How to download a file with Node.js using HTTPS?

Using standard Node modules only:

const fs = require('fs');
const http = require('http');
const https = require('https');

/**
 * Downloads file from remote HTTP[S] host and puts its contents to the
 * specified location.
 */
async function download(url, filePath) {
  const proto = !url.charAt(4).localeCompare('s') ? https : http;

  return new Promise((resolve, reject) => {
    const file = fs.createWriteStream(filePath);
    let fileInfo = null;

    const request = proto.get(url, response => {
      if (response.statusCode !== 200) {
        fs.unlink(filePath, () => {
          reject(new Error(`Failed to get '${url}' (${response.statusCode})`));
        });
        return;
      }

      fileInfo = {
        mime: response.headers['content-type'],
        size: parseInt(response.headers['content-length'], 10),
      };

      response.pipe(file);
    });

    // The destination stream is ended by the time it's called
    file.on('finish', () => resolve(fileInfo));

    request.on('error', err => {
      fs.unlink(filePath, () => reject(err));
    });

    file.on('error', err => {
      fs.unlink(filePath, () => reject(err));
    });

    request.end();
  });
}

You should use https module then. Quoting the docs:

HTTPS is the HTTP protocol over TLS/SSL. In Node this is implemented as a separate module.

The good news is that the request-related methods of that module (https.request(), https.get() etc.) support all the options that the ones from http do.

Keeping it simple:

var fs = require('fs-extra');
var fetch = require('node-fetch');

/**
 * Download a file to disk
 * @example downloadFile('https://orcascan.com', './barcode-tracking.html')
 * @param {string} fileUrl - url of file to download
 * @param {string} destPath - destination path
 * @returns {Promise} resolves once complete, otherwise rejects
 */
function downloadFile(fileUrl, destPath) {

    if (!fileUrl) return Promise.reject(new Error('Invalid fileUrl'));
    if (!destPath) return Promise.reject(new Error('Invalid destPath'));

    return new Promise(function(resolve, reject) {

        fetch(fileUrl).then(function(res) {
            var fileStream = fs.createWriteStream(destPath);
            res.body.on('error', reject);
            fileStream.on('finish', resolve);
            res.body.pipe(fileStream);
        });
    });
}