date-fns/parse/_lib/parsers/LocalWeekYearParser.js

Modern JavaScript date utility library

import { getWeekYear } from "../../../getWeekYear.js";

import { startOfWeek } from "../../../startOfWeek.js";
import { Parser } from "../Parser.js";

import { mapValue, normalizeTwoDigitYear, parseNDigits } from "../utils.js";

// Local week-numbering year
export class LocalWeekYearParser extends Parser {
  priority = 130;

  parse(dateString, token, match) {
    const valueCallback = (year) => ({
      year,
      isTwoDigitYear: token === "YY",
    });

    switch (token) {
      case "Y":
        return mapValue(parseNDigits(4, dateString), valueCallback);
      case "Yo":
        return mapValue(
          match.ordinalNumber(dateString, {
            unit: "year",
          }),
          valueCallback,
        );
      default:
        return mapValue(parseNDigits(token.length, dateString), valueCallback);
    }
  }

  validate(_date, value) {
    return value.isTwoDigitYear || value.year > 0;
  }

  set(date, flags, value, options) {
    const currentYear = getWeekYear(date, options);

    if (value.isTwoDigitYear) {
      const normalizedTwoDigitYear = normalizeTwoDigitYear(
        value.year,
        currentYear,
      );
      date.setFullYear(
        normalizedTwoDigitYear,
        0,
        options.firstWeekContainsDate,
      );
      date.setHours(0, 0, 0, 0);
      return startOfWeek(date, options);
    }

    const year =
      !("era" in flags) || flags.era === 1 ? value.year : 1 - value.year;
    date.setFullYear(year, 0, options.firstWeekContainsDate);
    date.setHours(0, 0, 0, 0);
    return startOfWeek(date, options);
  }

  incompatibleTokens = [
    "y",
    "R",
    "u",
    "Q",
    "q",
    "M",
    "L",
    "I",
    "d",
    "D",
    "i",
    "t",
    "T",
  ];
}