debugginglisted

<!-- Last updated: 2026-04-08T00:00+11:00 --> # Debugging & Investigation ## 4-Step Framework: Reproduce → Isolate → Fix → Validate - **Never skip to Fix.** Most wrong fixes come from jumping straight to code changes. - **Reproduce:** Run the faulty scenario. Note the exact error and conditions. - **Isolate:** Narrow down the failing component. 80% of bugs live in recently modified code — start there. **Compare against working code.** Find similar functionality that works and diff against the broken code. - **Validate:** Run the full test suite. Confirm the error is gone AND no regressions introduced. ## Validate Before Fixing - **Confirm root cause before proposing code changes.** One hypothesis at a time — test the most likely first. - **Explain root cause in writing** (file path, line number, actual vs expected behavior) before proposing code changes. - **Test means run code, not reason in your head.** Execute a command, write a failing test, or check real output. - **Read the user's evidence first.** Study screenshots/errors before forming hypotheses. The answer is usually visible. - **Add `console.error` to trace actual behavior** when reasoning about what code "should" do isn't working. Reading code is not observing behavior. - **Red flag phrases.** Catch yourself saying "This should work", "Let me just try...", or "Quick fix for now" — stop and re-evaluate. You're guessing. ## Anti-Loop Protocol - **Each attempt MUST use a different diagnosis.** If attempt 1 failed