JsMeetup - Streaming in javascript - Functional approach

intercom-drinks-functional.js

const request = require('request');
const fs = require('fs');
const intercomDrinks = require('intercom-drinks').default;

const radius = 100000; //in meters
const latitude = 53.3381985;
const longitude = -6.2592576;
const onlineSource = 'https://gist.githubusercontent.com/brianw/19896c50afa89ad4dec3/raw/6c11047887a03483c50017c1d451667fd62a53ca/gistfile1.txt';
const offlineSource = 'input.jsonl';

request(onlineSource, (error, allData, data) => { //1. read
// fs.readFile(offlineSource, 'utf8', (error, data) => {
  var customers = data
    .trim('')
    .split('\n') //2. split
    .map(row => {
      var customer = void 0;

      try {
        customer = JSON.parse(row); //3. parse customer
      } catch (e) {
        return void 0; //ignore
      }

      try {
        customer = intercomDrinks.validateCustomer(customer); //4. validate
      } catch (e) {
        return void 0; //ignore
      }

      return customer;
    })
    .filter(customer => customer !== void 0)// filter out invalid customers
    .filter(customer => intercomDrinks.isNearbyCustomer(latitude, longitude, radius, customer)) // 5. calculate distance and filter
  ;

  /* SORT
  // 6. sort
  customers = customers.sort((a, b) => {
    return a.user_id - b.user_id; //ascending
  });
  */

  const output = customers
    .map(customer => `${customer.user_id}:${customer.name}`) // 7. pick name and id
    .join('\n') //8. output
  ;

  console.log(output);
});