Merge pull request #8 from dwyl/google-token-#7

Google token and user profile

README.md

@@ -23,4 +23,16 @@ config :elixir_auth_google,
   google_client_id: <YOUR-CLIENT-ID-HERE>,
   google_scope: "profile",
   google_redirect_uri: <REDIRECT_URI>,
+```
+
+- Create a new endpoint matching the `google_redirect_uri`.
+On this endpoint you can exchange the google code for the user's token and 
+then get the user profile:
+
+```eixir
+  def index(conn, %{"code" => code}) do
+    token = ElixirAuthGoogle.get_token(code)
+    profile = ElixirAuthGoogle.get_user_profile(token["access_token"])
+    render(conn, "index.html", profile: profile)
+  en
 ```

config/config.exs

@@ -1,7 +1,5 @@
 use Mix.Config
 
 if Mix.env() == :test do
-  # define configuration specific to test environment
-  # It can be useful when testing/mocking
-  nil
+  config :elixir_auth_google, httpoison: ElixirAuthGoogle.HTTPoison.InMemory
 end

lib/elixir_auth_google.ex

@@ -2,13 +2,46 @@ defmodule ElixirAuthGoogle do
   @moduledoc """
   Minimalist Google OAuth Authentication for Elixir Apps
   """
-  @google_url "https://accounts.google.com/o/oauth2/v2/auth?response_type=code"
+  @httpoison Application.get_env(:elixir_auth_google, :httpoison) || HTTPoison
+  @google_auth_url "https://accounts.google.com/o/oauth2/v2/auth?response_type=code"
+  @google_token_url "https://oauth2.googleapis.com/token"
+  @google_user_profile "https://www.googleapis.com/oauth2/v3/userinfo"
 
   def generate_oauth_url do
     client_id = Application.get_env(:elixir_auth_google, :google_client_id)
     scope = Application.get_env(:elixir_auth_google, :google_scope ) || "profile"
     redirect_uri = Application.get_env(:elixir_auth_google, :google_redirect_uri)
 
-    "#{@google_url}&client_id=#{client_id}&scope=#{scope}&redirect_uri=#{redirect_uri}"
+    "#{@google_auth_url}&client_id=#{client_id}&scope=#{scope}&redirect_uri=#{redirect_uri}"
   end
+
+  def get_token(code) do
+    body = Poison.encode!(
+      %{ client_id: Application.get_env(:elixir_auth_google, :google_client_id),
+         client_secret: Application.get_env(:elixir_auth_google, :google_client_secret),
+         redirect_uri: Application.get_env(:elixir_auth_google, :google_redirect_uri),
+         grant_type: "authorization_code",
+         code: code
+    })
+
+    @httpoison.post(@google_token_url, body)
+    |> parse_body_response()
+  end
+
+  def get_user_profile(token) do
+    "#{@google_user_profile}?access_token=#{token}"
+    |> @httpoison.get()
+    |> parse_body_response()
+  end
+
+  defp parse_body_response({:error, err}), do: {:error, err}
+  defp parse_body_response({:ok, response}) do
+    body = Map.get(response, :body)
+    if body == nil do
+      {:error, :no_body}
+    else
+      Poison.decode(body)
+    end
+  end
+
 end

lib/httpoison/in_memory.ex

@@ -0,0 +1,9 @@
+defmodule ElixirAuthGoogle.HTTPoison.InMemory do
+  def get("https://www.googleapis.com/oauth2/v3/userinfo?access_token=wrong_token") do
+    {:error, :bad_request}
+  end
+
+  def get(_url), do: {:ok, %{body: Poison.encode!(%{name: "dwyl"})}}
+
+  def post(_url, _body), do: {:ok, %{body: Poison.encode!(%{access_token: "token1"})}}
+end

mix.exs

@@ -8,7 +8,7 @@ defmodule ElixirAuthGoogle.MixProject do
     [
       app: :elixir_auth_google,
       version: @version,
-      elixir: "~> 1.8",
+      elixir: "~> 1.9",
       start_permanent: Mix.env() == :prod,
       deps: deps(),
       description: @description,
@@ -26,7 +26,8 @@ defmodule ElixirAuthGoogle.MixProject do
   # Run "mix help deps" to learn about dependencies.
   defp deps do
     [
-      {:httpoison, "~> 1.6"}
+      {:httpoison, "~> 1.6"},
+      {:poison, "~> 4.0"}
     ]
   end
 

mix.lock

@@ -6,6 +6,7 @@
   "metrics": {:hex, :metrics, "1.0.1", "25f094dea2cda98213cecc3aeff09e940299d950904393b2a29d191c346a8486", [:rebar3], [], "hexpm"},
   "mimerl": {:hex, :mimerl, "1.2.0", "67e2d3f571088d5cfd3e550c383094b47159f3eee8ffa08e64106cdf5e981be3", [:rebar3], [], "hexpm"},
   "parse_trans": {:hex, :parse_trans, "3.3.0", "09765507a3c7590a784615cfd421d101aec25098d50b89d7aa1d66646bc571c1", [:rebar3], [], "hexpm"},
+  "poison": {:hex, :poison, "4.0.1", "bcb755a16fac91cad79bfe9fc3585bb07b9331e50cfe3420a24bcc2d735709ae", [:mix], [], "hexpm"},
   "ssl_verify_fun": {:hex, :ssl_verify_fun, "1.1.5", "6eaf7ad16cb568bb01753dbbd7a95ff8b91c7979482b95f38443fe2c8852a79b", [:make, :mix, :rebar3], [], "hexpm"},
   "unicode_util_compat": {:hex, :unicode_util_compat, "0.4.1", "d869e4c68901dd9531385bb0c8c40444ebf624e60b6962d95952775cac5e90cd", [:rebar3], [], "hexpm"},
 }

test/elixir_auth_google_test.exs

@@ -6,4 +6,16 @@ defmodule ElixirAuthGoogleTest do
     Application.put_env(:elixir_auth_google, :google_client_id, 123)
     assert ElixirAuthGoogle.generate_oauth_url() =~ "https://accounts.google.com/o/oauth2/v2/auth?response_type=code"
   end
+
+  test "get Google token" do
+    assert ElixirAuthGoogle.get_token("ok_code") == {:ok, %{"access_token" => "token1"}}
+  end
+
+  test "get user profile" do
+    assert ElixirAuthGoogle.get_user_profile("123") == {:ok, %{"name" => "dwyl"}}
+  end
+
+  test "return error with incorrect token" do
+    assert ElixirAuthGoogle.get_user_profile("wrong_token") == {:error, :bad_request }
+  end
 end