# Testing

Vitest (`vitest.config.ts`), covering targeted units under `src/lib/` — not a full-coverage suite. Run
with `npm test`.

**Rune modules cannot be imported by tests.** `vitest.config.ts` deliberately omits the SvelteKit plugin
to keep the suite fast and stable, so any `*.svelte.ts` file fails at import with `$state is not defined`.
Services reach the stores through `vi.mock('$lib/stores/…')`; logic that needs testing on its own is
extracted into a plain `.ts` module instead (`settingsMigrations.ts`, `advancedPanelView.ts`,
`stickiness.ts`, `recentTail.ts` are all this pattern). Those modules are production code with real
callers, not test scaffolding.

There is also no DOM environment (`environment: 'node'`), so components are not rendered by any test. A
Svelte-level mistake — a `bind:` to an undefined value, for instance — passes `check`, `lint` and the
whole suite, and only fails when the app runs.