#424

frontend/scripts/help-assets.test.ts

@@ -0,0 +1,112 @@
+import { mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import path from 'node:path'
+import { afterAll, afterEach, beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { generateHelpAssets } from './help-assets'
+
+import type { ArticleMeta, HelpChange, HelpSearchEntry, HelpTitleIndex } from '@/lib/help'
+
+vi.hoisted (() => {
+  vi.stubGlobal ('Uint8Array', Object.getPrototypeOf (new TextEncoder ().encode ('')).constructor)
+})
+afterAll (() => vi.unstubAllGlobals ())
+
+
+const readAsset = <T,> (modules: Map<string, string>, name: string): T => {
+  const source = modules.get (`virtual:help/${ name }`)!
+  const argument = source.slice ('export default JSON.parse('.length, -1)
+  return JSON.parse (JSON.parse (argument))
+}
+
+
+describe ('Build-time Help assets', () => {
+  let root: string
+
+  beforeEach (async () => {
+    root = await mkdtemp (path.join (tmpdir (), 'btrc-help-assets-'))
+  })
+
+  afterEach (async () => {
+    await rm (root, { recursive: true, force: true })
+  })
+
+  const writeArticle = async (
+      identifier: string,
+      editions: Record<string, string>,
+      current = '2026-10-02.10',
+  ) => {
+    const articleRoot = path.join (root, identifier)
+    const editionRoot = path.join (articleRoot, 'editions', 'ja')
+    await mkdir (editionRoot, { recursive: true })
+    await writeFile (path.join (articleRoot, 'article.yml'), [
+	`identifier: ${ identifier }`, 'canonical_language: ja', 'title: stale YAML title',
+	'languages:', '  ja:', `    current_edition: ${ current }`].join ('\n'))
+    await Promise.all (Object.entries (editions).map (([edition, source]) =>
+	writeFile (path.join (editionRoot, `${ edition }.mdx`), source)))
+  }
+
+  it ('generates current search and ordered published history from each edition H1', async () => {
+    await writeArticle ('guide', {
+	'2026-10-01': '# 旧ホーム\n\n過去本文',
+	'2026-10-02': '# ホーム\n\n最初の同日版',
+	'2026-10-02.2': '# ホーム\n\n第二版',
+	'2026-10-02.3': '# ホーム\n\n第三版',
+	'2026-10-02.10': '\uFEFF# 最新ホーム\r\n\r\n現在本文\r\n# 別見出し',
+	'2026-10-02.11': '# 未公開\n\n検索に含めない' })
+    const { modules } = await generateHelpAssets (root)
+    const articles = readAsset<Record<string, ArticleMeta>> (modules, 'articles')
+    expect (articles.guide.languages.ja).toEqual ({
+	currentEdition: '2026-10-02.10', publishedEditions: [
+	    '2026-10-01', '2026-10-02', '2026-10-02.2', '2026-10-02.3', '2026-10-02.10'] })
+    expect (readAsset<Record<string, HelpSearchEntry[]>> (modules, 'search').ja).toEqual ([{
+	identifier: 'guide', edition: '2026-10-02.10', title: '最新ホーム',
+	body: '\r\n現在本文\r\n# 別見出し' }])
+    const changes = readAsset<Record<string, HelpChange[]>> (modules, 'changes').ja
+    expect (changes.map (row => [row.edition, row.title, row.pred, row.change, row.date]))
+	.toEqual ([
+	    ['2026-10-02.10', '最新ホーム', '2026-10-02.3', 'update', '2026-10-02'],
+	    ['2026-10-02.3', 'ホーム', '2026-10-02.2', 'update', '2026-10-02'],
+	    ['2026-10-02.2', 'ホーム', '2026-10-02', 'update', '2026-10-02'],
+	    ['2026-10-02', 'ホーム', '2026-10-01', 'update', '2026-10-02'],
+	    ['2026-10-01', '旧ホーム', null, 'new', '2026-10-01']])
+    const titles = readAsset<Record<string, HelpTitleIndex>> (modules, 'titles').ja
+    expect (titles).toEqual ({ '旧ホーム': ['guide'], 'ホーム': ['guide'],
+	'最新ホーム': ['guide'] })
+    expect (modules.get ('virtual:help/loaders')).not.toContain ('2026-10-02.11')
+    expect (modules.get ('virtual:help/loaders')).toContain ('2026-10-02.10.mdx?raw')
+    expect (modules.get ('virtual:help/search')).not.toContain ('import(')
+  })
+
+  it ('retains ambiguous title identifiers and normalises width and case', async () => {
+    await writeArticle ('alpha', { '2026-10-02': '# ＨＯＭＥ\n本文' }, '2026-10-02')
+    await writeArticle ('beta', { '2026-10-02': '# Home\n本文' }, '2026-10-02')
+    const { modules } = await generateHelpAssets (root)
+    expect (readAsset<Record<string, HelpTitleIndex>> (modules, 'titles').ja.home)
+	.toEqual (['alpha', 'beta'])
+    expect (readAsset<Record<string, HelpChange[]>> (modules, 'changes').ja
+	.map (row => row.identifier)).toEqual (['alpha', 'beta'])
+  })
+
+  it ('rejects missing current files during generation', async () => {
+    await writeArticle ('guide', { '2026-10-02': '# ホーム' })
+    await expect (generateHelpAssets (root)).rejects.toThrow ('Missing current Help edition')
+  })
+
+  it.each (['本文\n# 遅い見出し', '#   \n本文']) (
+      'rejects missing leading H1 at build time: %s', async source => {
+	await writeArticle ('guide', { '2026-10-02.10': source })
+	await expect (generateHelpAssets (root)).rejects.toThrow ('Missing leading Help H1')
+      })
+
+  it ('rejects absent canonical metadata instead of generating incomplete assets', async () => {
+    await writeArticle ('guide', { '2026-10-02.10': '# ホーム' })
+    await writeFile (path.join (root, 'guide', 'article.yml'),
+	'identifier: guide\nlanguages:\n  ja:\n    current_edition: 2026-10-02.10')
+    await expect (generateHelpAssets (root)).rejects.toThrow ('Invalid Help metadata')
+  })
+
+  it ('rejects an empty Help checkout', async () => {
+    await expect (generateHelpAssets (root)).rejects.toThrow ('No Help articles found')
+  })
+})

frontend/src/lib/help.test.ts

@@ -60,4 +60,29 @@ describe ('Help file catalogue', () => {
     expect (await api.getHelpEdition ('guide', 'ja', '2026-10-02.11')).toBeNull ()
     expect (await api.getHelpEditionSource ('guide', 'ja', '2026-10-02.11')).toBeNull ()
   })
+
+  it ('compares raw H1 and body lines in the requested direction', async () => {
+    const { api } = createHelpFixture ()
+    const forward = await api.getHelpDiff ('guide', 'ja', '2026-10-01', '2026-10-02.10')
+    expect (forward?.from.title).toBe ('旧ホーム')
+    expect (forward?.to.title).toBe ('ホーム第十版')
+    expect (forward?.lines).toEqual (expect.arrayContaining ([
+	{ type: 'removed', content: '# 旧ホーム\n' },
+	{ type: 'added', content: '# ホーム第十版\n' },
+	{ type: 'unchanged', content: '\n' }]))
+    const reverse = await api.getHelpDiff ('guide', 'ja', '2026-10-02.10', '2026-10-01')
+    expect (reverse?.lines).toEqual (expect.arrayContaining ([
+	{ type: 'added', content: '# 旧ホーム\n' },
+	{ type: 'removed', content: '# ホーム第十版\n' }]))
+  })
+
+  it.each ([['missing', 'ja', '2026-10-01', '2026-10-02.10'],
+      ['guide', 'ja', '2026-10-01', '2026-10-02.11'],
+      ['guide', 'en', '2026-10-01', '2026-10-02']]) (
+      'rejects invalid diff editions for %s/%s without reading sources',
+      async (id, language, from, to) => {
+	const { api, raw } = createHelpFixture ()
+	expect (await api.getHelpDiff (id, language, from, to)).toBeNull ()
+	Object.values (raw).forEach (load => expect (load).not.toHaveBeenCalled ())
+      })
 })

frontend/src/lib/helpPrefetch.test.tsx

@@ -6,6 +6,7 @@ import { beforeEach, describe, expect, it, vi } from 'vitest'
 import PrefetchLink from '@/components/PrefetchLink'
 import * as prefetchers from '@/lib/prefetchers'
 import HelpDetailPage from '@/pages/help/HelpDetailPage'
+import HelpDiffPage from '@/pages/help/HelpDiffPage'
 import { helpFixture } from '@/test/helpFixtures'
 import { renderWithProviders } from '@/test/render'
 
@@ -76,6 +77,29 @@ describe ('Help prefetch integration', () => {
     Object.values (helpFixture.modules).forEach (load => expect (load).not.toHaveBeenCalled ())
   })
 
+  it ('reuses two prefetched raw editions when displaying their diff', async () => {
+    const path = '/help/guide/diff?from=2026-10-01&to=2026-10-02.10'
+    const { queryClient } = renderWithProviders (
+	<>
+	  <PrefetchLink to={path}>diff</PrefetchLink>
+	  <Routes>
+	    <Route path="/" element={null}/>
+	    <Route path="/help/:identifier/diff" element={<HelpDiffPage/>}/>
+	  </Routes>
+	</>)
+    await Promise.all ([prefetchers.prefetchForURL (queryClient, path),
+	prefetchers.prefetchForURL (queryClient, path)])
+    fireEvent.click (screen.getByRole ('link', { name: 'diff' }))
+    expect (await screen.findByRole ('link', { name: '旧ホーム (2026-10-01)' }))
+	.toHaveAttribute ('href', '/help/guide?edition=2026-10-01')
+    expect (screen.getByText ('+ # ホーム第十版')).toBeInTheDocument ()
+    Object.entries (helpFixture.raw).forEach (([name, load]) => {
+      const expected = /\/ja\/(2026-10-01|2026-10-02\.10)\.mdx$/.test (name) ? 1 : 0
+      expect (load).toHaveBeenCalledTimes (expected)
+    })
+    Object.values (helpFixture.modules).forEach (load => expect (load).not.toHaveBeenCalled ())
+  })
+
   it.each (['intent', 'off']) ('respects %s intent settings and still prefetches clicks',
       async mode => {
 	settings.linkPreload = mode

frontend/src/test/helpFixtures.tsx

@@ -4,7 +4,7 @@ import { vi } from 'vitest'
 
 import source from '@/lib/help.ts?raw'
 
-import type { ReactElement } from 'react'
+import type { ComponentType } from 'react'
 
 import type * as Help from '@/lib/help'
 
@@ -38,11 +38,11 @@ export const createHelpFixture = () => {
       vi.fn (async () => `# ${title}\n\n${body}`)]))
   const moduleLoads = Object.fromEntries (published.map (([id, language, edition, title, body]) => [
       `../../help/${id}/editions/${language}/${edition}.mdx`,
-      vi.fn (async (): Promise<{ default: () => ReactElement }> => ({
+      vi.fn (async (): Promise<{ default: ComponentType }> => ({
 	  default: () => createElement ('div', null,
 	      createElement ('h1', null, title), createElement ('p', null, body)) }))]))
   // Dynamic imports reuse a module namespace even when called more than once.
-  const caches: Record<string, { promise?: Promise<{ default: () => ReactElement }> }> = { }
+  const caches: Record<string, { promise?: Promise<{ default: ComponentType }> }> = { }
   const modules = Object.fromEntries (Object.entries (moduleLoads).map (([path, load]) => {
     caches[path] = { }
     return [path, vi.fn (() => caches[path].promise ??= load ())]