The tail of the `Long Skill Document` story collapsed and reopened the Skill
Resource accordion and then compared all four section heights against the
pre-collapse sample with an exact `toEqual`. `userEvent.click` resolves once the
event is dispatched, ahead of React committing the `openSections` update,
remounting the panel's content, and the browser running the layout pass that
redistributes height across the flex sections — so the read sampled the panes
mid-redistribution, two heights off by 23px in opposite directions and summing
to the same total.
There is no panel animation involved: the accordion sets `transitionDuration={0}`
because a height animation fights its flex sizing, and App.css restores a
transition only for the chevron transform.
Read the geometry under `waitFor` so it retries until the panes settle. The
reopened layout converges on the pre-collapse geometry rather than passing
through it, so retrying cannot mask a real regression; a tolerance would have
hidden the race instead of removing it, and would still fail on an early enough
sample.
Closes#2278
Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01XtdD6rzc1ddT28ZNE9wUjV
Signed-off-by: cliffhall <cliff@futurescale.com>
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