card-validator/src/__tests__/expiration-date.ts

A library for validating credit card fields

import { expirationDate, ExpirationDateVerification } from "../expiration-date";

const date = new Date();
const currentYear = date.getFullYear();
const twoDigitYear = Number(String(currentYear).substr(2, 2));
const firstTwoDigitsOfCurrentYear = Number(String(currentYear).substr(0, 2));
const nextYear = currentYear + 1;
const currentMonth = date.getMonth() + 1;
const previousMonth = currentMonth - 1 || currentMonth;
const nextMonth = currentMonth === 12 ? currentMonth : currentMonth + 1;

function yearsFromNow(fromNow: number): string {
  return String(currentYear + fromNow);
}

describe("expirationDate validates", () => {
  const stringContexts = [
    [
      "within current year",
      [
        [
          `${previousMonth} / ${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: previousMonth.toString(),
            year: nextYear.toString(),
          },
        ],
        [
          `${currentMonth} / ${currentYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: currentMonth.toString(),
            year: currentYear.toString(),
          },
        ],
        [
          `${nextMonth} / ${currentYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: nextMonth.toString(),
            year: currentYear.toString(),
          },
        ],
      ],
    ],
    [
      "valid expiration dates with dashes",
      [
        [
          `${currentYear}-${currentMonth}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: currentMonth.toString(),
            year: currentYear.toString(),
          },
        ],
        [
          `${nextYear}-10`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "10",
            year: nextYear.toString(),
          },
        ],
        [
          `${nextYear}-10`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "10",
            year: nextYear.toString(),
          },
        ],
        [
          `${nextYear}-12`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "12",
            year: nextYear.toString(),
          },
        ],
        [
          `${nextYear}-01`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: nextYear.toString(),
          },
        ],
        [
          `${nextYear}-1`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: nextYear.toString(),
          },
        ],
        [
          `${nextYear}-09`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "09",
            year: nextYear.toString(),
          },
        ],
        [
          `${nextYear}-01`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: nextYear.toString(),
          },
        ],
        [
          `${nextYear}-01`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: nextYear.toString(),
          },
        ],
      ],
    ],
    [
      "invalid expiration dates with dashes",
      [
        [
          `${nextYear}-00`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `${nextYear}-13`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "1999-01",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "2100-01",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
      ],
    ],
    [
      "valid expiration dates with slashes",
      [
        [
          `${currentMonth} / ${currentYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: currentMonth.toString(),
            year: currentYear.toString(),
          },
        ],
        [
          `10 / ${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "10",
            year: nextYear.toString(),
          },
        ],
        [
          `10/${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "10",
            year: nextYear.toString(),
          },
        ],
        [
          `12 / ${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "12",
            year: nextYear.toString(),
          },
        ],
        [
          `01 / ${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: nextYear.toString(),
          },
        ],
        [
          `1 / ${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: nextYear.toString(),
          },
        ],
        [
          `09 / ${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "09",
            year: nextYear.toString(),
          },
        ],
        [
          `01 / ${twoDigitYear + 1}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: (twoDigitYear + 1).toString(),
          },
        ],
        [
          `1 / ${twoDigitYear + 1}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: (twoDigitYear + 1).toString(),
          },
        ],
        [
          `01 / ${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: nextYear.toString(),
          },
        ],
        [
          `01 / ${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: nextYear.toString(),
          },
        ],
      ],
    ],
    [
      "invalid expiration dates with slashes",
      [
        [
          "11 / 11",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `00 / ${nextYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `13 / ${nextYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 / 1999",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01/1999",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 / 2100",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "10/123",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
      ],
    ],
    [
      "ambiguous expiration dates with slashes",
      [
        [
          "11 / 1",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "01 / 201",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "01 / 211",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 / 199",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01/199",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `02/${firstTwoDigitsOfCurrentYear}`,
          {
            isValid: false,
            isPotentiallyValid: true,
            month: null,
            year: null,
          },
        ],
      ],
    ],
    [
      "valid expiration dates with no slashes",
      [
        [
          `10${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "10",
            year: nextYear.toString(),
          },
        ],
        [
          `10${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "10",
            year: nextYear.toString(),
          },
        ],
        [
          `12${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "12",
            year: nextYear.toString(),
          },
        ],
        [
          `01${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: nextYear.toString(),
          },
        ],
        [
          `09${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "09",
            year: nextYear.toString(),
          },
        ],
        [
          `1${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: nextYear.toString(),
          },
        ],
        [
          `9${nextYear}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "9",
            year: nextYear.toString(),
          },
        ],
        [
          `1${twoDigitYear + 1}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: (twoDigitYear + 1).toString(),
          },
        ],
        [
          `9${twoDigitYear + 1}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "9",
            year: (twoDigitYear + 1).toString(),
          },
        ],
        [
          `12${twoDigitYear + 1}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "12",
            year: (twoDigitYear + 1).toString(),
          },
        ],
        [
          `01${twoDigitYear + 1}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: (twoDigitYear + 1).toString(),
          },
        ],
      ],
    ],
    [
      "valid space separated month and year",
      [
        [
          `01 ${currentYear + 4}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: (currentYear + 4).toString(),
          },
        ],
        [
          `01 ${currentYear + 5}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: (currentYear + 5).toString(),
          },
        ],
        [
          `01 ${twoDigitYear + 4}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: (twoDigitYear + 4).toString(),
          },
        ],
        [
          `01 ${twoDigitYear + 6}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: (twoDigitYear + 6).toString(),
          },
        ],
        [
          `1 ${currentYear + 4}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: (currentYear + 4).toString(),
          },
        ],
        [
          `1 ${currentYear + 5}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: (currentYear + 5).toString(),
          },
        ],
        [
          `1 ${twoDigitYear + 4}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: (twoDigitYear + 4).toString(),
          },
        ],
        [
          `1 ${twoDigitYear + 5}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: (twoDigitYear + 5).toString(),
          },
        ],
        [
          `9 ${currentYear + 4}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "9",
            year: (currentYear + 4).toString(),
          },
        ],
        [
          `9 ${currentYear + 5}`,
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "9",
            year: (currentYear + 5).toString(),
          },
        ],
      ],
    ],
    [
      "ambiguous space separated month and year",
      [
        [
          "1 2",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "1 202",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          `1 ${firstTwoDigitsOfCurrentYear}`,
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "1 ",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "12 2",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "12 202",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "12 ",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
      ],
    ],
    [
      "invalid space separated month and year",
      [
        [
          "11 11",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `00 ${nextYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `13 ${nextYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 1999",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 1999",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 2100",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
      ],
    ],
    [
      "invalid expiration dates with no slashes",
      [
        [
          " ",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          " ",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "1111",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `00${nextYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `13${nextYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "011999",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "011999",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "012100",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
      ],
    ],
    [
      "ambiguous expiration dates with no slashes",
      [
        [
          "011",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "111",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "2202",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "1202",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "01201",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "01211",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01199",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01199",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `02${firstTwoDigitsOfCurrentYear}`,
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
      ],
    ],
    [
      "empty strings",
      [
        [
          "",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "/",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          " / ",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
      ],
    ],
    [
      "non-strings",
      [
        [
          [],
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          {},
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          null,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          undefined, // eslint-disable-line no-undefined
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          Infinity,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          0 / 0,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          0,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          1,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          2,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          12,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          -1,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          -12,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          2015,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
      ],
    ],
    [
      "malformed strings",
      [
        [
          "foo",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "0120197",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "1.2",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          " 1",
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          "01 / 20015",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          `15 / ${currentYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 / 2016 / 2016",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 / 16/2016",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          "01 / 2016 / 01 / 2016",
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
      ],
    ],
  ] as Array<[string, Array<[string, ExpirationDateVerification]>]>;

  if (currentMonth !== 1) {
    stringContexts.push([
      "within current year",
      [
        [
          `${previousMonth} / ${currentYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: previousMonth.toString(),
            year: currentYear.toString(),
          },
        ],
      ],
    ]);

    stringContexts.push([
      "valid expiration dates with slashes",
      [
        [
          `${previousMonth} / ${currentYear}`,
          {
            isValid: false,
            isPotentiallyValid: false,
            month: previousMonth.toString(),
            year: currentYear.toString(),
          },
        ],
      ],
    ]);
  }

  describe.each(stringContexts)("String argument %s", (description, tests) => {
    it.each(tests)(
      "parses %s to be %p",
      (exp: string | number, meta: ExpirationDateVerification) => {
        expect(expirationDate(exp)).toEqual(meta);
      },
    );
  });

  const objectContexts = [
    [
      "within current year with number values",
      [
        [
          { month: previousMonth, year: nextYear },
          {
            isValid: true,
            isPotentiallyValid: true,
            month: previousMonth.toString(),
            year: nextYear.toString(),
          },
        ],
        [
          { month: currentMonth, year: currentYear },
          {
            isValid: true,
            isPotentiallyValid: true,
            month: currentMonth.toString(),
            year: currentYear.toString(),
          },
        ],
        [
          { month: nextMonth, year: currentYear },
          {
            isValid: true,
            isPotentiallyValid: true,
            month: nextMonth.toString(),
            year: currentYear.toString(),
          },
        ],
      ],
    ],
    [
      "valid expiration dates",
      [
        [
          { month: currentMonth, year: currentYear },
          {
            isValid: true,
            isPotentiallyValid: true,
            month: currentMonth.toString(),
            year: currentYear.toString(),
          },
        ], // eslint-disable-line max-len
        [
          { month: "10", year: nextYear },
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "10",
            year: nextYear.toString(),
          },
        ],
        [
          { month: "01", year: twoDigitYear + 1 },
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "01",
            year: (twoDigitYear + 1).toString(),
          },
        ],
        [
          { month: "1", year: twoDigitYear + 1 },
          {
            isValid: true,
            isPotentiallyValid: true,
            month: "1",
            year: (twoDigitYear + 1).toString(),
          },
        ],
      ],
    ],
    [
      "invalid expiration dates",
      [
        [
          { month: "11", year: "11" },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          { month: "00", year: nextYear },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          { month: "13", year: nextYear },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          { month: "01", year: "1999" },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          { month: "0", year: "1999" },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          { month: "01", year: "2100" },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          { month: "1", year: "123" },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
      ],
    ],
    [
      "ambiguous expiration dates",
      [
        [
          { month: "11", year: "1" },
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          { month: "01", year: "201" },
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
        [
          { month: "01", year: "211" },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
        [
          { month: "02", year: "20" },
          {
            isValid: false,
            isPotentiallyValid: true,
            month: null,
            year: null,
          },
        ],
        [
          { month: "0", year: "199" },
          {
            isValid: false,
            isPotentiallyValid: false,
            month: null,
            year: null,
          },
        ],
      ],
    ],
    [
      "empty strings",
      [
        [
          { month: "", year: "" },
          { isValid: false, isPotentiallyValid: true, month: null, year: null },
        ],
      ],
    ],
  ] as Array<
    [string, Array<[Record<string, number>, ExpirationDateVerification]>]
  >;

  if (currentMonth !== 1) {
    objectContexts[0][1].push([
      {
        month: previousMonth,
        year: currentYear,
      },
      {
        isValid: false,
        isPotentiallyValid: false,
        month: previousMonth.toString(),
        year: currentYear.toString(),
      },
    ]);
  }

  describe.each(objectContexts)("Object Argument %s", (description, tests) => {
    it.each([...tests])(
      "parses %s to be %p",
      (exp, meta: ExpirationDateVerification) => {
        expect(expirationDate(exp)).toEqual(meta);
      },
    );
  });

  describe("maxElapsedYear", () => {
    it("defaults maxElapsedYear is 19", () => {
      expect(expirationDate(`${currentMonth} / ${yearsFromNow(19)}`)).toEqual({
        isValid: true,
        isPotentiallyValid: true,
        month: currentMonth.toString(),
        year: yearsFromNow(19).toString(),
      });
      expect(expirationDate(`${currentMonth} / ${yearsFromNow(20)}`)).toEqual({
        isValid: false,
        isPotentiallyValid: false,
        month: null,
        year: null,
      });
    });

    it("accepts maxElapsedYear", () => {
      expect(
        expirationDate(`${currentMonth} / ${yearsFromNow(20)}`, 20),
      ).toEqual({
        isValid: true,
        isPotentiallyValid: true,
        month: currentMonth.toString(),
        year: yearsFromNow(20).toString(),
      });
      expect(
        expirationDate(`${currentMonth} / ${yearsFromNow(21)}`, 20),
      ).toEqual({
        isValid: false,
        isPotentiallyValid: false,
        month: null,
        year: null,
      });
    });
  });
});