index.js

const stat = require('fs').stat;
const spawn = require('child_process').spawn;

module.exports = function (src, options = [], pandocPath) {
  if (typeof pandocPath === 'undefined') {
    pandocPath = 'pandoc'
  }
  return new Promise((resolve, reject) => {

    let pdSpawn;
    let result = "";
    let isURL;

    // Event Handlers
    let onStdOutData;
    let onStdOutEnd;
    let onStdErrData;
    let onStatCheck;

    isURL = function (src) {
      return /^(https?|ftp):\/\//i.test(src);
    };

    onStdOutData = function (data) {
      result += data;
    };

    onStdOutEnd = function () {
      resolve(result);
    };

    onStdErrData = function (err) {
      reject(new Error(err));
    };

    onStatCheck = function (err, stats) {
      // If src is a file or valid web URL, push the src back into args array
      if ((stats && stats.isFile()) || isURL) {
        options.unshift(src);
      }

      // Create child_process.spawn
      pdSpawn = spawn(pandocPath, options);

      // If src is not a file, assume a string input.
      if ((typeof stats === "undefined") && !isURL) {
        pdSpawn.stdin.end(src, 'utf-8');
      }

      // Set handlers...
      pdSpawn.stdout.on('data', onStdOutData);
      pdSpawn.stdout.on('end', onStdOutEnd);
      pdSpawn.on('error', onStdErrData);
    };

    // Check if src is URL match.
    isURL = isURL(src);



    // Check file status of src
    stat(src, onStatCheck);
  })


};