# roo-rules.md

Behavioral guidelines to reduce common LLM coding mistakes. Merge with project-specific instructions as needed.

**Tradeoff:** These guidelines bias toward caution over speed. For trivial tasks, use judgment.

## 1. Think Before Coding

**Don't assume. Don't hide confusion. Surface tradeoffs.**

Before implementing:
- State your assumptions explicitly. If uncertain, ask.
- If multiple interpretations exist, present them - don't pick silently.
- If a simpler approach exists, say so. Push back when warranted.
- If something is unclear, stop. Name what's confusing. Ask.

## 2. Simplicity First

**Minimum code that solves the problem. Nothing speculative.**

- No features beyond what was asked.
- No abstractions for single-use code.
- No "flexibility" or "configurability" that wasn't requested.
- No error handling for impossible scenarios.
- If you write 200 lines and it could be 50, rewrite it.

Ask yourself: "Would a senior engineer say this is overcomplicated?" If yes, simplify.

## 3. Surgical Changes

**Touch only what you must. Clean up only your own mess.**

When editing existing code:
- Don't "improve" adjacent code, comments, or formatting.
- Don't refactor things that aren't broken.
- Match existing style, even if you'd do it differently.
- If you notice unrelated dead code, mention it - don't delete it.

When your changes create orphans:
- Remove imports/variables/functions that YOUR changes made unused.
- Don't remove pre-existing dead code unless asked.

The test: Every changed line should trace directly to the user's request.

## 4. Goal-Driven Execution

**Define success criteria. Loop until verified.**

Transform tasks into verifiable goals:
- "Add validation" → "Write tests for invalid inputs, then make them pass"
- "Fix the bug" → "Write a test that reproduces it, then make it pass"
- "Refactor X" → "Ensure tests pass before and after"

For multi-step tasks, state a brief plan:
```
1. [Step] → verify: [check]
2. [Step] → verify: [check]
3. [Step] → verify: [check]
```

Strong success criteria let you loop independently. Weak criteria ("make it work") require constant clarification.

## 5. Save the token & time - Roo code must keep this rule not API
- "Do not summarize the code or changes after completing a task"
- "Once the code is written, do not repeat the explanation"
- "Only output the final file content if necessary"

## 6. Backup + Diff Before Edit

**기존 파일을 수정하기 전에 반드시 다음 두 단계를 수행할 것.**

### Step 1 — 백업
수정 대상 파일을 `.rooBackup/` 폴더에 현재날짜와 시간으로 폴더를 만들고 그 폴더에 수정전 원본 그대로 저장한다.

- 저장 경로: `.rooBackup/<날짜-시간>/<원본경로>/<파일명>`
- 예: `src/Web/wwwroot/js/app.js` → `.rooBackup/src/Web/wwwroot/js/app.js`
- 백업 후 "백업 완료: `.rooBackup/...`" 를 출력할 것

### Step 2 — Diff 제시
변경 내용을 diff 형식으로 보여주고, 사용자 확인 후 실제 수정 진행.

```diff
- 기존 코드
+ 변경된 코드
```

변경 이유를 한 줄로 함께 설명할 것.

### 예외 (백업/diff 생략 가능)
- 신규 파일 생성
- 공백/포맷팅만 바뀌는 경우

**위반 사례 (금지):** 백업·diff 없이 바로 파일을 덮어쓰는 것 — roo가 이전에 fastRecord 섹션 전체를 날린 것이 이 케이스에 해당.

---

**These guidelines are working if:** fewer unnecessary changes in diffs, fewer rewrites due to overcomplication, and clarifying questions come before implementation rather than after mistakes.