index.js

const express = require('express');
const fetch = require('node-fetch');
const cheerio = require('cheerio');
const _ = require('lodash');

const app = express();
const { PORT = 3000 } = process.env;

app.use((req, res, next) => {
  res.header('Access-Control-Allow-Origin', '*');
  res.header(
    'Access-Control-Allow-Headers',
    'Origin, X-Requested-With, Content-Type, Accept',
  );
  next();
});

app.get('/:city', async (req, res) => {
  const city = _.words(_.startCase(req.params.city)).join('-');
  const currency = Object.keys(req.query)[0] ? Object.keys(req.query)[0] : 'CAD';

  const response = await fetch(
    `https://www.numbeo.com/cost-of-living/in/${city}?displayCurrency=${currency}`,
  );
  if (!response.ok) {
    return res.status(response.status).send(response.statusText);
  }
  const html = await response.text();

  const $ = cheerio.load(html);

  const rows = $('body > div.innerWidth > table > tbody > tr')
    .filter((i, el) => $(el).children('td').length === 3)
    .map((i, el) =>
      $(el)
        .children()
        .map((i, el) => $(el).text().trim())
        .toArray(),
    )
    .toArray();

  const costs = chunkArray(rows, 3).map(([item, costWithSymbol, range]) => {
    const cost = costWithSymbol.replace(/^.*?([\d,.]+).*?$/, '$1');
    const [rangeLow, rangeHigh] = range.split('-');
    return {
      item,
      cost,
      range: {
        low: rangeLow,
        high: rangeHigh,
      },
    };
  });
  return res.json({ city, currency, costs });
});

app.get('*', (req, res) =>
  res.status(400).json({
    error: 'No city supplied. Please navigate to `/:city` to obtain results.',
  }),
);

function chunkArray(arr, chunkSize) {
  let temp = [];
  for (let i = 0; i < arr.length; i += chunkSize) {
    temp.push(arr.slice(i, i + chunkSize));
  }
  return temp;
}

app.listen(PORT, () =>
  console.log(`Cost of Living API running on port ${PORT}`),
);