md052.mjs

// @ts-check

import { addError } from "../helpers/helpers.cjs";
import { getReferenceLinkImageData } from "./cache.mjs";

/** @type {import("markdownlint").Rule} */
export default {
  "names": [ "MD052", "reference-links-images" ],
  "description":
    "Reference links and images should use a label that is defined",
  "tags": [ "images", "links" ],
  "parser": "none",
  "function": function MD052(params, onError) {
    const { config, lines } = params;
    const shortcutSyntax = config.shortcut_syntax || false;
    const { definitions, references, shortcuts } = getReferenceLinkImageData();
    const entries = shortcutSyntax ?
      [ ...references.entries(), ...shortcuts.entries() ] :
      references.entries();
    // Look for links/images that use an undefined link reference
    for (const reference of entries) {
      const [ label, datas ] = reference;
      if (!definitions.has(label)) {
        for (const data of datas) {
          const [ lineIndex, index, length ] = data;
          // Context will be incomplete if reporting for a multi-line link
          const context = lines[lineIndex].slice(index, index + length);
          addError(
            onError,
            lineIndex + 1,
            `Missing link or image reference definition: "${label}"`,
            context,
            [ index + 1, context.length ]
          );
        }
      }
    }
  }
};