Quality Check Skill

Purpose

Unified code quality validation across Python, JavaScript/TypeScript, Shell, and SQL. Runs formatting checks, linting, type checking, and complexity analysis.

Quick Start

# Auto-detect language and run appropriate checks
/quality-check [path]

Language Detection

The skill auto-detects language based on file extensions:

• .py -> Python tools
• .js, .ts, .tsx, .jsx -> JavaScript/TypeScript tools
• .sh, .bash -> Shell tools
• .sql -> SQL validation

Tool Matrix

Language	Formatter	Linter	Type Check	Complexity
Python	ruff format	ruff check	mypy	radon cc
JS/TS	prettier	eslint	tsc	eslint complexity
Shell	shfmt	shellcheck	-	-
SQL	-	sqlfluff	-	-
Swift	-	swiftlint	swift build	-
Go	gofmt	golint	go vet	-
Rust	rustfmt	clippy	-	-

Commands by Language

Python

# Format check (replaces black + isort)
ruff format --check src/ tests/

# Lint
ruff check src/ tests/

# Type check
mypy src/

# Complexity (functions with cc > 10)
radon cc src/ -nc

JavaScript/TypeScript

# Format check
npx prettier --check "src/**/*.{ts,tsx,js,jsx}"

# Lint
npx eslint "src/**/*.{ts,tsx}"

# Type check
npx tsc --noEmit

# Dependency audit
npm audit --production

Shell

# Lint
shellcheck scripts/*.sh

# Format check (if shfmt installed)
shfmt -d scripts/*.sh

SQL

# Lint (if sqlfluff installed)
sqlfluff lint queries/

Swift

# Lint
swiftlint

# Build check (type checking)
swift build

Go

# Format check
gofmt -d .

# Lint
golint ./...

# Vet (static analysis)
go vet ./...

Rust

# Format check
cargo fmt --check

# Lint
cargo clippy -- -D warnings

Quality Standards

All Languages

Metric	Threshold
File size	< 500 lines
Function size	< 50 lines
Complexity	< 10 per function
Nesting depth	< 4 levels

Python-Specific

• Type hints on all functions
• Google-style docstrings on public API
• No bare except: clauses
• No mutable default arguments

TypeScript-Specific

• Strict mode enabled
• Explicit return types
• No any types (except justified)
• No unused variables

Output Format

# Quality Report

**Status**: PASS/FAIL
**Files Checked**: N
**Language**: Python/TypeScript/Mixed

## Results

| Check      | Status | Issues           |
| ---------- | ------ | ---------------- |
| Format     | PASS   | 0                |
| Lint       | PASS   | 0                |
| Types      | PASS   | 0                |
| Complexity | WARN   | 2 functions > 10 |

## Issues Found

### Critical

[None or list]

### Warnings

- `src/utils.py:45` - complexity 12 (function `process_data`)

## Auto-fix Available

Run: `ruff format src/ && ruff check --fix src/`

Integration

This skill is called by /pre-commit as part of the full validation suite.

Troubleshooting

Tool Not Found

# Python
pip install ruff mypy radon

# JS/TS
npm install -D prettier eslint typescript

# Shell
brew install shellcheck shfmt  # macOS
apt install shellcheck shfmt   # Ubuntu

Too Many Errors

Focus on one category at a time:

1. Fix formatting first (auto-fixable)
2. Then linting (many auto-fixable)
3. Then type errors (manual)
4. Complexity last (refactoring)