WIP

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

@@ -10,7 +10,9 @@ import {
 	ASYNC,
 	WAS_MARKED,
 	DESTROYED,
-	REACTION_RAN
+	REACTION_RAN,
+	CONNECTED,
+	CLEAN
 } from '#client/constants';
 import {
 	active_reaction,
@@ -400,6 +402,10 @@ export function update_derived(derived) {
 			derived.wv = write_version;
 		}
 	}
+
+	if (active_batch === null && (derived.f & CONNECTED) !== 0) {
+		derived.f |= CLEAN;
+	}
 }
 
 /**

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

@@ -337,9 +337,10 @@ export function mark_reactions(signal, wv, updated_during_traversal) {
 		if ((flags & DERIVED) !== 0) {
 			var derived = /** @type {Derived} */ (reaction);
 
-			active_batch?.values?.delete(derived);
-
 			if (wv > get_cv(derived)) {
+				active_batch?.values?.delete(derived);
+				derived.f &= ~CLEAN;
+
 				if ((flags & WAS_MARKED) === 0) {
 					// Only connected deriveds can be reliably unmarked right away
 					if (flags & CONNECTED) {

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

@@ -21,7 +21,8 @@ import {
 	WAS_MARKED,
 	MANAGED_EFFECT,
 	REACTION_RAN,
-	EFFECT_LEGACY
+	EFFECT_LEGACY,
+	CLEAN
 } from './constants.js';
 import { old_values } from './reactivity/sources.js';
 import {
@@ -167,6 +168,14 @@ export function is_dirty(reaction) {
 
 	if (flags & DERIVED) {
 		reaction.f &= ~WAS_MARKED;
+
+		if ((flags & CONNECTED) !== 0) {
+			if (active_batch !== null) {
+				if (active_batch.values?.has(reaction)) return false;
+			} else {
+				if ((reaction.f & CLEAN) !== 0) return false;
+			}
+		}
 	}
 
 	var dependencies = /** @type {Value[]} */ (reaction.deps);