marked-linkify-it with TypeScript

marked-linkify-it.ts

// taken directly from https://github.com/UziTech/marked-linkify-it and strongly typed
import LinkifyIt from 'linkify-it';
import { marked } from 'marked';
import tlds from 'tlds';

export class markedLinkifyIt implements marked.MarkedExtension {
  constructor(schemas = {}, options = {}) {
    const linkify = new LinkifyIt(schemas, options);

    linkify
        .tlds(tlds)                     // Reload with full tlds list
        .tlds('onion', true)            // Add unofficial `.onion` domain
        .set({ fuzzyIP: true });        // Enable IPs in fuzzy links (without schema)
  
    addTlds(linkify, options);

    return {
      extensions: [
        {
          name: 'autolink',
          level: 'inline',
          start: (src: string) => {
            const link = getNextLink(linkify, src);

            if (!link) {
              return;
            }

            return link.index;
          },
          tokenizer(src: string) {
            const link = getNextLink(linkify, src);

            if (!link) {
              return;
            }

            let raw;
            if (link.index === 0) {
              raw = link.raw;
            } else if (
              link.index === 1 &&
              src.charAt(0) === '<' &&
              src.charAt(link.lastIndex) === '>'
            ) {
              raw = `<${link.raw}>`;
            }

            if (!raw) {
              return;
            }

            return {
              type: 'link',
              raw,
              text: link.text,
              href: link.url,
              tokens: [
                {
                  type: 'text',
                  raw: link.text,
                  text: link.text,
                },
              ],
            };
          },
        },
      ],
    };
  }
}

function getNextLink(linkify: LinkifyIt.LinkifyIt, src: string) {
  const match = linkify.match(src);

  if (!match || !match.length) {
    return;
  }

  return match[0];
}

function addTlds(
  linkify: LinkifyIt.LinkifyIt,
  options: { tlds?: string[]; tldsKeepOld?: boolean }
) {
  const tlds = options.tlds;
  delete options.tlds;
  const tldsKeepOld = options.tldsKeepOld;
  delete options.tldsKeepOld;

  if (tlds) {
    linkify.tlds(tlds, tldsKeepOld);
  }
}