eslint.config.js

/**
 * Copyright 2025 Google LLC
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *	http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

import globals from 'globals';
import tseslint from 'typescript-eslint';
import prettierConfig from 'eslint-config-prettier';
import licenseHeader from 'eslint-plugin-license-header';
import importPlugin from 'eslint-plugin-import';

// eslint-disable-next-line import/no-default-export
export default tseslint.config(
  prettierConfig,
  {
    ignores: ['dist/', '**/dist/'],
  },
  ...tseslint.configs.recommended,
  {
    files: ['**/*.ts', '**/*.js'],
    languageOptions: {
      globals: {
        ...globals.node,
      },
    },
    plugins: {
      import: importPlugin,
    },
    settings: {
      'import/resolver': {
        node: true,
      },
    },
    rules: {
      ...importPlugin.configs.recommended.rules,
      ...importPlugin.configs.typescript.rules,
      'import/no-default-export': 'warn',
      'import/no-unresolved': 'off', // Disable for now, can be noisy with monorepos/paths

      // General Best Practice Rules (subset adapted for flat config)
      '@typescript-eslint/array-type': ['error', { default: 'array-simple' }],
      'arrow-body-style': ['error', 'as-needed'],
      curly: ['error', 'multi-line'],
      eqeqeq: ['error', 'always', { null: 'ignore' }],
      '@typescript-eslint/consistent-type-assertions': ['error', { assertionStyle: 'as' }],
      '@typescript-eslint/explicit-member-accessibility': ['error', { accessibility: 'no-public' }],
      '@typescript-eslint/no-explicit-any': 'error',
      '@typescript-eslint/no-inferrable-types': [
        'error',
        { ignoreParameters: true, ignoreProperties: true },
      ],
      '@typescript-eslint/no-namespace': ['error', { allowDeclarations: true }],
      '@typescript-eslint/no-unused-vars': [
        'error',
        {
          argsIgnorePattern: '^_',
          varsIgnorePattern: '^_',
          caughtErrorsIgnorePattern: '^_',
        },
      ],
      'import/no-internal-modules': [
        'error',
        {
          allow: ['react-dom/test-utils', 'memfs/lib/volume.js', 'yargs/**'],
        },
      ],
      'import/no-relative-packages': 'error',
      'no-cond-assign': 'error',
      // Do not use console.log in MCP servers.
      // See https://modelcontextprotocol.io/quickstart/server#logging-in-mcp-servers
      'no-console': 'error',
      'no-debugger': 'error',
      'no-duplicate-case': 'error',
      'no-restricted-syntax': [
        'error',
        {
          selector: 'CallExpression[callee.name="require"]',
          message: 'Avoid using require(). Use ES6 imports instead.',
        },
        {
          selector: 'ThrowStatement > Literal:not([value=/^\\w+Error:/])',
          message:
            'Do not throw string literals or non-Error objects. Throw new Error("...") instead.',
        },
      ],
      'no-unsafe-finally': 'error',
      'no-unused-expressions': 'off', // Disable base rule
      '@typescript-eslint/no-unused-expressions': [
        // Enable TS version
        'error',
        { allowShortCircuit: true, allowTernary: true },
      ],
      'no-var': 'error',
      'object-shorthand': 'error',
      'one-var': ['error', 'never'],
      'prefer-arrow-callback': 'error',
      'prefer-const': ['error', { destructuring: 'all' }],
      radix: 'error',
      'default-case': 'error',
    },
  },

  {
    files: [
      'packages/gcloud-mcp/src/utility/logger.ts',
      'packages/gcloud-mcp/src/utility/logger.test.ts',
    ],
    rules: {
      'no-console': 'off',
    },
  },
  {
    files: ['./**/*.{tsx,ts,js}'],
    plugins: {
      'license-header': licenseHeader,
    },
    rules: {
      'license-header/header': [
        'error',
        [
          '/**',
          ' * Copyright 2025 Google LLC',
          ' *',
          ' * Licensed under the Apache License, Version 2.0 (the "License");',
          ' * you may not use this file except in compliance with the License.',
          ' * You may obtain a copy of the License at',
          ' *',
          ' *	http://www.apache.org/licenses/LICENSE-2.0',
          ' *',
          ' * Unless required by applicable law or agreed to in writing, software',
          ' * distributed under the License is distributed on an "AS IS" BASIS,',
          ' * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.',
          ' * See the License for the specific language governing permissions and',
          ' * limitations under the License.',
          ' */',
        ],
      ],
    },
  },
  prettierConfig,
);