refactor vote calculation logic into module

Author: SophieDeBenedetto

lib/pointing_party/vote_calculator.ex

@@ -0,0 +1,29 @@
+defmodule PointingParty.VoteCalculator do
+  defp winning_vote(users) do
+    votes = Enum.map(users, fn {_username, %{metas: [%{points: points}]}} -> points end)
+    calculated_votes = Enum.reduce(votes, %{}, fn vote, acc ->
+      acc
+      |> Map.get_and_update(vote, &({&1, (&1 || 0) + 1}))
+      |> elem(1)
+    end)
+
+    total_votes = length(votes)
+
+    majority = Enum.reduce_while(calculated_votes, nil, fn {point, vote_count}, _acc ->
+      if vote_count == total_votes or rem(vote_count, total_votes) > 5 do
+        {:halt, point}
+      else
+        {:cont, nil}
+      end
+    end)
+
+    if is_nil(majority) do
+      calculated_votes
+      |> Enum.sort_by(&elem(&1, 1))
+      |> Enum.take(2)
+      |> Enum.map(&elem(&1, 0))
+    else
+      majority
+    end
+  end
+end

lib/pointing_party_web/channels/room_channel.ex

@@ -3,6 +3,7 @@ defmodule PointingPartyWeb.RoomChannel do
 
   alias PointingParty.Card
   alias PointingPartyWeb.Presence
+  alias PointingParty.VoteCalculator
 
   def join("room:lobby", _payload, socket) do
     send(self(), :after_join)
@@ -57,7 +58,7 @@ defmodule PointingPartyWeb.RoomChannel do
     current_users = Presence.list(socket)
 
     {event, points} =
-      case winning_vote(current_users) do
+      case VoteCalculator.winning_vote(current_users) do
         top_two when is_list(top_two) -> {"tie", top_two}
         winner -> {"winner", winner}
       end
@@ -91,32 +92,4 @@ defmodule PointingPartyWeb.RoomChannel do
     |> assign(:current, next)
     |> assign(:voted, [latest_card | socket.assigns[:voted]])
   end
-
-  defp winning_vote(users) do
-    votes = Enum.map(users, fn {_username, %{metas: [%{points: points}]}} -> points end)
-    calculated_votes = Enum.reduce(votes, %{}, fn vote, acc ->
-      acc
-      |> Map.get_and_update(vote, &({&1, (&1 || 0) + 1}))
-      |> elem(1)
-    end)
-
-    total_votes = length(votes)
-
-    majority = Enum.reduce_while(calculated_votes, nil, fn {point, vote_count}, _acc ->
-      if vote_count == total_votes or rem(vote_count, total_votes) > 5 do
-        {:halt, point}
-      else
-        {:cont, nil}
-      end
-    end)
-
-    if is_nil(majority) do
-      calculated_votes
-      |> Enum.sort_by(&elem(&1, 1))
-      |> Enum.take(2)
-      |> Enum.map(&elem(&1, 0))
-    else
-      majority
-    end
-  end
 end