Code Formatter & Linter Installer

Establish consistent code formatting and linting across your project.

Core Workflow

1. Detect stack: Identify language/framework (JS/TS, Python, Go, Rust)
2. Choose tools: Select appropriate formatters and linters
3. Generate configs: Create config files with best-practice rules
4. Add scripts: Include npm/package scripts for format/lint
5. Configure editor: Provide VS Code, IntelliJ, Vim settings
6. Setup pre-commit: Add git hooks for automatic formatting
7. CI integration: Suggest GitHub Actions or CI config

Tool Selection by Stack

JavaScript/TypeScript

• Formatter: Prettier
• Linter: ESLint + typescript-eslint
• Editor: EditorConfig
• Hooks: Husky + lint-staged

Python

• Formatter: Black + isort
• Linter: Ruff or Flake8 + mypy
• Hooks: pre-commit

Go

• Formatter: gofmt + goimports
• Linter: golangci-lint

Rust

• Formatter: rustfmt
• Linter: clippy

Configuration Templates

Prettier (.prettierrc.json)

{
  "semi": true,
  "trailingComma": "es5",
  "singleQuote": true,
  "printWidth": 100,
  "tabWidth": 2,
  "arrowParens": "avoid"
}

ESLint (.eslintrc.json)

{
  "extends": [
    "eslint:recommended",
    "plugin:@typescript-eslint/recommended",
    "plugin:react/recommended",
    "prettier"
  ],
  "rules": {
    "no-console": "warn",
    "@typescript-eslint/no-unused-vars": "error"
  }
}

EditorConfig (.editorconfig)

root = true

[*]
indent_style = space
indent_size = 2
end_of_line = lf
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true

[*.py]
indent_size = 4

[*.md]
trim_trailing_whitespace = false

Python (pyproject.toml)

[tool.black]
line-length = 100
target-version = ['py311']

[tool.isort]
profile = "black"
line_length = 100

[tool.mypy]
strict = true
warn_return_any = true

Package Scripts

JavaScript/TypeScript (package.json)

{
  "scripts": {
    "format": "prettier --write .",
    "format:check": "prettier --check .",
    "lint": "eslint . --ext .ts,.tsx,.js,.jsx",
    "lint:fix": "eslint . --ext .ts,.tsx,.js,.jsx --fix",
    "typecheck": "tsc --noEmit"
  }
}

Python

# Makefile or scripts
format:
	black .
	isort .

lint:
	ruff check .
	mypy .

format-check:
	black --check .
	isort --check .

Git Hooks Setup

Husky + lint-staged (Node.js)

1. Install dependencies:

npm install --save-dev husky lint-staged
npx husky init

2. Configure lint-staged (.lintstagedrc.json):

{
  "*.{ts,tsx,js,jsx}": ["eslint --fix", "prettier --write"],
  "*.{json,md,yml}": ["prettier --write"]
}

3. Add pre-commit hook (.husky/pre-commit):

#!/bin/sh
npx lint-staged

pre-commit (Python)

1. Create .pre-commit-config.yaml:

repos:
  - repo: https://github.com/psf/black
    rev: 24.1.1
    hooks:
      - id: black

  - repo: https://github.com/pycqa/isort
    rev: 5.13.2
    hooks:
      - id: isort

  - repo: https://github.com/astral-sh/ruff-pre-commit
    rev: v0.2.0
    hooks:
      - id: ruff
        args: [--fix]

  - repo: https://github.com/pre-commit/mirrors-mypy
    rev: v1.8.0
    hooks:
      - id: mypy

2. Install:

pip install pre-commit
pre-commit install

Editor Configuration

VS Code (settings.json)

{
  "editor.defaultFormatter": "esbenp.prettier-vscode",
  "editor.formatOnSave": true,
  "editor.codeActionsOnSave": {
    "source.fixAll.eslint": true
  },
  "[python]": {
    "editor.defaultFormatter": "ms-python.black-formatter"
  }
}

VS Code Extensions (.vscode/extensions.json)

{
  "recommendations": [
    "esbenp.prettier-vscode",
    "dbaeumer.vscode-eslint",
    "editorconfig.editorconfig",
    "ms-python.black-formatter"
  ]
}

IntelliJ/WebStorm

• Enable: Settings → Languages & Frameworks → JavaScript → Prettier → On save
• Enable: Settings → Tools → Actions on Save → Reformat code

CI Integration

GitHub Actions (.github/workflows/lint.yml)

name: Lint

on: [push, pull_request]

jobs:
  lint:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: actions/setup-node@v4
        with:
          node-version: 20
      - run: npm ci
      - run: npm run format:check
      - run: npm run lint
      - run: npm run typecheck

Pre-merge checks

# .github/workflows/pr-checks.yml
- name: Check formatting
  run: |
    npm run format:check || {
      echo "Code is not formatted. Run 'npm run format' locally."
      exit 1
    }

Installation Checklist

For every setup, provide:

• Config files (.prettierrc, .eslintrc, .editorconfig, etc.)
• Ignore files (.prettierignore, .eslintignore)
• Package scripts (format, lint, format:check, lint:fix)
• Git hooks (husky/pre-commit)
• Editor settings (.vscode/settings.json)
• CI workflow (.github/workflows/lint.yml)
• Documentation (README section on running lint/format)

Best Practices

1. Run formatter last: Prettier should override other formatting rules
2. Extend configs: Use popular presets (Airbnb, Standard, etc.)
3. Ignore generated files: Add build outputs to ignore files
4. Make hooks skippable: Allow git commit --no-verify for emergencies
5. Document process: Add "Code Style" section to CONTRIBUTING.md
6. Test on clean install: Ensure configs work without local editor setup
7. Keep rules minimal: Start strict, relax if needed

Common Configurations

See assets/configs/ for ready-to-use config files:

• Next.js + TypeScript
• React + TypeScript
• Node.js + TypeScript
• Python FastAPI
• Python Django

Bypass Instructions (Emergencies)

# Skip pre-commit hooks
git commit --no-verify

# Skip CI checks (not recommended)
git push --no-verify

Document when bypass is acceptable (hotfixes, emergencies only).