Function toDate

packages/common/src/i18n/format_date.ts:922–967

(value: string | number | Date)

 * Throws if unable to convert to a date.
 */
export function toDate(value: string | number | Date): Date {
  if (isDate(value)) {
    return value;
  }

  if (typeof value === 'number' && !isNaN(value)) {
    return new Date(value);
  }

  if (typeof value === 'string') {
    value = value.trim();

    if (/^(\d{4}(-\d{1,2}(-\d{1,2})?)?)$/.test(value)) {
      /* For ISO Strings without time the day, month and year must be extracted from the ISO String
      before Date creation to avoid time offset and errors in the new Date.
      If we only replace '-' with ',' in the ISO String ("2015,01,01"), and try to create a new
      date, some browsers (e.g. IE 9) will throw an invalid Date error.
      If we leave the '-' ("2015-01-01") and try to create a new Date("2015-01-01") the timeoffset
      is applied.
      Note: ISO months are 0 for January, 1 for February, ... */
      const [y, m = 1, d = 1] = value.split('-').map((val: string) => +val);
      return createDate(y, m - 1, d);
    }

    const parsedNb = parseFloat(value);

    // any string that only contains numbers, like "1234" but not like "1234hello"
    if (!isNaN((value as any) - parsedNb)) {
      return new Date(parsedNb);
    }

    let match: RegExpMatchArray | null;
    if ((match = value.match(ISO8601_DATE_REGEX))) {
      return isoStringToDate(match);
    }
  }

  const date = new Date(value as any);
  if (!isDate(date)) {
    throw new RuntimeError(
      RuntimeErrorCode.INVALID_TO_DATE_CONVERSION,
      ngDevMode && `Unable to convert "${value}" into a date`,
    );
  }
  return date;
}

/**
 * Converts a date in ISO8601 to a Date.