test: Add flushPromises utility function

test/integration/LockingResourceStore.test.ts

@@ -16,6 +16,8 @@ import { SingleThreadedResourceLocker } from '../../src/util/locking/SingleThrea
 import { WrappedExpiringReadWriteLocker } from '../../src/util/locking/WrappedExpiringReadWriteLocker';
 import { guardedStreamFrom } from '../../src/util/StreamUtil';
 import { PIM, RDF } from '../../src/util/Vocabularies';
+import { flushPromises } from '../util/Util';
+
 jest.useFakeTimers('legacy');
 
 describe('A LockingResourceStore', (): void => {
@@ -67,7 +69,7 @@ describe('A LockingResourceStore', (): void => {
 
     // Wait 1000ms and read
     jest.advanceTimersByTime(1000);
-    await new Promise(setImmediate);
+    await flushPromises();
     expect(representation.data.destroyed).toBe(true);
 
     // Verify a timeout error was thrown
@@ -95,7 +97,7 @@ describe('A LockingResourceStore', (): void => {
 
     // Wait 1000ms and watch the stream be destroyed
     jest.advanceTimersByTime(1000);
-    await new Promise(setImmediate);
+    await flushPromises();
     expect(representation.data.destroyed).toBe(true);
 
     // Verify a timeout error was thrown

test/integration/RedisResourceLockerIntegration.test.ts

@@ -1,7 +1,6 @@
 import fetch from 'cross-fetch';
 import type { App, RedisResourceLocker } from '../../src';
-
+import { describeIf, flushPromises, getPort } from '../util/Util';
-import { describeIf, getPort } from '../util/Util';
 import { getDefaultVariables, getTestConfigPath, instantiateFromConfig } from './Config';
 
 /**
@@ -139,7 +138,7 @@ describeIf('docker', 'A server with a RedisResourceLocker as ResourceLocker', ()
       const lock2 = locker.acquire(identifier);
       const lock3 = locker.acquire(identifier);
 
-      await new Promise((resolve): any => setImmediate(resolve));
+      await flushPromises();
 
       const l2 = lock2.then(async(): Promise<void> => {
         res += 'l2';

test/unit/init/AppRunner.test.ts

@@ -4,6 +4,7 @@ import { AppRunner } from '../../../src/init/AppRunner';
 import type { CliExtractor } from '../../../src/init/cli/CliExtractor';
 import type { SettingsResolver } from '../../../src/init/variables/SettingsResolver';
 import { joinFilePath } from '../../../src/util/PathUtil';
+import { flushPromises } from '../../util/Util';
 
 const app: jest.Mocked<App> = {
   start: jest.fn(),
@@ -315,9 +316,7 @@ describe('AppRunner', (): void => {
       new AppRunner().runCliSync({ argv: [ 'node', 'script' ]});
 
       // Wait until app.start has been called, because we can't await AppRunner.run.
-      await new Promise((resolve): void => {
+      await flushPromises();
-        setImmediate(resolve);
-      });
 
       expect(ComponentsManager.build).toHaveBeenCalledTimes(1);
       expect(ComponentsManager.build).toHaveBeenCalledWith({
@@ -348,9 +347,7 @@ describe('AppRunner', (): void => {
       new AppRunner().runCliSync({ argv: [ 'node', 'script' ]});
 
       // Wait until app.start has been called, because we can't await AppRunner.runCli.
-      await new Promise((resolve): void => {
+      await flushPromises();
-        setImmediate(resolve);
-      });
 
       expect(write).toHaveBeenCalledTimes(1);
       expect(write).toHaveBeenLastCalledWith(expect.stringMatching(/Cause: Fatal/mu));

test/unit/storage/LockingResourceStore.test.ts

@@ -7,6 +7,7 @@ import { LockingResourceStore } from '../../../src/storage/LockingResourceStore'
 import type { ResourceStore } from '../../../src/storage/ResourceStore';
 import type { ExpiringReadWriteLocker } from '../../../src/util/locking/ExpiringReadWriteLocker';
 import { guardedStreamFrom } from '../../../src/util/StreamUtil';
+import { flushPromises } from '../../util/Util';
 
 function emptyFn(): void {
   // Empty
@@ -170,7 +171,7 @@ describe('A LockingResourceStore', (): void => {
     registerEventOrder(representation.data, 'end');
 
     // Provide opportunity for async events
-    await new Promise(setImmediate);
+    await flushPromises();
 
     // Verify the lock was acquired and released at the right time
     expect(locker.withReadLock).toHaveBeenCalledTimes(1);
@@ -187,7 +188,7 @@ describe('A LockingResourceStore', (): void => {
     registerEventOrder(representation.data, 'end');
 
     // Provide opportunity for async events
-    await new Promise(setImmediate);
+    await flushPromises();
 
     // Verify the lock was acquired and released at the right time
     expect(locker.withReadLock).toHaveBeenCalledTimes(1);
@@ -205,7 +206,7 @@ describe('A LockingResourceStore', (): void => {
     registerEventOrder(representation.data, 'close');
 
     // Provide opportunity for async events
-    await new Promise(setImmediate);
+    await flushPromises();
 
     // Verify the lock was acquired and released at the right time
     expect(locker.withReadLock).toHaveBeenCalledTimes(1);
@@ -222,7 +223,7 @@ describe('A LockingResourceStore', (): void => {
     registerEventOrder(representation.data, 'close');
 
     // Provide opportunity for async events
-    await new Promise(setImmediate);
+    await flushPromises();
 
     // Verify the lock was acquired and released at the right time
     expect(locker.withReadLock).toHaveBeenCalledTimes(1);
@@ -241,7 +242,7 @@ describe('A LockingResourceStore', (): void => {
     });
 
     // Provide opportunity for async events
-    await new Promise(setImmediate);
+    await flushPromises();
 
     // Verify the lock was acquired and released at the right time
     expect(locker.withReadLock).toHaveBeenCalledTimes(1);
@@ -258,7 +259,7 @@ describe('A LockingResourceStore', (): void => {
     timeoutTrigger.emit('timeout');
 
     // Provide opportunity for async events
-    await new Promise(setImmediate);
+    await flushPromises();
 
     // Verify the lock was acquired and released at the right time
     expect(locker.withReadLock).toHaveBeenCalledTimes(1);

test/unit/util/StreamUtil.test.ts

@@ -8,6 +8,7 @@ import {
   guardedStreamFrom, pipeSafely, transformSafely,
   readableToString, readableToQuads, readJsonStream, getSingleItem,
 } from '../../../src/util/StreamUtil';
+import { flushPromises } from '../../util/Util';
 
 jest.mock('../../../src/logging/LogUtil', (): any => {
   const logger: Logger = { warn: jest.fn(), log: jest.fn() } as any;
@@ -132,7 +133,7 @@ describe('StreamUtil', (): void => {
 
       piped.destroy(new Error('this causes an unpipe!'));
       // Allow events to propagate
-      await new Promise(setImmediate);
+      await flushPromises();
       expect(input.destroyed).toBe(true);
     });
 
@@ -149,7 +150,7 @@ describe('StreamUtil', (): void => {
 
       piped.destroy(new Error('error!'));
       // Allow events to propagate
-      await new Promise(setImmediate);
+      await flushPromises();
       expect(input.destroyed).toBe(false);
     });
 

test/unit/util/locking/GreedyReadWriteLocker.test.ts

@@ -5,6 +5,7 @@ import { ForbiddenHttpError } from '../../../../src/util/errors/ForbiddenHttpErr
 import { InternalServerError } from '../../../../src/util/errors/InternalServerError';
 import { GreedyReadWriteLocker } from '../../../../src/util/locking/GreedyReadWriteLocker';
 import type { ResourceLocker } from '../../../../src/util/locking/ResourceLocker';
+import { flushPromises } from '../../../util/Util';
 
 // A simple ResourceLocker that keeps a queue of lock requests
 class MemoryLocker implements ResourceLocker {
@@ -86,7 +87,7 @@ describe('A GreedyReadWriteLocker', (): void => {
     }));
 
     // Allow time to attach listeners
-    await new Promise(setImmediate);
+    await flushPromises();
 
     emitter.emit('release2');
     await expect(promises[2]).resolves.toBe(2);
@@ -112,12 +113,12 @@ describe('A GreedyReadWriteLocker', (): void => {
     }));
 
     // Allow time to attach listeners
-    await new Promise(setImmediate);
+    await flushPromises();
 
     emitter.emit('release2');
 
     // Allow time to finish write 2
-    await new Promise(setImmediate);
+    await flushPromises();
 
     emitter.emit('release0');
     emitter.emit('release1');
@@ -140,7 +141,7 @@ describe('A GreedyReadWriteLocker', (): void => {
     }));
 
     // Allow time to attach listeners
-    await new Promise(setImmediate);
+    await flushPromises();
 
     emitter.emit('release1');
     await expect(promises[1]).resolves.toBe(1);
@@ -178,7 +179,7 @@ describe('A GreedyReadWriteLocker', (): void => {
     });
 
     // Allow time to attach listeners
-    await new Promise(setImmediate);
+    await flushPromises();
 
     const promAll = Promise.all([ delayedLockWrite, lockRead ]);
 
@@ -213,7 +214,7 @@ describe('A GreedyReadWriteLocker', (): void => {
     });
 
     // Allow time to attach listeners
-    await new Promise(setImmediate);
+    await flushPromises();
 
     const promAll = Promise.all([ delayedLockWrite, lockRead ]);
 
@@ -260,14 +261,14 @@ describe('A GreedyReadWriteLocker', (): void => {
     });
 
     // Allow time to attach listeners
-    await new Promise(setImmediate);
+    await flushPromises();
 
     const promAll = Promise.all([ delayedLockWrite, lockRead, delayedLockRead2 ]);
 
     emitter.emit('releaseRead1');
 
     // Allow time to finish read 1
-    await new Promise(setImmediate);
+    await flushPromises();
 
     emitter.emit('releaseRead2');
     await promAll;
@@ -302,7 +303,7 @@ describe('A GreedyReadWriteLocker', (): void => {
     });
 
     // Allow time to attach listeners
-    await new Promise(setImmediate);
+    await flushPromises();
 
     const promAll = Promise.all([ delayedLockRead, lockWrite ]);
 

test/util/Util.ts

@@ -44,6 +44,17 @@ export function describeIf(envFlag: string, name: string, fn: () => void): void
   return enabled ? describe(name, fn) : describe.skip(name, fn);
 }
 
+/**
+ * This is needed when you want to wait for all promises to resolve.
+ * Also works when using jest.useFakeTimers().
+ * For more details see the links below
+ *  - https://github.com/facebook/jest/issues/2157
+ *  - https://stackoverflow.com/questions/52177631/jest-timer-and-promise-dont-work-well-settimeout-and-async-function
+ */
+export async function flushPromises(): Promise<void> {
+  return new Promise(jest.requireActual('timers').setImmediate);
+}
+
 /**
  * Mocks (some) functions of the fs system library.
  * It is important that you call `jest.mock('fs');` in your test file before calling this!!!