From 2df4aeb207772e1579457732739f5fbbc880be38 Mon Sep 17 00:00:00 2001
From: friflo <ullrich@praetz.de>
Date: Thu, 13 Feb 2025 13:05:16 +0100
Subject: [PATCH] Test_StructuralChange_OldBehavior

---
 src/ECS/Archetype/EntityStore.cs              |   2 +-
 .../Arch/Test_StructuralChangeException.cs    |  14 +++
 .../Arch/Test_StructuralChange_OldBehavior.cs | 116 ++++++++++++++++++
 3 files changed, 131 insertions(+), 1 deletion(-)
 create mode 100644 src/Tests/ECS/Arch/Test_StructuralChange_OldBehavior.cs

diff --git a/src/ECS/Archetype/EntityStore.cs b/src/ECS/Archetype/EntityStore.cs
index c9eeb989..6c1a32fc 100644
--- a/src/ECS/Archetype/EntityStore.cs
+++ b/src/ECS/Archetype/EntityStore.cs
@@ -201,7 +201,7 @@ All methods calling MoveEntityTo() have a runtime exception upfront before calli
         }
     */
     internal static StructuralChangeException StructuralChangeWithinQueryLoop() {
-        return new StructuralChangeException("within a query loop");
+        return new StructuralChangeException("within query loop. See: https://friflo.gitbook.io/friflo.engine.ecs/documentation/query#structuralchangeexception");
     }
     
     /*
diff --git a/src/Tests/ECS/Arch/Test_StructuralChangeException.cs b/src/Tests/ECS/Arch/Test_StructuralChangeException.cs
index c6eae2cd..f941ae69 100644
--- a/src/Tests/ECS/Arch/Test_StructuralChangeException.cs
+++ b/src/Tests/ECS/Arch/Test_StructuralChangeException.cs
@@ -11,6 +11,20 @@ namespace Tests.ECS.Arch {
 
 public static class Test_StructuralChangeException
 {
+    [Test]
+    public static void Test_StructuralChangeException_Message()
+    {
+        var store = new EntityStore();
+        store.CreateEntity();
+        foreach (var entity in store.Entities)
+        {
+            var e = Assert.Throws<StructuralChangeException>(() => {
+                entity.AddTag<TestTag>();
+            });
+            Assert.AreEqual("within query loop. See: https://friflo.gitbook.io/friflo.engine.ecs/documentation/query#structuralchangeexception", e!.Message);
+        }
+    }
+    
     [Test]
     public static void Test_StructuralChangeException_Entities()
     {
diff --git a/src/Tests/ECS/Arch/Test_StructuralChange_OldBehavior.cs b/src/Tests/ECS/Arch/Test_StructuralChange_OldBehavior.cs
new file mode 100644
index 00000000..aa448326
--- /dev/null
+++ b/src/Tests/ECS/Arch/Test_StructuralChange_OldBehavior.cs
@@ -0,0 +1,116 @@
+using Friflo.Engine.ECS;
+using Friflo.Engine.ECS.Serialize;
+using NUnit.Framework;
+
+
+// ReSharper disable ConditionalTernaryEqualBranch
+// ReSharper disable CompareOfFloatsByEqualityOperator
+// ReSharper disable StringLiteralTypo
+// ReSharper disable InconsistentNaming
+namespace Tests.ECS.Arch {
+
+public static class Test_StructuralChange_OldBehavior
+{
+    [Test]
+    public static void Test_StructuralChange_OldBehavior_no_throw()
+    {
+        var store = new EntityStore();
+        store.CreateEntity(new MyComponent1(), new MyComponent2(), new MyComponent3(), new MyComponent4(), new MyComponent4());
+        {
+            var query = store.Query();
+            query.ThrowOnStructuralChange = false;
+            foreach (var entity in query.Entities)
+            {
+                TestNoExceptions(store, entity);
+            }
+        } {
+            var query = store.Query<MyComponent1>();
+            query.ThrowOnStructuralChange = false;
+            query.ForEachEntity((ref MyComponent1 _, Entity entity) =>
+            {
+                TestNoExceptions(store, entity);
+            });
+        }{
+            var query = store.Query<MyComponent1, MyComponent2>();
+            query.ThrowOnStructuralChange = false;
+            query.ForEachEntity((ref MyComponent1 _, ref MyComponent2 _, Entity entity) => 
+            {
+                TestNoExceptions(store, entity);
+            });
+        }{
+            var query = store.Query<MyComponent1, MyComponent2, MyComponent3>();
+            query.ThrowOnStructuralChange = false;
+            query.ForEachEntity((ref MyComponent1 _, ref MyComponent2 _, ref MyComponent3 _, Entity entity) => 
+            {
+                TestNoExceptions(store, entity);
+            });
+        }{
+            var query = store.Query<MyComponent1, MyComponent2, MyComponent3, MyComponent4>();
+            query.ThrowOnStructuralChange = false;
+            query.ForEachEntity((ref MyComponent1 _, ref MyComponent2 _, ref MyComponent3 _, ref MyComponent4 _, Entity entity) => 
+            {
+                TestNoExceptions(store, entity);
+            });
+        }{
+            var query = store.Query<MyComponent1, MyComponent2, MyComponent3, MyComponent4, MyComponent5>();
+            query.ThrowOnStructuralChange = false;
+            query.ForEachEntity((ref MyComponent1 _, ref MyComponent2 _, ref MyComponent3 _, ref MyComponent4 _, ref MyComponent5 _, Entity entity) => 
+            {
+                TestNoExceptions(store, entity);
+            });
+        }
+    }
+    
+    private static void TestNoExceptions(EntityStore store, Entity entity)
+    {
+        entity.AddTag<TestTag>();
+        entity.RemoveTag<TestTag>();
+
+        entity.AddComponent<Position>();
+        entity.RemoveComponent<Position>();
+        
+        var buffer = store.GetCommandBuffer();
+        buffer.Playback();
+        
+        var entityBatch = new EntityBatch();
+        entityBatch.ApplyTo(entity);
+        
+        TestMultiAddRemoveNoExceptions(entity);
+        
+        var converter = EntityConverter.Default;
+        var dataEntity = new DataEntity { pid = 1  };
+        converter.DataEntityToEntity(dataEntity, store, out _);
+    }
+    
+        
+    private static void TestMultiAddRemoveNoExceptions(Entity entity)
+    {
+        // --- add multiple components
+        entity.Add(new Position());
+        entity.Add(new Position(), new Scale3());
+        entity.Add(new Position(), new Scale3(), new Rotation());
+        entity.Add(new Position(), new Scale3(), new Rotation(), new MyComponent1());
+        entity.Add(new Position(), new Scale3(), new Rotation(), new MyComponent1(), new MyComponent2());
+        entity.Add(new Position(), new Scale3(), new Rotation(), new MyComponent1(), new MyComponent2(), new MyComponent3());
+        entity.Add(new Position(), new Scale3(), new Rotation(), new MyComponent1(), new MyComponent2(), new MyComponent3(), new MyComponent4());
+        entity.Add(new Position(), new Scale3(), new Rotation(), new MyComponent1(), new MyComponent2(), new MyComponent3(), new MyComponent4(), new MyComponent5());
+        entity.Add(new Position(), new Scale3(), new Rotation(), new MyComponent1(), new MyComponent2(), new MyComponent3(), new MyComponent4(), new MyComponent5(), new MyComponent6());
+        entity.Add(new Position(), new Scale3(), new Rotation(), new MyComponent1(), new MyComponent2(), new MyComponent3(), new MyComponent4(), new MyComponent5(), new MyComponent6(), new MyComponent7());
+        
+        // --- remove multiple components
+        entity.Remove<Position>();
+        entity.Remove<Position, Scale3>();
+        entity.Remove<Position, Scale3, Rotation>();
+        entity.Remove<Position, Scale3, Rotation, MyComponent1>();
+        entity.Remove<Position, Scale3, Rotation, MyComponent1, MyComponent2>();
+        entity.Remove<Position, Scale3, Rotation, MyComponent1, MyComponent2, MyComponent3>();
+        entity.Remove<Position, Scale3, Rotation, MyComponent1, MyComponent2, MyComponent3, MyComponent4>();
+        entity.Remove<Position, Scale3, Rotation, MyComponent1, MyComponent2, MyComponent3, MyComponent4, MyComponent5>();
+        entity.Remove<Position, Scale3, Rotation, MyComponent1, MyComponent2, MyComponent3, MyComponent4, MyComponent5, MyComponent6>();
+        entity.Remove<Position, Scale3, Rotation, MyComponent1, MyComponent2, MyComponent3, MyComponent4, MyComponent5, MyComponent6, MyComponent7>();
+    }
+    
+}
+
+}
+