OnChange should invoke after data has been set

CHANGELOG.md

@@ -18,7 +18,7 @@ The format is based on [Keep a Changelog][kac], and this project adheres to
         -   Specifically happened when you had at least two pairs of different relations with multiple targets each
 -   `[hooks]`:
     -   Replaced `OnSet` with `OnChange`
-        -   The former was used to detect emplace/move actions. Now the behaviour for `OnChange` is that it will run only when the value is about to be changed allowing you to retrieve the old value when needed
+        -   The former was used to detect emplace/move actions. Now the behaviour for `OnChange` is that it will run only when the value has changed
     -   Changed `OnAdd` to specifically run after the data has been set for non-zero-sized components. Also returns the value that the component was set to
         -   This should allow a more lenient window for modifying data
     -   Changed `OnRemove` to lazily lookup which archetype the entity will move to

jecs.luau

@@ -124,12 +124,9 @@ local EcsOnArchetypeCreate =        HI_COMPONENT_ID + 12
 local EcsOnArchetypeDelete =        HI_COMPONENT_ID + 13
 local EcsRest =                     HI_COMPONENT_ID + 14
 
-local ECS_ID_DELETE =                        0b0000_0001
-local ECS_ID_IS_TAG =                        0b0000_0010
-local ECS_ID_HAS_ON_ADD =                    0b0000_0100
-local ECS_ID_HAS_ON_SET =                    0b0000_1000
-local ECS_ID_HAS_ON_REMOVE =                 0b0001_0000
-local ECS_ID_MASK =                          0b0000_0000
+local ECS_ID_DELETE =                        		0b01
+local ECS_ID_IS_TAG =                        		0b10
+local ECS_ID_MASK =                          		0b00
 
 local ECS_ENTITY_MASK =              bit32.lshift(1, 24)
 local ECS_GENERATION_MASK =          bit32.lshift(1, 16)
@@ -930,6 +927,10 @@ local function world_set(world: ecs_world_t, entity: i53, id: i53, data: unknown
 	local idr_hooks = idr.hooks
 
 	if from == to then
+		local tr = to.records[id]
+		local column = from.columns[tr]
+		column[record.row] = data
+
 		-- If the archetypes are the same it can avoid moving the entity
 		-- and just set the data directly.
 		local on_change = idr_hooks.on_change
@@ -937,9 +938,6 @@ local function world_set(world: ecs_world_t, entity: i53, id: i53, data: unknown
 			on_change(entity, data)
 		end
 
-		local tr = to.records[id]
-		local column = from.columns[tr]
-		column[record.row] = data
 		return
 	end
 
@@ -962,8 +960,6 @@ local function world_set(world: ecs_world_t, entity: i53, id: i53, data: unknown
 	if on_add then
 		on_add(entity, data)
 	end
-
-
 end
 
 local function world_component(world: World): i53

test/tests.luau

@@ -1665,11 +1665,20 @@ TEST("Hooks", function()
 		local Number = world:component()
 		local e1 = world:entity()
 
+		local call = 0
 		world:set(Number, jecs.OnChange, function(entity, data)
 			CHECK(e1 == entity)
-			CHECK(world:get(entity, Number) == nil)
+			if call == 1 then
+				CHECK(false)
+			elseif call == 2 then
+				CHECK(world:get(entity, Number) == data)
+			end
 			CHECK(data == 1)
 		end)
+
+		call = 1
+		world:set(e1, Number, 1)
+		call = 2
 		world:set(e1, Number, 1)
 	end