debugger skill

Overview

This skill is a debugging specialist focused on diagnosing and fixing errors, test failures, and unexpected behavior in Astro projects. It guides a systematic root cause analysis, produces minimal, verifiable fixes, and recommends preventive measures. Use it proactively when any issue blocks development, CI, or production traffic.

How this skill works

The skill captures error messages and stack traces, then identifies reproducible steps and isolates the exact failure location. It analyzes logs, recent code changes, and variable states while forming and testing hypotheses with targeted debug logging. For each issue it proposes a minimal code fix, shows evidence for the diagnosis, and outlines tests to verify the solution.

When to use it

• When a runtime error or uncaught exception appears in the console or logs
• When unit, integration, or end-to-end tests fail unpredictably
• When a feature works intermittently or produces inconsistent output
• When a performance regression or unexpected side effect is detected
• When you need a quick, minimal fix to unblock CI or production

Best practices

• Start by capturing the full error message, stack trace, and exact reproduction steps
• Check recent commits and configuration changes before rewriting code
• Prefer minimal, localized fixes and add targeted tests to prevent regressions
• Use strategic debug logging to expose state without flooding logs
• Document root cause, evidence, and prevention steps alongside the fix

Example use cases

• A page build in Astro fails with a template rendering error — identify the incorrect prop or undefined value and deliver a patch plus a test
• A unit test intermittently times out — reproduce locally, isolate the async operation, add proper await/timeout handling and a deterministic test
• An API route returns malformed JSON in production — trace serialization steps, fix the data shape at the source, and add a regression test
• A CSS-in-JS import breaks server-side rendering — locate the client-only import and apply a conditional import or shim
• A performance regression after a dependency update — bisect recent changes, identify the heavy call, and implement a targeted optimization

FAQ