update state param handling to ueberauth v0.7.0

From v0.7.0 Ueberauth core lib handles state validation and passing it
directly through params no longer works.

Fix is to load state using new `with_state_param` helper that was added
in 0.7.0.

Author: robuye

lib/ueberauth/strategy/github.ex

@@ -74,6 +74,7 @@ defmodule Ueberauth.Strategy.Github do
   use Ueberauth.Strategy,
     uid_field: :id,
     default_scope: "",
+    send_redirect_uri: true,
     oauth2_module: Ueberauth.Strategy.Github.OAuth
 
   alias Ueberauth.Auth.Info
@@ -87,22 +88,14 @@ defmodule Ueberauth.Strategy.Github do
   them as part of your url:
 
       "/auth/github?scope=user,public_repo,gist"
-
-  You can also include a `:state` param that github will return to you.
   """
-  def handle_request!(conn) do
-    scopes = conn.params["scope"] || option(conn, :default_scope)
-    send_redirect_uri = Keyword.get(options(conn), :send_redirect_uri, true)
-
-    opts =
-      if send_redirect_uri do
-        [redirect_uri: callback_url(conn), scope: scopes]
-      else
-        [scope: scopes]
-      end
 
+  def handle_request!(conn) do
     opts =
-      if conn.params["state"], do: Keyword.put(opts, :state, conn.params["state"]), else: opts
+      []
+      |> with_scopes(conn)
+      |> with_state_param(conn)
+      |> with_redirect_uri(conn)
 
     module = option(conn, :oauth2_module)
     redirect!(conn, apply(module, :authorize_url!, [opts]))
@@ -279,4 +272,18 @@ defmodule Ueberauth.Strategy.Github do
   defp option(conn, key) do
     Keyword.get(options(conn), key, Keyword.get(default_options(), key))
   end
+
+  defp with_scopes(opts, conn) do
+    scopes = conn.params["scope"] || option(conn, :default_scope)
+
+    opts |> Keyword.put(:scope, scopes)
+  end
+
+  defp with_redirect_uri(opts, conn) do
+    if option(conn, :send_redirect_uri) do
+      opts |> Keyword.put(:redirect_uri, callback_url(conn))
+    else
+      opts
+    end
+  end
 end

mix.exs

@@ -27,7 +27,7 @@ defmodule Ueberauth.Github.Mixfile do
   defp deps do
     [
       {:oauth2, "~> 1.0 or ~> 2.0"},
-      {:ueberauth, "~> 0.6.0"},
+      {:ueberauth, "~> 0.7.0"},
       {:credo, "~> 0.8", only: [:dev, :test], runtime: false},
       {:ex_doc, ">= 0.0.0", only: :dev, runtime: false}
     ]