TriggerFactory Cron Expression Detection Fix

Date: 2026-04-14 Issue: #34 Status: Approved

Problem

TriggerFactory::create() uses a fragile heuristic to detect cron expressions:

is_string($expression) && count(explode(' ', $expression)) === 5 && str_contains($expression, '*')

This fails for valid cron expressions without asterisks, such as 0 0 1 1 1 (January 1st at midnight, on Monday).

Solution

Replace the fragile heuristic with CronExpression::isValidExpression() from the dragonmantank/cron-expression library, which is already a dependency.

Changes

File: src/Scheduler/Trigger/TriggerFactory.php

1. Add import: use Cron\CronExpression;
2. Replace lines 39-40 with single condition:

   is_string($expression) && CronExpression::isValidExpression($expression) => new CronExpressionTrigger($expression),
   

The str_starts_with($expression, '@') check is no longer needed because CronExpression::isValidExpression() handles alias expressions (@daily, @hourly, etc.).

Test Updates

File: tests/TriggerFactoryTest.php

1. Add test case 0 0 1 1 1 to cronExpressionProvider
2. Update testFivePartNonCronExpressionThrowsException - remove or adjust since 1 2 3 4 5 is now considered a valid cron expression by the library (which is correct - it's a valid cron expression for 1:02:03 on April 5th)

Verification

Run existing tests to ensure no regressions:

./vendor/bin/phpunit tests/TriggerFactoryTest.php