feat: frontmatter description predefined variable

src/client/app/composables/head.ts

@@ -28,6 +28,7 @@ export function useUpdateHead(route: Route, siteDataByRouteRef: Ref<SiteData>) {
     const pageData = route.data
     const siteData = siteDataByRouteRef.value
     const pageTitle = pageData && pageData.title
+    const pageDescription = pageData && pageData.description
     document.title = (pageTitle ? pageTitle + ` | ` : ``) + siteData.title
     updateHeadTags([
       ['meta', { charset: 'utf-8' }],
@@ -42,7 +43,7 @@ export function useUpdateHead(route: Route, siteDataByRouteRef: Ref<SiteData>) {
         'meta',
         {
           name: 'description',
-          content: siteData.description
+          content: pageDescription || siteData.description
         }
       ],
       ...siteData.head,

src/node/build/render.ts

@@ -63,7 +63,9 @@ export async function renderPage(
     <title>
       ${pageData.title ? pageData.title + ` | ` : ``}${siteData.title}
     </title>
-    <meta name="description" content="${siteData.description}">
+    <meta name="description" content="${
+      pageData.description || siteData.description
+    }">
     <link rel="stylesheet" href="${assetPath}${cssChunk.fileName}">
     ${preloadLinks}
     ${renderHead(siteData.head)}

src/node/markdownToVue.ts

@@ -42,7 +42,7 @@ export function createMarkdownToVueRenderFn(
     const pageData: PageData = {
       title: inferTitle(frontmatter, content),
       description: inferDescription(frontmatter),
-      frontmatter,
+      frontmatter: withHeadDescriptionRemoved(frontmatter),
       headers: data.headers,
       relativePath: file.replace(/\\/g, '/'),
       lastUpdated
@@ -109,11 +109,11 @@ const inferTitle = (frontmatter: any, content: string) => {
 }
 
 const inferDescription = (frontmatter: Record<string, any>) => {
-  if (!frontmatter.head) {
+  const { description, head } = frontmatter
-    return ''
+  if (description !== undefined) {
+    return description
   }
-
+  return (head && getHeadMetaContent(head, 'description')) || ''
-  return getHeadMetaContent(frontmatter.head, 'description') || ''
 }
 
 const getHeadMetaContent = (
@@ -130,3 +130,25 @@ const getHeadMetaContent = (
 
   return meta && meta[1].content
 }
+
+function isMetaDescription(headConfig: HeadConfig) {
+  return (
+    headConfig[0] === 'meta' &&
+    headConfig[1] &&
+    headConfig[1].name === 'description'
+  )
+}
+
+function rejectHeadDescription(head: HeadConfig[]) {
+  return head.filter((h: HeadConfig) => !isMetaDescription(h))
+}
+
+function withHeadDescriptionRemoved(frontmatter: Record<string, any>) {
+  if (frontmatter.head) {
+    return {
+      ...frontmatter,
+      head: rejectHeadDescription(frontmatter.head)
+    }
+  }
+  return frontmatter
+}