@sylphlab/eslint-config-sylph

Strict, AI-optimized ESLint Flat Config for modern TypeScript. Extreme code quality, maintainability, and developer/AI efficiency. Core of all SylphLab TypeScript projects.

Philosophy

• Strictest possible: All critical rules are errors. No compromise.
• Modern Flat Config: ESLint v9+, TypeScript 5+, ESM, Prettier 3+.
• AI & developer optimized: Explicit typing, clear naming, strict structure, Prettier formatting.
• Functional & secure: Immutability, no-throw, security, bug detection, complexity limits.
• Performance: Static analysis, code splitting, low complexity, short functions/files.

Included Plugins

• @eslint/js (recommended)
• @typescript-eslint/eslint-plugin (strict, stylistic)
• eslint-plugin-unicorn
• eslint-plugin-functional
• eslint-plugin-security
• eslint-plugin-sonarjs
• eslint-plugin-promise
• eslint-plugin-regexp
• eslint-plugin-import-x
• eslint-config-prettier, eslint-plugin-prettier
• globals

Install

pnpm add -D @sylphlab/eslint-config-sylph eslint@^9 typescript@^5 prettier@^3
npx install-peerdeps --dev @sylphlab/eslint-config-sylph -p pnpm

Usage

Create eslint.config.ts:

import sylphConfig from '@sylphlab/eslint-config-sylph';

export default [
  ...sylphConfig,
  // project-specific overrides
];

Key Features

• Flat Config, ESM, type-safe
• Strictest rules:
  • No any, no unused, explicit return types, strict type imports/exports
  • Immutability, no-throw, no-mutable-exports, strict import order
  • Complexity, max-lines, max-lines-per-function, max-depth, max-params
  • Security, bug detection, promise handling, regex safety
• Functional programming:
  • Immutability, pure functions, no-throw, no-mixed-types
• Prettier enforced:
  • All formatting handled by Prettier, no conflicts
• AI/Developer ergonomics:
  • Explicit, predictable, easy for AI to refactor/extend

Example: Override

export default [
  ...sylphConfig,
  {
    files: ['src/**/*.ts'],
    rules: {
      'no-console': 'off',
      'unicorn/prevent-abbreviations': ['error', { replacements: { props: false, ref: false } }],
    },
  },
  {
    ignores: ['dist/', 'build/', 'coverage/', 'my-custom-ignored-folder/'],
  },
];

See Also

• Monorepo README for full philosophy, structure, and all configs.