Test Fix

Systematic approach to diagnosing and fixing failing tests.

Process

Step 1: Identify Failing Tests

cargo test --all cargo test test_name -- --exact --nocapture

Step 2: Reproduce Locally

With debug logging

RUST_LOG=debug cargo test test_name

Force single-threaded for race conditions

cargo test test_name -- --test-threads=1

Step 3: Diagnose Root Cause

Pattern Symptom Fix

Async/Await "future cannot be sent" Add .await , use Arc

Database "connection refused" Check env vars, use test DB

Race Intermittent assertion failure Add Mutex, sequential execution

Type "expected X, found Y" Update signatures, add conversions

Lifetime "borrowed value" Clone data, adjust lifetimes

Step 4: Verify Fix

Run multiple times

for i in {1..10}; do cargo test test_name -- --exact || break; done

Run full suite

cargo test --all

Step 5: Regression Prevention

Add test for the specific bug that was fixed.

Debugging Checklist

• Run failing test in isolation

• Check environment variables

• Review recent changes

• Check for missing .await

• Verify database connections

• Look for race conditions

• Check type compatibility

Tools

Debug logging

RUST_LOG=debug cargo test

Full backtrace

RUST_BACKTRACE=full cargo test

Specific module

RUST_LOG=memory_core=debug cargo test

When to Skip vs Fix

Skip (temporarily):

• External service down

• Platform-specific issue

• Known upstream bug

Fix immediately:

• Logic error

• Incorrect assertion

• Missing error handling