Flaky test: test_tooltip_demo[app-express.py-webkit] — tooltip body not found after update

[schloerke]

Occurrence

• Failed job: https://github.com/posit-dev/py-shiny/actions/runs/31397735515/job/93484713496 (playwright-ai (3.14, webkit, 1), on PR fix(render): Honor @output(id=) for download renderers #2415)
• Passed on gh run rerun --failed of the same commit, so this is a flake rather than a regression. main was green at the time.
• Result in the original job: 1 failed, 43 passed in 73.94s

Test

tests/playwright/ai_generated_apps/core_express/update_tooltip/test_update_tooltip_core_express.py::test_tooltip_demo[app-express.py-webkit]

Only the webkit + Express parameterization failed; the other browsers and the Core app variant passed in the same run.

Error

>       playwright_expect(self.get_loc_overlay_body(timeout=timeout)).to_have_text(
            value, timeout=timeout
        )
E       AssertionError: Locator expected to have text 'Tooltip updated 2 times!'
E       Actual value: None
E       Error: element(s) not found
E       Call log:
E         - Expect "to_have_text" with timeout 5000ms
E         - waiting for locator("#None.tooltip > div.tooltip-inner")

.venv/lib/python3.14/site-packages/shiny/playwright/controller/_overlay.py:112: AssertionError

Aria snapshot at failure time shows the page rendered and the trigger buttons present, but no tooltip overlay in the DOM:

- heading "Update Tooltip Demo" [level=2]
- text: Tooltip Demo
- button " Show tooltip"
- button " Close tooltip"
- button " Update tooltip"
- separator
- button " Hover over me!"

Notes

Two things stand out in the call log and may be worth a look beyond the timing flake itself:

• The locator is #None.tooltip > div.tooltip-inner — the None suggests the overlay controller resolved a placeholder id rather than the real tooltip id, so the selector may be unable to match even when the overlay is present. Worth confirming whether _overlay.py's get_loc_overlay_body() is constructing the selector correctly for this app.
• The assertion waits for the updated text ("Tooltip updated 2 times!") with the overlay expected to already be open; on webkit the show/update sequence may race, leaving the overlay closed at assertion time.

[schloerke]

New occurrence

• Failed job: https://github.com/posit-dev/py-shiny/actions/runs/31411043827/job/93528979963 (playwright-ai (3.13, webkit, 1), on PR fix: render data frames with non-string column names (#2115) #2358)
• Passed on gh run rerun --failed of the same commit (run attempt 2 was green), so this is the same flake, not a regression.
• Commit: bfacb3e1

This is the app-core.py parameterization, whereas the original report was app-express.py. Same test, same browser, same assertion — so the Core/Express split does not look meaningful:

FAILED tests/playwright/ai_generated_apps/core_express/update_tooltip/test_update_tooltip_core_express.py::test_tooltip_demo[app-core.py-webkit]
E       AssertionError: Locator expected to have text 'Tooltip updated 2 times!'
E       Error: element(s) not found

.venv/lib/python3.13/site-packages/shiny/playwright/controller/_overlay.py:112: AssertionError

Same failure site (_overlay.py:112) as the original report. Only the webkit parameterization failed; the other browsers passed in the same run.

Worth noting for the #None.tooltip theory in the issue body: this occurrence was on Python 3.13 and the original was 3.14, so the trigger is not version-specific either.