nodebrainz/lib/request.js

A MusicBrainz JSON Web Service Version 2 client

"use strict";

const http = require('http');

module.exports = function(config, callback) {

  let options = {
    host: config.host,
    path: config.path,
    port: config.port,
    headers: {
      'user-agent': config.userAgent
    },
    json: true
  };

  // If you are looking to debug, this would be a great place to put:
  // console.log(options.path);

  // Make the request
  http.get(options, res => {

    // Server did not like our request because ...

    // Not authorized
    if (res.statusCode === 401) {
      const err = new Error('Authorization required');
      err.statusCode = res.statusCode;
      return callback(err);
    }

    // A generic server error
    else if (res.statusCode === 500) {
      const err = new Error('Server side issue');
      err.statusCode = res.statusCode;
      return callback(err);
    }

    // We are being rate limited
    else if (res.statusCode === 503) {
      const err = new Error('Rate limited');
      err.statusCode = res.statusCode;
      return callback(err);
    }

    // It wasn't found
    else if (res.statusCode === 404) {
      const err = new Error('Not Found');
      err.statusCode = res.statusCode;
      return callback(err);
    }

    // Some other reason
    else if (res.statusCode !== 200 && res.statusCode !== 400) {
      const err = new Error('Well that didn\'t work...');
      err.statusCode = res.statusCode;
      return callback(err);
    }

    // Output data
    let data = '';

    // Gather up all the data chunks
    res.on('data', chunk => {
      data += chunk;
    });

    // ... When they are all gathered
    res.on('end', () => {

      // ... try to
      try {

        // ... parse the data as JSON
        data = JSON.parse(data);

        // ... catching any errors
      } catch (e) {
        return callback(new Error('Could not parse response as JSON'));
      }

      // 400 errors contain useful information
      if (res.statusCode === 400) {
        const err = new Error('Bad request');
        err.statusCode = res.statusCode;
        err.data = data;
        return callback(err);
      }

      // Should be good, call the callback
      callback(null, data);
    });

  // Error on request
  }).on('error', e => callback(e));
};