astro-takumi/src/extract.ts

Generate Open Graph images for your Astro site using Takumi.

import type { PageDetails } from "./types.js";

// Astro CSS parsing fails: Error: Could not parse CSS stylesheet
// Remove CSS from the HTML
// https://github.com/jsdom/jsdom/issues/2005#issuecomment-1758940894
export function sanitizeHtml(html: string): string {
  return html
    .replace(/<style([\S\s]*?)>([\S\s]*?)<\/style>/gim, "")
    .replace(/<script([\S\s]*?)>([\S\s]*?)<\/script>/gim, "");
}

export function extract(document: Document): PageDetails {
  const title = document.querySelector("meta[property='og:title']")?.getAttribute("content");
  const description = document.querySelector("meta[property='og:description']")?.getAttribute("content");
  const url = document.querySelector("meta[property='og:url']")?.getAttribute("content");
  const type = document.querySelector("meta[property='og:type']")?.getAttribute("content");
  const image = document.querySelector("meta[property='og:image']")?.getAttribute("content");

  const errors = [];
  if (!title) {
    errors.push("og:title");
  }
  if (!url) {
    errors.push("og:url");
  }
  if (!type) {
    errors.push("og:type");
  }
  if (!image) {
    errors.push("og:image");
  }

  if (errors.length > 0) {
    const html = errors.map((error) => {
      return `<meta property="${error}" content="some value"/>`;
    });
    throw new Error(
      `Missing required meta tags: ${errors.join(", ")}. Add the following to your page:\n${html.join("\n")}`,
    );
  }

  // these casts are safe because we check for existence above
  const returnVal: PageDetails = {
    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
    title: title!,
    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
    url: url!,
    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
    type: type!,
    // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
    image: image!,
  };
  if (description && description != title) {
    returnVal.description = description;
  }
  return returnVal;
}