test(quick-261022-imo): settings section panel coverage

- settingsSectionOf: null cases, category order, link entry placement
- SettingsPanel: labels, links, current entry, empty category, collapse
- AppShell: hidden cases, settings-link controllers, collapse, offset, narrow, focus hand-off

admin/tests/state/useSettings.test.ts

@@ -8,6 +8,7 @@ import {
   settingsGroups,
   settingsLinkFor,
   settingsPath,
+  settingsSectionOf,
   useSettings,
 } from '../../src/state/useSettings'
 import { settingsFixture } from '../fixtures/typed'
@@ -65,3 +66,41 @@ describe('useSettings (D-21)', () => {
     expect(useSettings().settingsLinkFor).toBe(settingsLinkFor)
   })
 })
+
+describe('settingsSectionOf (quick-261022-imo)', () => {
+  const link = (code: string, order: number, controller: string) => ({
+    ...settingsFixture.list.data[0]!,
+    code,
+    label: code,
+    model: '',
+    controller,
+    order,
+  })
+
+  it('is null without a current entry or for a one-entry category', () => {
+    setSettings(settingsFixture.list.data)
+    expect(settingsSectionOf(null)).toBeNull()
+    expect(settingsSectionOf(settingsEntry('branding'))).toBeNull()
+  })
+
+  it('returns the current category in settingsGroups order', () => {
+    setSettings(settingsFixture.list.data)
+    const section = settingsSectionOf(settingsEntry('mail'))
+    expect(section?.category).toBe('System')
+    expect(section?.current.code).toBe('mail')
+    expect(section?.entries.map((entry) => entry.code)).toEqual(['mail', 'search'])
+  })
+
+  it('places a link entry by its order and never lists another category', () => {
+    setSettings([...settingsFixture.list.data, link('locales', 15, 'acme.lang.locales')])
+    const section = settingsSectionOf(settingsLinkFor('acme.lang.locales'))
+    expect(section?.current.code).toBe('locales')
+    expect(section?.entries.map((entry) => entry.code)).toEqual(['mail', 'locales', 'search'])
+    expect(section?.entries.some((entry) => entry.category === 'Appearance')).toBe(false)
+    expect(settingsSectionOf(settingsEntry('search'))?.entries.map((entry) => entry.code)).not.toContain('branding')
+  })
+
+  it('is exposed through useSettings', () => {
+    expect(useSettings().settingsSectionOf).toBe(settingsSectionOf)
+  })
+})