From 9aafbdc975ff82f0f85e1c80b912f41edc30a676 Mon Sep 17 00:00:00 2001
From: "Dylan M. Taylor" <dylan@dylanmtaylor.com>
Date: Mon, 26 Oct 2026 11:27:47 -0400
Subject: [PATCH] Split effect upgrade step out of upgrade_effects to cut
 cognitive complexity

Moves the per-group body into upgrade_effect_group. Behavior is unchanged;
the engine test suite passes (664 tests).
---
 crates/engine/src/lib.rs | 39 ++++++++++++++++++++++++++-------------
 1 file changed, 26 insertions(+), 13 deletions(-)

diff --git a/crates/engine/src/lib.rs b/crates/engine/src/lib.rs
index c6c6c5733..44759126f 100644
--- a/crates/engine/src/lib.rs
+++ b/crates/engine/src/lib.rs
@@ -1218,19 +1218,7 @@ pub fn upgrade_effects(p: &mut Project) {
             let Some(fx) = l.props.sub_mut("effects") else { continue };
             for n in &mut fx.children {
                 let effectcraft_project::Node::Group(g) = n else { continue };
-                let effectcraft_project::GroupKind::Effect { effect } = &g.kind else { continue };
-                if let Some(spec) = effectcraft_effects::find(effect) {
-                    let composite = legacy_particles
-                        && matches!(spec.id, "ec.sim.ccparticlesystems2" | "ec.sim.ccparticleworld")
-                        && g.get("compositeWithOriginal").is_none();
-                    effectcraft_effects::migrate::upgrade_instance(spec, g, &mut effectcraft_project::build::Ids(&mut next), size);
-                    if composite && let Some(pr) = g.get_mut("compositeWithOriginal") {
-                        pr.value = effectcraft_keyframe::Value::Bool(true);
-                    }
-                    if to_effect_space {
-                        effectcraft_effects::migrate::to_effect_space(spec, g, size, d, &clone_d);
-                    }
-                }
+                upgrade_effect_group(g, legacy_particles, to_effect_space, size, d, &clone_d, &mut next);
             }
         }
     }
@@ -1239,6 +1227,31 @@ pub fn upgrade_effects(p: &mut Project) {
     p.saved_by = effectcraft_project::APP_VERSION.to_string();
 }
 
+/// Upgrade one effect group of a layer: its instance, the legacy composite flag, and (when the
+/// project predates effect space) its positions.
+fn upgrade_effect_group(
+    g: &mut effectcraft_project::PropGroup,
+    legacy_particles: bool,
+    to_effect_space: bool,
+    size: [f64; 2],
+    d: [f64; 2],
+    clone_d: &dyn Fn(Option<u64>) -> [f64; 2],
+    next: &mut u64,
+) {
+    let effectcraft_project::GroupKind::Effect { effect } = &g.kind else { return };
+    let Some(spec) = effectcraft_effects::find(effect.as_str()) else { return };
+    let composite = legacy_particles
+        && matches!(spec.id, "ec.sim.ccparticlesystems2" | "ec.sim.ccparticleworld")
+        && g.get("compositeWithOriginal").is_none();
+    effectcraft_effects::migrate::upgrade_instance(spec, g, &mut effectcraft_project::build::Ids(next), size);
+    if composite && let Some(pr) = g.get_mut("compositeWithOriginal") {
+        pr.value = effectcraft_keyframe::Value::Bool(true);
+    }
+    if to_effect_space {
+        effectcraft_effects::migrate::to_effect_space(spec, g, size, d, clone_d);
+    }
+}
+
 #[cfg(test)]
 mod rq_tests;
 #[cfg(test)]