#155

frontend/src/lib/prefetchers.test.ts

@@ -0,0 +1,112 @@
+import { QueryClient } from '@tanstack/react-query'
+import { beforeEach, describe, expect, it, vi } from 'vitest'
+
+import { prefetchForURL } from '@/lib/prefetchers'
+
+const postsApi = vi.hoisted (() => ({
+  fetchPost:        vi.fn (),
+  fetchPostChanges: vi.fn (),
+  fetchPosts:       vi.fn (),
+}))
+
+const tagsApi = vi.hoisted (() => ({
+  fetchTag:        vi.fn (),
+  fetchTagByName:  vi.fn (),
+  fetchTagChanges: vi.fn (),
+  fetchTags:       vi.fn (),
+}))
+
+const wikiApi = vi.hoisted (() => ({
+  fetchWikiPage:        vi.fn (),
+  fetchWikiPageByTitle: vi.fn (),
+  fetchWikiPages:       vi.fn (),
+}))
+
+vi.mock ('@/lib/posts', () => postsApi)
+vi.mock ('@/lib/tags', () => tagsApi)
+vi.mock ('@/lib/wiki', () => wikiApi)
+
+const qc = () => new QueryClient ({
+  defaultOptions: { queries: { retry: false } },
+})
+
+describe ('prefetchForURL', () => {
+  beforeEach (() => {
+    vi.clearAllMocks ()
+    postsApi.fetchPosts.mockResolvedValue ({ posts: [], count: 0 })
+    postsApi.fetchPost.mockResolvedValue ({ id: 1 })
+    postsApi.fetchPostChanges.mockResolvedValue ({ versions: [], count: 0 })
+    tagsApi.fetchTags.mockResolvedValue ({ tags: [], count: 0 })
+    tagsApi.fetchTag.mockResolvedValue ({ id: 1 })
+    tagsApi.fetchTagByName.mockResolvedValue (null)
+    tagsApi.fetchTagChanges.mockResolvedValue ({ versions: [], count: 0 })
+    wikiApi.fetchWikiPages.mockResolvedValue ([])
+    wikiApi.fetchWikiPage.mockResolvedValue ({ id: 1 })
+    wikiApi.fetchWikiPageByTitle.mockResolvedValue (null)
+  })
+
+  it ('prefetches post indexes from query parameters', async () => {
+    await prefetchForURL (
+        qc (),
+        'http://localhost/posts?tags=a+b&match=any&page=2&limit=5&order=title%3Aasc',
+    )
+
+    expect (postsApi.fetchPosts).toHaveBeenCalledWith (
+        expect.objectContaining ({
+          tags:  'a b',
+          match: 'any',
+          page:  2,
+          limit: 5,
+          order: 'title:asc',
+        }),
+    )
+  })
+
+  it ('prefetches post detail pages', async () => {
+    await prefetchForURL (qc (), 'http://localhost/posts/12')
+
+    expect (postsApi.fetchPost).toHaveBeenCalledWith ('12')
+  })
+
+  it ('prefetches tag indexes from query parameters', async () => {
+    await prefetchForURL (
+        qc (),
+        'http://localhost/tags?post=9&name=x&category=general&page=4&post_count_lte=10',
+    )
+
+    expect (tagsApi.fetchTags).toHaveBeenCalledWith (
+        expect.objectContaining ({
+          post:         9,
+          name:         'x',
+          category:     'general',
+          page:         4,
+          postCountLTE: 10,
+        }),
+    )
+  })
+
+  it ('prefetches wiki show pages and related tag/post data', async () => {
+    wikiApi.fetchWikiPageByTitle.mockResolvedValueOnce ({
+      id:    3,
+      title: 'Actual',
+      body:  'body',
+    })
+
+    await prefetchForURL (qc (), 'http://localhost/wiki/Alias')
+
+    expect (wikiApi.fetchWikiPageByTitle).toHaveBeenCalledWith ('Alias', { version: undefined })
+    expect (wikiApi.fetchWikiPage).toHaveBeenCalledWith ('3', {})
+    expect (tagsApi.fetchTagByName).toHaveBeenCalledWith ('Actual')
+    expect (postsApi.fetchPosts).toHaveBeenCalledWith (
+        expect.objectContaining ({ tags: 'Actual', limit: 8 }),
+    )
+  })
+
+  it ('ignores routes without a prefetcher', async () => {
+    await prefetchForURL (qc (), 'http://localhost/unknown')
+
+    expect (postsApi.fetchPosts).not.toHaveBeenCalled ()
+    expect (tagsApi.fetchTags).not.toHaveBeenCalled ()
+    expect (wikiApi.fetchWikiPages).not.toHaveBeenCalled ()
+  })
+})