From 04fe864ad8a9a55be942d1c2eede2ecac47b18cb Mon Sep 17 00:00:00 2001
From: Evan You <yyx990803@gmail.com>
Date: Thu, 30 Apr 2020 14:17:00 -0400
Subject: [PATCH] should update head in production as well

---
 bin/vitepress.js            |  5 ++---
 lib/app/composables/head.js | 42 ++++++++++++++++++-------------------
 lib/app/index.js            |  7 ++++---
 src/build/build.ts          |  2 +-
 src/build/render.ts         |  5 +++--
 5 files changed, 30 insertions(+), 31 deletions(-)

diff --git a/bin/vitepress.js b/bin/vitepress.js
index d270d565..96473d71 100755
--- a/bin/vitepress.js
+++ b/bin/vitepress.js
@@ -1,5 +1,4 @@
 #!/usr/bin/env node
-const path = require('path')
 const chalk = require('chalk')
 const argv = require('minimist')(process.argv.slice(2))
 
@@ -18,11 +17,11 @@ if (!command || command === 'dev') {
       console.log(`listening at http://localhost:${port}`)
     })
   }).catch(err => {
-    console.error(`failed to start server. error: `, err)
+    console.error(chalk.red(`failed to start server. error:\n`), err)
   })
 } else if (command === 'build') {
   require('../dist').build(argv).catch(err => {
-    console.error(`build error: `, err)
+    console.error(chalk.red(`build error:\n`), err)
   })
 } else {
   console.log(chalk.red(`unknown command "${command}".`))
diff --git a/lib/app/composables/head.js b/lib/app/composables/head.js
index bb078671..a106ba87 100644
--- a/lib/app/composables/head.js
+++ b/lib/app/composables/head.js
@@ -5,33 +5,29 @@ import { siteDataRef } from './siteData'
  * @param {import('./pageData').PageDataRef} pageDataRef
  */
 export function useUpdateHead(pageDataRef) {
-  const descriptionTag = createHeadElement(['meta', {
-    name: 'description',
-    content: siteDataRef.value.description
-  }])
-  document.head.appendChild(descriptionTag)
-
   /**
    * @type {HTMLElement[]}
    */
-  const siteHeadTags = []
-  /**
-   * @type {HTMLElement[]}
-   */
-  const pageHeadTags = []
+  const metaTags = Array.from(document.querySelectorAll('meta'))
 
+  let isFirstUpdate = true
   /**
-   * @param {HTMLElement[]} tags
    * @param {import('src').HeadConfig[]} newTags
    */
-  const updateHeadTags = (tags, newTags) => {
-    tags.forEach((el) => document.head.removeChild(el))
-    tags.length = 0
+  const updateHeadTags = (newTags) => {
+    if (!__DEV__ && isFirstUpdate) {
+      // in production, the initial meta tags are already pre-rendered so we
+      // skip the first update.
+      isFirstUpdate = false
+      return
+    }
+    metaTags.forEach((el) => document.head.removeChild(el))
+    metaTags.length = 0
     if (newTags && newTags.length) {
       newTags.forEach((headConfig) => {
         const el = createHeadElement(headConfig)
         document.head.appendChild(el)
-        tags.push(el)
+        metaTags.push(el)
       })
     }
   }
@@ -41,12 +37,14 @@ export function useUpdateHead(pageDataRef) {
     const siteData = siteDataRef.value
     const pageTitle = pageData && pageData.title
     document.title = (pageTitle ? pageTitle + ` | ` : ``) + siteData.title
-    descriptionTag.setAttribute('content', siteData.description)
-    updateHeadTags(siteHeadTags, siteData.head)
-    updateHeadTags(
-      pageHeadTags,
-      pageData && pageData.frontmatter.head
-    )
+    updateHeadTags([
+      ['meta', {
+        name: 'description',
+        content: siteData.description
+      }],
+      ...siteData.head,
+      ...(pageData && pageData.frontmatter.head || [])
+    ])
   })
 }
 
diff --git a/lib/app/index.js b/lib/app/index.js
index c1ac51e2..c7428ad6 100644
--- a/lib/app/index.js
+++ b/lib/app/index.js
@@ -16,11 +16,12 @@ export function createApp() {
   // distinct per-request.
   const pageDataRef = ref()
 
-  if (__DEV__ && inBrowser) {
-    // dynamically update head tags during dev since it's an SPA
-    // this is not needed in production.
+  if (inBrowser) {
+    // dynamically update head tags
     useUpdateHead(pageDataRef)
+  }
 
+  if (__DEV__ && inBrowser) {
     // hot reload pageData
     hot.on('vitepress:pageData', (data) => {
       if (
diff --git a/src/build/build.ts b/src/build/build.ts
index 8352e0e4..b3487cb8 100644
--- a/src/build/build.ts
+++ b/src/build/build.ts
@@ -20,6 +20,6 @@ export async function build(buildOptions: BuildOptions = {}) {
     }
   } finally {
     await fs.rmdir(siteConfig.tempDir, { recursive: true })
-    console.log('done.')
   }
+  console.log('done.')
 }
diff --git a/src/build/render.ts b/src/build/render.ts
index ede95d5d..4b7eab7f 100644
--- a/src/build/render.ts
+++ b/src/build/render.ts
@@ -24,17 +24,18 @@ export async function renderPage(
     '_assets',
     pageJsPath
   ))
+  const pageData = JSON.parse(__pageData)
 
   const html = `
 <html lang="en-US">
   <head>
-    <title>${__pageData.title ? __pageData.title + ` | ` : ``}${
+    <title>${pageData.title ? pageData.title + ` | ` : ``}${
     config.site.title
   }</title>
     <meta name="description" content="${config.site.description}">
     <link rel="stylesheet" href="${assetPath}/style.css">${renderHead(
     config.site.head
-  )}${renderHead(__pageData.frontmatter.head)}
+  )}${renderHead(pageData.frontmatter.head)}
   </head>
   <body>
     <div id="app">${content}</div>