`position()` interleaved geometry reads with inline-style writes: the horizontal
branch wrote `minWidth`/`left` and the vertical branch then read `scrollHeight`,
`getComputedStyle`, `offsetHeight` and `offsetTop`, and a second write of
`bottom` was followed by a read of `clientHeight`. Each read after a write
forces a synchronous layout, so a single placement cost at least two — and
placement runs on mount, on resize and while scrolling an expanding panel.
Split it into measure, compute and commit: every read now happens before the
first write, and the result is applied as one object rather than nine separate
property assignments.
The commit also always writes both edges of each axis. A resize can flip the
vertical branch from `bottom` to `top`, and the previous code left the old edge
in place, over-constraining the box.
No behavioural change — the arithmetic is untouched, and the placement tests
pass unchanged.
Item-aligned placement centres the panel on the selected item, and `position()`
returned early unless both the item and its text node were known. The content
already adopts the first valid item as the anchor when the model matches no
option, but only the item is registered — the text node registers solely for the
selected value, so the pair was never complete and the early return fired. The
wrapper is `position: fixed`, so it stayed at the viewport origin: to a user the
dropdown simply does not open.
This is not an edge case. A stale id, a deleted record or a directory that has
not finished loading all leave the model unmatched, and the whole select then
looks broken rather than merely unlabelled.
Recover the text node from the item's own `aria-labelledby` instead of adding a
second registration — writing the anchor refs from inside the item's tracking
effect closes a reactive cycle ("Maximum recursive updates exceeded"). Reset the
text ref alongside the item ref per open cycle so a stale node cannot pair with
a fresh item. Finally, keep the guard from ever stranding the panel again: with
no anchors at all — an empty option list — fall back to a plain trigger-aligned
drop instead of returning with the wrapper unplaced.
Both paths are covered by browser tests that fail on the previous code.
Consuming the package under `verbatimModuleSyntax` + `strictTemplates` surfaced
four defects that forced workarounds downstream.
- Drop the deprecated `SelectValue` string alias. It collided with the
`SelectValue` component exported from the same barrel, so the component
resolved to the type meaning and could not be imported (TS1484).
- Narrow the select's model to `SelectModelValue<T, Multiple>` and make
`TabsRoot` generic over its value, so a plain `v-model` on a `Ref<string>`
type-checks. Both roots declare the value prop and emit explicitly instead of
via `defineModel`, which would widen the payload with `| undefined` even
though neither control ever clears its value.
- Stop declaring `defineModel` keys in `defineEmits` as well. The duplicate
erased the payload type from the generated declarations, shipping
`(...args: unknown[]) => any` for eleven components' model events.
- Let every part accept global DOM attributes (`id`, `role`, `aria-*`,
`data-*`, ...) through `PrimitiveAttributes`. The heritage clause is marked
`@vue-ignore`, so they stay out of the runtime props and keep falling through
via `$attrs` exactly as before.
- Give `SelectContent` and `SelectViewport` a single styleable root: the
content forwards `$attrs` onto the panel, and the viewport's scrollbar CSS
moves to a reference-counted `<head>` style tag. A forwarded `class` was
previously dropped, leaving the panel unstyled.
The tsconfig vue preset gains `htmlAttributes: ["aria-*", "data-*"]` so
hyphenated data attributes are not camelized before they reach those types.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
robonen