Why

calendar-1-single-booking: ui tests in assets/tests/template/template-calendar.spec.js is intermittently flaky — observed failing then passing on a Playwright rerun of the exact same commit, with no template/JSX changes between runs.

Root cause

The render that produces "Ledigt" / "Optaget" depends on currentTime, which the component initializes via useState(dayjs()) (line 70 of calendar-single-booking.jsx). A useEffect then calls intervalChecking() which resets currentTime to the (mocked) clock value and starts a 60s setInterval. Between mount and the first effect, the rendered .status text can briefly reflect non-mocked time. The instantBookingEnabled path also kicks off an async fetch to /action whose latency varies under CI load.

The previous assertion form amplified that race:

toHaveText against a specific locator is the auto-retrying pattern Playwright already documents for time-sensitive UI, and matches the passing calendar-0-single-booking sibling test (line 202).

What

 test("calendar-1-single-booking: ui tests", async ({ page }) => {
   await fixTime(page);
   await page.goto("/template/calendar-1-single-booking");
-  await expect(page.getByText("Ledigt")).toHaveCount(1);
-  await expect(page.getByText("Ledigt")).toBeVisible();
+  await expect(page.locator(".room-info")).toBeVisible();
+
+  const status = page.locator(".status");
+  await expect(status).toHaveText("Ledigt");

   await page.clock.runFor(61000);

-  await expect(page.getByText("Optaget")).toHaveCount(1);
-  await expect(page.getByText("Optaget")).toBeVisible();
+  await expect(status).toHaveText("Optaget");
 });

No production code touched.

Why not patch the component instead

Lazy-initializing currentTime from inside the effect (e.g. useState(null) then set on mount) would remove the brief "real time" render window, but risks the passing calendar-0-* sibling tests that already rely on the current behavior. Production change with a wider blast radius is the wrong tool for a test-side timing assumption — keep the fix where the problem is observed.

Test plan

• CI Playwright green on this PR
• No regression in the other calendar-* tests (they don't share the assertion form being changed)

🤖 Generated with Claude Code