query-cdc.js

const https  = require('https');

main();

async function main() {
  let args = process.argv.slice(2);
  let days = parseInt(args[0]) || 14;
  
  let urlStr = 'https://www.cdc.gov/coronavirus/2019-ncov/json/new-cases-chart-data.json';

  let jsonText = await new Promise((resolve, reject) => {
    https.get(urlStr, res => {
      let data = '';
      res.on('data', (d) => data += d );
      res.on('end', () => resolve(data) );
      res.statusCode == 200 || reject(res.statusCode);
    }).on('error', (e) => reject(e));
  });
  
  let columns = JSON.parse(jsonText);
  columns[0].shift();
  columns[1].shift();
  
  let graph = columns[0].map((v,i) => {
    return { 
      day: v.replace('/2020',''),
      val: parseInt(columns[1][i]) 
    }; 
  });
  
  graph = graph.slice(-days);

  let values = graph.map((v) => v.val);
  let sum = values.reduce((a, b) => a + b, 0);
  let avg = Math.round(sum / values.length) || 0;
  
  console.log('\nAverage new cases: ' + new Intl.NumberFormat().format(avg));
  console.log('day\t\tval');
  console.log('------------------------');
  graph.forEach((row) => {
    console.log(row.day + '\t\t' + new Intl.NumberFormat().format(row.val));
  });
}