investigate

Investigate

Trace bugs to their root cause and assess the safety of proposed changes.

Debugging Workflow

1. Search for the symptom -- search("TypeError in payment processing")
2. Inspect suspects -- search("processPayment") for full context
3. Follow execution flow -- Check callers/callees and process steps
4. Trace dependencies -- trace_dependencies(target="processPayment", dependents=true)
5. Correlate with changes -- diff_analysis(diff_spec="HEAD~5..HEAD")

Safety Analysis Workflow

1. Trace what depends on the target:

   trace_dependencies(target="UserModel", dependents=true)
   

2. Review depth groups:

   • Depth 1 -- Direct dependents, most likely to break
   • Depth 2 -- Second-order, may need testing
   • Depth 3+ -- Transitive, monitor for surprises

3. Assess risk level (weighted formula: dependents + processes x 8):

   Risk	Score	Action
   CRITICAL	>= 40	Phased rollout, comprehensive testing
   HIGH	>= 20	Thorough review, dedicated test pass
   MEDIUM	>= 8	Standard review, verify affected paths
   LOW	< 8	Normal review process

4. Check both directions for major refactors:

   trace_dependencies(target="UserModel", dependents=true, dependencies=true)
   

Debugging Patterns

Pattern	Strategy
Null reference	search for the field, check assignments via context
Wrong output	Follow process trace through data transforms
Import error	Check IMPORTS edges in symbol context
Race condition	trace_dependencies to find concurrent accessors
Regression	diff_analysis to correlate with recent changes

Tips

• Confidence decays by depth (0.9x per level) -- deeper = less certain
• High process count is often more concerning than high dependent count
• Use explore_structure to see if a change crosses module boundaries
• EXTENDS and IMPLEMENTS edges represent contracts -- breaking these is high risk