WIP

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

@@ -2,7 +2,9 @@
 import { CLEAN, DIRTY } from '#client/constants';
 import {
 	flush_queued_effects,
+	process_effects,
 	schedule_effect,
+	set_queued_root_effects,
 	set_signal_status,
 	update_effect
 } from '../runtime.js';
@@ -52,9 +54,28 @@ export class Batch {
 	/** @type {Set<Effect>} */
 	skipped_effects = new Set();
 
-	apply() {
+	apply() {}
+
+	/**
+	 *
+	 * @param {Effect[]} root_effects
+	 */
+	process(root_effects) {
+		set_queued_root_effects([]);
+
 		var current_values = new Map();
 
+		for (const batch of batches) {
+			if (batch === this) continue;
+
+			for (const [source, previous] of batch.#previous) {
+				if (!this.#current.has(source)) {
+					current_values.set(source, source.v);
+					source.v = previous;
+				}
+			}
+		}
+
 		for (const [source, current] of this.#current) {
 			// TODO this shouldn't be necessary, but tests fail otherwise,
 			// presumably because we need a try-finally somewhere, and the
@@ -72,21 +93,13 @@ export class Batch {
 			schedule_effect(e);
 		}
 
-		for (const batch of batches) {
-			if (batch === this) continue;
-
-			for (const [source, previous] of batch.#previous) {
-				if (!this.#previous.has(source)) {
-					current_values.set(source, source.v);
-					source.v = previous;
-				}
-			}
-		}
-
 		this.render_effects = [];
 		this.effects = [];
 
-		return () => {
+		for (const root of root_effects) {
+			process_effects(this, root);
+		}
+
 		if (this.async_effects.length === 0 && this.settled()) {
 			var render_effects = this.render_effects;
 			var effects = this.effects;
@@ -106,7 +119,6 @@ export class Batch {
 		} else {
 			for (const e of this.render_effects) set_signal_status(e, CLEAN);
 			for (const e of this.effects) set_signal_status(e, CLEAN);
-			}
 
 			for (const [source, value] of current_values) {
 				source.v = value;
@@ -117,7 +129,7 @@ export class Batch {
 			}
 
 			this.async_effects = [];
-		};
+		}
 	}
 
 	/**

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

@@ -77,6 +77,11 @@ export function set_is_destroying_effect(value) {
 /** @type {Effect[]} */
 let queued_root_effects = [];
 
+/** @param {Effect[]} v */
+export function set_queued_root_effects(v) {
+	queued_root_effects = v;
+}
+
 /** @type {Effect[]} Stack of effects, dev only */
 let dev_effect_stack = [];
 // Handle signal reactivity tree dependencies and reactions
@@ -695,16 +700,7 @@ function flush_queued_root_effects() {
 				infinite_loop_guard();
 			}
 
-			var revert = batch.apply();
-
-			var root_effects = queued_root_effects;
-			queued_root_effects = [];
-
-			for (const root of root_effects) {
-				process_effects(batch, root);
-			}
-
-			revert();
+			batch.process(queued_root_effects);
 
 			old_values.clear();
 		}
@@ -805,7 +801,7 @@ export function schedule_effect(signal) {
  * @param {Batch} batch
  * @param {Effect} root
  */
-function process_effects(batch, root) {
+export function process_effects(batch, root) {
 	root.f ^= CLEAN;
 
 	var effect = root.first;