CLI Interface

Command-line interface for interactive ESLint configuration setup with support for different configuration modes and legacy formats.

Capabilities

Command Execution

The main CLI executable handles command-line arguments and orchestrates the configuration generation process.

/**
 * Main CLI entry point that processes command-line arguments
 * Supports interactive mode and direct configuration modes
 * Located at: bin/create-config.js
 */

Command Line Options:

• No arguments: Interactive mode with prompts
• --config <package-name>: Use specific shared configuration package
• --eslintrc --config <package-name>: Generate legacy eslintrc-style configuration

Usage Examples:

# Interactive mode - asks questions about project setup
npx @eslint/create-config@latest

# Use a specific shared config (flat config format)
npx @eslint/create-config@latest -- --config eslint-config-standard

# Use a specific shared config (legacy eslintrc format)  
npx @eslint/create-config@latest -- --eslintrc --config eslint-config-standard

# Use scoped package
npx @eslint/create-config@latest -- --config @company/eslint-config

# Alternative using npm init
npm init @eslint/config@latest -- --config eslint-config-airbnb

Interactive Mode

When run without arguments, the CLI launches an interactive setup process:

1. Language Selection: Choose what to lint (JavaScript, JSON, Markdown, CSS)
2. Purpose Selection: Syntax checking only or syntax + problem detection
3. JavaScript Configuration: Module type, framework, TypeScript usage, environment
4. Markdown Configuration: CommonMark vs GitHub Flavored Markdown (if selected)
5. Config File Language: JavaScript vs TypeScript for the config file
6. Jiti Integration: For TypeScript config files on older Node.js versions
7. Installation: Package manager choice and dependency installation

Direct Configuration Mode

When --config flag is provided:

• Skips interactive prompts
• Installs specified shared configuration package
• Determines configuration type (flat vs eslintrc) based on --eslintrc flag presence
• Automatically installs peer dependencies

Error Handling

The CLI handles several error conditions:

// Package.json validation
if (packageJsonPath === null) {
  throw new Error("A package.json file is necessary to initialize ESLint. Run `npm init` to create a package.json file and try again.");
}

Common error scenarios:

• Missing package.json file in current directory
• Invalid shared configuration package names
• Network failures during peer dependency fetching
• File system permissions for config file creation
• Package manager availability (npm, yarn, pnpm, bun)

Process Flow

The CLI follows this execution flow:

1. Initialization: Load package.json metadata and parse command arguments
2. Mode Detection: Determine if running in interactive or direct config mode
3. Configuration: Either prompt user or use provided configuration
4. Generation: Create ConfigGenerator instance with appropriate options
5. Calculation: Generate configuration content and dependency list
6. Output: Create config file and optionally install dependencies

Exit Codes

• 0: Successful configuration creation
• 1: Error during execution (missing package.json, configuration errors, etc.)

Environment Requirements

• Node.js: ^18.18.0 || ^20.9.0 || >=21.1.0 (with SSL support)
• Package Manager: npm, yarn, pnpm, or bun (for dependency installation)
• File System: Write permissions in current working directory