Add additional Tooltip support to ActionList and NavList

[TylerJDev]

Part of https://github.com/github/core-ux/issues/3279

Extends current Tooltip support in ActionList to be prop-based. Previously, tooltips would only be rendered if content within the ActionList was truncated. This allows private usage of the tooltip via prop (_PrivateTooltipText)

Why is this needed?

There isn't an accessible path to utilizing a custom tooltip with ActionList / NavList. This is because wrapping an ActionList item or NavList item in a tooltip will break the permitted parent/child structure of a list, as the tooltip <span> is rendered directly within the list (<ul>) as a direct child.

Since we already support tooltips in some capacity (truncated content), this makes internal usage with tooltips easier. We should consider if we want to keep this prop "private", or if we wanted to allow it publicly. I implemented it as private as tooltips should generally be used sparingly.

Changelog

New

• Added prop-based tooltip support to ActionList / NavList

Rollout strategy

• Patch release
• Minor release
• Major release; if selected, include a written rollout or migration plan
• None; if selected, include a brief description as to why

Testing & Reviewing

[changeset-bot]

🦋 Changeset detected

Latest commit: 33bb6a7

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@primer/react	Minor

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[github-actions]

⚠️ Action required

👋 Hi, this pull request contains changes to the source code that github/github-ui depends on. If you are GitHub staff, test these changes with github/github-ui using the integration workflow. Check the integration testing docs for step-by-step instructions. Or, apply the integration-tests: skipped manually label to skip these checks.

[primer]

🤖 Lint and formatting issues have been automatically fixed and committed to this PR.

[Copilot]

Pull request overview

This PR expands existing Tooltip behavior in ActionList/NavList by allowing tooltips to be triggered via an explicit prop (instead of only via truncation), enabling tooltips to render inside list items without breaking list structure.

Changes:

• Added tooltipText support to NavList.Item, wiring it into the underlying ActionList item/link implementations.
• Introduced a private _PrivateTooltipText pathway in ActionList to drive tooltip rendering for both ActionList.Item (button-semantics) and ActionList.LinkItem.
• Added unit tests covering tooltip rendering/association for NavList.Item in both link and expandable (subnav) variants.

Show a summary per file

File	Description
packages/react/src/NavList/NavList.tsx	Adds tooltipText prop to NavList.Item and forwards it into underlying ActionList items.
packages/react/src/NavList/NavList.test.tsx	Adds tests ensuring tooltips render inside the correct list item and are associated via aria-describedby.
packages/react/src/ActionList/shared.ts	Adds private _PrivateTooltipText to ActionListItemProps.
packages/react/src/ActionList/LinkItem.tsx	Wraps link trigger in Tooltip when _PrivateTooltipText is provided.
packages/react/src/ActionList/Item.tsx	Allows private tooltip text to override truncation tooltip text for button-semantic items.
.changeset/warm-tools-smile.md	Declares a minor release for the new NavList tooltip prop.

Review details

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• Files reviewed: 6/6 changed files
• Comments generated: 2
• Review effort level: Lite

[primer-integration]

Integration test results from github/github-ui PR:

  CI Passed
  VRT Passed
  Projects Passed

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