fix: respect the unidirectional nature of time (#14541)

* fix: respect the unidirectional nature of time * note to our future selves
sveltejs · Dec 4, 2024 · 4e77bde · 4e77bde
1 parent d511104
commit 4e77bde
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diff --git a/.changeset/sixty-tables-fold.md b/.changeset/sixty-tables-fold.md
@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: respect the unidirectional nature of time
diff --git a/packages/svelte/src/internal/client/loop.js b/packages/svelte/src/internal/client/loop.js
@@ -4,10 +4,13 @@ import { raf } from './timing.js';
 // TODO move this into timing.js where it probably belongs
 
 /**
- * @param {number} now
  * @returns {void}
  */
-function run_tasks(now) {
+function run_tasks() {
+	// use `raf.now()` instead of the `requestAnimationFrame` callback argument, because
+	// otherwise things can get wonky https://github.com/sveltejs/svelte/pull/14541
+	const now = raf.now();
+
 	raf.tasks.forEach((task) => {
 		if (!task.c(now)) {
 			raf.tasks.delete(task);