WIP

packages/svelte/src/internal/client/reactivity/batch.js

@@ -35,8 +35,8 @@ export class Batch {
 
 	#pending = 0;
 
-	/** @type {Set<Effect>} */
-	effects = new Set();
+	/** @type {Effect[]} */
+	effects = [];
 
 	/** @type {Set<Effect>} */
 	skipped_effects = new Set();
@@ -56,6 +56,8 @@ export class Batch {
 			schedule_effect(e);
 		}
 
+		this.effects = [];
+
 		for (const batch of batches) {
 			if (batch === this) continue;
 

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

@@ -722,14 +722,14 @@ function flush_queued_root_effects() {
 				// store the effects on the batch so that they run next time,
 				// even if they don't get re-dirtied
 				for (const e of render_effects) {
-					batch.effects.add(e);
 					set_signal_status(e, CLEAN);
 				}
 
 				for (const e of effects) {
-					batch.effects.add(e);
 					set_signal_status(e, CLEAN);
 				}
+
+				batch.effects.push(...render_effects, ...effects);
 			}
 
 			revert();