make ordering work with rust systems

Author: makspll

assets/tests/add_system/added_system_can_be_queried.lua

@@ -0,0 +1,48 @@
+-- add two systems, one before and one after the existing `on_test_post_update` callback, then assert all systems have run
+-- in the `on_test_last` callback
+
+local runs = {}    
+
+-- runs on `Update`
+function on_test()
+    local post_update_schedule = world.get_schedule_by_name("PostUpdate")
+    
+    local test_system = post_update_schedule:get_system_by_name("on_test_post_update")
+    
+    local system_after = world.add_system(
+        post_update_schedule,
+        system_builder("custom_system_after", script_id)
+            :after(test_system)
+    )
+        
+    local system_before = world.add_system(
+        post_update_schedule,
+        system_builder("custom_system_before", script_id)
+            :before(test_system)
+    )    
+end
+
+
+function custom_system_before()
+    print("custom_system_before")
+    runs[#runs + 1] = "custom_system_before"
+end
+
+-- runs on post_update 
+function on_test_post_update()
+    print("on_test_post_update")
+    runs[#runs + 1] = "on_test_post_update"
+end
+
+function custom_system_after()
+    print("custom_system_after")
+    runs[#runs + 1] = "custom_system_after"
+end
+
+-- runs in the `Last` bevy schedule
+function on_test_last()
+    assert(#runs == 3, "Expected 3 runs, got: " .. #runs)
+    assert(runs[1] == "custom_system_before", "Expected custom_system_before to run first, got: " .. runs[1])
+    assert(runs[2] == "on_test_post_update", "Expected on_test_post_update to run second, got: " .. runs[2])
+    assert(runs[3] == "custom_system_after", "Expected custom_system_after to run third, got: " .. runs[3])
+end

assets/tests/add_system/adds_system.lua

@@ -0,0 +1,34 @@
+let runs = [];
+
+fn on_test() {
+    let post_update_schedule = world.get_schedule_by_name.call("PostUpdate");
+    let test_system = post_update_schedule.get_system_by_name.call("on_test_post_update");
+
+    let builder_after = system_builder.call("custom_system_after", script_id).after.call(test_system);
+    let system_after = world.add_system.call(post_update_schedule, builder_after);
+    
+    let builder_before = system_builder.call("custom_system_before", script_id).before.call(test_system);
+    let system_before = world.add_system.call(post_update_schedule, builder_before);
+}
+
+fn custom_system_before() {
+    print("custom_system_before");
+    runs.push("custom_system_before");
+}
+
+fn on_test_post_update() {
+    print("on_test_post_update");
+    runs.push("on_test_post_update");
+}
+
+fn custom_system_after() {
+    print("custom_system_after");
+    runs.push("custom_system_after");
+}
+
+fn on_test_last() {
+    assert(runs.len() == 3, "Expected 3 runs, got: " + runs.len().to_string());
+    assert(runs[0] == "custom_system_before", "Expected custom_system_before to run first, got: " + runs[0]);
+    assert(runs[1] == "on_test_post_update", "Expected on_test_post_update to run second, got: " + runs[1]);
+    assert(runs[2] == "custom_system_after", "Expected custom_system_after to run third, got: " + runs[2]);
+}

assets/tests/add_system/adds_system_in_correct_order.lua

@@ -1,7 +1,13 @@
-local schedule = world.get_schedule_by_name("Startup")
-local systems = schedule:systems()
+function on_test()
+    local startup_schedule = world.get_schedule_by_name("Startup")
 
--- contains event_handler system
-assert(#systems == 1, "Schedule does not contain all systems")
 
-assert(schedule:get_system_by_name("dummy_startup_system"):identifier() == "dummy_startup_system", "System identifier was wrong")
+    local expected_systems = {
+        "dummy_startup_system",
+    }
+
+    for i, system in ipairs(expected_systems) do
+        local found_system = startup_schedule:get_system_by_name(system)
+        assert(found_system ~= nil, "Expected system not found: " .. system)
+    end
+end

assets/tests/add_system/adds_system_in_correct_order.rhai

@@ -1,5 +1,13 @@
-let schedule = world.get_schedule_by_name.call("Startup");
-let systems = schedule.systems.call();
+fn on_test() { 
+    let startup_schedule = world.get_schedule_by_name.call("Startup");
 
-assert(systems.len() == 1, "Schedule does not contain all systems");
-assert(schedule.get_system_by_name.call("dummy_startup_system").identifier.call() == "dummy_startup_system", "System identifier was wrong");
+
+    let expected_systems = [
+        "dummy_startup_system"
+    ];
+
+    for system in expected_systems {
+        let found_system = startup_schedule.get_system_by_name.call(system);
+        assert(type_of(found_system) != "()", "Expected system not found: " + system);
+    }
+}

assets/tests/rhai_tests.rs

@@ -41,6 +41,7 @@ derivative = "2.2"
 profiling = { workspace = true }
 bevy_mod_scripting_derive = { workspace = true }
 fixedbitset = "0.5"
+petgraph = "0.6"
 
 [dev-dependencies]
 test_utils = { workspace = true }