From 2d801249bd708457a8e9d02d5a7752cdaa658d35 Mon Sep 17 00:00:00 2001
From: Javier Peletier <jpeletier@users.noreply.github.com>
Date: Thu, 31 Oct 2024 15:41:58 +0100
Subject: [PATCH] #1414 Notify on enum modifications

---
 distr/flecs.c             |  1 +
 src/addons/meta/meta.c    |  1 +
 test/meta/project.json    |  3 ++-
 test/meta/src/EnumTypes.c | 48 +++++++++++++++++++++++++++++++++++++++
 test/meta/src/main.c      |  7 +++++-
 5 files changed, 58 insertions(+), 2 deletions(-)

diff --git a/distr/flecs.c b/distr/flecs.c
index ab0c925acb..5c718e12aa 100644
--- a/distr/flecs.c
+++ b/distr/flecs.c
@@ -50168,6 +50168,7 @@ int flecs_add_constant_to_enum(
     cptr = ecs_ensure_id(world, e, type);
     cptr[0] = value;
 
+    ecs_modified(world, type, EcsEnum);
     return 0;
 }
 
diff --git a/src/addons/meta/meta.c b/src/addons/meta/meta.c
index a0e9af38c1..45660a4392 100644
--- a/src/addons/meta/meta.c
+++ b/src/addons/meta/meta.c
@@ -638,6 +638,7 @@ int flecs_add_constant_to_enum(
     cptr = ecs_ensure_id(world, e, type);
     cptr[0] = value;
 
+    ecs_modified(world, type, EcsEnum);
     return 0;
 }
 
diff --git a/test/meta/project.json b/test/meta/project.json
index 8609a38fd8..df98e2a79e 100644
--- a/test/meta/project.json
+++ b/test/meta/project.json
@@ -81,7 +81,8 @@
                 "struct_w_enum",
                 "zero_initialized",
                 "enum_relation",
-                "enum_w_short_notation"
+                "enum_w_short_notation",
+                "enum_modified_event"
             ]
         }, {
             "id": "BitmaskTypes",
diff --git a/test/meta/src/EnumTypes.c b/test/meta/src/EnumTypes.c
index f040c45a57..86650d9343 100644
--- a/test/meta/src/EnumTypes.c
+++ b/test/meta/src/EnumTypes.c
@@ -263,3 +263,51 @@ void EnumTypes_constant_w_type_prefix(void) {
 void EnumTypes_constant_w_name_type_prefix(void) {
     // Implement testcase
 }
+
+
+int enum_modified_calls = 0;
+
+static
+void enum_modified(ecs_iter_t *it) {
+    enum_modified_calls ++;
+}
+
+/* Checks that observers watching enum changes are notified */
+void EnumTypes_enum_modified_event(void) {
+    ecs_world_t *world = ecs_init();
+
+    ecs_observer(world, {
+        .query.terms[0] = { .id = ecs_id(EcsEnum) },
+        .events = {EcsOnSet},
+        .callback = enum_modified
+    });
+
+    ecs_entity_t e = ecs_enum_init(world, &(ecs_enum_desc_t){
+        .constants = {
+            {"Red"}, {"Blue"}
+        }
+    });
+
+    test_assert(e != 0);
+    /* must receive two calls, one for each enum member added */
+    test_int(enum_modified_calls, 2); 
+
+    /* run-time add a new member constant to the enum: */
+    ecs_entity_t old_scope = ecs_set_scope(world, e);
+    ecs_entity_t c = ecs_entity(world, {
+        .name = "Orange"
+    });
+    ecs_add_id(world, c, EcsConstant);
+    ecs_set_scope(world, old_scope);
+
+    /* check if observer was called after adding */
+    /* a new member constant */
+    test_int(enum_modified_calls, 3); 
+
+    meta_test_enum(world, e, 3);
+    meta_test_constant(world, e, "Red", 0);
+    meta_test_constant(world, e, "Blue", 1);
+    meta_test_constant(world, e, "Orange", 2);
+
+    ecs_fini(world);
+}
\ No newline at end of file
diff --git a/test/meta/src/main.c b/test/meta/src/main.c
index a17c93c890..e65dd4a340 100644
--- a/test/meta/src/main.c
+++ b/test/meta/src/main.c
@@ -75,6 +75,7 @@ void EnumTypes_struct_w_enum(void);
 void EnumTypes_zero_initialized(void);
 void EnumTypes_enum_relation(void);
 void EnumTypes_enum_w_short_notation(void);
+void EnumTypes_enum_modified_event(void);
 
 // Testsuite 'BitmaskTypes'
 void BitmaskTypes_bitmask_1_constant(void);
@@ -1257,6 +1258,10 @@ bake_test_case EnumTypes_testcases[] = {
     {
         "enum_w_short_notation",
         EnumTypes_enum_w_short_notation
+    },
+    {
+        "enum_modified_event",
+        EnumTypes_enum_modified_event
     }
 };
 
@@ -4866,7 +4871,7 @@ static bake_test_suite suites[] = {
         "EnumTypes",
         NULL,
         NULL,
-        8,
+        9,
         EnumTypes_testcases
     },
     {