@penkov/tasks_queue/dist/cron-expression-utils.js

A lightweight PostgreSQL-backed task queue system with scheduling, retries, backoff strategies, and priority handling. Designed for efficiency and observability in modern Node.js applications.

import { option } from "scats";
import { CronExpressionParser } from "cron-parser";
export class CronExpressionUtils {
    static DEFAULT_TIMEZONE = "UTC";
    static validate(expression, timezone = CronExpressionUtils.DEFAULT_TIMEZONE) {
        this.nextExecutionDate(expression, new Date(), timezone);
    }
    static nextExecutionDate(expression, baseDate, timezone = CronExpressionUtils.DEFAULT_TIMEZONE) {
        const normalizedExpression = expression.trim();
        if (normalizedExpression.length === 0) {
            throw new Error("Cron expression must not be blank");
        }
        try {
            const parsed = CronExpressionParser.parse(normalizedExpression, {
                currentDate: baseDate,
                tz: option(timezone).filter((s) => s.trim().length > 0).orUndefined,
            });
            return parsed.next().toDate();
        }
        catch (e) {
            throw new Error(`Invalid cron expression '${normalizedExpression}': ${e.message}`);
        }
    }
}