fix(markdown): preserve page data when injecting scripts (#5440)

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

@@ -0,0 +1,73 @@
+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 { createMarkdownToVueRenderFn } from 'node/markdownToVue'
+import { compileScript, parse } from 'vue/compiler-sfc'
+
+describe('page data script serialization', () => {
+  let root: string
+  let file: string
+  let render: Awaited<ReturnType<typeof createMarkdownToVueRenderFn>>
+
+  beforeAll(async () => {
+    root = await mkdtemp(path.join(tmpdir(), 'vitepress-page-data-'))
+    file = path.join(root, 'index.md')
+    await writeFile(file, '# Page\n')
+    const siteConfig = await resolveConfig(root, 'build', 'production')
+    disposeMdItInstance()
+    render = await createMarkdownToVueRenderFn(
+      root,
+      { cache: false },
+      '/',
+      false,
+      false,
+      siteConfig
+    )
+  })
+
+  afterAll(async () => {
+    disposeMdItInstance()
+    await rm(root, { recursive: true, force: true })
+  })
+
+  describe.each([
+    ['no script', ''],
+    ['named export', '<script>\nexport const custom = true\n</script>'],
+    [
+      'default export',
+      '<script>\nexport default { name: "Custom" }\n</script>'
+    ],
+    ['script setup', '<script setup>\nconst custom = true\n</script>']
+  ])('%s', (_, script) => {
+    test.each([
+      'Document </script> tags literally',
+      "Regular-expression substitutions: $&, $`, $' and $$"
+    ])('preserves %j', async (description) => {
+      const src = [
+        '---',
+        `description: ${JSON.stringify(description)}`,
+        '---',
+        '',
+        '# Page',
+        '',
+        script
+      ].join('\n')
+
+      const result = await render(src, file)
+      const { descriptor, errors } = parse(result.vueSrc, { filename: file })
+
+      expect(errors).toEqual([])
+      expect(() => compileScript(descriptor, { id: 'page-data' })).not.toThrow()
+      const module = await import(
+        'data:text/javascript;base64,' +
+          Buffer.from(descriptor.script!.content).toString('base64')
+      )
+      expect(module.__pageData).toEqual(result.pageData)
+      expect(module.__pageData.description).toBe(description)
+      expect(module.__pageData.frontmatter.description).toBe(description)
+    })
+  })
+})

src/node/markdownToVue.ts

@@ -322,9 +322,10 @@ export async function createMarkdownToVueRenderFn(
 }
 
 function injectPageDataCode(tags: string[], data: PageData) {
+  // Keep HTML closing tags in page data from terminating the SFC script.
   const code = `\nexport const __pageData = JSON.parse(${JSON.stringify(
     JSON.stringify(data)
-  )})`
+  ).replace(/</g, '\\u003c')})`
 
   const existingScriptIndex = tags.findIndex((tag) => {
     return (
@@ -344,7 +345,8 @@ function injectPageDataCode(tags: string[], data: PageData) {
       defaultExportRE.test(tagSrc) || namedDefaultExportRE.test(tagSrc)
     tags[existingScriptIndex] = tagSrc.replace(
       scriptRE,
-      code +
+      () =>
+        code +
         (hasDefaultExport
           ? ``
           : `\nexport default {name:${JSON.stringify(data.relativePath)}}`) +