src/formatters/formatCaption.test.ts

import { DateLib, defaultLocale } from "../classes/DateLib.js";
import { es } from "../locale/es.js";
import { ja } from "../locale/ja.js";

import { formatCaption } from "./formatCaption";

const date = new Date(2022, 10, 21);

test("should return the formatted caption", () => {
  expect(
    formatCaption(date, {}, new DateLib({ locale: defaultLocale })),
  ).toEqual("November 2022");
});

describe("when a locale is passed in through dateLib argument", () => {
  test("should format using the locale", () => {
    expect(formatCaption(date, {}, new DateLib({ locale: es }))).toEqual(
      "noviembre 2022",
    );
  });
});

describe("when a locale is passed in from options", () => {
  test("should format using the locale", () => {
    expect(formatCaption(date, { locale: es })).toEqual("noviembre 2022");
  });
});

test("places the year before the month when required", () => {
  expect(formatCaption(date, { locale: ja })).toEqual("2022年11月");
});