[select] Fix highlightItemOnHover not being respected

[sarthakmalik0810]

• I have followed (at least) the PR section of the contributing guide.

When highlightItemOnHover is false, data-highlighted should not be applied to Select.Item's. Adding condition to onMouseEnter fixes it.

Unit tests did not fail as they were using fireEvent.mouseMove, UserEvent should trigger mouseEnter and mouseMove.

Fixes #3867

[mui-bot]

Bundle size report

Bundle	Parsed size	Gzip size
@base-ui/react	🔺+3B(0.00%)	🔺+3B(0.00%)

Details of bundle changes

---

Check out the code infra dashboard for more information about this PR.

[greptile-apps]

Greptile Overview

Greptile Summary

Fixed highlightItemOnHover={false} not being respected on Select.Item components. The onMouseEnter handler was applying data-highlighted regardless of the highlightItemOnHover prop value.

• Added highlightItemOnHover check to onMouseEnter handler in SelectItem.tsx:151, matching the existing pattern in onMouseMove and onMouseLeave
• Updated tests to use user.hover() instead of fireEvent.mouseMove() to properly simulate user interactions and trigger both mouseEnter and mouseMove events

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The fix correctly addresses the bug by adding the missing highlightItemOnHover condition to the onMouseEnter handler, consistent with the existing pattern in onMouseMove and onMouseLeave. The test updates properly simulate user interactions using user.hover() instead of fireEvent.mouseMove(), which correctly triggers both mouseEnter and mouseMove events as would happen in real usage.
• No files require special attention

Important Files Changed

Filename	Overview
packages/react/src/select/item/SelectItem.tsx	Added highlightItemOnHover check to onMouseEnter handler to properly respect the prop when false
packages/react/src/select/root/SelectRoot.test.tsx	Updated tests to use user.hover() instead of fireEvent.mouseMove() to properly trigger both mouseEnter and mouseMove events

[netlify]

✅ Deploy Preview for base-ui ready!

Name	Link
🔨 Latest commit	5ce9550
🔍 Latest deploy log	https://app.netlify.com/projects/base-ui/deploys/6977b84f082782000939aba5
😎 Deploy Preview	https://deploy-preview-3868--base-ui.netlify.app
📱 Preview on mobile	Toggle QR Code... Use your smartphone camera to open QR code link.

---

To edit notification comments on pull requests, go to your Netlify project configuration.

[pkg-pr-new]

• base-ui-tanstack-start

• vite-css-base-ui-example

  pnpm add https://pkg.pr.new/mui/base-ui/@base-ui/react@3868
  

  pnpm add https://pkg.pr.new/mui/base-ui/@base-ui/utils@3868
  

commit: 5ce9550

[LukasTy]

Nice attention to detail. 👍
Thank you for fixing this issue. 🙏