this-month/lib/utils.js

Utility library to get details about an specific month.

'use strict';

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.numberOfSpecificDay = numberOfSpecificDay;
exports.getDaysOff = getDaysOff;
exports.isValidHolidayFormat = isValidHolidayFormat;
exports.getHolidays = getHolidays;
var daysMap = exports.daysMap = {
  sunday: 0,
  monday: 1,
  tuesday: 2,
  wednesday: 3,
  thursday: 4,
  friday: 5,
  saturday: 6
};

function numberOfSpecificDay(options) {
  var month = options.month - 1;
  var daysCounter = 0;
  var day = 1;
  var date = new Date(options.year, month, day); // day 1

  while (date.getMonth() === month) {
    if (date.getDay() === options.day) {
      // 0 = sunday, 1 = monday, 2 = tuesday, etc
      daysCounter += 1;
    }
    day += 1;
    date = new Date(options.year, month, day);
  }
  return daysCounter;
}

function getDaysOff() {
  var daysOff = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];

  if (daysOff.length < 1) {
    return [0, 6]; // sunday and saturday
  }

  var definedDaysOff = [];
  for (var i = 0; i < daysOff.length; i += 1) {
    var dayName = daysOff[i].toLowerCase();

    var dayNumber = daysMap[dayName];

    if (!dayNumber) throw new Error('Invalid day name.');

    definedDaysOff.push(dayNumber);
  }

  return definedDaysOff;
}

function isValidHolidayFormat(dateString) {
  var regEx = /^\d{4}-\d{2}-\d{2}$/;

  if (!dateString.match(regEx)) return false; // Invalid format

  var d = new Date(dateString);

  if (!d.getTime() > 0) {
    // Invalid Date (or this could be epoch)
    // d.getTime() === NaN
    // the date object returns Invalid Date
    return false;
  }

  return d.toISOString().slice(0, 10) === dateString;
}

function getHolidays() {
  var holidays = arguments.length > 0 && arguments[0] !== undefined ? arguments[0] : [];

  var validatedDates = [];
  for (var i = 0; i < holidays.length; i += 1) {
    var isValid = isValidHolidayFormat(holidays[i]);

    if (!isValid) {
      throw new Error(holidays[i] + ' is not in the correct format');
    }

    validatedDates[i] = holidays[i];
  }

  return validatedDates;
}