From abc8cf2b480aa7e56fc6dee65f4412c42a2472a4 Mon Sep 17 00:00:00 2001
From: Klemen Plestenjak <plestenjak.klemen@gmail.com>
Date: Sun, 3 Dec 2023 08:29:00 +0100
Subject: [PATCH] Add ecs defer test

---
 engine/tests/CMakeLists.txt   |  3 ++
 engine/tests/ecs_defer_test.c | 93 +++++++++++++++++++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 engine/tests/ecs_defer_test.c

diff --git a/engine/tests/CMakeLists.txt b/engine/tests/CMakeLists.txt
index 58d6b16..4e7b52c 100644
--- a/engine/tests/CMakeLists.txt
+++ b/engine/tests/CMakeLists.txt
@@ -8,6 +8,9 @@ target_link_libraries(window_test LINK_PRIVATE Breeze)
 add_executable(cute_tiled_test cute_tiled_test.c)
 target_link_libraries(cute_tiled_test LINK_PRIVATE Breeze)
 
+add_executable(ecs_defer_test ecs_defer_test.c)
+target_link_libraries(ecs_defer_test LINK_PRIVATE Breeze)
+
 add_executable(heap_test heap_test.c)
 target_link_libraries(heap_test LINK_PRIVATE Breeze)
 
diff --git a/engine/tests/ecs_defer_test.c b/engine/tests/ecs_defer_test.c
new file mode 100644
index 0000000..757b135
--- /dev/null
+++ b/engine/tests/ecs_defer_test.c
@@ -0,0 +1,93 @@
+#include <flecs.h>
+#include <stdio.h>
+
+typedef struct Data {
+    int x;
+} Data;
+
+typedef struct Test {
+    Data* ptr;
+} Test;
+
+ECS_COMPONENT_DECLARE(Test);
+
+ECS_CTOR(Test, ptr, {
+    ptr->ptr = ecs_os_malloc(sizeof(Data));
+    ptr->ptr->x = 0; // Default value
+    printf("ctor: %d\n", ptr->ptr->x);
+})
+ECS_DTOR(Test, ptr, {
+    printf("dtor: %d\n", ptr->ptr->x);
+    ecs_os_free(ptr->ptr);
+})
+ECS_MOVE(Test, dst, src, {
+    printf("move: %d->%d\n", src->ptr->x, dst->ptr->x);
+    dst->ptr = src->ptr;
+    // Clear the pointer in src since it's been moved tp dst and we
+    // don't want to free it when `src` ges destroyed
+    src->ptr = NULL;
+})
+
+void testRemoved(ecs_iter_t *it) {
+    Test *test = ecs_field(it, Test, 1);
+    for (int i = 0; i < it->count; i++) {
+        printf("on_remove: %d\n", test[i].ptr->x);
+    }
+}
+void testSet(ecs_iter_t *it) {
+    Test *test = ecs_field(it, Test, 1);
+    for (int i = 0; i < it->count; i++) {
+        printf("on_set: %d\n", test[i].ptr->x);
+    }
+}
+
+void ecs_copy_illegal(void *dst, const void *src, int32_t c, const ecs_type_info_t *ti) {
+    ecs_abort(ECS_INVALID_OPERATION, "invalid copy assignment for %s", ti->name);
+}
+
+int main(int argc, char *argv[]) {
+    ecs_world_t *ecs = ecs_init();
+    ECS_COMPONENT_DEFINE(ecs, Test);
+
+    ecs_set_hooks(ecs, Test, {
+        .ctor = ecs_ctor(Test),
+        .dtor = ecs_dtor(Test),
+        .move = ecs_move(Test),
+        .copy = ecs_copy_illegal, // Prevent Test from being copied so that they never share the same pointer
+
+        .on_remove = testRemoved,
+        .on_set = testSet
+    });
+
+    ecs_entity_t entity = ecs_new_id(ecs);
+    Test* test = ecs_emplace(ecs, entity, Test); // Emplace the component, this doesn't call the ctor allowing us to initialize the data in the table directly
+    Data* ptr = ecs_os_malloc(sizeof(Data));
+    ptr->x = 1;
+    test->ptr = ptr;
+    ecs_modified(ecs, entity, Test); // Tell the ECS that we are done with modifying the component
+
+    // Modify the data in the component without doing any copy/move
+    test = ecs_get_mut(ecs, entity, Test);
+    test->ptr->x = 2;
+    ecs_modified(ecs, entity, Test);
+
+    ecs_remove(ecs, entity, Test); // testRemoved called for {2}
+
+    // Since the component was previously removed this will call the constructor to initialize the
+    // default value in the table, and then return that.
+    test = ecs_get_mut(ecs, entity, Test);
+    test->ptr->x = 3;
+    ecs_modified(ecs, entity, Test);
+
+    ecs_defer_begin(ecs);
+    ecs_remove(ecs, entity, Test);
+
+    test = ecs_get_mut(ecs, entity, Test);
+    test->ptr->x = 4;
+    ecs_modified(ecs, entity, Test);
+
+    ecs_defer_end(ecs);
+
+    ecs_fini(ecs); // testRemoved called for {4}
+}
+