plugin integration round 2

quartz/plugins/transformers/description.ts

@@ -0,0 +1,54 @@
+import { PluggableList } from "unified"
+import { Root as HTMLRoot } from 'hast'
+import { toString } from "hast-util-to-string"
+import { QuartzTransformerPlugin } from "../types"
+
+export interface Options {
+  descriptionLength: number
+}
+
+const defaultOptions: Options = {
+  descriptionLength: 150
+}
+
+export class Description extends QuartzTransformerPlugin {
+  name = "Description"
+  opts: Options
+
+  constructor(opts?: Options) {
+    super()
+    this.opts = { ...defaultOptions, ...opts }
+  }
+
+  markdownPlugins(): PluggableList {
+    return []
+  }
+
+  htmlPlugins(): PluggableList {
+    return [
+      () => {
+        return async (tree: HTMLRoot, file) => {
+          const frontMatterDescription = file.data.frontmatter?.description
+          const desc = frontMatterDescription ?? toString(tree)
+          const sentences = desc.replace(/\s+/g, ' ').split('.')
+          let finalDesc = ""
+          let sentenceIdx = 0
+          const len = this.opts.descriptionLength
+          while (finalDesc.length < len) {
+            finalDesc += sentences[sentenceIdx] + '.'
+            sentenceIdx++
+          }
+
+          file.data.description = finalDesc
+        }
+      }
+    ]
+  }
+}
+
+declare module 'vfile' {
+  interface DataMap {
+    description: string
+  }
+}
+