Unit Testing @Scheduled and @Async Methods

Overview

Patterns for unit testing Spring @Scheduled and @Async methods with JUnit 5. Test CompletableFuture results, use Awaitility for race conditions, mock scheduled task execution, and validate error handling — without waiting for real scheduling intervals.

When to Use

• Testing @Scheduled method logic
• Testing @Async method behavior
• Verifying CompletableFuture results
• Testing async error handling
• Testing cron expression logic without waiting for actual scheduling
• Validating thread pool behavior and execution counts
• Testing background task logic in isolation

Instructions

1. Call @Async methods directly — bypass Spring's async proxy; the annotation is irrelevant in unit tests