[select] `<Select.Root multiple>` always has `[data-filled=true]`, even when no options are selected

[guisehn]

Bug report

Current behavior

When using the Select component with multiple selection enabled, data-filled is always set, even when no options are selected.

Note: The screenshot above is from the documentation running locally, with the MultiSelectExample code changed to wrap the select in a <Field.Root> to get the data- attributes.

Expected behavior

When no options are selected, data-filled should be absent.

Base UI version

1.0.0

Which browser are you using?

Chrome 142

Which OS are you using?

macOS

Which assistive tech are you using (if applicable)?

N/A

Additional context

Select multiples have a default value of [] instead of null.

The code that sets filled checks for null only:

base-ui/packages/react/src/select/root/SelectRoot.tsx

Line 197 in 52ba9fd

setFilled(value !== null);

[mnajdova]

It's going to be fixed by #3608, thanks for reporting it.

[github-actions]

This fix will be available in the next npm release of Base UI.

In the meantime, you can try it out on our Canary release channel:

npm i https://pkg.pr.new/@base-ui/react@3608