gatsby-remark-embedder/dist/index.js

Gatsby Remark plugin to embed well known services by their URL.

"use strict";

var _interopRequireDefault = require("@babel/runtime/helpers/interopRequireDefault");
var _parse = _interopRequireDefault(require("parse5"));
var _hastUtilFromParse = _interopRequireDefault(require("hast-util-from-parse5"));
var _unistUtilVisit = _interopRequireDefault(require("unist-util-visit"));
var _transformers = require("./transformers");
// results in an AST node of type "root" with a single "children" node of type "element"
// so we return the first (and only) child "element" node
const htmlToHast = string => (0, _hastUtilFromParse.default)(_parse.default.parseFragment(string)).children[0];
const getUrlString = url => {
  const urlString = url.startsWith('http') ? url : `https://${url}`;
  try {
    return new URL(urlString).toString();
  } catch (error) {
    return null;
  }
};
module.exports = async ({
  cache,
  markdownAST
}, {
  customTransformers = [],
  services = {}
} = {}) => {
  const transformers = [..._transformers.defaultTransformers, ...customTransformers];
  const transformations = [];
  (0, _unistUtilVisit.default)(markdownAST, 'paragraph', paragraphNode => {
    if (paragraphNode.children.length !== 1) {
      return;
    }
    const [node] = paragraphNode.children;
    const isText = node.type === 'text';
    // it's a valid link if there's no title, and the value is the same as the URL
    const isValidLink = node.type === 'link' && node.title === null && node.children.length === 1 && node.children[0].value === node.url;
    if (!isText && !isValidLink) {
      return;
    }
    const {
      url,
      value = url
    } = node;
    const urlString = getUrlString(value);
    if (!urlString) {
      return;
    }
    transformers.filter(({
      shouldTransform
    }) => shouldTransform(urlString)).forEach(({
      getHTML,
      name = ''
    }) => {
      transformations.push(async () => {
        try {
          let html = await cache.get(urlString);
          if (!html) {
            html = await getHTML(urlString, services[name] || {});
            await cache.set(urlString, html);
          }

          // if nothing's returned from getHTML, then no modifications are needed
          if (!html) return;

          // convert the HTML string into an AST
          const htmlElement = htmlToHast(html);

          // set the paragraphNode.data with the necessary properties
          paragraphNode.data = {
            hName: htmlElement.tagName,
            hProperties: htmlElement.properties,
            hChildren: htmlElement.children
          };
        } catch (error) {
          error.message = `The following error appeared while processing '${urlString}':\n\n${error.message}`;
          throw error;
        }
      });
    });
  });
  await Promise.all(transformations.map(t => t()));
  return markdownAST;
};