Use timers/promises for promisified setTimeout

Change-type: patch

src/compose/images.ts

@@ -22,6 +22,7 @@ import type { Service } from './service';
 import { strict as assert } from 'assert';
 
 import log from '../lib/supervisor-console';
+import { setTimeout } from 'timers/promises';
 
 interface FetchProgressEvent {
 	percentage: number;
@@ -695,7 +696,7 @@ async function removeImageIfNotNeeded(image: Image): Promise<void> {
 		// that can lead to weird behavior with the error
 		// `(HTTP code 500) server error - unrecognized image ID`.
 		// This random delay tries to prevent that
-		await new Promise((resolve) => setTimeout(resolve, Math.random() * 100));
+		await setTimeout(Math.random() * 100);
 
 		// Remove all matching tags in sequence
 		// as removing in parallel causes some engine weirdness (see above)

src/lib/backoff.ts

@@ -38,7 +38,8 @@ export function withBackoff<T extends (...args: any[]) => any>(
 	// otherwise use the actual return
 	type TReturn = ReturnType<T> extends Promise<infer R> ? R : ReturnType<T>;
 
-	// TODO use standard lib async setTimout (requires node 16)
+	// TODO: use standard lib async setTimeout (Node 16). Tests for backoff will fail
+	// due to Sinon fake timers, so those will need to be redone too.
 	const sleep = promisify(setTimeout);
 
 	const normalizedOptions: Options = {

test/integration/device-state.spec.ts

@@ -13,6 +13,7 @@ import { initializeContractRequirements } from '~/lib/contracts';
 import { testfs } from 'mocha-pod';
 import { createDockerImage } from '~/test-lib/docker-helper';
 import * as Docker from 'dockerode';
+import { setTimeout } from 'timers/promises';
 
 describe('device-state', () => {
 	const docker = new Docker();
@@ -238,7 +239,7 @@ describe('device-state', () => {
 		).to.be.rejected;
 	});
 
-	it('allows triggering applying the target state', (done) => {
+	it('allows triggering applying the target state', async () => {
 		const applyTargetStub = sinon
 			.stub(deviceState, 'applyTarget')
 			.returns(Promise.resolve());
@@ -246,14 +247,12 @@ describe('device-state', () => {
 		deviceState.triggerApplyTarget({ force: true });
 		expect(applyTargetStub).to.not.be.called;
 
-		setTimeout(() => {
-			expect(applyTargetStub).to.be.calledWith({
-				force: true,
-				initial: false,
-			});
-			applyTargetStub.restore();
-			done();
-		}, 1000);
+		await setTimeout(1000);
+		expect(applyTargetStub).to.be.calledWith({
+			force: true,
+			initial: false,
+		});
+		applyTargetStub.restore();
 	});
 
 	it('accepts a target state with an valid contract', async () => {

test/legacy/40-target-state.spec.ts

@@ -4,12 +4,12 @@ import * as _ from 'lodash';
 import rewire = require('rewire');
 import { expect } from 'chai';
 
-import { sleep } from '~/test-lib/helpers';
 import * as TargetState from '~/src/device-state/target-state';
 import Log from '~/lib/supervisor-console';
 import * as request from '~/lib/request';
 import * as deviceConfig from '~/src/device-config';
 import { UpdatesLockedError } from '~/lib/errors';
+import { setTimeout } from 'timers/promises';
 
 const deviceState = rewire('~/src/device-state');
 
@@ -210,7 +210,7 @@ describe('Target state', () => {
 			await TargetState.update(false, false);
 
 			// Wait for interval to tick a few times
-			await sleep(2000); // 2 seconds
+			await setTimeout(2000); // 2 seconds
 
 			// Trigger another update but say it's from the API
 			await TargetState.update(false, true);

test/lib/helpers.ts

@@ -1,6 +0,0 @@
-/**
- * Delays for input ms before resolving
- */
-export async function sleep(ms: number): Promise<void> {
-	return new Promise((resolve) => setTimeout(resolve, ms));
-}