fix(hmr): invalidate all cached revisions of an importing page (#5448)

__tests__/unit/node/markdownToVue-cache.test.ts

@@ -0,0 +1,70 @@
+import { mkdtemp, rm, writeFile } from 'node:fs/promises'
+import { tmpdir } from 'node:os'
+import path from 'node:path'
+
+import { resolveConfig } from 'node/config'
+import { disposeMdItInstance } from 'node/markdown/markdown'
+import { clearCache, createMarkdownToVueRenderFn } from 'node/markdownToVue'
+
+describe('node/markdownToVue cache invalidation', () => {
+  let root: string
+
+  beforeEach(async () => {
+    clearCache()
+    disposeMdItInstance()
+    root = await mkdtemp(path.join(tmpdir(), 'vitepress-md-cache-'))
+  })
+
+  afterEach(async () => {
+    clearCache()
+    disposeMdItInstance()
+    await rm(root, { recursive: true, force: true })
+  })
+
+  test.each([
+    ['include', '<!-- @include: ./shared.md -->'],
+    ['snippet', '<<< ./shared.md{txt}']
+  ])(
+    'invalidates every source version when its %s changes',
+    async (_, importSrc) => {
+      const file = path.join(root, 'page.md')
+      const otherFile = path.join(root, 'other-page.md')
+      const sharedFile = path.join(root, 'shared.md')
+      const sources = ['First', 'Second', 'Third'].map(
+        (title) => `# ${title}\n\n${importSrc}\n`
+      )
+      await writeFile(file, sources[0])
+      await writeFile(otherFile, '# Other page')
+      await writeFile(sharedFile, 'old shared content')
+
+      const config = await resolveConfig(root, 'serve', 'development')
+      const render = await createMarkdownToVueRenderFn(
+        config.srcDir,
+        { highlight: (code) => code },
+        '/',
+        false,
+        false,
+        config
+      )
+
+      // Editing the page creates several cached versions of the same path.
+      const first = await render(sources[0], file)
+      expect(await render(sources[0], file)).toBe(first)
+      await render(sources[1], file)
+      const other = await render('# Other page', otherFile)
+      await render(sources[2], file)
+
+      await writeFile(sharedFile, 'updated shared content')
+      // The include/snippet HMR handler invalidates each importing page by path.
+      clearCache('page.md')
+
+      // Undoing a page edit must not revive a stale version of the dependency.
+      for (const src of [...sources].reverse()) {
+        const result = await render(src, file)
+        expect(result.vueSrc).toContain('updated shared content')
+        expect(result.vueSrc).not.toContain('old shared content')
+      }
+      expect(await render('# Other page', otherFile)).toBe(other)
+    }
+  )
+})

src/node/markdownToVue.ts

@@ -59,7 +59,9 @@ export function clearCache(relativePath?: string) {
     return
   }
 
-  cache.find((_, key) => key.endsWith(`:${relativePath}`) && cache.delete(key))
+  for (const key of cache.keys()) {
+    if (key.endsWith(`:${relativePath}`)) cache.delete(key)
+  }
 }
 
 function normalizeDriveLetter(file: string) {