feat: add test for changes to room

lib/viral_spiral/entity/room.ex

@@ -33,6 +33,19 @@ defmodule ViralSpiral.Entity.Room do
           volatality: EngineConfig.volatility()
         }
 
+  def new() do
+    engine_config = %EngineConfig{}
+
+    %Room{
+      id: UXID.generate!(prefix: "room", size: :small),
+      name: name(),
+      state: :uninitialized,
+      chaos_counter: engine_config.chaos_counter,
+      chaos: engine_config.chaos_counter,
+      volatality: engine_config.volatility
+    }
+  end
+
   @doc """
   Reserve a room.
 
@@ -80,19 +93,6 @@ defmodule ViralSpiral.Entity.Room do
     }
   end
 
-  def new() do
-    engine_config = %EngineConfig{}
-
-    %Room{
-      id: UXID.generate!(prefix: "room", size: :small),
-      name: name(),
-      state: :uninitialized,
-      chaos_counter: engine_config.chaos_counter,
-      chaos: engine_config.chaos_counter,
-      volatality: engine_config.volatility
-    }
-  end
-
   def set_state(%Room{} = room, state) when state in @all_states do
     %{room | state: state}
   end
@@ -162,7 +162,6 @@ defmodule ViralSpiral.Entity.Room do
 end
 
 defimpl ViralSpiral.Entity.Change, for: ViralSpiral.Entity.Room do
-  alias ViralSpiral.Game.State
   alias ViralSpiral.Entity.Room
 
   @doc """

test/viral_spiral/entity/room_test.exs

@@ -0,0 +1,44 @@
+defmodule ViralSpiral.Entity.RoomTest do
+  alias ViralSpiral.Room.EngineConfig
+  alias ViralSpiral.Room.ChangeDescriptions
+  alias ViralSpiral.Entity.Change
+  alias ViralSpiral.Entity.Room
+  use ExUnit.Case
+
+  describe "deterministic room configs" do
+    test "communities - yellow, red; affinities - sock, houseboat" do
+      :rand.seed(:exsss, {1, 8, 12})
+      room = Room.reserve("hello") |> Room.start(4)
+
+      assert room.name == "hello"
+      assert room.affinities == [:houseboat, :skub]
+      assert room.communities == [:red, :yellow, :blue]
+      assert room.chaos == 0
+      assert room.chaos_counter == 10
+    end
+  end
+
+  describe "changes" do
+    setup do
+      room = %Room{chaos: 4}
+      %{room: room}
+    end
+
+    test "change chaos countdown", %{room: room} do
+      new_room = Change.apply_change(room, ChangeDescriptions.change_chaos(5))
+      assert new_room.chaos == 9
+    end
+
+    test "pass invalid offset in change description", %{room: room} do
+      assert_raise ArithmeticError, fn ->
+        Change.apply_change(room, ChangeDescriptions.change_chaos("hi"))
+      end
+    end
+
+    test "pass opts without required fields", %{room: room} do
+      assert_raise ArgumentError, fn ->
+        Change.apply_change(room, invalid: "random")
+      end
+    end
+  end
+end