mistykey/packages/backend/test/unit/misc/QuantumKVCacheTests.ts
2025-11-12 00:53:39 -05:00

1774 lines
51 KiB
TypeScript

/*
* SPDX-FileCopyrightText: hazelnoot and other Sharkey contributors
* SPDX-License-Identifier: AGPL-3.0-only
*/
import { jest } from '@jest/globals';
import { GodOfTimeService } from '../../misc/GodOfTimeService.js';
import { MockInternalEventService } from '../../misc/MockInternalEventService.js';
import * as assert from '../../misc/custom-assertions.js';
import { QuantumKVCache, type QuantumKVOpts } from '@/misc/QuantumKVCache.js';
import { KeyNotFoundError } from '@/misc/errors/KeyNotFoundError.js';
import { FetchFailedError } from '@/misc/errors/FetchFailedError.js';
import { DisposedError, DisposingError } from '@/misc/errors/DisposeError.js';
describe(QuantumKVCache, () => {
let mockTimeService: GodOfTimeService;
let mockInternalEventService: MockInternalEventService;
let madeCaches: QuantumKVCache<unknown>[] = [];
function makeCache<T>(opts?: Partial<QuantumKVOpts<T>> & { name?: string }): QuantumKVCache<T> {
const _opts = {
name: expect.getState().currentTestName || 'test',
lifetime: Infinity,
fetcher: () => { throw new Error('not implemented'); },
} satisfies QuantumKVOpts<T> & { name: string };
if (opts) {
Object.assign(_opts, opts);
}
const services = {
internalEventService: mockInternalEventService,
timeService: mockTimeService,
};
const cache = new QuantumKVCache<T>(_opts.name, services, _opts);
madeCaches.push(cache);
return cache;
}
beforeAll(() => {
mockTimeService = new GodOfTimeService();
mockInternalEventService = new MockInternalEventService();
});
afterEach(async () => {
for (const cache of madeCaches) {
await cache.dispose();
}
madeCaches = [];
mockTimeService.reset();
mockInternalEventService.mockReset();
});
describe('dispose', () => {
it('should disconnect events', async () => {
const cache = makeCache();
await cache.dispose();
expect(mockInternalEventService._calls).toContainEqual(['off', ['quantumCacheUpdated', expect.anything()]]);
expect(mockInternalEventService._calls).toContainEqual(['off', ['quantumCacheReset', expect.anything()]]);
});
it('should clear memory cache', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
await cache.dispose();
expect(cache.size).toBe(0);
});
it('should prevent future calls', async () => {
const cache = makeCache();
await cache.dispose();
await assert.throwsAsync(DisposedError, async () => {
return await cache.set('foo', 'bar');
});
});
it('should pass dispose signal to fetchers', async () => {
let abortReason: unknown = undefined;
const cache = makeCache<string>({
fetcher: (key, meta) => {
meta.disposeSignal.addEventListener('abort', () => {
abortReason = meta.disposeSignal.reason;
}, { once: true });
return `${key}#value`;
},
});
await cache.fetch('foo');
await cache.dispose();
expect(abortReason).toBeDefined();
expect(abortReason).toBeInstanceOf(DisposingError);
});
it('should abort active fetches', async () => {
const testReady = Promise.withResolvers<void>();
const testComplete = Promise.withResolvers<void>();
const cache = makeCache<string>({
fetcher: async () => {
testReady.resolve();
await testComplete.promise;
return 'test ending';
},
});
const promise = cache.fetch('foo').finally(() => {});
await testReady.promise;
// must be in here:
await cache.dispose();
await assert.rejectsAsync(FetchFailedError, promise);
testComplete.resolve();
});
});
describe('set', () => {
it('should store in memory cache', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
await cache.set('alpha', 'omega');
const result1 = cache.get('foo');
expect(result1).toBe('bar');
const result2 = cache.get('alpha');
expect(result2).toBe('omega');
});
it('should emit event when storing', async () => {
const cache = makeCache<string>({ name: 'fake' });
await cache.set('foo', 'bar');
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo'] }]]);
});
it('should call onChanged when storing', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
onChanged: fakeOnChanged,
});
await cache.set('foo', 'bar');
expect(fakeOnChanged).toHaveBeenCalledWith(['foo'], expect.objectContaining({ cache }));
});
it('should not emit event when storing unchanged value', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
await cache.set('foo', 'bar');
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(1);
});
it('should not call onChanged when storing unchanged value', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
onChanged: fakeOnChanged,
});
await cache.set('foo', 'bar');
await cache.set('foo', 'bar');
expect(fakeOnChanged).toHaveBeenCalledTimes(1);
});
});
describe('constructor', () => {
it('should connect quantumCacheUpdated event', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
name: 'fake',
onChanged: fakeOnChanged,
});
await cache.set('foo', 'foo');
await cache.set('bar', 'bar');
await mockInternalEventService.mockEmit('quantumCacheUpdated', { name: 'fake', keys: ['foo'] });
expect(cache.size).toBe(1);
expect(cache.has('foo')).toBe(false);
expect(cache.has('bar')).toBe(true);
expect(fakeOnChanged).toHaveBeenCalledWith(['foo'], expect.objectContaining({ cache }));
expect(mockInternalEventService._calls).toContainEqual(['on', ['quantumCacheUpdated', expect.anything(), { ignoreLocal: true }]]);
});
it('should connect quantumCacheReset event', async () => {
const fakeOnReset = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
name: 'fake',
onReset: fakeOnReset,
});
await cache.set('foo', 'foo');
await cache.set('bar', 'bar');
await mockInternalEventService.mockEmit('quantumCacheReset', { name: 'fake' });
expect(cache.size).toBe(0);
expect(fakeOnReset).toHaveBeenCalledWith(expect.objectContaining({ cache }));
expect(mockInternalEventService._calls).toContainEqual(['on', ['quantumCacheReset', expect.anything(), { ignoreLocal: true }]]);
});
});
describe('get', () => {
it('should return value if present', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
const result = cache.get('foo');
expect(result).toBe('bar');
});
it('should throw KeyNotFoundError if missing', () => {
const cache = makeCache<string>();
assert.throws(KeyNotFoundError, () => {
cache.get('foo');
});
});
});
describe('getMaybe', () => {
it('should return value if present', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
const result = cache.getMaybe('foo');
expect(result).toBe('bar');
});
it('should return undefined if missing', () => {
const cache = makeCache<string>();
const result = cache.getMaybe('foo');
expect(result).toBe(undefined);
});
});
describe('setMany', () => {
it('should populate all values', async () => {
const cache = makeCache<string>();
await cache.setMany([['foo', 'bar'], ['alpha', 'omega']]);
expect(cache.has('foo')).toBe(true);
expect(cache.has('alpha')).toBe(true);
});
it('should emit one event', async () => {
const cache = makeCache<string>({
name: 'fake',
});
await cache.setMany([['foo', 'bar'], ['alpha', 'omega']]);
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo', 'alpha'] }]]);
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(1);
});
it('should call onChanged once with all items', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
onChanged: fakeOnChanged,
});
await cache.setMany([['foo', 'bar'], ['alpha', 'omega']]);
expect(fakeOnChanged).toHaveBeenCalledWith(['foo', 'alpha'], expect.objectContaining({ cache }));
expect(fakeOnChanged).toHaveBeenCalledTimes(1);
});
it('should emit events only for changed items', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
name: 'fake',
onChanged: fakeOnChanged,
});
await cache.set('foo', 'bar');
fakeOnChanged.mockClear();
mockInternalEventService.mockReset();
await cache.setMany([['foo', 'bar'], ['alpha', 'omega']]);
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['alpha'] }]]);
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(1);
expect(fakeOnChanged).toHaveBeenCalledWith(['alpha'], expect.objectContaining({ cache }));
expect(fakeOnChanged).toHaveBeenCalledTimes(1);
});
});
describe('getMany', () => {
it('should return empty for empty input', () => {
const cache = makeCache();
const result = cache.getMany([]);
expect(result).toEqual([]);
});
it('should return the value for all keys', () => {
const cache = makeCache();
cache.add('foo', 'bar');
cache.add('alpha', 'omega');
const result = cache.getMany(['foo', 'alpha']);
expect(result).toEqual([['foo', 'bar'], ['alpha', 'omega']]);
});
it('should return undefined for missing keys', () => {
const cache = makeCache();
cache.add('foo', 'bar');
const result = cache.getMany(['foo', 'alpha']);
expect(result).toEqual([['foo', 'bar'], ['alpha', undefined]]);
});
});
describe('fetch', () => {
it('should fetch an unknown value', async () => {
const cache = makeCache<string>({
fetcher: key => `value#${key}`,
});
const result = await cache.fetch('foo');
expect(result).toBe('value#foo');
});
it('should store fetched value in memory cache', async () => {
const cache = makeCache<string>({
name: 'fake',
fetcher: key => `value#${key}`,
});
await cache.fetch('foo');
const result = cache.has('foo');
expect(result).toBe(true);
});
it('should call onChanged', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
fetcher: key => `value#${key}`,
onChanged: fakeOnChanged,
});
await cache.fetch('foo');
expect(fakeOnChanged).toHaveBeenCalledWith(['foo'], expect.objectContaining({ cache }));
});
it('should not emit event', async () => {
const cache = makeCache<string>({
name: 'fake',
fetcher: key => `value#${key}`,
});
await cache.fetch('foo');
expect(mockInternalEventService._calls).not.toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo'] }]]);
});
it('should throw FetchFailedError when fetcher throws error', async () => {
const cache = makeCache<string>({
fetcher: () => { throw new Error('test error'); },
});
await assert.throwsAsync(FetchFailedError, async () => {
return await cache.fetch('foo');
});
});
it('should throw KeyNotFoundError when fetcher returns null', async () => {
const cache = makeCache<string>({
fetcher: () => null,
});
await assert.throwsAsync(KeyNotFoundError, async () => {
return await cache.fetch('foo');
});
});
it('should throw KeyNotFoundError when fetcher returns undefined', async () => {
const cache = makeCache<string>({
fetcher: () => undefined,
});
await assert.throwsAsync(KeyNotFoundError, async () => {
return await cache.fetch('foo');
});
});
it('should respect fetcherConcurrency', async () => {
await testConcurrency(
{
fetcher: key => `value#${key}`,
fetcherConcurrency: 2,
},
(cache, key) => cache.fetch(key),
['value#foo', 'value#bar', 'value#baz'],
);
});
it('should respect maxConcurrency', async () => {
await testConcurrency(
{
fetcher: key => `value#${key}`,
maxConcurrency: 2,
},
(cache, key) => cache.fetch(key),
['value#foo', 'value#bar', 'value#baz'],
);
});
it('should de-duplicate calls', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const cache = makeCache<string>({ fetcher: mockFetcher });
// Act
const fetch1 = cache.fetch('foo');
const fetch2 = cache.fetch('foo');
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toBe('value#foo');
await expect(fetch2).resolves.toBe('value#foo');
expect(mockFetcher).toHaveBeenCalledTimes(1);
});
});
describe('fetchMaybe', () => {
it('should return value when found by fetcher', async () => {
const cache = makeCache<string>({
optionalFetcher: () => 'bar',
});
const result = await cache.fetchMaybe('foo');
expect(result).toBe('bar');
});
it('should persist value when found by fetcher', async () => {
const cache = makeCache<string>({
optionalFetcher: () => 'bar',
});
await cache.fetchMaybe('foo');
const result = cache.get('foo');
expect(result).toBe('bar');
});
it('should call onChanged when found by fetcher', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
optionalFetcher: () => 'bar',
onChanged: fakeOnChanged,
});
await cache.fetchMaybe('foo');
expect(fakeOnChanged).toHaveBeenCalled();
});
it('should return undefined when fetcher returns undefined', async () => {
const cache = makeCache<string>({
optionalFetcher: () => undefined,
});
const result = await cache.fetchMaybe('foo');
expect(result).toBe(undefined);
});
it('should not call onChanged when fetcher returns undefined', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
optionalFetcher: () => undefined,
onChanged: fakeOnChanged,
});
await cache.fetchMaybe('foo');
expect(fakeOnChanged).not.toHaveBeenCalled();
});
it('should return undefined when fetcher returns null', async () => {
const cache = makeCache<string>({
optionalFetcher: () => null,
});
const result = await cache.fetchMaybe('foo');
expect(result).toBe(undefined);
});
it('should not call onChanged when fetcher returns null', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
optionalFetcher: () => null,
onChanged: fakeOnChanged,
});
await cache.fetchMaybe('foo');
expect(fakeOnChanged).not.toHaveBeenCalled();
});
it('should throw FetchFailedError when fetcher throws error', async () => {
const cache = makeCache<string>({
optionalFetcher: () => { throw new Error('test error'); },
});
await assert.throwsAsync(FetchFailedError, async () => {
return await cache.fetchMaybe('foo');
});
});
it('should fall back on fetcher when optionalFetcher is not defined', async () => {
const cache = makeCache<string>({
fetcher: () => 'bar',
});
const result = await cache.fetchMaybe('foo');
expect(result).toBe('bar');
});
it('should respect optionalFetcherConcurrency', async () => {
await testConcurrency(
{
optionalFetcher: key => `value#${key}`,
optionalFetcherConcurrency: 2,
},
(cache, key) => cache.fetchMaybe(key),
['value#foo', 'value#bar', 'value#baz'],
);
});
it('should respect maxConcurrency', async () => {
await testConcurrency(
{
optionalFetcher: key => `value#${key}`,
maxConcurrency: 2,
},
(cache, key) => cache.fetchMaybe(key),
['value#foo', 'value#bar', 'value#baz'],
);
});
it('should de-duplicate calls', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const cache = makeCache<string>({ optionalFetcher: mockFetcher });
// Act
const fetch1 = cache.fetchMaybe('foo');
const fetch2 = cache.fetchMaybe('foo');
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toBe('value#foo');
await expect(fetch2).resolves.toBe('value#foo');
expect(mockFetcher).toHaveBeenCalledTimes(1);
});
});
describe('fetchMany', () => {
it('should do nothing for empty input', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache({
onChanged: fakeOnChanged,
});
await cache.fetchMany([]);
expect(fakeOnChanged).not.toHaveBeenCalled();
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
});
it('should return existing items', async () => {
const cache = makeCache();
cache.add('foo', 'bar');
cache.add('alpha', 'omega');
const result = await cache.fetchMany(['foo', 'alpha']);
expect(result).toEqual([['foo', 'bar'], ['alpha', 'omega']]);
});
it('should return existing items without events', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache({
onChanged: fakeOnChanged,
});
cache.add('foo', 'bar');
cache.add('alpha', 'omega');
await cache.fetchMany(['foo', 'alpha']);
expect(fakeOnChanged).not.toHaveBeenCalled();
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
});
it('should call bulkFetcher for missing items', async () => {
const cache = makeCache({
bulkFetcher: keys => keys.map(k => [k, `${k}#many`]),
fetcher: key => `${key}#single`,
});
const results = await cache.fetchMany(['foo', 'alpha']);
expect(results).toEqual([['foo', 'foo#many'], ['alpha', 'alpha#many']]);
});
it('should call bulkFetcher only once', async () => {
const mockBulkFetcher = jest.fn((keys: string[]) => keys.map(k => [k, `${k}#value`] as [string, string]));
const cache = makeCache({
bulkFetcher: mockBulkFetcher,
});
await cache.fetchMany(['foo', 'bar']);
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
});
it('should call optionalFetcher for single item', async () => {
const cache = makeCache({
optionalFetcher: () => 'good',
bulkFetcher: keys => keys.map(k => [k, 'bad']),
fetcher: () => 'bad',
});
const results = await cache.fetchMany(['foo']);
expect(results).toEqual([['foo', 'good']]);
});
it('should call fetcher for single item when optionalFetcher is not defined', async () => {
const cache = makeCache({
bulkFetcher: keys => keys.map(k => [k, 'bad']),
fetcher: () => 'good',
});
const results = await cache.fetchMany(['foo']);
expect(results).toEqual([['foo', 'good']]);
});
it('should call fetcher when fetchMany is undefined', async () => {
const cache = makeCache({
fetcher: key => `${key}#single`,
});
const results = await cache.fetchMany(['foo', 'alpha']);
expect(results).toEqual([['foo', 'foo#single'], ['alpha', 'alpha#single']]);
});
it('should call onChanged', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache({
onChanged: fakeOnChanged,
fetcher: k => k,
});
await cache.fetchMany(['foo', 'alpha']);
expect(fakeOnChanged).toHaveBeenCalledWith(['foo', 'alpha'], expect.objectContaining({ cache }));
expect(fakeOnChanged).toHaveBeenCalledTimes(1);
});
it('should call onChanged only for changed', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache({
onChanged: fakeOnChanged,
fetcher: k => k,
});
cache.add('foo', 'bar');
await cache.fetchMany(['foo', 'alpha']);
expect(fakeOnChanged).toHaveBeenCalledWith(['alpha'], expect.objectContaining({ cache }));
expect(fakeOnChanged).toHaveBeenCalledTimes(1);
});
it('should not emit event', async () => {
const cache = makeCache({
fetcher: k => k,
});
await cache.fetchMany(['foo', 'alpha']);
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
});
it('should respect bulkFetcherConcurrency', async () => {
await testConcurrency(
{
bulkFetcher: keys => [[keys[0], `value#${keys[0]}`]],
bulkFetcherConcurrency: 2,
},
(cache, key) => cache.fetchMany([key, `${key}#dupe`]),
[[['foo', 'value#foo']], [['bar', 'value#bar']], [['baz', 'value#baz']]],
);
});
it('should respect maxConcurrency', async () => {
await testConcurrency(
{
bulkFetcher: keys => [[keys[0], `value#${keys[0]}`]],
maxConcurrency: 2,
},
(cache, key) => cache.fetchMany([key, `${key}#dupe`]),
[[['foo', 'value#foo']], [['bar', 'value#bar']], [['baz', 'value#baz']]],
);
});
it('should de-duplicate calls using fetcher', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const mockBulkFetcher = jest.fn(async (keys: string[]) => {
await testComplete.promise;
return keys.map(key => [key, `value#${key}`] as [string, string]);
});
const cache = makeCache<string>({
fetcher: mockFetcher,
bulkFetcher: mockBulkFetcher,
});
// Act
const fetch1 = cache.fetch('foo');
const fetch2 = cache.fetchMany(['foo', 'bar', 'baz']);
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toEqual('value#foo');
await expect(fetch2).resolves.toEqual([['foo', 'value#foo'], ['bar', 'value#bar'], ['baz', 'value#baz']]);
expect(mockFetcher).toHaveBeenCalledTimes(1);
expect(mockFetcher).toHaveBeenCalledWith('foo', expect.objectContaining({ cache }));
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
expect(mockBulkFetcher).toHaveBeenCalledWith(['bar', 'baz'], expect.objectContaining({ cache }));
});
it('should de-duplicate calls using optionalFetcher', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const mockBulkFetcher = jest.fn(async (keys: string[]) => {
await testComplete.promise;
return keys.map(key => [key, `value#${key}`] as [string, string]);
});
const cache = makeCache<string>({
optionalFetcher: mockFetcher,
bulkFetcher: mockBulkFetcher,
});
// Act
const fetch1 = cache.fetchMaybe('foo');
const fetch2 = cache.fetchMany(['foo', 'bar', 'baz']);
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toEqual('value#foo');
await expect(fetch2).resolves.toEqual([['foo', 'value#foo'], ['bar', 'value#bar'], ['baz', 'value#baz']]);
expect(mockFetcher).toHaveBeenCalledTimes(1);
expect(mockFetcher).toHaveBeenCalledWith('foo', expect.objectContaining({ cache }));
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
expect(mockBulkFetcher).toHaveBeenCalledWith(['bar', 'baz'], expect.objectContaining({ cache }));
});
it('should de-duplicate calls using fetcher and optionalFetcher', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const mockOptionalFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const mockBulkFetcher = jest.fn(async (keys: string[]) => {
await testComplete.promise;
return keys.map(key => [key, `value#${key}`] as [string, string]);
});
const cache = makeCache<string>({
fetcher: mockFetcher,
optionalFetcher: mockOptionalFetcher,
bulkFetcher: mockBulkFetcher,
});
// Act
const fetch1 = cache.fetch('foo');
const fetch2 = cache.fetchMaybe('bar');
const fetch3 = cache.fetchMany(['foo', 'bar', 'baz', 'wow']);
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toEqual('value#foo');
await expect(fetch2).resolves.toEqual('value#bar');
await expect(fetch3).resolves.toEqual([['foo', 'value#foo'], ['bar', 'value#bar'], ['baz', 'value#baz'], ['wow', 'value#wow']]);
expect(mockFetcher).toHaveBeenCalledTimes(1);
expect(mockFetcher).toHaveBeenCalledWith('foo', expect.objectContaining({ cache }));
expect(mockOptionalFetcher).toHaveBeenCalledTimes(1);
expect(mockOptionalFetcher).toHaveBeenCalledWith('bar', expect.objectContaining({ cache }));
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
expect(mockBulkFetcher).toHaveBeenCalledWith(['baz', 'wow'], expect.objectContaining({ cache }));
});
});
describe('refresh', () => {
it('should populate the value', async () => {
const cache = makeCache<string>({
fetcher: key => `value#${key}`,
});
await cache.refresh('foo');
const result = cache.has('foo');
expect(result).toBe(true);
});
it('should return the value', async () => {
const cache = makeCache<string>({
fetcher: key => `value#${key}`,
});
const result = await cache.refresh('foo');
expect(result).toBe('value#foo');
});
it('should replace the value if it exists', async () => {
const cache = makeCache<string>({
fetcher: key => `value#${key}`,
});
await cache.set('foo', 'bar');
const result = await cache.refresh('foo');
expect(result).toBe('value#foo');
});
it('should call onChanged', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
fetcher: key => `value#${key}`,
onChanged: fakeOnChanged,
});
await cache.refresh('foo');
expect(fakeOnChanged).toHaveBeenCalledWith(['foo'], expect.objectContaining({ cache }));
});
it('should emit event', async () => {
const cache = makeCache<string>({
name: 'fake',
fetcher: key => `value#${key}`,
});
await cache.refresh('foo');
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo'] }]]);
});
it('should respect fetcherConcurrency', async () => {
await testConcurrency(
{
fetcher: key => `value#${key}`,
fetcherConcurrency: 2,
},
(cache, key) => cache.refresh(key),
['value#foo', 'value#bar', 'value#baz'],
);
});
it('should respect maxConcurrency', async () => {
await testConcurrency(
{
fetcher: key => `value#${key}`,
maxConcurrency: 2,
},
(cache, key) => cache.refresh(key),
['value#foo', 'value#bar', 'value#baz'],
);
});
it('should de-duplicate calls', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const cache = makeCache<string>({ fetcher: mockFetcher });
// Act
const fetch1 = cache.refresh('foo');
const fetch2 = cache.refresh('foo');
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toBe('value#foo');
await expect(fetch2).resolves.toBe('value#foo');
expect(mockFetcher).toHaveBeenCalledTimes(1);
});
});
describe('refreshMaybe', () => {
it('should return value when found by fetcher', async () => {
const cache = makeCache<string>({
optionalFetcher: () => 'bar',
});
const result = await cache.refreshMaybe('foo');
expect(result).toBe('bar');
});
it('should persist value when found by fetcher', async () => {
const cache = makeCache<string>({
optionalFetcher: () => 'bar',
});
await cache.refreshMaybe('foo');
const result = cache.get('foo');
expect(result).toBe('bar');
});
it('should call onChanged when found by fetcher', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
optionalFetcher: () => 'bar',
onChanged: fakeOnChanged,
});
await cache.refreshMaybe('foo');
expect(fakeOnChanged).toHaveBeenCalledWith(['foo'], expect.objectContaining({ cache }));
});
it('should return undefined when fetcher returns undefined', async () => {
const cache = makeCache<string>({
optionalFetcher: () => undefined,
});
const result = await cache.refreshMaybe('foo');
expect(result).toBe(undefined);
});
it('should call onChanged when fetcher returns undefined', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
optionalFetcher: () => undefined,
onChanged: fakeOnChanged,
});
await cache.refreshMaybe('foo');
expect(fakeOnChanged).toHaveBeenCalledWith(['foo'], expect.objectContaining({ cache }));
});
it('should return undefined when fetcher returns null', async () => {
const cache = makeCache<string>({
optionalFetcher: () => null,
});
const result = await cache.refreshMaybe('foo');
expect(result).toBe(undefined);
});
it('should call onChanged when fetcher returns null', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
optionalFetcher: () => null,
onChanged: fakeOnChanged,
});
await cache.refreshMaybe('foo');
expect(fakeOnChanged).toHaveBeenCalledWith(['foo'], expect.objectContaining({ cache }));
});
it('should throw FetchFailedError when fetcher throws error', async () => {
const cache = makeCache<string>({
optionalFetcher: () => { throw new Error('test error'); },
});
await assert.throwsAsync(FetchFailedError, async () => {
return await cache.refreshMaybe('foo');
});
});
it('should fall back on fetcher when optionalFetcher is not defined', async () => {
const cache = makeCache<string>({
fetcher: () => 'bar',
});
const result = await cache.refreshMaybe('foo');
expect(result).toBe('bar');
});
it('should replace the value if it exists', async () => {
const cache = makeCache<string>({
optionalFetcher: key => `value#${key}`,
});
await cache.set('foo', 'bar');
const result = await cache.refreshMaybe('foo');
expect(result).toBe('value#foo');
});
it('should emit event when found', async () => {
const cache = makeCache<string>({
name: 'fake',
optionalFetcher: key => `value#${key}`,
});
await cache.refreshMaybe('foo');
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo'] }]]);
});
it('should emit event when not found', async () => {
const cache = makeCache<string>({
name: 'fake',
optionalFetcher: () => undefined,
});
await cache.refreshMaybe('foo');
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo'] }]]);
});
it('should respect optionalFetcherConcurrency', async () => {
await testConcurrency(
{
optionalFetcher: key => `value#${key}`,
optionalFetcherConcurrency: 2,
},
(cache, key) => cache.refreshMaybe(key),
['value#foo', 'value#bar', 'value#baz'],
);
});
it('should respect maxConcurrency', async () => {
await testConcurrency(
{
fetcher: key => `value#${key}`,
maxConcurrency: 2,
},
(cache, key) => cache.refreshMaybe(key),
['value#foo', 'value#bar', 'value#baz'],
);
});
it('should de-duplicate calls', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const cache = makeCache<string>({ optionalFetcher: mockFetcher });
// Act
const fetch1 = cache.refreshMaybe('foo');
const fetch2 = cache.refreshMaybe('foo');
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toBe('value#foo');
await expect(fetch2).resolves.toBe('value#foo');
expect(mockFetcher).toHaveBeenCalledTimes(1);
});
});
describe('refreshMany', () => {
it('should do nothing for empty input', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache({
onChanged: fakeOnChanged,
});
const result = await cache.refreshMany([]);
expect(result).toEqual([]);
expect(fakeOnChanged).not.toHaveBeenCalled();
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
});
it('should call bulkFetcher for all keys', async () => {
const mockBulkFetcher = jest.fn((keys: string[]) => keys.map(k => [k, `${k}#value`] as [string, string]));
const cache = makeCache({
bulkFetcher: mockBulkFetcher,
});
const result = await cache.refreshMany(['foo', 'alpha']);
expect(result).toEqual([['foo', 'foo#value'], ['alpha', 'alpha#value']]);
expect(mockBulkFetcher).toHaveBeenCalledWith(['foo', 'alpha'], expect.objectContaining({ cache }));
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
});
it('should replace any existing keys', async () => {
const mockBulkFetcher = jest.fn((keys: string[]) => keys.map(k => [k, `${k}#value`] as [string, string]));
const cache = makeCache({
bulkFetcher: mockBulkFetcher,
});
cache.add('foo', 'bar');
const result = await cache.refreshMany(['foo', 'alpha']);
expect(result).toEqual([['foo', 'foo#value'], ['alpha', 'alpha#value']]);
expect(mockBulkFetcher).toHaveBeenCalledWith(['foo', 'alpha'], expect.objectContaining({ cache }));
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
});
it('should call onChanged for all keys', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache({
bulkFetcher: keys => keys.map(k => [k, `${k}#value`]),
onChanged: fakeOnChanged,
});
cache.add('foo', 'bar');
await cache.refreshMany(['foo', 'alpha']);
expect(fakeOnChanged).toHaveBeenCalledWith(['foo', 'alpha'], expect.objectContaining({ cache }));
expect(fakeOnChanged).toHaveBeenCalledTimes(1);
});
it('should emit event for all keys', async () => {
const cache = makeCache({
name: 'fake',
bulkFetcher: keys => keys.map(k => [k, `${k}#value`]),
});
cache.add('foo', 'bar');
await cache.refreshMany(['foo', 'alpha']);
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo', 'alpha'] }]]);
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(1);
});
it('should call optionalFetcher for single item', async () => {
const cache = makeCache({
optionalFetcher: () => 'good',
bulkFetcher: keys => keys.map(k => [k, 'bad']),
fetcher: () => 'bad',
});
const results = await cache.refreshMany(['foo']);
expect(results).toEqual([['foo', 'good']]);
});
it('should call fetcher for single item when optionalFetcher is not defined', async () => {
const cache = makeCache({
bulkFetcher: keys => keys.map(k => [k, 'bad']),
fetcher: () => 'good',
});
const results = await cache.refreshMany(['foo']);
expect(results).toEqual([['foo', 'good']]);
});
it('should throw FetchFailedError when bulk fetcher throws error', async () => {
const cache = makeCache<string>({
bulkFetcher: () => { throw new Error('test error'); },
});
await assert.throwsAsync(FetchFailedError, async () => {
return await cache.refreshMany(['foo']);
});
});
it('should throw FetchFailedError when fallback fetcher throws error', async () => {
const cache = makeCache<string>({
fetcher: () => { throw new Error('test error'); },
});
await assert.throwsAsync(FetchFailedError, async () => {
return await cache.refreshMany(['foo']);
});
});
it('should not throw when fallback fetcher returns null', async () => {
const cache = makeCache<string>({
fetcher: () => null,
});
const result = await cache.refreshMany(['foo']);
expect(result).toHaveLength(0);
});
it('should not throw when fallback fetcher returns undefined', async () => {
const cache = makeCache<string>({
fetcher: () => undefined,
});
const result = await cache.refreshMany(['foo']);
expect(result).toHaveLength(0);
});
it('should not throw when bulk fetcher returns empty', async () => {
const cache = makeCache<string>({
bulkFetcher: () => [],
});
const result = await cache.refreshMany(['foo', 'bar']);
expect(result).toHaveLength(0);
});
it('should respect bulkFetcherConcurrency', async () => {
await testConcurrency(
{
bulkFetcher: keys => [[keys[0], `value#${keys[0]}`]],
bulkFetcherConcurrency: 2,
},
(cache, key) => cache.refreshMany([key, `${key}#dupe`]),
[[['foo', 'value#foo']], [['bar', 'value#bar']], [['baz', 'value#baz']]],
);
});
it('should respect maxConcurrency', async () => {
await testConcurrency(
{
bulkFetcher: keys => [[keys[0], `value#${keys[0]}`]],
maxConcurrency: 2,
},
(cache, key) => cache.refreshMany([key, `${key}#dupe`]),
[[['foo', 'value#foo']], [['bar', 'value#bar']], [['baz', 'value#baz']]],
);
});
it('should de-duplicate calls using fetcher', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const mockBulkFetcher = jest.fn(async (keys: string[]) => {
await testComplete.promise;
return keys.map(key => [key, `value#${key}`] as [string, string]);
});
const cache = makeCache<string>({
fetcher: mockFetcher,
bulkFetcher: mockBulkFetcher,
});
// Act
const fetch1 = cache.fetch('foo');
const fetch2 = cache.refreshMany(['foo', 'bar', 'baz']);
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toEqual('value#foo');
await expect(fetch2).resolves.toEqual([['foo', 'value#foo'], ['bar', 'value#bar'], ['baz', 'value#baz']]);
expect(mockFetcher).toHaveBeenCalledTimes(1);
expect(mockFetcher).toHaveBeenCalledWith('foo', expect.objectContaining({ cache }));
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
expect(mockBulkFetcher).toHaveBeenCalledWith(['bar', 'baz'], expect.objectContaining({ cache }));
});
it('should de-duplicate calls using optionalFetcher', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockOptionalFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const mockBulkFetcher = jest.fn(async (keys: string[]) => {
await testComplete.promise;
return keys.map(key => [key, `value#${key}`] as [string, string]);
});
const cache = makeCache<string>({
optionalFetcher: mockOptionalFetcher,
bulkFetcher: mockBulkFetcher,
});
// Act
const fetch1 = cache.fetchMaybe('foo');
const fetch2 = cache.refreshMany(['foo', 'bar', 'baz']);
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toEqual('value#foo');
await expect(fetch2).resolves.toEqual([['foo', 'value#foo'], ['bar', 'value#bar'], ['baz', 'value#baz']]);
expect(mockOptionalFetcher).toHaveBeenCalledTimes(1);
expect(mockOptionalFetcher).toHaveBeenCalledWith('foo', expect.objectContaining({ cache }));
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
expect(mockBulkFetcher).toHaveBeenCalledWith(['bar', 'baz'], expect.objectContaining({ cache }));
});
it('should de-duplicate calls using fetcher and optionalFetcher', async () => {
// Arrange
const testComplete = Promise.withResolvers<void>();
const mockFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const mockOptionalFetcher = jest.fn(async (key: string) => {
await testComplete.promise;
return `value#${key}`;
});
const mockBulkFetcher = jest.fn(async (keys: string[]) => {
await testComplete.promise;
return keys.map(key => [key, `value#${key}`] as [string, string]);
});
const cache = makeCache<string>({
fetcher: mockFetcher,
optionalFetcher: mockOptionalFetcher,
bulkFetcher: mockBulkFetcher,
});
// Act
const fetch1 = cache.fetch('foo');
const fetch2 = cache.fetchMaybe('bar');
const fetch3 = cache.refreshMany(['foo', 'bar', 'baz', 'wow']);
// Assert
testComplete.resolve();
await expect(fetch1).resolves.toEqual('value#foo');
await expect(fetch2).resolves.toEqual('value#bar');
await expect(fetch3).resolves.toEqual([['foo', 'value#foo'], ['bar', 'value#bar'], ['baz', 'value#baz'], ['wow', 'value#wow']]);
expect(mockFetcher).toHaveBeenCalledTimes(1);
expect(mockFetcher).toHaveBeenCalledWith('foo', expect.objectContaining({ cache }));
expect(mockOptionalFetcher).toHaveBeenCalledTimes(1);
expect(mockOptionalFetcher).toHaveBeenCalledWith('bar', expect.objectContaining({ cache }));
expect(mockBulkFetcher).toHaveBeenCalledTimes(1);
expect(mockBulkFetcher).toHaveBeenCalledWith(['baz', 'wow'], expect.objectContaining({ cache }));
});
});
describe('delete', () => {
it('should delete from memory cache', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
await cache.delete('foo');
const result = cache.has('foo');
expect(result).toBe(false);
});
it('should call onChanged when deleting', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
onChanged: fakeOnChanged,
});
await cache.set('foo', 'bar');
await cache.delete('foo');
expect(fakeOnChanged).toHaveBeenCalledWith(['foo'], expect.objectContaining({ cache }));
});
it('should emit event when deleting', async () => {
const cache = makeCache<string>({ name: 'fake' });
await cache.set('foo', 'bar');
await cache.delete('foo');
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo'] }]]);
});
});
describe('deleteMany', () => {
it('should remove keys from memory cache', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
await cache.set('alpha', 'omega');
await cache.deleteMany(['foo', 'alpha']);
expect(cache.has('foo')).toBe(false);
expect(cache.has('alpha')).toBe(false);
});
it('should emit only one event', async () => {
const cache = makeCache<string>({
name: 'fake',
});
await cache.deleteMany(['foo', 'alpha']);
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheUpdated', { name: 'fake', keys: ['foo', 'alpha'] }]]);
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(1);
});
it('should call onChanged once with all items', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
onChanged: fakeOnChanged,
});
await cache.deleteMany(['foo', 'alpha']);
expect(fakeOnChanged).toHaveBeenCalledWith(['foo', 'alpha'], expect.objectContaining({ cache }));
expect(fakeOnChanged).toHaveBeenCalledTimes(1);
});
it('should do nothing if no keys are provided', async () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
onChanged: fakeOnChanged,
});
await cache.deleteMany([]);
expect(fakeOnChanged).not.toHaveBeenCalled();
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
});
});
describe('reset', () => {
it('should erase all items', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
await cache.set('alpha', 'omega');
await cache.reset();
expect(cache.size).toBe(0);
});
it('should call onReset', async () => {
const fakeOnReset = jest.fn(() => Promise.resolve());
const cache = makeCache<string>({
onReset: fakeOnReset,
});
await cache.set('foo', 'bar');
await cache.set('alpha', 'omega');
await cache.reset();
expect(fakeOnReset).toHaveBeenCalled();
});
it('should emit event', async () => {
const cache = makeCache<string>({
name: 'fake',
});
await cache.set('foo', 'bar');
await cache.set('alpha', 'omega');
await cache.reset();
expect(mockInternalEventService._calls).toContainEqual(['emit', ['quantumCacheReset', { name: 'fake' }]]);
});
});
describe('add', () => {
it('should add the item', () => {
const cache = makeCache();
cache.add('foo', 'bar');
expect(cache.has('foo')).toBe(true);
});
it('should not emit event', () => {
const cache = makeCache();
cache.add('foo', 'bar');
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
});
it('should not call onChanged', () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache({
onChanged: fakeOnChanged,
});
cache.add('foo', 'bar');
expect(fakeOnChanged).not.toHaveBeenCalled();
});
});
describe('addMany', () => {
it('should add all items', () => {
const cache = makeCache();
cache.addMany([['foo', 'bar'], ['alpha', 'omega']]);
expect(cache.has('foo')).toBe(true);
expect(cache.has('alpha')).toBe(true);
});
it('should not emit event', () => {
const cache = makeCache();
cache.addMany([['foo', 'bar'], ['alpha', 'omega']]);
expect(mockInternalEventService._calls.filter(c => c[0] === 'emit')).toHaveLength(0);
});
it('should not call onChanged', () => {
const fakeOnChanged = jest.fn(() => Promise.resolve());
const cache = makeCache({
onChanged: fakeOnChanged,
});
cache.addMany([['foo', 'bar'], ['alpha', 'omega']]);
expect(fakeOnChanged).not.toHaveBeenCalled();
});
});
describe('has', () => {
it('should return false when empty', () => {
const cache = makeCache();
const result = cache.has('foo');
expect(result).toBe(false);
});
it('should return false when value is not in memory', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
const result = cache.has('alpha');
expect(result).toBe(false);
});
it('should return true when value is in memory', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
const result = cache.has('foo');
expect(result).toBe(true);
});
});
describe('size', () => {
it('should return 0 when empty', () => {
const cache = makeCache();
expect(cache.size).toBe(0);
});
it('should return correct size when populated', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
expect(cache.size).toBe(1);
});
});
describe('entries', () => {
it('should return empty when empty', () => {
const cache = makeCache();
const result = Array.from(cache.entries());
expect(result).toHaveLength(0);
});
it('should return all entries when populated', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
const result = Array.from(cache.entries());
expect(result).toEqual([['foo', 'bar']]);
});
});
describe('keys', () => {
it('should return empty when empty', () => {
const cache = makeCache();
const result = Array.from(cache.keys());
expect(result).toHaveLength(0);
});
it('should return all keys when populated', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
const result = Array.from(cache.keys());
expect(result).toEqual(['foo']);
});
});
describe('values', () => {
it('should return empty when empty', () => {
const cache = makeCache();
const result = Array.from(cache.values());
expect(result).toHaveLength(0);
});
it('should return all values when populated', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
const result = Array.from(cache.values());
expect(result).toEqual(['bar']);
});
});
describe('[Symbol.iterator]', () => {
it('should return empty when empty', () => {
const cache = makeCache();
const result = Array.from(cache);
expect(result).toHaveLength(0);
});
it('should return all entries when populated', async () => {
const cache = makeCache<string>();
await cache.set('foo', 'bar');
const result = Array.from(cache);
expect(result).toEqual([['foo', 'bar']]);
});
});
async function testConcurrency<TFetch>(opts: Partial<QuantumKVOpts<string>>, fetchCallback: (cache: QuantumKVCache<string>, key: string) => Promise<TFetch>, expectedResults: unknown): Promise<void> {
const fetcher = opts.fetcher;
const optionalFetcher = opts.optionalFetcher;
const bulkFetcher = opts.bulkFetcher;
// Arrange
const fetches = {} as Record<string, FetchController<TFetch>>;
const testReady = Promise.withResolvers<void>();
const cache = makeCache<string>({
fetcherConcurrency: 4,
optionalFetcherConcurrency: 4,
bulkFetcherConcurrency: 4,
maxConcurrency: 4,
...opts,
fetcher: fetcher ? async (key, meta) => {
await waitForSignalBeforeFetch(testReady, key, fetches);
return fetcher(key, meta);
} : undefined,
optionalFetcher: optionalFetcher ? async (key, meta) => {
await waitForSignalBeforeFetch(testReady, key, fetches);
return optionalFetcher(key, meta);
} : undefined,
bulkFetcher: bulkFetcher ? async (keys, meta) => {
await waitForSignalBeforeFetch(testReady, keys[0], fetches);
return bulkFetcher(keys, meta);
} : undefined,
});
for (const key of ['foo', 'bar', 'baz']) {
const fetcher = {
created: false,
creating: Promise.withResolvers<void>(),
gate: Promise.withResolvers<void>(),
promise: fetchCallback(cache, key),
execute: async () => {
await fetcher.creating.promise;
return await fetcher.execute();
},
complete: async () => {
if (!fetcher.created) throw new Error(`test error: cannot complete an unstarted fetcher for ${key}`);
fetcher.gate.resolve();
return await fetcher.promise;
},
};
fetches[key] = fetcher;
}
// Act
testReady.resolve();
// Assert: should create fetchers up to the limit
await Promise.all([fetches.foo.creating.promise, fetches.bar.creating.promise]);
expect(fetches.foo.created).toBe(true);
expect(fetches.bar.created).toBe(true);
expect(fetches.baz.created).toBe(false);
// Assert: when one completes, should create the next one
await fetches.foo.complete();
await fetches.baz.creating.promise;
expect(fetches.baz.created).toBe(true);
// Assert: when all complete, final results should be correct
const results = await Promise.all([
fetches.foo.complete(),
fetches.bar.complete(),
fetches.baz.complete(),
]);
expect(results).toEqual(expectedResults);
}
});
// used for concurrency tests
async function waitForSignalBeforeFetch<T>(testReady: PromiseWithResolvers<void>, key: string, fetches: Record<string, FetchController<T>>) {
await testReady.promise;
const fetch = fetches[key];
expect(fetch).toBeTruthy();
fetch.created = true;
fetch.creating.resolve();
await fetch.gate.promise;
}
// used for concurrency tests
interface FetchController<T> {
// create phase
/** set to true when fetch callback is executed */
created: boolean,
/** triggered internally when the callback is executed */
creating: PromiseWithResolvers<void>,
// execute phase
/** triggered externally to start the fetcher */
gate: PromiseWithResolvers<void>,
/** resolves when fetcher completes */
promise: Promise<T>,
// controls
/** starts and executes the fetcher */
complete: () => Promise<T>;
/** awaits creation, then starts and executes the fetcher */
execute: () => Promise<T>;
}