Support private email as uid (#29)

* Support private email as uid

Handle email uid as a special case, s. #10 (comment)

* refactor email and uid fetching #29

* minor refactor #29

Author: bcat-eu

lib/ueberauth/strategy/github.ex

@@ -136,11 +136,7 @@ defmodule Ueberauth.Strategy.Github do
   Fetches the uid field from the Github response. This defaults to the option `uid_field` which in-turn defaults to `id`
   """
   def uid(conn) do
-    user =
-      conn
-      |> option(:uid_field)
-      |> to_string
-    conn.private.github_user[user]
+    conn |> option(:uid_field) |> to_string() |> fetch_uid(conn)
   end
 
   @doc """
@@ -170,7 +166,7 @@ defmodule Ueberauth.Strategy.Github do
     %Info{
       name: user["name"],
       nickname: user["login"],
-      email: user["email"] || Enum.find(user["emails"] || [], &(&1["primary"]))["email"],
+      email: fetch_email!(user),
       location: user["location"],
       image: user["avatar_url"],      
       urls: %{
@@ -203,6 +199,27 @@ defmodule Ueberauth.Strategy.Github do
     }
   end
 
+  defp fetch_uid("email", %{private: %{github_user: user}}) do
+    # private email will not be available as :email and must be fetched
+    fetch_email!(user)
+  end
+
+  defp fetch_uid(field, conn) do
+    conn.private.github_user[field]
+  end
+
+  defp fetch_email!(user) do
+    user["email"] || get_primary_email!(user)
+  end
+
+  defp get_primary_email!(user) do
+    unless user["emails"] && (Enum.count(user["emails"]) > 0) do
+      raise "Unable to access the user's email address"
+    end
+
+    Enum.find(user["emails"], &(&1["primary"]))["email"]
+  end
+
   defp fetch_user(conn, token) do
     conn = put_private(conn, :github_token, token)
     # Will be better with Elixir 1.3 with/else