Files
freeCodeCamp/api-server/server/utils/in-memory-cache.test.js
2018-12-04 17:42:12 +05:30

50 lines
1.3 KiB
JavaScript

/* global describe expect it beforeEach */
import inMemoryCache from './in-memory-cache';
describe('InMemoryCache', () => {
const theAnswer = 42;
const before = 'before';
const after = 'after';
const emptyCacheValue = null;
describe('get', () => {
it('returns null for an empty cache', () => {
const cache = inMemoryCache();
expect(cache.get()).toBe(emptyCacheValue);
});
it('returns an initial value', () => {
const cache = inMemoryCache(theAnswer);
expect(cache.get()).toBe(theAnswer);
});
});
describe('update', () => {
it('updates the cached value', () => {
const cache = inMemoryCache(before);
cache.update(() => after);
expect(cache.get()).toBe(after);
});
it('can handle promises correctly', done => {
const cache = inMemoryCache(before);
cache.update(() => new Promise(resolve => resolve(after)));
// because async
setImmediate(() => {
expect(cache.get()).toBe(after);
done();
});
});
});
describe('clear', () => {
it('clears the cache', () => {
expect.assertions(2);
const cache = inMemoryCache(theAnswer);
expect(cache.get()).toBe(theAnswer);
cache.clear();
expect(cache.get()).toBe(emptyCacheValue);
});
});
});