@omny/eslint

Shared ESLint configuration for Omny projects with TypeScript, SonarJS, and Prettier support.

Features

• ✅ Modern ESLint 9+ - Built on the latest ESLint flat config system
• 🔒 Strict TypeScript - Comprehensive type-checked rules for type safety
• 🔍 SonarJS Integration - Advanced bug detection and code smell analysis
• 📦 Import Management - Automatic import sorting and validation
• 🎨 Prettier Compatible - Optional Prettier configuration export
• ⚙️ EditorConfig Template - Consistent editor settings across IDEs
• 🧩 Modular - Use all rules or pick specific configurations

Installation

npm install --save-dev @omny/eslint eslint typescript

Peer Dependencies

This package requires:

• eslint ^9.0.0
• typescript ^5.0.0

Usage

Basic Usage (Recommended)

Import the complete configuration in your eslint.config.mjs:

import omnyConfig from '@omny/eslint';

export default [
	...omnyConfig,
	// Your custom rules here
];

Modular Usage

Import only the configurations you need:

import baseConfig from '@omny/eslint/base';
import typescriptConfig from '@omny/eslint/typescript';
import importConfig from '@omny/eslint/import';
import sonarConfig from '@omny/eslint/sonar';

export default [
	...baseConfig,
	...typescriptConfig,
	importConfig,
	sonarConfig,
	// Your custom rules here
];

With Custom Overrides

import omnyConfig from '@omny/eslint';

export default [
	...omnyConfig,
	{
		// Override specific rules for your project
		rules: {
			'no-console': 'off', // Allow console in this project
		},
	},
];

Prettier Integration

This package includes an optional Prettier configuration that matches the ESLint rules.

Option 1: Using .prettierrc.js (Recommended)

Create a .prettierrc.js file in your project root:

import prettierConfig from '@omny/eslint/prettier';

export default prettierConfig;

Option 2: Extending with Custom Options

import prettierConfig from '@omny/eslint/prettier';

export default {
	...prettierConfig,
	printWidth: 100, // Override specific options
	semi: false,     // Customize as needed
};

Option 3: Using package.json

Add to your package.json:

{
	"prettier": "@omny/eslint/prettier"
}

Prettier Configuration Details

The included Prettier configuration:

{
	semi: true,
	trailingComma: 'es5',
	singleQuote: true,
	printWidth: 120,
	tabWidth: 4,
	useTabs: true,
	arrowParens: 'always',
	endOfLine: 'lf',
}

EditorConfig

An EditorConfig template is included in templates/.editorconfig. Copy it to your project root:

cp node_modules/@omny/eslint/templates/.editorconfig .editorconfig

Or create .editorconfig manually:

root = true

[*.{js,ts,json,md}]
indent_style = space
indent_size = 4
end_of_line = lf
charset = utf-8
trim_trailing_whitespace = true
insert_final_newline = true

Included Configurations

Base Configuration

• ESLint recommended rules
• Common code quality rules
• No console.log in production
• Prefer const over let
• Strict equality (===)
• No parameter reassignment

TypeScript Configuration

• Strict type-checked rules
• Stylistic type-checked rules
• Explicit function return types
• Explicit module boundary types
• Naming conventions (PascalCase for classes, camelCase for functions, etc.)
• Strict boolean expressions
• Switch exhaustiveness checking
• No variable shadowing

Import Configuration

• Automatic import ordering and grouping
• Alphabetical sorting within groups
• Newlines between import groups
• File extension validation
• No duplicate imports
• No circular dependencies
• DevDependencies validation

SonarJS Configuration

Bug Detection

• No duplicated branches
• No element overwrite
• No identical conditions
• No identical expressions
• No one-iteration loops

Code Smell Detection

• Cognitive complexity limit (15)
• Max switch cases (30)
• No collapsible if statements
• No duplicate strings (threshold: 3)
• No identical functions
• Prefer immediate return
• Prefer single boolean return

Security

• No clear-text protocols

Configuration Exports

| Export | Description | |--------|-------------| | @omny/eslint | Complete configuration (recommended) | | @omny/eslint/base | Base ESLint rules only | | @omny/eslint/typescript | TypeScript rules only | | @omny/eslint/import | Import plugin rules only | | @omny/eslint/sonar | SonarJS rules only | | @omny/eslint/prettier | Prettier configuration | | @omny/eslint/all | Alias for main configuration |

TypeScript Configuration

This package requires a tsconfig.json in your project root. The TypeScript parser uses project: true to automatically detect your TypeScript configuration.

Example tsconfig.json:

{
	"compilerOptions": {
		"target": "ES2022",
		"module": "ESNext",
		"moduleResolution": "bundler",
		"strict": true,
		"esModuleInterop": true,
		"skipLibCheck": true,
		"forceConsistentCasingInFileNames": true
	},
	"include": ["src/**/*"],
	"exclude": ["node_modules", "dist"]
}

Scripts

Add these scripts to your package.json:

{
	"scripts": {
		"lint": "eslint src --ext .ts",
		"lint:fix": "eslint src --ext .ts --fix",
		"format": "prettier --write \"src/**/*.ts\"",
		"format:check": "prettier --check \"src/**/*.ts\""
	}
}

Migration from Existing Configuration

From eslint.config.mjs

If you have an existing eslint.config.mjs, replace it with:

import omnyConfig from '@omny/eslint';

export default [
	...omnyConfig,
	// Keep your project-specific rules here
];

From .eslintrc.json (Legacy)

1. Remove .eslintrc.json
2. Create eslint.config.mjs with the configuration above
3. Update your scripts to use the new config

Customization

Disabling Specific Rules

import omnyConfig from '@omny/eslint';

export default [
	...omnyConfig,
	{
		rules: {
			'@typescript-eslint/explicit-function-return-type': 'off',
			'sonarjs/cognitive-complexity': ['error', 20], // Increase limit
		},
	},
];

Project-Specific Ignore Patterns

import omnyConfig from '@omny/eslint';
import { globalIgnores } from 'eslint/config';

export default [
	globalIgnores([
		'**/generated/**',
		'**/vendor/**',
	]),
	...omnyConfig,
];

Different Rules for Tests

import omnyConfig from '@omny/eslint';

export default [
	...omnyConfig,
	{
		files: ['**/*.test.ts', '**/*.spec.ts'],
		rules: {
			'@typescript-eslint/no-explicit-any': 'off',
			'sonarjs/no-duplicate-string': 'off',
		},
	},
];

Troubleshooting

"Parsing error: Cannot read file 'tsconfig.json'"

Make sure you have a tsconfig.json in your project root. The TypeScript parser needs it to perform type-aware linting.

"Unable to resolve path to module"

Install eslint-import-resolver-typescript:

npm install --save-dev eslint-import-resolver-typescript

Prettier and ESLint Conflicts

This configuration includes eslint-config-prettier to disable conflicting rules. Make sure Prettier runs after ESLint:

{
	"scripts": {
		"lint": "eslint src --ext .ts --fix && prettier --write \"src/**/*.ts\""
	}
}

Contributing

Issues and pull requests are welcome! Please ensure your changes:

1. Follow the existing code style
2. Include tests if applicable
3. Update documentation as needed

License

MIT

Changelog

1.0.0 (Initial Release)

• ✨ Complete ESLint 9+ configuration
• ✨ TypeScript strict type-checked rules
• ✨ SonarJS integration for bug detection
• ✨ Import plugin with automatic sorting
• ✨ Prettier configuration export
• ✨ EditorConfig template
• ✨ Modular configuration exports

Related Packages

• eslint - Pluggable JavaScript linter
• typescript-eslint - TypeScript support for ESLint
• eslint-plugin-sonarjs - SonarJS rules
• eslint-plugin-import - Import/export validation
• prettier - Opinionated code formatter