date-holidays-parser/src/Easter.js

parser for worldwide holidays

import easter from 'date-easter'
import CalDate from 'caldate'
import CalEvent from './CalEvent.js'

export default class Easter extends CalEvent {
  /**
   * @param {object} [opts]
   * @param {string} opts.type - type of eastern (easter|orthodox)
   * @param {number|string} opts.offset - offset in days
   */
  constructor (opts) {
    opts = opts || {}
    super(opts)

    this._fn = easter.easter
    if (opts.type === 'orthodox') {
      this._fn = easter.orthodoxEaster
    }
  }

  inYear (year) {
    const d = (new CalDate(this._fn(year))).setOffset(this.offset)
    this.dates.push(d)
    return this
  }
}