Hover-prefetch has two surfaces in SvelteKit:
- data-sveltekit-preload-data (route loader data)
- data-sveltekit-preload-code (route JS chunks)
The original fix turned off only the loader-data side. Route-code chunks
prefetched on hover can also include manually-mocked module URLs; an
in-flight code prefetch landing after iframe teardown hits the same
Playwright route handler that resolves manual mocks, raising the
unhandled rejection. Disable both surfaces.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Hover-prefetch fires real fetch requests for route loader chunks; those
requests go through the same Playwright route handler that serves mocked
modules. An in-flight prefetch landing after iframe teardown can hit the
handler with a closed birpc channel, raising an unhandled rejection that
exits the run with code 1 even when every individual test was green.
Add `src/test-setup.ts` that sets `document.body.dataset.sveltekitPreloadData
= 'off'` and wire it via `setupFiles` in both `vite.config.ts` (client
project) and `vitest.client-coverage.config.ts` (Istanbul coverage config).
Add `src/__meta__/browser-preload-disabled.svelte.test.ts` asserting the
setup ran. Zero production impact.
Issue #553 secondary trigger.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
