test.js

const test = require('ava');
const Cache = require('./src/index');
const sleep = ms => new Promise(r => setTimeout(r, ms));

test('initializes a cache correctly', t => {
	const cache = new Cache(3);
	t.is(cache.limit, 3);
	t.is(cache.size, 0);
	t.is(typeof cache, 'object')
});

test('sets new keys in cache without expiry', t => {
	const cache = new Cache(3);

	cache.set("Sapiens", 5);
	t.is(Object.keys(cache.hashMap).length, 1);

	cache.set("Book Thief", 4);
	t.is(Object.keys(cache.hashMap).length, 2);

	cache.set("Catcher In The Rye", 0);
	t.is(Object.keys(cache.hashMap).length, 3);

	cache.set("Thus Spoke Zarathustra", 4);
	t.is(Object.keys(cache.hashMap).length, 3);
	t.is(cache.hashMap.Sapiens, undefined);
});

test('get key without expiry', async t => {
	const cache = new Cache(3);

	cache.set("Sapiens", 5);
	t.is(Object.keys(cache.hashMap).length, 1);

	cache.set("Book Thief", 4);
	t.is(Object.keys(cache.hashMap).length, 2);

	cache.set("Catcher In The Rye", 0);
	t.is(Object.keys(cache.hashMap).length, 3);

	await sleep(10);

	const sapiensRating = cache.get("Sapiens");
	t.is(sapiensRating, 5);

	cache.set("Thus Spoke Zarathustra", 4);
	t.is(Object.keys(cache.hashMap).length, 3);

	t.is(cache.hashMap.Sapiens.content.value, 5);
	t.is(cache.hashMap["Book Thief"], undefined);
});

test('sets with expiry', t => {
	const cache = new Cache(3, 10);

	cache.set("Sapiens", 5);
	t.is(cache.maxAge, 10);
	t.is(cache.hashMap.Sapiens.maxAge, 10);

	cache.set("Book Thief", 4, 7);
	t.is(cache.hashMap["Book Thief"].maxAge, 7);

	cache.set("Catcher In The Rye", 0);
	t.is(cache.hashMap["Catcher In The Rye"].maxAge, 10);
});

test('throws for undefinded key and value', t => {
	const cache = new Cache(3, 10);

	const errorKey = t.throws(() => {
		cache.set(undefined, 5);
	});

	t.is(errorKey.message, 'Key not provided');

	const errorValue = t.throws(() => {
		cache.set('Book Thief', undefined);
	});

	t.is(errorValue.message, 'Value not provided');
});

test('gets with expiry', async t => {
	const cache = new Cache(3, 10);
	cache.set("Sapiens", 5);
	const sapiens = cache.get("Sapiens");
	t.is(sapiens, 5);

	await sleep(3);
	const sapiensAfter3s = await cache.get("Sapiens");
	t.is(sapiensAfter3s, 5);

	await sleep(11);
	const sapiensAfter11s = await cache.get("Sapiens");
	t.is(sapiensAfter11s, null);
	t.is(cache.hashMap.Sapiens, undefined);

	cache.set("Book Thief", 4, 25);
	const bookThief = cache.get("Book Thief");
	t.is(bookThief, 4);

	await sleep(10);
	const bookThiefAfter10s = await cache.get("Book Thief");
	t.is(bookThiefAfter10s, 4);

	await sleep(10);
	const bookThiefAfter20s = await cache.get("Book Thief");
	t.is(bookThiefAfter20s, 4);

	await sleep(10);
	const bookThiefAfter30s = await cache.get("Book Thief");
	t.is(bookThiefAfter30s, 4);

	await sleep(30);
	const bookThiefAfter30sWithoutReset = await cache.get("Book Thief");
	t.is(bookThiefAfter30sWithoutReset, null);
});

test('stale', async t => {
	const cache = new Cache(3, 10, true);
	cache.set("Sapiens", 5);
	await sleep(11)
	t.is(cache.get("Sapiens"), 5);
	t.is(cache.get("Sapiens"), null);
	t.is(cache.hashMap.Sapiens, undefined);
});

test('peek', t => {
	const cache = new Cache(3);

	cache.set("Sapiens", 5);
	const sapiens = cache.peek("Sapiens");
	t.is(sapiens, 5);

	const test = cache.peek("test");
	t.is(test, null);

	cache.set("Book Thief", 4);
	cache.set("Catcher In The Rye", 0);
	cache.peek("test");
	cache.set("Thus Spoke Zarathustra", 4);
	t.is(cache.hashMap["Sapiens"], undefined);
});

test('reset', t => {
	const cache = new Cache(3, 10, true);

	cache.set("Sapiens", 5);
	cache.set("Book Thief", 4);
	cache.set("Catcher In The Rye", 0);
	cache.reset();
	t.is(cache.size, 0);
	t.is(cache.limit, 3);
	t.is(cache.maxAge, 10);
	t.is(cache.stale, true);
	t.deepEqual(cache.hashMap, {});
	t.is(cache.head, null);
	t.is(cache.tail, null);
});

test('toArray', t => {
	const cache = new Cache(3, 10, true);

	cache.set("Sapiens", 5);
	cache.set("Book Thief", 4);
	cache.set("Catcher In The Rye", 0);
	t.deepEqual(cache.toArray(), [{key: 'Catcher In The Rye', value: 0},
		{key: 'Book Thief', value: 4},
		{key: 'Sapiens', value: 5}])
});

test('contains', t => {
	const cache = new Cache(3, 10, true);

	cache.set("Sapiens", 5);
	cache.set("Book Thief", 4);
	cache.set("Catcher In The Rye", 0);
	t.is(cache.contains("Sapiens"), true);
	t.is(cache.contains("x"), false);
	t.is(cache.contains("Catcher In The Rye"), true);
});

test('has', t => {
  const cache = new Cache(3, 10, true);

  cache.set("Sapiens", 5);
  cache.set("Book Thief", 4);
  cache.set("Catcher In The Rye", 0);
  t.is(cache.has("Sapiens"), true);
  t.is(cache.has("x"), false);
  t.is(cache.has("Catcher In The Rye"), true);
});

test('forEach', t => {
	const cache = new Cache(3, 10, true);

	cache.set("Sapiens", 5);
	cache.set("Book Thief", 4);
	cache.set("Catcher In The Rye", 0);
	cache.forEach((key, value, index) => {
		if(index === 0){
			t.is(key, "Catcher In The Rye");
			t.is(value, 0);
		}
		if(index === 1){
			t.is(key, "Book Thief");
			t.is(value, 4);
		}
		if(index === 2){
			t.is(key, "Sapiens");
			t.is(value, 5);
		}
	})
});

test('getSize', t => {
	const cache = new Cache(3, 10, true);

	cache.set("Sapiens", 5);
	t.is(cache.getSize(), 1);
	cache.set("Book Thief", 4);
	t.is(cache.getSize(), 2);
	cache.set("Catcher In The Rye", 0);
	t.is(cache.getSize(), 3);
});

test('delete', t => {
	const cache = new Cache(3, 10, true);

	cache.set("Sapiens", 5);
	cache.set("Book Thief", 4);
	cache.set("Catcher In The Rye", 0);
	cache.delete("Catcher In The Rye");
	t.is(cache.size, 2);
	t.is(cache.hashMap["Catcher In The Rye"], undefined);
	t.is(cache.head.content.key, "Book Thief")
});