map-blast-radius

name

map-blast-radius

description

Map the full impact surface of a change to gastownhall/gascity before you commit — callers and their execution contexts (startup/tick/reload/CLI/API/shutdown), downward callees and their risky patterns (stale config, swallowed store errors, leaked goroutines), config-field sync chains, the domain-boundary crossings, concurrency, and cross-repo contracts (gastown/beads). Self-contained — runs on plain git + grep + gh, no internal tooling. Dual-use — Phase 2 of the plan-implementation skill, and a standalone impact map (scoping a refactor, ad-hoc impact mapping, mapping a change for someone else). Use before committing anything that touches the reconciler, controller, lifecycle, dispatch, config, or any cross-subsystem code.

Map the Blast Radius

You are working on a change to gastownhall/gascity and need to know what it ripples to before you commit. A narrow-looking change can run on a config reload, leak a goroutine in a CLI path, or read stale config — the failures a maintainer's adoption review catches. This skill maps the surface so you catch them first.

Run it from your local checkout. It uses only git, grep, and gh — no special index required. (If you've run codegraph init in the repo, its codegraph_callers / codegraph_impact are faster than grep for caller traces; fall back to grep when it returns nothing or the call is dynamic.)

main below means the upstream main you're targeting — origin/main if origin is gastownhall/gascity, else upstream/main.

Step 1 — Enumerate touched functions

git diff main...HEAD --stat
git diff main...HEAD -- '*.go' | grep '^[+-]func ' | grep -v _test.go