The `filter-search` spec was flaky (~3%: 5 failures in 180 runs), always as
"element was detached from the DOM" while clicking a suggestion. It was not a test
bug — it was reporting a real defect.
`selectSuggestion` sets `showAutocomplete = false`, which unmounts the dropdown, so a
suggestion button DESTROYS ITSELF when activated. It was wired to `onmousedown` — the
first event of the click sequence — purely to beat the input's `onblur`, which would
otherwise close the dropdown before a click could land. So whether the node survived to
`mouseup` depended on whether Svelte's flush happened to fall between the two events.
Under load it did, and the click was lost. That is also a real user-facing bug: because
it committed on PRESS, sliding off a suggestion you didn't mean to hit still applied the
filter, with no way to abort.
Fixed the standard combobox way: preventDefault on the dropdown's mousedown suppresses
the blur, which is the only thing onmousedown was buying — so the handler moves to
`onclick`, the LAST event, where self-destruction is harmless and press-then-slide-off
aborts like a button should. Because the input now keeps focus across a selection,
`onfocus` no longer re-fires, so reopening is also wired to click/input — without that
the picker could not be reopened without clicking away first.
Also freezes the suggestion SOURCE while the dropdown is open. `allTags` is ordered by
frequency and derives from `uploads`, which every `upload-processed` SSE replaces via
refreshFeedInPlace — so an arriving photo could REORDER the open dropdown under the
user's finger. At a party, where photos stream in continuously, that is a live mis-tap
hazard. This was NOT the cause of the flake (I first believed it was; a clean 60-run
said so and a 120-run refuted it), but it is a genuine defect on the same interaction,
so it stays.
Verified: 240/240 consecutive passes on the previously-flaky spec (baseline 2.8%, so
~0.1% odds of luck), full suite 162 passed / 1 skipped with zero failures.
Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
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