feat: markdown extended features from fuwari

src/plugins/remark-excerpt.ts

@@ -1,26 +1,21 @@
 import type { Root } from 'mdast'
+import type { VFile } from 'vfile'
 import { toString } from 'mdast-util-to-string'
 
-interface AstroData {
-  data: {
-    astro: {
-      frontmatter: {
-        excerpt: string
-      }
-    }
-  }
-}
-
 export function remarkExcerpt() {
-  return (tree: Root, file: AstroData) => {
+  return function (tree: Root, file: VFile) {
     let excerpt = ''
     for (const node of tree.children) {
-      if (node.type !== 'paragraph') {
-        continue
+      if (node.type === 'paragraph') {
+        excerpt = toString(node)
+        break
       }
-      excerpt = toString(node)
-      break
     }
+
+    // 确保 data.astro.frontmatter 存在
+    file.data.astro = file.data.astro || {}
+    file.data.astro.frontmatter = file.data.astro.frontmatter || {}
+
     file.data.astro.frontmatter.excerpt = excerpt
   }
 }

src/plugins/remark-reading-time.ts

@@ -1 +1,18 @@
- 
+import type { Root } from 'mdast'
+import type { VFile } from 'vfile'
+import { toString } from 'mdast-util-to-string'
+import getReadingTime from 'reading-time'
+
+export function remarkReadingTime() {
+  return function (tree: Root, file: VFile) {
+    const textOnPage = toString(tree)
+    const readingTime = getReadingTime(textOnPage)
+
+    // 确保 data.astro.frontmatter 存在
+    file.data.astro = file.data.astro || {}
+    file.data.astro.frontmatter = file.data.astro.frontmatter || {}
+
+    file.data.astro.frontmatter.minutes = Math.max(1, Math.round(readingTime.minutes))
+    file.data.astro.frontmatter.words = readingTime.words
+  }
+}