Quest factory follows mod reloads; unknown saved quests kept; mod unit tests

tests/QuestsSaveableTests.cs

@@ -0,0 +1,48 @@
+namespace Cthangover.Mods.Quests.Tests
+{
+    using System.Collections.Generic;
+    using System.Linq;
+    using System.Text.Json;
+    using Cthangover.Core.Mods.Testing;
+    using Cthangover.Core.Quests;
+    using Cthangover.Core.Settings;
+
+    /// <summary>
+    /// The quests slot holds the state of every content mod's quests, so a
+    /// quest whose mod left the game is still in a loaded save: it must not
+    /// take part in the game, and the next save must write it back so its
+    /// progress returns with the mod.
+    /// </summary>
+    public class QuestsSaveableTests
+    {
+        private const string UnknownId = "__test_no_such_quest";
+
+        [ModTest("save/unknown_quest_survives_load_and_save")]
+        static void UnknownQuestSurvivesLoadAndSave(ModTestContext ctx)
+        {
+            var factory = QuestFactory.Instance;
+            var before = JsonSerializer.Serialize(factory.GetAll());
+            try
+            {
+                var unknown = new QuestBase { ID = UnknownId, Status = QuestStatus.Progress };
+                unknown.Data.Tags.Add("met");
+                var slot = new ModSlot();
+                slot.Data["Quests"] = new DataBlob(1, new List<QuestBase> { unknown });
+                var saveable = new QuestsSaveable();
+
+                ModAssert.True(saveable.OnLoad(slot, out _), "slot with an unknown quest loads");
+                ModAssert.False(factory.GetAll().Any(q => q.ID == UnknownId), "unknown quest takes no part in the game");
+
+                var saved = new ModSlot();
+                saveable.OnSave(saved);
+                var kept = saved.Data["Quests"].ReadJson<List<QuestBase>>().SingleOrDefault(q => q.ID == UnknownId);
+                ModAssert.NotNull(kept, "unknown quest written back");
+                ModAssert.True(kept.Status == QuestStatus.Progress && kept.Data.Tags.Contains("met"), "its status and tags kept");
+            }
+            finally
+            {
+                factory.SetAll(JsonSerializer.Deserialize<List<QuestBase>>(before));
+            }
+        }
+    }
+}