gitnexus-debugging

# Debugging with GitNexus ## When to Use - "Why is this function failing?" - "Trace where this error comes from" - "Who calls this method?" - "This endpoint returns 500" - Investigating bugs, errors, or unexpected behavior ## Workflow ``` 1. gitnexus_query({query: "<error or symptom>"}) → Find related execution flows 2. gitnexus_context({name: "<suspect>"}) → See callers/callees/processes 3. READ gitnexus://repo/{name}/process/{name} → Trace execution flow 4. gitnexus_cypher({query: "MATCH path..."}) → Custom traces if needed ``` > If "Index is stale" → run `npx gitnexus analyze` in terminal. ## Checklist ``` - [ ] Understand the symptom (error message, unexpected behavior) - [ ] gitnexus_query for error text or related code - [ ] Identify the suspect function from returned processes - [ ] gitnexus_context to see callers and callees - [ ] Trace execution flow via process resource if applicable - [ ] gitnexus_cypher for custom call chain traces if needed - [ ] Read source files to confirm root cause ``` ## Debugging Patterns | Symptom | GitNexus Approach | |---------|-------------------| | Error message | `gitnexus_query` for error text → `context` on throw sites | | Wrong return value | `context` on the function → trace callees for data flow | | Intermittent failure | `context` → look for external calls, async deps | | Performance issue | `context` → find symbols with many callers (hot paths) | | Recent regression | `detect_changes` to see what your changes affect | ## Tools **gitnexus_query** — find code related to error: ``` gitnexus_query({query: "payment validation error"}) → Processes: CheckoutFlow, ErrorHandling → Symbols: validatePayment, handlePaymentError, PaymentException ``` **gitnexus_context** — full context for a suspect: ``` gitnexus_context({name: "validatePayment"}) → Incoming calls: processCheckout, webhookHandler → Outgoing calls: verifyCard, fetchRates (external API!) → Processes: CheckoutFlow (step 3/7) ``` **gitnexus_cypher** — custom call chain traces: ```cypher MATCH path = (a)-[:CodeRelation {type: 'CALLS'}*1..2]->(b:Function {name: "validatePayment"}) RETURN [n IN nodes(path) | n.name] AS chain ``` ## Example: "Payment endpoint returns 500 intermittently" ``` 1. gitnexus_query({query: "payment error handling"}) → Processes: CheckoutFlow, ErrorHandling → Symbols: validatePayment, handlePaymentError 2. gitnexus_context({name: "validatePayment"}) → Outgoing calls: verifyCard, fetchRates (external API!) 3. READ gitnexus://repo/my-app/process/CheckoutFlow → Step 3: validatePayment → calls fetchRates (external) 4. Root cause: fetchRates calls external API without proper timeout ```