(attrs)
     do
-      build_payload(attributes, relationships)
+      %{
+        "data" => %{
+          "attributes" => attributes,
+          "relationships" => relationships
+        }
+      }
     end
   end
 
   defp build_attributes(attrs) do
     attrs
     |> Enum.filter(&is_attribute(&1))
-    |> Enum.reduce(%{}, &insert_string_key(&1, &2))
+    |> Enum.reduce(%{}, &add_attribute(&1, &2))
   end
 
   defp build_relationships(attrs) do
@@ -19,11 +24,12 @@ defmodule CodeCorps.JsonAPIHelpers do
     |> Enum.reduce(%{}, &Map.merge(&2, &1))
   end
 
-  defp build_relationship({key, record}) do
-    with id <- record.id,
-         type <- model_name_as_string(record)
+  defp build_relationship({atom_key, record}) do
+    with id <- record.id |> to_correct_type(),
+         type <- record |> model_name_as_string(),
+         string_key = atom_key |> Atom.to_string
     do
-      %{} |> Map.put(Atom.to_string(key), %{"data" => %{"id" => id, "type" => type}})
+      %{} |> Map.put(string_key, %{"data" => %{"id" => id, "type" => type}})
     end
   end
 
@@ -40,16 +46,10 @@ defmodule CodeCorps.JsonAPIHelpers do
     |> String.downcase
   end
 
-  defp insert_string_key({key, value}, map) do
-    with string_key <- Atom.to_string(key), do: Map.put(map, string_key, value)
+  defp add_attribute({key, value}, %{} = attrs) do
+    attrs |> Map.put(key |> Atom.to_string, value)
   end
 
-  defp build_payload(attributes, relationships) do
-    %{
-      "data" => %{
-        "attributes" => attributes,
-        "relationships" => relationships
-      }
-    }
-  end
+  defp to_correct_type(value) when is_integer(value), do: value |> Integer.to_string
+  defp to_correct_type(value), do: value
 end