//@ requireOptions("--useTemporal=1")
function shouldBe(actual, expected) {
    if (actual !== expected)
        throw new Error(`expected ${expected} but got ${actual}`);
}

function shouldThrow(func, errorType, message) {
    let error;
    try {
        func();
    } catch (e) {
        error = e;
    }

    if (!(error instanceof errorType))
        throw new Error(`Expected ${errorType.name}!`);
    if (message !== undefined)
        shouldBe(String(error), message);
}

shouldBe(Temporal.Calendar instanceof Function, true);
shouldBe(Temporal.Calendar.length, 0);
shouldBe(Object.getOwnPropertyDescriptor(Temporal.Calendar, 'prototype').writable, false);
shouldBe(Object.getOwnPropertyDescriptor(Temporal.Calendar, 'prototype').enumerable, false);
shouldBe(Object.getOwnPropertyDescriptor(Temporal.Calendar, 'prototype').configurable, false);
shouldBe(Temporal.Calendar.prototype.constructor, Temporal.Calendar);

{
    let calendar = new Temporal.Calendar("iso8601");
    shouldBe(calendar.id, `iso8601`);
    shouldBe(String(calendar), `iso8601`);
}
{
    let calendar = new Temporal.Calendar("gregory");
    shouldBe(calendar.id, `gregory`);
    shouldBe(String(calendar), `gregory`);
}

shouldThrow(() => {
    new Temporal.Calendar("discordian");
}, RangeError, `RangeError: invalid calendar ID`);

{
    let input = ["monthCode", "day"];
    let fields = Temporal.Calendar.from("iso8601").fields(input);
    shouldBe(input !== fields, true);
    shouldBe(JSON.stringify(fields), `["monthCode","day"]`);
}
{
    let input = ["monthCode", "day"];
    let fields = Temporal.Calendar.from("gregory").fields(input);
    shouldBe(input !== fields, true);
    shouldBe(JSON.stringify(fields), `["monthCode","day"]`);
}
{
    let input = ["monthCode", "day", "year"];
    let fields = Temporal.Calendar.from("iso8601").fields(input);
    shouldBe(input !== fields, true);
    shouldBe(JSON.stringify(fields), `["monthCode","day","year"]`);
}

{
    let input = ["monthCode", "day", "year"];
    let fields = Temporal.Calendar.from("gregory").fields(input);
    shouldBe(input !== fields, true);
    shouldBe(JSON.stringify(fields), `["monthCode","day","year","era","eraYear"]`);
}
{
    let merged = Temporal.Calendar.from('iso8601').mergeFields(
      { year: 2006, month: 7, day: 31 },
      { monthCode: 'M08' }
    );
    shouldBe(JSON.stringify(merged), `{"year":2006,"day":31,"monthCode":"M08"}`);
}
{
    let merged = Temporal.Calendar.from('gregory').mergeFields(
      { year: 2006, month: 7, day: 31 },
      { monthCode: 'M08' }
    );
    shouldBe(JSON.stringify(merged), `{"year":2006,"day":31,"monthCode":"M08"}`);
}

{
    const user = {
        id: 775,
        username: 'robotcat',
        password: 'hunter2', // Note: Don't really store passwords like that
        userCalendar: Temporal.Calendar.from('gregory')
    };
    let string = JSON.stringify(user);
    shouldBe(string, `{"id":775,"username":"robotcat","password":"hunter2","userCalendar":"gregory"}`);
    // To rebuild from the string:
    function reviver(key, value) {
        if (key.endsWith('Calendar'))
            return Temporal.Calendar.from(value);
        return value;
    }
    shouldBe(JSON.parse(string, reviver).userCalendar instanceof Temporal.Calendar, true);
}