import { Root as HTMLRoot } from "hast" import { toString } from "hast-util-to-string" import { QuartzTransformerPlugin } from "../types" import { escapeHTML } from "../../util/escape" export interface Options { descriptionLength: number replaceExternalLinks: boolean } const defaultOptions: Options = { descriptionLength: 150, replaceExternalLinks: true, } const urlRegex = new RegExp( /(https?:\/\/)?(?([\da-z\.-]+)\.([a-z\.]{2,6})(:\d+)?)(?[\/\w\.-]*)(\?[\/\w\.=&;-]*)?/, "g", ) export const Description: QuartzTransformerPlugin | undefined> = (userOpts) => { const opts = { ...defaultOptions, ...userOpts } return { name: "Description", htmlPlugins() { return [ () => { return async (tree: HTMLRoot, file) => { let frontMatterDescription = file.data.frontmatter?.description let text = escapeHTML(toString(tree)) if (opts.replaceExternalLinks) { frontMatterDescription = frontMatterDescription?.replace( urlRegex, "$" + "$", ) text = text.replace(urlRegex, "$" + "$") } const desc = frontMatterDescription ?? text const sentences = desc.replace(/\s+/g, " ").split(/\.\s/) const finalDesc: string[] = [] const len = opts.descriptionLength let sentenceIdx = 0 if (sentences[0] !== undefined && sentences[0].length >= len) { const firstSentence = sentences[0].split(" ") while (finalDesc.length < len) { const sentence = firstSentence[sentenceIdx] if (!sentence) break finalDesc.push(sentence) sentenceIdx++ } finalDesc.push("...") } else { while (finalDesc.length < len) { const sentence = sentences[sentenceIdx] if (!sentence) break finalDesc.push(sentence.endsWith(".") ? sentence : sentence + ".") sentenceIdx++ } } file.data.description = finalDesc.join(" ") file.data.text = text } }, ] }, } } declare module "vfile" { interface DataMap { description: string text: string } }