module.exports = {
  env: {
    node: true,
    es2021: true,
    jest: true,
  },
  extends: 'eslint:recommended',
  parserOptions: {
    ecmaVersion: 2021,
  },
  rules: {
    // Possible errors
    'no-await-in-loop': 'warn',
    'no-console': 'off', // We use console in server code
    'no-template-curly-in-string': 'error',
    
    // Best practices
    'curly': ['error', 'multi-line'],
    'eqeqeq': ['error', 'always', { null: 'ignore' }],
    'no-eval': 'error',
    'no-implied-eval': 'error',
    'no-return-await': 'error',
    'no-throw-literal': 'error',
    'prefer-promise-reject-errors': 'error',
    'require-await': 'warn',
    
    // Variables
    'no-unused-vars': ['error', { 
      argsIgnorePattern: '^_',
      varsIgnorePattern: '^_',
    }],
    'no-use-before-define': ['error', { 
      functions: false,
      classes: true,
    }],
    
    // Stylistic
    'comma-dangle': ['error', 'always-multiline'],
    'quotes': ['error', 'single', { avoidEscape: true }],
    'semi': ['error', 'always'],
    'indent': ['error', 2, { SwitchCase: 1 }],
    'max-len': ['warn', { 
      code: 120,
      ignoreUrls: true,
      ignoreStrings: true,
      ignoreTemplateLiterals: true,
    }],
    
    // ES6
    'arrow-spacing': 'error',
    'no-var': 'error',
    'prefer-const': 'error',
    'prefer-arrow-callback': 'warn',
    'prefer-template': 'warn',
  },
};