TypeScript Scheduler with node-schedule

// First install the required packages: // npm install node-schedule @types/node-schedule import * as schedule from 'node-schedule'; import { Job } from 'node-schedule'; interface TaskConfig { name: string; schedule: string | Date; task: () => Promise<void> | void; enabled?: boolean; } class TaskScheduler { private jobs: Map<string, Job> = new Map(); /** * Schedule a task with cron-like syntax or specific date * @param config Task configuration * @returns Job instance */ scheduleTask(config: TaskConfig): Job | null { if (!config.enabled && config.enabled !== undefined) { console.log(`Task ${config.name} is disabled, skipping...`); return null; } try { const job = schedule.scheduleJob(config.name, config.schedule, async () => { console.log(`[${new Date().toISOString()}] Executing task: ${config.name}`); try { await config.task(); console.log(`[${new Date().toISOString()}] Task completed: ${config.name}`); } catch (error) { console.error(`[${new Date().toISOString()}] Task failed: ${config.name}`, error); } }); if (job) { this.jobs.set(config.name, job); console.log(`Task scheduled: ${config.name} - Next run: ${job.nextInvocation()}`); } return job; } catch (error) { console.error(`Failed to schedule task: ${config.name}`, error); return null; } } /** * Schedule multiple tasks at once * @param configs Array of task configurations */ scheduleTasks(configs: TaskConfig[]): void { configs.forEach(config => this.scheduleTask(config)); } /** * Cancel a specific task * @param taskName Name of the task to cancel */ cancelTask(taskName: string): boolean { const job = this.jobs.get(taskName); if (job) { job.cancel(); this.jobs.delete(taskName); console.log(`Task cancelled: ${taskName}`); return true; } console.warn(`Task not found: ${taskName}`); return false; } /** * Cancel all scheduled tasks */ cancelAllTasks(): void { this.jobs.forEach((job, name) => { job.cancel(); console.log(`Task cancelled: ${name}`); }); this.jobs.clear(); } /** * Get information about all scheduled tasks */ getTasksInfo(): Array<{name: string, nextRun: Date | null}> { const tasksInfo: Array<{name: string, nextRun: Date | null}> = []; this.jobs.forEach((job, name) => { tasksInfo.push({ name, nextRun: job.nextInvocation() }); }); return tasksInfo; } /** * Reschedule an existing task * @param taskName Name of the task to reschedule * @param newSchedule New schedule (cron or date) */ rescheduleTask(taskName: string, newSchedule: string | Date): boolean { const job = this.jobs.get(taskName); if (job) { const success = job.reschedule(newSchedule); if (success) { console.log(`Task rescheduled: ${taskName} - Next run: ${job.nextInvocation()}`); } return success; } console.warn(`Task not found: ${taskName}`); return false; } /** * Graceful shutdown - cancel all jobs */ shutdown(): void { console.log('Shutting down scheduler...'); this.cancelAllTasks(); schedule.gracefulShutdown(); } } 

* * * * * * ┬ ┬ ┬ ┬ ┬ ┬ │ │ │ │ │ │ │ │ │ │ │ └ day of week (0 - 7) (0 or 7 is Sun) │ │ │ │ └───── month (1 - 12) │ │ │ └────────── day of month (1 - 31) │ │ └─────────────── hour (0 - 23) │ └──────────────────── minute (0 - 59) └───────────────────────── second (0 - 59, optional) 

 // Example usage const scheduler = new TaskScheduler(); // Example tasks const exampleTasks: TaskConfig[] = [ { name: 'daily-report', schedule: '0 9 * * *', // Every day at 9:00 AM task: async () => { console.log('Generating daily report...'); // Simulate async work await new Promise(resolve => setTimeout(resolve, 1000)); console.log('Daily report generated successfully'); }, enabled: true }, { name: 'database-cleanup', schedule: '0 2 * * 0', // Every Sunday at 2:00 AM task: async () => { console.log('Starting database cleanup...'); // Database cleanup logic here await new Promise(resolve => setTimeout(resolve, 2000)); console.log('Database cleanup completed'); }, enabled: true }, { name: 'health-check', schedule: '*/5 * * * *', // Every 5 minutes task: () => { console.log('Performing health check...'); // Health check logic here console.log('Health check passed'); }, enabled: true }, { name: 'monthly-summary', schedule: '0 0 1 * *', // First day of every month at midnight task: async () => { console.log('Generating monthly summary...'); await new Promise(resolve => setTimeout(resolve, 1500)); console.log('Monthly summary generated'); }, enabled: false // Disabled for this example }, { name: 'one-time-task', schedule: new Date(Date.now() + 10000), // Run once in 10 seconds task: () => { console.log('Executing one-time task...'); }, enabled: true } ]; // Schedule all tasks scheduler.scheduleTasks(exampleTasks); // Display scheduled tasks info console.log('\n=== Scheduled Tasks ==='); const tasksInfo = scheduler.getTasksInfo(); tasksInfo.forEach(task => { console.log(`${task.name}: Next run at ${task.nextRun}`); }); // Example of rescheduling a task after 30 seconds setTimeout(() => { console.log('\n=== Rescheduling health-check task ==='); scheduler.rescheduleTask('health-check', '*/10 * * * *'); // Change to every 10 minutes }, 30000); // Example of cancelling a specific task after 1 minute setTimeout(() => { console.log('\n=== Cancelling one-time-task ==='); scheduler.cancelTask('one-time-task'); }, 60000); // Graceful shutdown on process termination process.on('SIGINT', () => { console.log('\nReceived SIGINT, shutting down gracefully...'); scheduler.shutdown(); process.exit(0); }); process.on('SIGTERM', () => { console.log('\nReceived SIGTERM, shutting down gracefully...'); scheduler.shutdown(); process.exit(0); }); // Advanced scheduling examples: // Schedule with RecurrenceRule for more complex patterns const complexRule = new schedule.RecurrenceRule(); complexRule.dayOfWeek = [1, 3, 5]; // Monday, Wednesday, Friday complexRule.hour = 14; // 2 PM complexRule.minute = 30; // 30 minutes past the hour scheduler.scheduleTask({ name: 'weekday-notification', schedule: complexRule, task: () => { console.log('Weekday notification sent!'); }, enabled: true }); // Schedule for specific dates const specificDates = [ new Date(2024, 11, 25, 10, 0, 0), // Christmas Day 2024, 10:00 AM new Date(2025, 0, 1, 0, 0, 0), // New Year 2025, midnight ]; specificDates.forEach((date, index) => { scheduler.scheduleTask({ name: `holiday-task-${index + 1}`, schedule: date, task: () => { console.log(`Holiday task executed at ${date}`); }, enabled: true }); }); console.log('\nScheduler is running. Press Ctrl+C to exit.'); // Export the scheduler for use in other modules export { TaskScheduler, TaskConfig };