Tabulate total time spend on Toronto Bikeshare

bikeshare.js

(function () {
  const days = new Map();

  Array.prototype.forEach.call(
    document.querySelectorAll('tbody tr'),
    el => {
      const start = new Date(el.querySelector('td:nth-child(3)').textContent);
      const end = new Date(el.querySelector('td:nth-child(5)').textContent);
      const duration = (end - start) / 1000; // in seconds

      const day = `${start.getFullYear()}-${start.getMonth() + 1}-${start.getDate()}`;

      days.set(day, (days.get(day) || 0) + duration);
    });

  const displayTime = t => {
    const seconds = Math.floor(t % 60); t /= 60;
    const minutes = Math.floor(t % 60); t /= 60;
    const hours = Math.floor(t);

    const strParts = [];

    if (hours > 0) {
      strParts.push(`${hours}h`);
    }

    if (minutes > 0) {
      strParts.push(`${minutes}m`);
    }

    if (seconds > 0) {
      strParts.push(`${seconds}s`);
    }

    return strParts.join(' ');
  };

  const table = {};
  let total = 0;

  for (const [day, time] of days.entries()) {
    table[day] = { duration: displayTime(time) };
    total += time;
  }

  table['total'] = { duration: displayTime(total) };

  console.table(table);
})();