How to get node.js HTTP request promise without a single dependency

Sometimes one needs just to read a body of simple HTTP(S) GET response, without any complicated logic and dozens of NPM dependencies involved. So why not to use all the goodies node.js core provides us.

const getContent = function(url) {
  // return new pending promise
  return new Promise((resolve, reject) => {
    // select http or https module, depending on reqested url
    const lib = url.startsWith('https') ? require('https') : require('http');
    const request = lib.get(url, (response) => {
      // handle http errors
      if (response.statusCode < 200 || response.statusCode > 299) {
         reject(new Error('Failed to load page, status code: ' + response.statusCode));
       }
      // temporary data holder
      const body = [];
      // on every content chunk, push it to the data array
      response.on('data', (chunk) => body.push(chunk));
      // we are done, resolve promise with those joined chunks
      response.on('end', () => resolve(body.join('')));
    });
    // handle connection errors of the request
    request.on('error', (err) => reject(err))
    })
};

There is not a single external dependency included. Usage is then rather simple, due to Promise interface:

getContent('https://www.random.org/integers/?num=1&min=1&max=100&col=1&base=10&format=plain&rnd=new')
  .then((html) => console.log(html))
  .catch((err) => console.error(err));

Sure, we have no body parsing, no JSON validation, no encoding conversion. But do you need it anyway?

The typical recommended solution includes frequently request package. Have you ever seen the dependencies tree of this?



Source: david-dm.org/request/request

There were 32 new releases of request package in 2015. Are you ready to update your project every time one of those dependencies discovers a security vulnerability and forces the whole tree to release new versions? Or would you rather use the standard library for such a simple task?

Of course, if you have much more complicated requirements, dozens of dependencies already included, maybe you should just add request-promise and let it do its job:

var rp = require('request-promise');
rp('http://www.google.com')
    .then((html) => console.log(html)) // Process html...
    .catch((err) => console.error(err)); // Crawling failed...



But before you do that, think how to keep things simple.

Source