---
name: lint-and-validate
description: "MANDATORY: Run appropriate validation tools after EVERY code change. Do not finish a task until the code is error-free."
risk: unknown
source: community
date_added: "2026-02-27"
---

# Lint and Validate Skill

> **MANDATORY:** Run appropriate validation tools after EVERY code change. Do not finish a task until the code is error-free.

### Procedures by Ecosystem

#### Node.js / TypeScript
1. **Lint/Fix:** `npm run lint` or `npx eslint "path" --fix`
2. **Types:** `npx tsc --noEmit`
3. **Security:** `npm audit --audit-level=high`

#### Python
1. **Linter (Ruff):** `ruff check "path" --fix` (Fast & Modern)
2. **Security (Bandit):** `bandit -r "path" -ll`
3. **Types (MyPy):** `mypy "path"`

## The Quality Loop
1. **Write/Edit Code**
2. **Run Audit:** `npm run lint && npx tsc --noEmit`
3. **Analyze Report:** Check the "FINAL AUDIT REPORT" section.
4. **Fix & Repeat:** Submitting code with "FINAL AUDIT" failures is NOT allowed.

## Error Handling
- If `lint` fails: Fix the style or syntax issues immediately.
- If `tsc` fails: Correct type mismatches before proceeding.
- If no tool is configured: Check the project root for `.eslintrc`, `tsconfig.json`, `pyproject.toml` and suggest creating one.

---
**Strict Rule:** No code should be committed or reported as "done" without passing these checks.

---

## Scripts

| Script | Purpose | Command |
|--------|---------|---------|
| `scripts/lint_runner.py` | Unified lint check | `python scripts/lint_runner.py <project_path>` |
| `scripts/type_coverage.py` | Type coverage analysis | `python scripts/type_coverage.py <project_path>` |

## When to Use
This skill is applicable to execute the workflow or actions described in the overview.

## Limitations
- Use this skill only when the task clearly matches the scope described above.
- Do not treat the output as a substitute for environment-specific validation, testing, or expert review.
- Stop and ask for clarification if required inputs, permissions, safety boundaries, or success criteria are missing.