gitnexus-impact-analysis_skill

Overview

This skill performs pre-change safety and blast-radius analysis so you know what will break before editing code. It maps symbol dependencies, execution processes, and current git diffs to produce a concise risk assessment and prioritized list of affected callers. Use it to make informed, low-risk edits and to prepare tests or rollback plans.

How this skill works

The skill queries a dependency index to find upstream dependents of a target symbol and classifies them by depth (d=1 WILL BREAK, d=2 LIKELY AFFECTED, d=3 MAY NEED TESTING). It can also read process manifests to locate affected runtime flows and run a git-diff based detector to map current staged or working changes to impacted symbols. Results are summarized as a risk level with counts and concrete file:line callers.

When to use it

• Before changing a function, API, or config to check impact
• Prior to committing non-trivial code edits
• When you need to know who or what uses a symbol
• To estimate test and rollout scope for a change
• To prioritize fixes when multiple areas are affected

Best practices

• Run impact analysis with direction='upstream' to find callers first
• Review d=1 items immediately — these are direct breakage risks
• Set minConfidence to filter noisy transitive links (e.g., 0.8)
• Combine gitnexus_detect_changes() with staged diffs for pre-commit checks
• Inspect process manifests to understand runtime/critical-path effects

Example use cases

• Is it safe to change validateUser? — find direct callers, affected flows, and risk level
• What will break if I rename this exported symbol? — list d=1 callers and files to update
• Pre-commit safety check — map staged changes to processes and get a MEDIUM/HIGH risk flag
• Assess blast radius for a config change in auth or payments — identify critical-path processes