chore: simplify process_effects

packages/svelte/src/internal/client/constants.js

@@ -18,6 +18,7 @@ export const EFFECT_TRANSPARENT = 1 << 15;
 export const LEGACY_DERIVED_PROP = 1 << 16;
 export const INSPECT_EFFECT = 1 << 17;
 export const HEAD_EFFECT = 1 << 18;
+export const EFFECT_HAS_DIRTY_CHILDREN = 1 << 19;
 
 export const STATE_SYMBOL = Symbol('$state');
 export const STATE_SYMBOL_METADATA = Symbol('$state metadata');

packages/svelte/src/internal/client/runtime.js

@@ -22,7 +22,8 @@ import {
 	BLOCK_EFFECT,
 	ROOT_EFFECT,
 	LEGACY_DERIVED_PROP,
-	DISCONNECTED
+	DISCONNECTED,
+	EFFECT_HAS_DIRTY_CHILDREN
 } from './constants.js';
 import { flush_tasks } from './dom/task.js';
 import { add_owner } from './dev/ownership.js';
@@ -582,17 +583,21 @@ export function schedule_effect(signal) {
 
 	var effect = signal;
 
-	while (effect.parent !== null) {
-		effect = effect.parent;
-		var flags = effect.f;
+	while (true) {
+		if ((effect.f & EFFECT_HAS_DIRTY_CHILDREN) !== 0) {
+			return;
+		}
+
+		var parent = effect.parent;
 
-		if ((flags & BRANCH_EFFECT) !== 0) {
-			if ((flags & CLEAN) === 0) return;
-			set_signal_status(effect, MAYBE_DIRTY);
+		if (parent === null) {
+			queued_root_effects.push(effect);
+			return;
 		}
-	}
 
-	queued_root_effects.push(effect);
+		effect.f |= EFFECT_HAS_DIRTY_CHILDREN;
+		effect = parent;
+	}
 }
 
 /**
@@ -608,69 +613,50 @@ export function schedule_effect(signal) {
  */
 function process_effects(effect, collected_effects) {
 	var current_effect = effect.first;
-	var effects = [];
+	var deferred = [];
 
-	main_loop: while (current_effect !== null) {
+	while (current_effect !== null) {
 		var flags = current_effect.f;
-		var is_active = (flags & INERT) === 0;
-		var is_branch = (flags & BRANCH_EFFECT) !== 0;
-		var is_clean = (flags & CLEAN) !== 0;
-		var child = current_effect.first;
-
-		// Skip this branch if it's clean
-		if (is_active && (!is_branch || !is_clean)) {
-			if (is_branch) {
-				set_signal_status(current_effect, CLEAN);
-			}
 
-			if ((flags & RENDER_EFFECT) !== 0) {
-				if (!is_branch && check_dirtiness(current_effect)) {
+		if ((flags & INERT) === 0) {
+			var has_dirty_children = (flags & EFFECT_HAS_DIRTY_CHILDREN) !== 0;
+			if (has_dirty_children) current_effect.f ^= EFFECT_HAS_DIRTY_CHILDREN;
+
+			if (check_dirtiness(current_effect)) {
+				if ((flags & RENDER_EFFECT) !== 0) {
 					update_effect(current_effect);
+					has_dirty_children = true;
+				} else {
+					deferred.push(current_effect);
 				}
-				// Child might have been mutated since running the effect or checking dirtiness
-				child = current_effect.first;
+			}
+
+			if (has_dirty_children) {
+				var first = current_effect.first;
 
-				if (child !== null) {
-					current_effect = child;
+				if (first) {
+					current_effect = first;
 					continue;
 				}
-			} else if ((flags & EFFECT) !== 0) {
-				if (is_branch || is_clean) {
-					if (child !== null) {
-						current_effect = child;
-						continue;
-					}
-				} else {
-					effects.push(current_effect);
-				}
 			}
 		}
 
-		var sibling = current_effect.next;
-
-		if (sibling === null) {
-			let parent = current_effect.parent;
+		while (current_effect !== null) {
+			var sibling = current_effect.next;
 
-			while (parent !== null) {
-				if (effect === parent) {
-					break main_loop;
-				}
-				var parent_sibling = parent.next;
-				if (parent_sibling !== null) {
-					current_effect = parent_sibling;
-					continue main_loop;
-				}
-				parent = parent.parent;
+			if (sibling) {
+				current_effect = sibling;
+				break;
 			}
-		}
 
-		current_effect = sibling;
+			current_effect = current_effect.parent;
+		}
 	}
 
 	// We might be dealing with many effects here, far more than can be spread into
 	// an array push call (callstack overflow). So let's deal with each effect in a loop.
-	for (var i = 0; i < effects.length; i++) {
-		child = effects[i];
+	for (var i = 0; i < deferred.length; i++) {
+		var child = deferred[i];
 		collected_effects.push(child);
 		process_effects(child, collected_effects);
 	}

packages/svelte/src/reactivity/map.test.ts

@@ -192,14 +192,14 @@ test('map handling of undefined values', () => {
 		render_effect(() => {
 			log.push(map.get(1));
 		});
+	});
 
-		flushSync(() => {
-			map.delete(1);
-		});
+	flushSync(() => {
+		map.delete(1);
+	});
 
-		flushSync(() => {
-			map.set(1, 1);
-		});
+	flushSync(() => {
+		map.set(1, 1);
 	});
 
 	assert.deepEqual(log, [undefined, undefined, 1]);
@@ -220,14 +220,14 @@ test('not invoking reactivity when value is not in the map after changes', () =>
 		render_effect(() => {
 			log.push(map.get(2));
 		});
+	});
 
-		flushSync(() => {
-			map.delete(1);
-		});
+	flushSync(() => {
+		map.delete(1);
+	});
 
-		flushSync(() => {
-			map.set(1, 1);
-		});
+	flushSync(() => {
+		map.set(1, 1);
 	});
 
 	assert.deepEqual(log, [1, undefined, undefined, undefined, 1, undefined]);