test-patterns

name	test-patterns
description	Unified testing patterns for Rust: unit testing quality, episodic memory operations, and async/tokio code. Use when writing tests, reviewing test code, or diagnosing test failures.

Test Patterns for Rust Self-Learning Memory

Unified testing patterns covering unit testing quality, episodic memory domain tests, and async/tokio patterns.

Naming Convention

test_<function>_<scenario>_<expected_behavior> (e.g., test_withdraw_valid_amount_decreases_balance)

AAA Pattern

#[tokio::test]
async fn test_save_episode() -> anyhow::Result<()> {
    let memory = create_test_memory().await;    // Arrange
    memory.save_episode(&episode).await?;       // Act
    assert_eq!(retrieved.task_description, "Test");  // Assert
    Ok(())
}

Core Principles

• Single behavior per test, one reason to fail
• Mock external deps (APIs, DBs, filesystem); don't mock value types
• Use do-memory-test-utils for setup

Anti-Patterns

Bad	Fix
Testing std library	Test your code
No assertions	Verify outcomes
Multiple behaviors	Split tests
.unwrap() chains	Use Result<()> with ?

Episodic Memory Testing

State: Created -> InProgress -> Completed/Failed

#[tokio::test]
async fn test_episode_lifecycle() {
    let id = memory.start_episode("Test", ctx, TaskType::CodeGen).await;
    memory.complete_episode(id.clone(), TaskOutcome::Success, None).await?;
    assert_eq!(memory.get_episode(&id).await?.outcome, TaskOutcome::Success);
}

Async/Tokio Patterns

#[tokio::test]                                       // Basic async
#[tokio::test(start_paused = true)]                  // Time control (no real wait)
#[tokio::test(flavor = "multi_thread", worker_threads = 4)]  // Concurrent

Mock Storage

pub struct MockTursoStorage { episodes: Arc<Mutex<Vec<Episode>>> }
#[async_trait]
impl StorageBackend for MockTursoStorage {
    async fn create_episode(&self, episode: &Episode) -> Result<()> { /* ... */ }
}

Async Pitfalls

Bad	Good
std::thread::sleep()	tokio::time::sleep().await
Blocking runtime	spawn_blocking for sync

Pre-Commit Checklist

• Names: test_<function>_<scenario>_<expected>, AAA separation, single behavior
• Dependencies mocked, #[tokio::test] for async, Result<()> with ?

Success Metrics

Deploy without manual testing | Failures pinpoint exact problems | Tests run in milliseconds