.eslintrc.js

'use strict';

module.exports = {
  root: true,
  parser: '@babel/eslint-parser',
  parserOptions: {
    babelOptions: {
      plugins: [['@babel/plugin-proposal-decorators', { legacy: true }]],
    },
    ecmaVersion: 2018,
    ecmaFeatures: {
      legacyDecorators: true,
    },
    requireConfigFile: false,
    sourceType: 'module',
  },
  plugins: ['ember', 'prettier', 'promise', 'import-helpers'],
  extends: ['eslint:recommended', 'plugin:ember/recommended', 'plugin:prettier/recommended'],
  env: {
    browser: true,
  },
  rules: {
    'require-yield': 'off',

    // Possible Errors
    'no-async-promise-executor': 'error',
    'no-template-curly-in-string': 'error',
    'require-atomic-updates': 'error',

    // Best Practices
    'array-callback-return': 'error',
    eqeqeq: 'error',
    'no-eval': 'error',
    'no-extend-native': 'error',
    'no-extra-bind': 'error',
    'no-implicit-coercion': 'error',
    'no-implied-eval': 'error',
    'no-lone-blocks': 'error',
    'no-new-func': 'error',
    'no-new-wrappers': 'error',
    'no-octal-escape': 'error',
    'no-return-assign': 'error',
    'no-self-compare': 'error',
    'no-sequences': 'error',
    'no-throw-literal': 'error',
    'no-unused-expressions': 'error',
    'no-useless-call': 'error',
    'no-useless-catch': 'error',
    'no-useless-concat': 'error',
    'no-useless-escape': 'error',
    'no-useless-return': 'error',
    'no-void': 'error',
    'no-with': 'error',
    'prefer-promise-reject-errors': 'error',
    radix: 'error',
    'wrap-iife': 'error',
    yoda: 'error',

    // ECMAScript 6
    'no-duplicate-imports': 'error',
    'no-useless-computed-key': 'error',
    'no-useless-constructor': 'error',
    'no-useless-rename': 'error',
    'no-var': 'error',
    'object-shorthand': 'error',
    'prefer-numeric-literals': 'error',

    'prettier/prettier': 'error',

    'promise/catch-or-return': 'error',
    'promise/no-return-wrap': 'error',
    'promise/param-names': 'error',
    'promise/no-nesting': 'error',
    'promise/no-new-statics': 'error',
    'promise/no-return-in-finally': 'error',
    'promise/valid-params': 'error',

    'import-helpers/order-imports': [
      'error',
      {
        newlinesBetween: 'always',
        groups: [
          '/^(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/'],
          // Ember.js modules
          ['/^ember$/', '/^@ember/', '/^ember-data/'],
          ['module'],
          [`/^${require('./package.json').name}\\//`],
          ['parent', 'sibling', 'index'],
        ],
        alphabetize: { order: 'asc', ignoreCase: true },
      },
    ],

    // Legacy Ember
    'ember/no-actions-hash': 'off',
    'ember/no-assignment-of-untracked-properties-used-in-tracking-contexts': 'off',
    'ember/no-classic-classes': 'off',
    'ember/no-classic-components': 'off',
    'ember/no-component-lifecycle-hooks': 'off',
    'ember/require-tagless-components': 'off',
  },
  overrides: [
    // node files
    {
      files: [
        './.eslintrc.js',
        './.prettierrc.js',
        './.release-it.js',
        './.template-lintrc.js',
        './blueprints/*/index.js',
        './config/**/*.js',
        './ember-cli-build.js',
        './index.js',
        './testem.js',
        './tests/dummy/config/**/*.js',
      ],
      parserOptions: {
        sourceType: 'script',
      },
      env: {
        browser: false,
        node: true,
      },
      plugins: ['node'],
      extends: ['plugin:node/recommended'],
    },
    {
      // test files
      files: ['tests/**/*-test.{js,ts}'],
      extends: ['plugin:qunit/recommended'],
    },
  ],
};