eslint.config.mjs

// Copyright 2026 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import { defineConfig } from 'eslint/config';
import eslint from '@eslint/js';
import jsdoc from 'eslint-plugin-jsdoc';
import tseslint from 'typescript-eslint';
import stylistic from '@stylistic/eslint-plugin';

export default defineConfig(
  eslint.configs.recommended,
  tseslint.configs.recommended,
  ...tseslint.configs.recommendedTypeChecked.map(config => ({
    ...config,

    // Only apply type-checked rules to TypeScript files.
    files: ['**/*.ts'],
  })),
  ...tseslint.configs.stylisticTypeChecked.map(config => ({
    ...config,

    // Only apply type-checked rules to TypeScript files.
    files: ['**/*.ts'],
  })),
  [
    {
      ignores: ['.vscode-test/**', 'dist/**', 'test-dist/**'],
    },

    // Shared JS and TS rules
    {
      plugins: {
        '@jsdoc': jsdoc,
        '@stylistic': stylistic,
      },
      rules: {
        // Best Practices
        'prefer-promise-reject-errors': 'error',
        'curly': 'error',
        'eqeqeq': 'error',

        // JSDoc
        '@jsdoc/require-jsdoc': 'error',
        '@jsdoc/require-description': 'error',

        // Stylistic
        '@stylistic/indent': ['error', 2],
        '@stylistic/max-len': ['error', {
          code: 100,
          ignoreComments: true,
          ignoreStrings: true,
        }],
        '@stylistic/quotes': ['error', 'single'],
        '@stylistic/semi': ['error', 'always'],
      },
    },

    // TypeScript specific rules
    {
      files: ['**/*.ts'],
      languageOptions: {
        parserOptions: {
          project: 'tsconfig.json',
        },
      },

      plugins: {
        '@typescript-eslint': tseslint.plugin,
      },

      rules: {
        // Additions to recommended
        '@typescript-eslint/naming-convention': 'error',
      },
    },

    // JavaScript specific rules
    {
      files: ['**/*.mjs', '**/*.js'],
      languageOptions: {
        ecmaVersion: 'latest',
        sourceType: 'module',
        globals: {
          process: 'readonly',
          console: 'readonly',
        },
      },
      rules: {
        'no-undef': 'error',
        'no-unused-vars': 'error',
      },
    },
  ],
);