Fixing some issues with the cron job waiting until 7 and adding a unit test for it

src/reservations/cron.ts

@@ -1,6 +1,7 @@
 import { InjectQueue } from '@nestjs/bull'
 import { Inject, Injectable } from '@nestjs/common'
 import { Cron, CronExpression } from '@nestjs/schedule'
+import { Dayjs } from 'dayjs'
 
 import dayjs from '../common/dayjs'
 import { LoggerService } from '../logger/service.logger'
@@ -30,6 +31,19 @@ export class ReservationsCronService {
 		private readonly loggerService: LoggerService,
 	) {}
 
+	private async sleepUntil(time: Dayjs) {
+		let keepSleeping = true
+
+		while (keepSleeping) {
+			const now = dayjs()
+			keepSleeping = !time.isBefore(now)
+			if (!keepSleeping) break
+			await new Promise((res) => {
+				setTimeout(() => res(null), 50)
+			})
+		}
+	}
+
 	@Cron('55 06 * * *', {
 		name: 'handleDailyReservations',
 		timeZone: 'Europe/Amsterdam',
@@ -48,19 +62,13 @@ export class ReservationsCronService {
 
 			this.loggerService.log(`Warmed up! Waiting for go-time`)
 
-			let not7AM = true
-			const waitTime = 10
-			const time7AM = dayjs()
-				.set('hour', 7)
-				.set('minute', 0)
-				.set('second', 0)
-				.set('millisecond', 0)
-
-			while (not7AM) {
-				not7AM = !time7AM.isBefore(dayjs()) && time7AM.diff(dayjs()) >= waitTime // current time is more than 100ms from 7am
-				if (!not7AM) break
-				await new Promise((res) => setTimeout(res, waitTime)) // wait for waitTime and then try again
-			}
+			await this.sleepUntil(
+				dayjs()
+					.set('hour', 7)
+					.set('minute', 0)
+					.set('second', 0)
+					.set('millisecond', 0),
+			)
 
 			this.loggerService.log(`It's go-time`)
 

test/unit/reservations/cron.spec.ts

@@ -0,0 +1,121 @@
+import { ConfigModule } from '@nestjs/config'
+import { Test, TestingModule } from '@nestjs/testing'
+import { TypeOrmModule } from '@nestjs/typeorm'
+
+import { LoggerModule } from '../../../src/logger/module'
+import { LoggerService } from '../../../src/logger/service.logger'
+import { NtfyModule } from '../../../src/ntfy/module'
+import { NtfyProvider } from '../../../src/ntfy/provider'
+import { ReservationsCronService } from '../../../src/reservations/cron'
+import { Reservation } from '../../../src/reservations/entity'
+import { ReservationsModule } from '../../../src/reservations/module'
+import { ReservationsService } from '../../../src/reservations/service'
+import { BaanReserverenService } from '../../../src/runner/baanreserveren/service'
+import { RunnerModule } from '../../../src/runner/module'
+
+describe('reservations.cron', () => {
+	let module: TestingModule
+	let cronService: ReservationsCronService
+
+	beforeAll(async () => {
+		module = await Test.createTestingModule({
+			imports: [
+				ReservationsModule,
+				RunnerModule,
+				NtfyModule,
+				LoggerModule,
+				ConfigModule.forRoot({ isGlobal: true }),
+				TypeOrmModule.forRoot({
+					type: 'sqlite',
+					database: ':memory:',
+					entities: [Reservation],
+				}),
+			],
+		}).compile()
+
+		cronService = module.get<ReservationsCronService>(ReservationsCronService)
+	})
+
+	afterAll(async () => {
+		await module.close()
+	})
+
+	describe('handleDailyReservations', () => {
+		beforeEach(() => {
+			jest.spyOn(
+				module.get<NtfyProvider>(NtfyProvider),
+				'sendCronStartNotification',
+			)
+			jest.spyOn(
+				module.get<NtfyProvider>(NtfyProvider),
+				'sendCronStopNotification',
+			)
+		})
+
+		describe('has scheduleable reservations', () => {
+			const stubbedReservation = { id: 'abc-123' }
+			let warmupSpy: jest.SpyInstance
+			let performReservationSpy: jest.SpyInstance
+			let loggerSpy: jest.SpyInstance
+			const loggerInvocationDates: { msg: string; timestamp: Date }[] = []
+
+			beforeAll(async () => {
+				jest
+					.spyOn(
+						module.get<ReservationsService>(ReservationsService),
+						'getSchedulable',
+					)
+					// @ts-expect-error stubbed reservation
+					.mockResolvedValue([stubbedReservation])
+
+				warmupSpy = jest
+					.spyOn(
+						module.get<BaanReserverenService>(BaanReserverenService),
+						'warmup',
+					)
+					.mockReturnValue(new Promise((res) => setTimeout(res, 1000)))
+
+				performReservationSpy = jest
+					.spyOn(
+						module.get<BaanReserverenService>(BaanReserverenService),
+						'performReservation',
+					)
+					.mockResolvedValue()
+
+				loggerSpy = jest
+					.spyOn(module.get<LoggerService>(LoggerService), 'log')
+					.mockImplementation((msg: string) => {
+						loggerInvocationDates.push({ msg, timestamp: new Date() })
+					})
+
+				jest
+					.useFakeTimers({ advanceTimers: true })
+					.setSystemTime(new Date('2024-01-01T06:59:58.050+01:00'))
+
+				await cronService.handleDailyReservations()
+			})
+
+			afterAll(() => {
+				jest.useRealTimers()
+			})
+
+			it('should perform warmup', () => {
+				expect(warmupSpy).toHaveBeenCalledTimes(1)
+			})
+
+			it('should wait until 7am', () => {
+				expect(loggerSpy).toHaveBeenCalledTimes(5)
+				const { timestamp: goTimeInvocation } =
+					loggerInvocationDates.find(({ msg }) => msg === `It's go-time`) ?? {}
+				expect(goTimeInvocation).toBeDefined()
+				expect(goTimeInvocation?.getHours()).toEqual(7)
+				expect(goTimeInvocation?.getSeconds()).toEqual(0)
+				expect(goTimeInvocation?.getMilliseconds()).toBeLessThanOrEqual(100)
+			})
+
+			it('should perform reservations', () => {
+				expect(performReservationSpy).toHaveBeenCalledWith(stubbedReservation)
+			})
+		})
+	})
+})