import { TtlCache } from '../ttl-cache';

describe(`${TtlCache.name}`, () => {
    const key = 'foo';
    const value = 'bar';

    let cache: TtlCache<string>;

    beforeEach(() => {
        jest.useFakeTimers();
        cache = new TtlCache();
    });

    test('cache rejects invalid default ttl', () => {
        expect(() => new TtlCache({ ttlMs: -1 })).toThrow();
    });

    describe('when cache omits key', () => {
        test('has returns false', () => {
            expect(cache.has(key)).toBe(false);
        });

        test('get returns undefined', () => {
            expect(cache.get(key)).toBeUndefined();
        });
    });

    describe('when cache contains key', () => {
        const elements = {
            [key]: value,
            [`other-${key}`]: `other-${value}`,
        };

        beforeEach(() => {
            Object.entries(elements).map(([key, value]) => cache.set(key, value));
        });

        test('has returns true', () => {
            expect(cache.has(key)).toBe(true);
        });

        test('get returns value', () => {
            expect(cache.get(key)).toBe(value);
        });

        test('set replaces value', () => {
            const newValue = `new-${value}`;

            cache.set(key, newValue);

            expect(cache.get(key)).toBe(newValue);
        });

        test('delete removes key', () => {
            cache.delete(key);

            expect(cache.has(key)).toBe(false);
        });

        test('clear removes all keys', () => {
            cache.clear();

            Object.keys(elements).forEach(key => expect(cache.has(key)).toBe(false));
        });

        test('removes keys after five minutes', () => {
            jest.advanceTimersByTime(1000 * 60 * 5 - 1);
            Object.keys(elements).forEach(key => expect(cache.has(key)).toBe(true));

            jest.advanceTimersByTime(1);
            Object.keys(elements).forEach(key => expect(cache.has(key)).toBe(false));
        });

        describe('when key has custom ttl', () => {
            const ttl = 1000 * 60 * 10;

            beforeEach(() => cache.set(key, value, ttl));

            test('removes key after custom ttl', () => {
                jest.advanceTimersByTime(ttl - 1);
                expect(cache.has(key)).toBe(true);

                jest.advanceTimersByTime(1);
                expect(cache.has(key)).toBe(false);
            });
        });

        describe('when key has negative ttl', () => {
            beforeEach(() => cache.set(key, value, -1));

            test('never removes key', () => {
                jest.runOnlyPendingTimers();

                expect(cache.has(key)).toBe(true);
            });
        });
    });
});