Client-side load functions and SSR create flaky/unmockable tests

6/10 Medium

Since client-side load functions (`+page.js`) started serializing responses, they cannot be mocked effectively. SSR can cause flaky tests in Playwright when selectors click before hydration completes, causing event handlers to not attach.

SvelteKitPlaywright
Category
testing
Workaround
partial
Stage
testing
Freshness
persistent
Scope
framework
Upstream
open
Recurring
Yes
Buyer Type
team
Maintainer
active

Sources

Collection History

Query: “What are the most common pain points with Svelte for developers in 2025?”4/5/2026

Since client-side load functions (`+page.js`) started serializing responses, it has become impossible to mock them effectively. A Playwright selector might click a button before hydration is complete, causing the test to fail.

Created: 4/5/2026Updated: 4/5/2026