dx-swe-debugging

Follow a four-phase process: investigate the root cause by reading errors and reproducing the issue, analyze patterns against working examples, form and test a single hypothesis, then implement one verified fix. Never propose fixes before completing the investigation phase.

Replace arbitrary setTimeout or sleep delays with condition-based waiting that polls for the actual expected state, such as waiting for a specific event or count. This eliminates timing guesses that pass on fast machines but fail under load.

Stop and return to root cause investigation with the new information rather than stacking more fixes. If three or more fixes have failed, treat it as an architectural problem and discuss the fundamental design before attempting further changes.

Trace backward from the error location through each caller, checking what values were passed at each level until you find the original trigger. Add stack trace instrumentation with console.error before the failing operation if manual tracing is insufficient.

The methodology states it is never acceptable, including during production emergencies. Systematic investigation is faster than guess-and-check thrashing, and quick symptom patches typically create new bugs and require rework.

Use the included find-polluter.sh bisection script, which runs test files one by one and checks whether the unwanted file or directory appears after each run. It stops and reports the first test that creates the pollution.