Extracts the first image url from a markdown text

image-parser-markdown.ts

/**
  Extracts the first image url from a markdown text
  Copyright 2019 Adrian Barwicki
*/

const IMAGE_EXTENSIONS = ["jpeg", "jpg", "png", "gif"];

const getExtension = (path: string): string => {
  return path.split(".").pop();
};

/**
 * Extracts the first image url from a markdown text
 * @param bodyMD markdown text
 * @returns extracts the first image url found in the text
 */
export const extractImageUrlFromMarkdown = (
  bodyMD: string
): string | undefined => {
  // extracts ![]() from markdown
  const matches = bodyMD.match(/(?:!\[(.*?)\]\((.*?)\))/g);

  if (!matches) {
    return undefined;
  }

  return (
    matches
      // maps ![]() to urls
      .map(match => {
        const matches = match.match(/\((.*?)\)/g);

        return matches.map(b => b.replace(/\(|(.*?)\)/g, "$1"))[0];
      })
      // finds the first url with the specifed extension
      .find(url => {
        return (
          url && IMAGE_EXTENSIONS.indexOf(getExtension(url)) !== -1
        );
      })
  );
};

function extractImageUrlFromMarkdown(content) {
    return (content.match(/!\[.+?\]\((.*?(?:\.jpe?g|png|gif))\)/i) || [])[1]
}