WIP

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

@@ -23,7 +23,8 @@ import {
 	push_reaction_value,
 	is_destroying_effect,
 	update_effect,
-	remove_reactions
+	remove_reactions,
+	write_version
 } from '../runtime.js';
 import { equals, safe_equals } from './equality.js';
 import * as e from '../errors.js';
@@ -384,11 +385,13 @@ export function execute_derived(derived) {
  * @returns {void}
  */
 export function update_derived(derived) {
+	derived.rv = write_version;
+
 	var old_value = derived.v;
 	var value = execute_derived(derived);
 
 	if (!derived.equals(value)) {
-		derived.wv = increment_write_version();
+		derived.wv = write_version;
 
 		// in a fork, we don't update the underlying value, just `batch_values`.
 		// the underlying value will be updated when the fork is committed.

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

@@ -238,7 +238,7 @@ export function internal_set(source, value, updated_during_traversal = null) {
 			}
 		}
 
-		source.wv = increment_write_version();
+		source.wv = source.rv = increment_write_version();
 
 		// For debugging, in case you want to know which reactions are being scheduled:
 		// log_reactions(source);

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

@@ -259,8 +259,6 @@ export function update_reaction(reaction) {
 	}
 
 	try {
-		reaction.wv = reaction.rv = write_version;
-
 		reaction.f |= REACTION_IS_UPDATING;
 		var fn = /** @type {Function} */ (reaction.fn);
 		var result = fn();
@@ -464,10 +462,13 @@ export function update_effect(effect) {
 			destroy_effect_children(effect);
 		}
 
+		effect.rv = write_version;
+
 		execute_effect_teardown(effect);
 		var teardown = update_reaction(effect);
 		effect.teardown = typeof teardown === 'function' ? teardown : null;
-		effect.wv = write_version;
+
+		effect.wv = write_version; // TODO should this be assigned before the update?
 
 		// In DEV, increment versions of any sources that were written to during the effect,
 		// so that they are correctly marked as dirty when the effect re-runs