Configuration Options

interface OptionsFormatters {
  /**
   * Enable formatting support for CSS, Less, Sass, and SCSS.
   * Currently only supports Prettier.
   */
  css?: 'prettier' | boolean;

  /**
   * Enable formatting support for HTML.
   * Currently only supports Prettier.
   */
  html?: 'prettier' | boolean;

  /**
   * Enable formatting support for XML.
   * Currently only supports Prettier.
   */
  xml?: 'prettier' | boolean;

  /**
   * Enable formatting support for SVG.
   * Currently only supports Prettier.
   */
  svg?: 'prettier' | boolean;

  /**
   * Enable formatting support for Markdown.
   * Support both Prettier and dprint.
   * When set to true, it will use Prettier.
   */
  markdown?: 'prettier' | 'dprint' | boolean;

  /**
   * Enable formatting support for GraphQL.
   */
  graphql?: 'prettier' | boolean;

  /**
   * Custom options for Prettier.
   * By default it's controlled by our own config.
   */
  prettierOptions?: any;

  /**
   * Custom options for dprint.
   * By default it's controlled by our own config.
   */
  dprintOptions?: boolean;
}

import { createConfigForNuxt } from "@nuxt/eslint-config";

// Enable all formatters with Prettier
export default createConfigForNuxt({
  features: {
    formatters: {
      css: true,
      html: true,
      xml: true,
      svg: true,
      markdown: "prettier",
      graphql: true
    }
  }
});

// Mixed formatter configuration
export default createConfigForNuxt({
  features: {
    formatters: {
      css: "prettier",
      html: "prettier",
      markdown: "dprint", // Use dprint for markdown
      prettierOptions: {
        printWidth: 100,
        singleQuote: true,
        trailingComma: "es5"
      }
    }
  }
});

// Enable formatters with boolean shorthand
export default createConfigForNuxt({
  features: {
    formatters: true // Enables CSS, HTML, GraphQL with Prettier; SVG/XML if @prettier/plugin-xml is available
  }
});

/**
 * Stylistic customization options from @stylistic/eslint-plugin
 * Controls code formatting and style preferences
 */
interface StylisticCustomizeOptions {
  /**
   * Indentation configuration
   * @default 2
   */
  indent?: number | 'tab';
  
  /**
   * Quote style preference
   * @default 'single'
   */
  quotes?: 'single' | 'double';
  
  /**
   * Semicolon usage
   * @default false
   */
  semi?: boolean;
  
  /**
   * Additional stylistic options
   */
  [key: string]: any;
}

// Custom stylistic configuration
export default createConfigForNuxt({
  features: {
    stylistic: {
      indent: 4,
      quotes: "double",
      semi: true
    }
  }
});

// Tab-based indentation
export default createConfigForNuxt({
  features: {
    stylistic: {
      indent: "tab",
      quotes: "single",
      semi: false
    }
  }
});

// Enable with defaults
export default createConfigForNuxt({
  features: {
    stylistic: true // Uses: indent: 2, quotes: 'single', semi: false
  }
});

interface NuxtESLintConfigOptionsResolved {
  /** Resolved feature configuration with all defaults applied */
  features: Required<NotNill<NuxtESLintFeaturesOptions>>;
  /** Resolved directory configuration with all defaults applied */
  dirs: Required<NotNill<DirectoriesConfig>>;
}

/**
 * Utility type that excludes null and undefined
 */
type NotNill<T> = T extends null | undefined ? never : T;

/**
 * Type that can be a value or promise of that value
 */
type Awaitable<T> = T | Promise<T>;

// Function that accepts both sync and async configs
function processConfig(config: Awaitable<ESLintConfig>) {
  // Handle both sync and async cases
  return Promise.resolve(config).then(resolvedConfig => {
    // Process the resolved config
    return resolvedConfig;
  });
}

// Using with different input types
processConfig({ rules: { "no-console": "warn" } }); // Sync
processConfig(import("./config.js")); // Async

// Default values applied during resolution:
const defaults = {
  features: {
    standalone: true,
    stylistic: false,
    typescript: isPackageExists('typescript'), // Auto-detected
    tooling: false,
    formatters: false,
    nuxt: {},
    import: {}
  },
  dirs: {
    root: ['.', './app'], // Support both Nuxt 3 and 4 conventions
    src: [], // Defaults to root directories
    pages: [], // Defaults to src/pages for each src directory
    layouts: [], // Defaults to src/layouts for each src directory
    // ... other directories follow the same pattern
  }
};

// Minimal config - uses all defaults
export default createConfigForNuxt();

// Partial config - merges with defaults
export default createConfigForNuxt({
  features: {
    typescript: { strict: true } // Only override specific options
  },
  dirs: {
    src: ["./src"] // Override specific directories
  }
});

// Understanding directory resolution
export default createConfigForNuxt({
  dirs: {
    root: ["./app"],
    src: ["./app"] // Will generate pages: ["./app/pages"], components: ["./app/components"], etc.
  }
});