eslint.config.mjs

import typescriptEslint from '@typescript-eslint/eslint-plugin';
import typescriptParser from '@typescript-eslint/parser';
import unicorn from 'eslint-plugin-unicorn';

export default [
  // TODO: enable js.configs.recommended and typescript-eslint "recommended".
  {
    files: ['packages/neovim/bin/cli.js', '**/*.ts'],
    ignores: [
      '**/*.d.ts',
      // TODO: these are probably broken because they don't end with "**"?
      // irrelevant for now because --ignore-pattern is specified in the "lint" task directly.
      'packages/*/lib/',
      'packages/*/bin/',
      'packages/neovim/scripts/',
      'packages/integration-tests/__tests__/',
      'examples/rplugin/node/',
      'packages/example-plugin/',
      'packages/example-plugin-decorators/',
    ],
    languageOptions: {
      parser: typescriptParser,
      parserOptions: {
        project: './tsconfig.json',
        ecmaVersion: 'latest',
        sourceType: 'module',
      },
    },
    plugins: {
      '@typescript-eslint': typescriptEslint,
      unicorn,
    },
    linterOptions: {
      reportUnusedDisableDirectives: true,
    },
    rules: {
      curly: 'error', // Enforce braces on "if"/"for"/etc.
      // Avoid accidental use of "==" instead of "===".
      eqeqeq: 'error',
      camelcase: ['error', { properties: 'never' }],
      'class-methods-use-this': 'off',
      'comma-dangle': [
        'error',
        {
          arrays: 'only-multiline',
          objects: 'only-multiline',
          imports: 'only-multiline',
          exports: 'only-multiline',
          functions: 'ignore',
        },
      ],
      'no-restricted-syntax': 'off',
      'no-case-declarations': 'off',
      'no-prototype-builtins': 'off',
      'no-underscore-dangle': 'off',
      'no-mixed-operators': 'off',
      'func-names': 'off',
      'max-classes-per-file': 'off',
      'operator-assignment': ['error', 'never'],

      // For overloading (and typescript throws when dupe members anyway)
      'no-dupe-class-members': 'off',

      // Causes issues with enums
      'no-shadow': 'off',
      'prefer-destructuring': 'off', // Intentionally disabled trash.

      'global-require': 'error',
      'new-cap': 'error',
      'no-console': 'error',
      'no-param-reassign': ['error', { props: true }],
      'no-void': 'error',

      '@typescript-eslint/no-misused-new': 'error',
      '@typescript-eslint/no-namespace': 'error',
      // TODO: '@typescript-eslint/no-floating-promises': 'error', // Promises must catch errors or be awaited.
      // TODO? '@typescript-eslint/no-unsafe-assignment': 'error',
      // TODO? '@typescript-eslint/no-unsafe-return': 'error',
      // TODO? '@typescript-eslint/no-unsafe-call': 'error',
      '@typescript-eslint/no-explicit-any': 'off',
      '@typescript-eslint/explicit-member-accessibility': 'off',
      '@typescript-eslint/no-unused-vars': 'error',
      '@typescript-eslint/no-empty-function': 'off',
      '@typescript-eslint/explicit-function-return-type': 'off',
      '@typescript-eslint/ban-types': 'off',
      '@typescript-eslint/explicit-module-boundary-types': 'off',

      // Rules from https://github.com/sindresorhus/eslint-plugin-unicorn
      // TODO: 'unicorn/no-useless-promise-resolve-reject': 'error',
      // TODO: 'unicorn/prefer-event-target': 'error',
      // TODO: 'unicorn/prefer-string-slice': 'error',
      // TODO? 'unicorn/custom-error-definition': 'error',
      // TODO? 'unicorn/prefer-json-parse-buffer': 'error',
      // TODO? ESM modules https://github.com/sindresorhus/eslint-plugin-unicorn/blob/main/docs/rules/prefer-module.md
      // 'unicorn/prefer-module': 'error',
      // 'unicorn/no-null': 'error',
      'unicorn/no-abusive-eslint-disable': 'error',
      'unicorn/prefer-at': 'error',
      'unicorn/prefer-negative-index': 'error',
      'unicorn/prefer-regexp-test': 'error',
      'unicorn/prefer-ternary': 'error',
      'unicorn/no-unnecessary-polyfills': 'error',
      'unicorn/no-useless-spread': 'error',
      'unicorn/prefer-array-some': 'error',
      'unicorn/prefer-blob-reading-methods': 'error',
      'unicorn/prefer-code-point': 'error',
      'unicorn/prefer-date-now': 'error',
      'unicorn/prefer-dom-node-text-content': 'error',
      'unicorn/prefer-includes': 'error',
      'unicorn/prefer-keyboard-event-key': 'error',
      'unicorn/prefer-modern-dom-apis': 'error',
      'unicorn/prefer-modern-math-apis': 'error',
      'unicorn/prefer-native-coercion-functions': 'error',
      'unicorn/prefer-node-protocol': 'error',
      'unicorn/prefer-object-from-entries': 'error',
      'unicorn/prefer-reflect-apply': 'error',
      'unicorn/prefer-string-trim-start-end': 'error',
      'unicorn/prefer-type-error': 'error',
    },
  },
  {
    files: ['**/*.test.ts'],
    rules: {
      // This rule requires es2022(?) but the CI node14 job runs the tests
      // in node14, but the test code is not compiled/polyfilled... so the
      // test code needs to be compatible with node14.
      // TODO: can the back-compat CI jobs for older node.js versions run
      // `jest` against the compiled .js results (would require compiling
      // the test files as well)?
      'unicorn/prefer-at': 'off',
      'new-cap': 'off',
    },
  },
];