Refactor SelectPanel behind a feature flag with mode-specific next architecture

.changeset/curvy-lamps-smell.md

@@ -0,0 +1,5 @@
+---
+'@primer/react': patch
+---
+
+SelectPanel: add classname-coverage test for the next implementation and align feature-flag migration follow-up checks.

packages/react/src/FeatureFlags/DefaultFeatureFlags.ts

@@ -3,6 +3,7 @@ import {FeatureFlagScope} from './FeatureFlagScope'
 export const DefaultFeatureFlags = FeatureFlagScope.create({
   primer_react_breadcrumbs_overflow_menu: false,
   primer_react_css_anchor_positioning: false,
+  primer_react_select_panel_next: false,
   primer_react_select_panel_fullscreen_on_narrow: false,
   primer_react_select_panel_order_selected_at_top: false,
   primer_react_select_panel_remove_active_descendant: false,

packages/react/src/SelectPanel/SelectPanel.features.stories.tsx

@@ -1,6 +1,7 @@
 import React, {useState, useRef, useEffect} from 'react'
 import type {Meta, StoryObj} from '@storybook/react-vite'
 import {Button} from '../Button'
+import {FeatureFlags} from '../FeatureFlags'
 import type {ItemInput, GroupedListProps} from '.'
 import Link from '../Link'
 import {SelectPanel, type SelectPanelProps} from './SelectPanel'
@@ -333,6 +334,42 @@ export const WithSecondaryActionLink = () => {
   )
 }
 
+export const NextArchitecturePreview = () => {
+  const [selected, setSelected] = useState<ItemInput[]>(items.slice(1, 3))
+  const [filter, setFilter] = useState('')
+  const filteredItems = items.filter(item => item.text.toLowerCase().startsWith(filter.toLowerCase()))
+  const [open, setOpen] = useState(false)
+
+  return (
+    <FeatureFlags flags={{primer_react_select_panel_next: true}}>
+      <FormControl>
+        <FormControl.Label>Labels</FormControl.Label>
+        <SelectPanel
+          title="Select labels"
+          subtitle="Preview the new SelectPanel architecture behind its feature flag"
+          placeholder="Select labels"
+          renderAnchor={({children, ...anchorProps}) => (
+            <Button trailingAction={TriangleDownIcon} {...anchorProps} aria-haspopup="dialog">
+              {children}
+            </Button>
+          )}
+          open={open}
+          onOpenChange={setOpen}
+          items={filteredItems}
+          selected={selected}
+          onSelectedChange={setSelected}
+          onFilterChange={setFilter}
+          width="medium"
+          onCancel={() => setOpen(false)}
+          secondaryAction={<SelectPanel.SecondaryActionButton>Edit labels</SelectPanel.SecondaryActionButton>}
+          notice={{text: 'This story is rendered with primer_react_select_panel_next enabled.', variant: 'info'}}
+          message={filteredItems.length === 0 ? NoResultsMessage(filter) : undefined}
+        />
+      </FormControl>
+    </FeatureFlags>
+  )
+}
+
 export const WithNotice = () => {
   const [selected, setSelected] = useState<ItemInput[]>(items.slice(1, 3))
   const [filter, setFilter] = useState('')

packages/react/src/SelectPanel/SelectPanel.shared.tsx

@@ -0,0 +1,195 @@
+import {TriangleDownIcon, type IconProps} from '@primer/octicons-react'
+import {announce} from '@primer/live-region-element'
+import type React from 'react'
+
+import type {AnchoredOverlayProps} from '../AnchoredOverlay'
+import type {AnchoredOverlayWrapperAnchorProps} from '../AnchoredOverlay/AnchoredOverlay'
+import {Button, LinkButton} from '../Button'
+import type {ButtonProps, LinkButtonProps} from '../Button/types'
+import type {FilteredActionListProps, ItemInput} from '../FilteredActionList'
+import type {FocusZoneHookSettings} from '../hooks/useFocusZone'
+import type {OverlayProps} from '../Overlay'
+import {SelectPanelMessage} from './SelectPanelMessage'
+
+export const SHORT_DELAY_MS = 500
+export const LONG_DELAY_MS = 1000
+
+const EMPTY_MESSAGE = {
+  title: 'No items available',
+  description: '',
+}
+
+export const DefaultEmptyMessage = (
+  <SelectPanelMessage variant="empty" title={EMPTY_MESSAGE.title} key="empty-message">
+    {EMPTY_MESSAGE.description}
+  </SelectPanelMessage>
+)
+
+async function announceText(text: string, delayMs = SHORT_DELAY_MS) {
+  const liveRegion = document.querySelector('live-region')
+
+  liveRegion?.clear()
+
+  await announce(text, {
+    delayMs,
+    from: liveRegion || undefined,
+  })
+}
+
+export async function announceLoading() {
+  await announceText('Loading.')
+}
+
+export interface SelectPanelSingleSelection {
+  selected: ItemInput | undefined
+  onSelectedChange: (selected: ItemInput | undefined) => void
+}
+
+export interface SelectPanelMultiSelection {
+  selected: ItemInput[]
+  onSelectedChange: (selected: ItemInput[]) => void
+}
+
+export type InitialLoadingType = 'spinner' | 'skeleton'
+
+export function SecondaryActionButton(props: ButtonProps) {
+  return <Button block {...props} />
+}
+
+export function SecondaryActionLink(props: LinkButtonProps & ButtonProps) {
+  return <LinkButton {...props} variant="invisible" block />
+}
+
+export type SelectPanelSecondaryAction =
+  | React.ReactElement<typeof SecondaryActionButton>
+  | React.ReactElement<typeof SecondaryActionLink>
+
+export interface SelectPanelBaseProps {
+  // TODO: Make `title` required in the next major version
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  title?: string | React.ReactElement<any>
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  subtitle?: string | React.ReactElement<any>
+  onOpenChange: (
+    open: boolean,
+    gesture: 'anchor-click' | 'anchor-key-press' | 'click-outside' | 'escape' | 'selection' | 'cancel',
+  ) => void
+  secondaryAction?: SelectPanelSecondaryAction
+  placeholder?: string
+  // TODO: Make `inputLabel` required in next major version
+  inputLabel?: string
+  overlayProps?: Partial<OverlayProps>
+  initialLoadingType?: InitialLoadingType
+  className?: string
+  notice?: {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    text: string | React.ReactElement<any>
+    variant: 'info' | 'warning' | 'error'
+  }
+  message?: {
+    title: string
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    body: string | React.ReactElement<any>
+    variant: 'empty' | 'error' | 'warning'
+    icon?: React.ComponentType<IconProps>
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    action?: React.ReactElement<any>
+  }
+  /**
+   * @deprecated Use `secondaryAction` instead.
+   */
+  // eslint-disable-next-line @typescript-eslint/no-explicit-any
+  footer?: string | React.ReactElement<any>
+  showSelectedOptionsFirst?: boolean
+  /**
+   * Whether to disable fullscreen behavior on narrow viewports.
+   * When `true`, the panel will maintain its anchored position regardless of viewport size.
+   * When `false`, the panel will go fullscreen on narrow viewports (if feature flag is enabled).
+   * @default undefined (uses feature flag default)
+   */
+  disableFullscreenOnNarrow?: boolean
+  showSelectAll?: boolean
+  /**
+   * Set to true to allow focus to move to elements that are dynamically prepended to the container.
+   * Default is false.
+   */
+  focusPrependedElements?: boolean
+}
+
+export type SelectPanelListProps = Omit<FilteredActionListProps, 'selectionVariant' | 'variant' | 'message'>
+
+export type SelectPanelVariantProps =
+  | {variant?: 'anchored'; onCancel?: () => void}
+  | {variant: 'modal'; onCancel: () => void}
+
+export type SelectPanelProps = SelectPanelBaseProps &
+  SelectPanelListProps &
+  Pick<AnchoredOverlayProps, 'open' | 'height' | 'width' | 'align' | 'displayInViewport'> &
+  AnchoredOverlayWrapperAnchorProps &
+  (SelectPanelSingleSelection | SelectPanelMultiSelection) &
+  SelectPanelVariantProps
+
+type SelectPanelPropsWithoutSelection = Omit<
+  SelectPanelProps,
+  keyof SelectPanelSingleSelection | keyof SelectPanelMultiSelection
+>
+
+export type SelectPanelNextMode = 'single' | 'multi'
+
+export type SelectPanelNextSingleProps = SelectPanelPropsWithoutSelection &
+  SelectPanelSingleSelection & {
+    mode: 'single'
+  }
+
+export type SelectPanelNextMultiProps = SelectPanelPropsWithoutSelection &
+  SelectPanelMultiSelection & {
+    mode: 'multi'
+  }
+
+export type SelectPanelNextProps = SelectPanelNextSingleProps | SelectPanelNextMultiProps
+
+export function isMultiSelectProps(props: SelectPanelProps): props is SelectPanelProps & SelectPanelMultiSelection {
+  return isMultiSelectVariant(props.selected)
+}
+
+export function isMultiSelectVariant(
+  selected: SelectPanelSingleSelection['selected'] | SelectPanelMultiSelection['selected'],
+): selected is SelectPanelMultiSelection['selected'] {
+  return Array.isArray(selected)
+}
+
+export function toSelectedItemArray(
+  selected: SelectPanelSingleSelection['selected'] | SelectPanelMultiSelection['selected'],
+) {
+  return Array.isArray(selected) ? selected : selected ? [selected] : []
+}
+
+export const focusZoneSettings: Partial<FocusZoneHookSettings> = {
+  disabled: true,
+}
+
+export const closeButtonProps = {'aria-label': 'Cancel and close'}
+
+export const areItemsEqual = (itemA: ItemInput, itemB: ItemInput) => {
+  if (typeof itemA.id !== 'undefined') {
+    return itemA.id === itemB.id
+  }
+
+  return itemA === itemB
+}
+
+export const doesItemsIncludeItem = (items: ItemInput[], item: ItemInput) => {
+  return items.some(currentItem => areItemsEqual(currentItem, item))
+}
+
+export const defaultRenderAnchor: NonNullable<SelectPanelProps['renderAnchor']> = props => {
+  const {children, ...rest} = props
+
+  return (
+    <Button trailingAction={TriangleDownIcon} {...rest}>
+      {children}
+    </Button>
+  )
+}
+
+export const SELECT_PANEL_SLOT = Symbol('SelectPanel')