impact-check

Skill: impact-check

WHAT

Purpose and context

• Purpose: Before modifying any symbol (function, class, variable, config key), map all dependents so no callers blindsided.
• Trigger (when to use):
  • Before editing shared utility, base class, or widely-imported module
  • Before renaming or deleting anything
  • As first step of safe-change or propose
• Non-goals: does not modify code (output only); does not create wiki pages for undocumented symbols (only record gaps).

Mental model

symbol → mọi reference (import · call · đọc output) → Direct / Indirect → test refs tách riêng → báo cáo + wiki gap.

Input and output contract

	Field	Required?	Meaning
In	symbol(s) to change	yes	function, class, variable, config key
Out	reference list	yes	file path, line number, usage, Direct/Indirect label; if zero outside the file, state it clearly
Out	test refs	yes if any	list separately
Out	wiki gap	if any	symbol not yet in wiki/
Out	draft output report	yes (unless 0 artefacts)	llmwiki/wiki/sources/draft/DDMMYY-<ten>.md

Rules and capabilities

• RULE-01 (MUST): Do not modify anything during this skill — output only.
• RULE-02 (MUST): If codebase large, search by symbol name AND file pattern (e.g. all *.ts files).
• RULE-03 (MUST): Do not assume symbol unused because no direct callers — check indirect dependents too.
• Capabilities: read/search the entire codebase (text search or code graph); write draft report + wiki index/log.

Failure boundaries

• Ambiguous symbol (multiple definitions with the same name) → clarify the exact symbol.
• Zero references outside the file → succeeded, state clearly "0 references outside the file".
• Cannot find everything (codebase too large, search error) → partial, record the scope scanned.

HOW

Main workflow

Step	Type	Inputs	Action	Outputs/exit	Failure/next
W01	judgment	change request	Identify the exact symbol	symbol list	ambiguous → clarify
W02	deterministic	symbol	Find all imports/calls/references across the codebase	hits	large → name + file pattern
W03	deterministic	hits	Record file path, line, usage	ref table	—
W04	judgment	ref table	Classify Direct / Indirect	labeled refs	—
W05	deterministic	ref	Report fully, separate test refs, if zero state explicitly	report	—
W06	deterministic	wiki/	Note gap if symbol not yet documented (do not create entry)	gap note	—
W07	effect	result	Output Report draft	draft + index + log	0 artefacts → skip

Step-by-step details (source of truth for W01–W07):

1. Identify exact symbol(s) to change.
2. Search entire codebase for all imports, calls, references to each symbol.
3. For each reference: note file path, line number, how it uses symbol.
4. Classify each reference:
   • Direct — calls or imports symbol itself
   • Indirect — depends on behaviour symbol produces (e.g. reads its output)
5. Report full list. If zero references found outside file, state explicitly.
6. Flag any reference in test file separately — those must update or give false confidence.
7. If symbol not yet documented in wiki/, note as gap — do not create entry now. Wiki entries only written after code committed (see verify-before-commit).

Branches

ID	Kind	Guard	Behaviour	Skip / failure	Rejoin
B01	conditional_required	large codebase	search by symbol name AND file pattern (RULE-02)	—	W03
B02	conditional_required	there are references in test file	list separately, warn must update	none → skip	W06

Validation and stopping

Stop when every hit has path + line + Direct/Indirect label. Do not conclude "unused" just because there is no direct caller (RULE-03). No code file is modified.

Examples

• Positive: changed signature formatDate(d) in src/utils/date.ts → 12 Direct (import) + 2 Indirect (read output string to parse) + 3 test refs listed separately → report + draft DDMMYY-impact-format-date.md.
• Boundary/failure: config key retry_limit has no direct caller but is read via config[key] dynamically → classify as Indirect, do NOT report "unused"; if scan is incomplete, report partial with scope.

Delivery — Output Report

After all main skill tasks complete, write a propose draft to the wiki.

Steps

1. Build the filename:

• Format: DDMMYY-<ten>.md
• DDMMYY = today (e.g., 020626 for 2 June 2026)
• <ten> = 2–4 kebab-case words summarising what was done (e.g., landing-page-coteccons, brand-kit-fintech, ingest-auth-spec)

2. Write llmwiki/wiki/sources/draft/DDMMYY-<ten>.md:

---
type: draft
title: "DDMMYY-<ten>"
status: proposed
tags: [<skill-name>, output-report]
timestamp: YYYY-MM-DD
---

# DDMMYY-<ten>
**Type:** draft
**Status:** proposed
**Tags:** <skill-name>, output-report
**Proposed:** YYYY-MM-DD

## What
<One sentence — what this skill invocation produced or decided>

## Output
<Key artefacts, files created/modified, or decisions made>

## Files
| File | Action |
|------|--------|
| `path/to/file` | created / modified |

## Notes
- Invoked via: `/<skill-name>` skill

## Origin
- **Draft:** `wiki/sources/draft/DDMMYY-<ten>.md`
- **Commit:** _(filled by verify-before-commit)_
- **Date promoted:** _(filled by verify-before-commit)_

3. Update wiki index & log:

• llmwiki/wiki/index.md — append one row: | [DDMMYY-<ten>](sources/draft/DDMMYY-<ten>.md) | draft | YYYY-MM-DD |
• llmwiki/wiki/log.md — append: ## YYYY-MM-DD — <skill-name> — <ten>

Skip only when the skill produces zero artefacts and zero decisions (e.g., a pure display mode like /caveman-stats).