Debugging

Execution Workflow

1. Reproduce the issue with the smallest possible app, route, or test case.
2. Identify the failing layer first: requests, routing, dependency injection, middleware, auth, responses, exception handling, or lifecycle.
3. Turn on only the minimum safe diagnostics needed: local debug=True, focused logs, or temporary assertions.
4. Inspect the boundary where the behavior diverges from expectation.
5. Fix the root cause, remove temporary diagnostics, and add a regression test.
6. Re-run the affected tests and re-check the surrounding contract for regressions.

Core Rules

• Keep debug=True local-only.
• Prefer deterministic logs, assertions, and focused reproduction apps over ad hoc print debugging.
• Narrow the failing layer before changing code.
• Use request and app loggers for evidence, not speculation.
• Keep debug output free of secrets and sensitive payloads.
• Remove temporary diagnostics once the root cause is understood.
• Always codify the fix with a regression test when feasible.

Decision Guide

• Use a tiny repro app when the existing app is too large to reason about quickly.
• Use litestar-testing clients when the bug is observable through the HTTP or websocket contract.
• Use litestar-logging when the main gap is missing evidence rather than a code defect.
• Use debug=True only when local traceback detail materially shortens the investigation.
• Hand off to the more specific Litestar skill once the failing subsystem is clear.

Reference Files

Read only the sections you need:

• For reproduction strategy, layer isolation, and temporary diagnostic tactics, read references/reproduction-and-isolation.md.
• For common subsystem debugging patterns across requests, auth, responses, exceptions, and lifecycle, read references/subsystem-patterns.md.

Recommended Defaults

• Reproduce with the smallest route and the smallest input that still fails.
• Keep one hypothesis at a time and test it quickly.
• Add evidence before changing behavior.
• Use logs to compare expected and actual values at subsystem boundaries.
• Convert the repro into a stable test once the bug is found.

Anti-Patterns

• Leaving debug=True or verbose diagnostics enabled after the fix.
• Changing several subsystems at once before isolating the failure.
• Catching broad exceptions to hide symptoms instead of understanding them.
• Assuming a request, auth, or response bug without reproducing the exact contract.
• Logging secrets, tokens, or raw sensitive request bodies during debugging.

Validation Checklist

• Confirm the issue reproduces before the fix and stops reproducing after it.
• Confirm both happy-path and failure-path contracts still behave correctly.
• Confirm no sensitive values are leaked by temporary or permanent diagnostics.
• Confirm the regression test fails before the fix and passes after it.
• Confirm temporary debugging code is removed.

Cross-Skill Handoffs

• Use litestar-logging when better evidence collection is the main need.
• Use litestar-testing to codify the repro and lock the fix.
• Use litestar-requests, litestar-responses, litestar-exception-handling, or litestar-authentication once the failing boundary is known.
• Use litestar-metrics only after the runtime bug is understood and ongoing visibility is needed.

Litestar References

• https://docs.litestar.dev/latest/usage/debugging.html
• https://docs.litestar.dev/latest/usage/testing.html