avoid component reload on hmr due to pageData export

lib/app/index.js

@@ -51,13 +51,15 @@ export function createApp() {
     if (inBrowser) {
       // in browser: native dynamic import
       return import(pagePath).then((page) => {
-        pageDataRef.value = readonly(page.__pageData)
+        if (page.__pageData) {
+          pageDataRef.value = readonly(JSON.parse(page.__pageData))
+        }
         return page.default
       })
     } else {
       // SSR, sync require
       const page = require(pagePath)
-      pageDataRef.value = page.__pageData
+      pageDataRef.value = JSON.parse(page.__pageData)
       return page.default
     }
   }, NotFound)

src/markdownToVue.ts

@@ -19,7 +19,12 @@ export function createMarkdownToVueRenderFn(
 ) {
   const md = createMarkdownRenderer(options)
 
-  return (src: string, file: string, lastUpdated: number) => {
+  return (
+    src: string,
+    file: string,
+    lastUpdated: number,
+    injectData = true
+  ) => {
     file = path.relative(root, file)
     const cached = cache.get(src)
     if (cached) {
@@ -41,10 +46,9 @@ export function createMarkdownToVueRenderFn(
       lastUpdated
     }
 
-    const additionalBlocks = injectPageData(
+    const additionalBlocks = injectData
-      data.hoistedTags || [],
+      ? injectPageData(data.hoistedTags || [], pageData)
-      pageData
+      : data.hoistedTags || []
-    )
 
     // double wrapping since tempalte root node is never hoisted or turned into
     // a static node.
@@ -61,11 +65,10 @@ export function createMarkdownToVueRenderFn(
 
 const scriptRE = /<\/script>/
 
-function injectPageData(
+function injectPageData(tags: string[], data: PageData) {
-  tags: string[],
+  const code = `\nexport const __pageData = ${JSON.stringify(
-  data: PageData
+    JSON.stringify(data)
-) {
+  )}`
-  const code = `\nexport const __pageData = ${JSON.stringify(data)}`
   const existingScriptIndex = tags.findIndex((tag) => scriptRE.test(tag))
   if (existingScriptIndex > -1) {
     tags[existingScriptIndex] = tags[existingScriptIndex].replace(

src/server.ts

@@ -5,11 +5,7 @@ import {
   Plugin,
   ServerConfig
 } from 'vite'
-import {
+import { resolveConfig, SiteConfig, resolveSiteData } from './config'
-  resolveConfig,
-  SiteConfig,
-  resolveSiteData
-} from './config'
 import { createMarkdownToVueRenderFn } from './markdownToVue'
 import { APP_PATH, SITE_DATA_REQUEST_PATH } from './utils/pathResolver'
 
@@ -43,7 +39,16 @@ function createVitePressPlugin(config: SiteConfig): Plugin {
         debugHmr(`reloading ${file}`)
         const content = await cachedRead(null, file)
         const timestamp = Date.now()
-        const { pageData, vueSrc } = markdownToVue(content, file, timestamp)
+        const { pageData, vueSrc } = markdownToVue(
+          content,
+          file,
+          timestamp,
+          // do not inject pageData on HMR
+          // it leads to vite to think <script> has changed and reloads the
+          // component instead of re-rendering.
+          // pageData needs separate HMR logic anyway (see below)
+          false
+        )
 
         // notify the client to update page data
         watcher.send({