@primer/react@38.7.0

Minor Changes

• #7293 d418509 Thanks @lindseywild! - Adds character counts to TextInput and TextArea components

Patch Changes

• #7354 efbebdf Thanks @llastflowers! - update SelectPanel Multi Select Modal story

• #7426 094be60 Thanks @kelsey-myers! - Add focusPrependedElements prop to useFocusZone, FilteredActionList, and SelectPanel

• #7349 713d5a5 Thanks @mattcosta7! - PageLayout: Optimize drag/resize performance with inline styles and new optimizations

  Refactored:

  • Use direct attribute selectors (.Pane[data-dragging='true']) instead of descendant selectors for CSS containment (O(1) vs O(n) selector matching)
  • Extract optimization utilities to paneUtils.ts
  • Apply drag handle visual feedback via inline styles and CSS variables

  Added:

  • content-visibility: auto during drag/resize to skip off-screen content rendering
  • rAF throttle for drag updates (one update per frame, latest position wins)
  • Containment during window resize (parity with drag)

  These changes improve style recalculation performance on large DOMs (100k+ nodes) by eliminating descendant selector traversal.

• #7337 de970d6 Thanks @mattcosta7! - perf(Autocomplete): Split context to reduce unnecessary re-renders

  Split AutocompleteContext into separate contexts for static values, setters, and dynamic state.
  Components now subscribe only to the context slices they need, reducing re-renders.

• #7325 cc7e10e Thanks @mattcosta7! - perf(BaseStyles): Remove expensive :has([data-color-mode]) selectors

  Remove :has([data-color-mode]) selectors that scanned the entire DOM on every style recalculation.
  Input color-scheme is already handled by global selectors in the codebase.

• #7329 501a41f Thanks @mattcosta7! - perf(Dialog): Add feature flag for CSS :has() selector performance optimization

  • Add primer_react_css_has_selector_perf feature flag (default: false)
  • When flag is OFF: uses legacy body:has(.Dialog.DisableScroll) selector
  • When flag is ON: uses optimized direct body[data-dialog-scroll-disabled] data attribute with ref counting
  • Enables gradual rollout and easy rollback of performance optimization

• #7342 a8b42b2 Thanks @mattcosta7! - perf(hasInteractiveNodes): Optimize with combined selector and early attribute checks

  • Use combined querySelectorAll selector instead of recursive traversal
  • Check attribute-based states (disabled, hidden, inert) before getComputedStyle
  • Only call getComputedStyle when CSS-based visibility check is needed