eslint.config.mjs

import babelParser from '@babel/eslint-parser';
import { FlatCompat } from '@eslint/eslintrc';
import js from '@eslint/js';
import ember from 'eslint-plugin-ember';
import emberConcurrency from 'eslint-plugin-ember-concurrency';
import importHelpers from 'eslint-plugin-import-helpers';
import prettier from 'eslint-plugin-prettier';
import eslintPluginUnicorn from 'eslint-plugin-unicorn';
import globals from 'globals';
import path from 'node:path';
import { fileURLToPath } from 'node:url';

const __filename = fileURLToPath(import.meta.url);
const __dirname = path.dirname(__filename);
const compat = new FlatCompat({
  baseDirectory: __dirname,
  recommendedConfig: js.configs.recommended,
  allConfig: js.configs.all,
});

export default [
  eslintPluginUnicorn.configs.recommended,
  {
    ignores: [
      '.git/**/*',
      'crates/',
      'playwright-report/',
      'target/',
      'test-results/',
      'tmp/',
      // unconventional js
      'blueprints/*/files/',
      'vendor/',
      // compiled output
      'dist/',
      'tmp/',
      // dependencies
      'bower_components/',
      'node_modules/',
      // misc
      'coverage/',
      '!**/.*',
      // ember-try
      '.node_modules.ember-try/',
      'bower.json.ember-try',
      'package.json.ember-try',
    ],
  },
  ...compat.extends(
    'eslint:recommended',
    'plugin:ember/recommended',
    'plugin:qunit/recommended',
    'plugin:qunit-dom/recommended',
    'plugin:prettier/recommended',
  ),
  {
    plugins: {
      ember,
      'ember-concurrency': emberConcurrency,
      prettier,
      'import-helpers': importHelpers,
    },

    languageOptions: {
      globals: {
        ...globals.browser,
      },

      parser: babelParser,
      ecmaVersion: 2018,
      sourceType: 'module',

      parserOptions: {
        requireConfigFile: false,

        babelOptions: {
          plugins: [
            [
              '@babel/plugin-proposal-decorators',
              {
                decoratorsBeforeExport: true,
              },
            ],
          ],
        },
      },
    },

    rules: {
      // it's fine to use `return` without a value and rely on the implicit `undefined` return value
      'getter-return': 'off',

      // declaration sort is taken care of by `import-helpers/order-imports`
      'sort-imports': ['error', { ignoreDeclarationSort: true, ignoreCase: true }],

      'prettier/prettier': 'error',

      // disabled because we still use `this.set()` in a few places and it works just fine
      'ember/classic-decorator-no-classic-methods': 'off',
      // disabled because the alternatives are currently not worth the additional complexity
      'ember/no-array-prototype-extensions': 'off',

      'ember-concurrency/no-perform-without-catch': 'warn',
      'ember-concurrency/require-task-name-suffix': 'error',

      // disabled because of false positives in `assert.rejects()` calls
      'qunit/require-expect': 'off',

      // disabled because of false positives related to ember-concurrency usage
      'unicorn/consistent-function-scoping': 'off',
      'unicorn/explicit-length-check': ['error', { 'non-zero': 'not-equal' }],
      // disabled because it conflicts with Ember.js conventions
      'unicorn/no-anonymous-default-export': 'off',
      // disabled because of false positives related to `EmberArray`
      'unicorn/no-array-for-each': 'off',
      // disabled because it is annoying in some cases...
      'unicorn/no-await-expression-member': 'off',
      // disabled because we need `null` since JSON has no `undefined`
      'unicorn/no-null': 'off',
      // disabled because this rule conflicts with prettier
      'unicorn/no-nested-ternary': 'off',
      // disabled because of unfixable false positives
      'unicorn/prevent-abbreviations': 'off',
      // disabled because we are targeting only browsers at the moment
      'unicorn/prefer-global-this': 'off',
      // disabled because we don't want to go all-in on ES6 modules for Node.js code yet
      'unicorn/prefer-module': 'off',
      // disabled because it seems unnecessary
      'unicorn/prefer-number-properties': 'off',
      // disabled because it seems unnecessary
      'unicorn/prefer-reflect-apply': 'off',
      // disabled because of false positives related to `EmberArray`
      'unicorn/prefer-spread': 'off',
      // disabled because it seems unnecessary
      'unicorn/prefer-string-raw': 'off',
      // disabled because of Sentry issues
      'unicorn/prefer-string-replace-all': 'off',
      // disabled because switch statements in JS are quite error-prone
      'unicorn/prefer-switch': 'off',
      // disabled because of false positives
      'unicorn/consistent-destructuring': 'off',
      'unicorn/filename-case': ['error', { case: 'kebabCase', ignore: ['^-'] }],

      'import-helpers/order-imports': [
        'error',
        {
          newlinesBetween: 'always',
          groups: [
            // Node.js built-in modules
            '/^(assert|async_hooks|buffer|child_process|cluster|console|constants|crypto|dgram|dns|domain|events|fs|http|http2|https|inspector|module|net|os|path|perf_hooks|process|punycode|querystring|readline|repl|stream|string_decoder|timers|tls|trace_events|tty|url|util|v8|vm|zli)/',
            // Testing modules
            ['/^(qunit|ember-qunit|@ember/test-helpers|ember-exam|htmlbars-inline-precompile)$/', '/^ember-exam\\//'],
            // Ember.js modules
            ['/^@(ember|ember-data|glimmer)\\//', '/^(ember|ember-data|rsvp)$/', '/^ember-data\\//'],
            ['module'],
            ['/^crates-io\\//'],
            ['parent', 'sibling', 'index'],
          ],
          alphabetize: { order: 'asc', ignoreCase: true },
        },
      ],
    },
  },

  // test files
  {
    files: ['tests/**/*.js'],

    rules: {
      'unicorn/consistent-function-scoping': 'off',
      'unicorn/prefer-dom-node-dataset': 'off',
    },
  },

  // node files
  {
    files: [
      'eslint.config.mjs',
      '**/.template-lintrc.js',
      '**/ember-cli-build.js',
      '**/testem.js',
      'blueprints/*/index.js',
      'config/**/*.js',
      'lib/*/index.js',
      'server/**/*.js',
    ],

    languageOptions: {
      globals: {
        ...Object.fromEntries(Object.entries(globals.browser).map(([key]) => [key, 'off'])),
        ...globals.node,
      },

      ecmaVersion: 2018,
      sourceType: 'script',
    },
  },
];