Add PresenceChannel.my_user_id/1

lib/poxa/presence_channel.ex

@@ -18,4 +18,15 @@ defmodule Poxa.PresenceChannel do
   """
   @spec user_count(binary) :: non_neg_integer
   def user_count(channel), do: channel |> users |> Enum.count
+
+  @doc """
+  Returns user data for a presence channel
+  """
+  @spec my_user_id(binary) :: {binary, map} | nil
+  def my_user_id(channel) do
+    case Poxa.registry.fetch(channel) do
+      {user_id, _} -> user_id
+      _ -> nil
+    end
+  end
 end

test/presence_channel_test.exs

@@ -25,4 +25,19 @@ defmodule Poxa.PresenceChannelTest do
 
     assert user_count("presence-channel") == 2
   end
+
+  test "return user_id if available" do
+    expect(Poxa.registry, :fetch, fn "presence-channel" ->
+      {:user_id, :user_info}
+    end)
+
+    assert my_user_id("presence-channel") == :user_id
+  end
+
+
+  test "return nil if user_id is not available" do
+    expect(Poxa.registry, :fetch, fn "presence-channel" -> nil end)
+
+    assert my_user_id("presence-channel") == nil
+  end
 end