Stop nullify cache

Author: vtm9

README.md

@@ -2,9 +2,6 @@
 
 [![Actions Status](https://github.com/hexlet-codebattle/codebattle/workflows/Build%20master/badge.svg)](https://github.com/hexlet-codebattle/codebattle/actions)
 [![codecov](https://codecov.io/gh/hexlet-codebattle/codebattle/branch/master/graph/badge.svg)](https://codecov.io/gh/hexlet-codebattle/codebattle)
-[![Maintainability](https://api.codeclimate.com/v1/badges/a99a88d28ad37a79dbf6/maintainability)](https://codeclimate.com/github/hexlet-codebattle/codebattle/maintainability)
-[![codebeat badge](https://codebeat.co/badges/7557979e-74a7-45a6-b9ab-dcd44bab7e5b)](https://codebeat.co/projects/github-com-hexlet-codebattle-codebattle-master)
-[![Hits](https://hits.seeyoufarm.com/api/count/incr/badge.svg?url=https%3A%2F%2Fgithub.com%2Fhexlet-codebattle%2Fcodebattle&count_bg=%2379C83D&title_bg=%23555555&icon=&icon_color=%23E7E7E7&title=hits&edge_flat=false)](https://hits.seeyoufarm.com)
 
 Codebattle - is an open source game being developed by the Hexlet community.
 The current version of the application is available at [codebattle.hexlet.io](https://codebattle.hexlet.io).

apps/codebattle/lib/codebattle/game/elo.ex

@@ -94,8 +94,8 @@ defmodule Codebattle.Game.Elo do
       end
 
     {
-      round(winner_rating + k * (s_winner - e_winner)),
-      round(loser_rating + k * (s_loser - e_loser))
+      (winner_rating + k * (s_winner - e_winner)) |> round() |> max(0),
+      (loser_rating + k * (s_loser - e_loser)) |> round() |> max(0)
     }
   end
 

apps/codebattle/lib/codebattle/game/engine.ex

@@ -613,7 +613,19 @@ defmodule Codebattle.Game.Engine do
       editor_text = Utils.sanitize_jsonb(player.editor_text)
 
       player
-      |> Map.take([:id, :result, :result_percent, :name, :clan_id, :is_bot, :lang, :editor_lang])
+      |> Map.take([
+        :id,
+        :result,
+        :result_percent,
+        :name,
+        :clan_id,
+        :is_bot,
+        :lang,
+        :editor_lang,
+        :rating,
+        :rating_diff,
+        :rank
+      ])
       |> Map.put(:editor_text, editor_text)
     end)
   end

apps/codebattle/lib/codebattle/game/player.ex

@@ -15,6 +15,7 @@ defmodule Codebattle.Game.Player do
   alias Runner.Languages
 
   @primary_key false
+  @default_rating 1200
   @default_editor_text ~s|const _ = require("lodash");\nconst R = require("rambda");\n\nconst solution = () => {\n\n};\n\nmodule.exports = solution;|
 
   @derive {Jason.Encoder,
@@ -70,7 +71,7 @@ defmodule Codebattle.Game.Player do
     field(:name, :string, default: "Ada Lovelace")
     field(:playbook_id, :integer, default: nil)
     field(:rank, :integer, default: -1)
-    field(:rating, :integer, default: 0)
+    field(:rating, :integer, default: @default_rating)
     field(:rating_diff, :integer, default: 0)
     field(:result, :string, default: "undefined")
     field(:result_percent, :float, default: 0.0)
@@ -119,7 +120,7 @@ defmodule Codebattle.Game.Player do
             clan_id: user.clan_id,
             name: user.name,
             avatar_url: user.avatar_url,
-            rating: user_game.rating,
+            rating: default_rating(user_game.rating, user.rating),
             rating_diff: user_game.rating_diff,
             editor_lang: get_editor_lang(user, params),
             lang: user.lang || Application.get_env(:codebattle, :default_lang_slug),
@@ -141,7 +142,7 @@ defmodule Codebattle.Game.Player do
       is_guest: false,
       clan_id: player.clan_id,
       name: player.name,
-      rating: player.rating,
+      rating: default_rating(player.rating),
       rank: player.rank,
       avatar_url: player.avatar_url,
       editor_lang: get_editor_lang(player, params),
@@ -167,7 +168,7 @@ defmodule Codebattle.Game.Player do
       is_guest: player.is_guest,
       clan_id: player.clan_id,
       name: player.name,
-      rating: player.rating,
+      rating: default_rating(player.rating),
       rank: player.rank,
       editor_lang: get_editor_lang(player, params),
       lang: player.lang || Application.get_env(:codebattle, :default_lang_slug),
@@ -198,7 +199,7 @@ defmodule Codebattle.Game.Player do
             is_guest: user.is_guest,
             name: user.name,
             clan_id: user.clan_id,
-            rating: user.rating,
+            rating: default_rating(user.rating),
             rank: user.rank,
             editor_lang: get_editor_lang(user, params),
             lang: user.lang || Application.get_env(:codebattle, :default_lang_slug),
@@ -277,4 +278,10 @@ defmodule Codebattle.Game.Player do
     do: user.style_lang || Application.get_env(:codebattle, :default_style_lang_slug)
 
   defp get_editor_lang(user, _params), do: user.lang || Application.get_env(:codebattle, :default_lang_slug)
+
+  defp default_rating(nil), do: @default_rating
+  defp default_rating(rating), do: rating
+
+  defp default_rating(nil, fallback), do: default_rating(fallback)
+  defp default_rating(rating, _fallback), do: rating
 end

apps/codebattle/lib/codebattle/tournament/player.ex

@@ -7,6 +7,7 @@ defmodule Codebattle.Tournament.Player do
   @type t :: %__MODULE__{}
 
   @primary_key false
+  @default_rating 1200
 
   @derive Jason.Encoder
 
@@ -58,7 +59,7 @@ defmodule Codebattle.Tournament.Player do
     field(:name, :string)
     field(:place, :integer, default: 0)
     field(:rank, :integer, default: 5432)
-    field(:rating, :integer)
+    field(:rating, :integer, default: @default_rating)
     field(:score, :integer, default: 0)
     field(:state, :string, default: "active")
     field(:task_ids, {:array, :integer}, default: [])

apps/codebattle/lib/codebattle/user.ex

@@ -171,7 +171,7 @@ defmodule Codebattle.User do
       name: "John Doe",
       subscription_type: :free,
       lang: Application.get_env(:codebattle, :default_lang_slug),
-      rating: 0,
+      rating: 1200,
       locale: Application.get_env(:codebattle, :default_locale, "en"),
       points: 0,
       rank: 0,

apps/codebattle/test/codebattle/game/context_test.exs

@@ -1,6 +1,7 @@
 defmodule Codebattle.Game.ContextTest do
   use Codebattle.DataCase
 
+  alias Codebattle.Game.GlobalSupervisor
   alias Codebattle.Game.Player
   alias Codebattle.Game.Server
   alias Codebattle.PubSub.Message
@@ -55,6 +56,18 @@ defmodule Codebattle.Game.ContextTest do
       assert {:error, :handoff_in_progress} = Game.Context.trigger_timeout(game_id)
       assert :ok == Server.unfreeze(game_id)
     end
+
+    test "preserves player ratings when reloading timed out game from db", %{user1: user1, user2: user2} do
+      {:ok, %{id: game_id}} =
+        Game.Context.create_game(%{state: "playing", players: [user1, user2], level: "easy"})
+
+      assert {:ok, _new_game} = Game.Context.trigger_timeout(game_id)
+      assert :ok = GlobalSupervisor.terminate_game(game_id)
+
+      reloaded_game = Game.Context.get_game!(game_id)
+
+      assert Enum.map(reloaded_game.players, & &1.rating) == [user1.rating, user2.rating]
+    end
   end
 
   describe "fetch_head_to_head_by_game_id/1" do

apps/codebattle/test/codebattle/game/elo_test.exs

@@ -0,0 +1,16 @@
+defmodule Codebattle.Game.EloTest do
+  use ExUnit.Case, async: true
+
+  alias Codebattle.Game.Elo
+
+  test "never returns negative ratings for low-rated losers" do
+    {winner_rating, loser_rating} = Elo.calc_elo(11, 0, "grand_slam", :win)
+
+    assert winner_rating >= 11
+    assert loser_rating == 0
+  end
+
+  test "preserves zero-change behavior for open tournaments" do
+    assert {0, 0} = Elo.calc_elo(0, 0, "open", :win)
+  end
+end