.eslintrc.js

module.exports = {
  root: true,
  parser: '@babel/eslint-parser',
  parserOptions: {
    requireConfigFile: false,
    ecmaVersion: 2020,
    sourceType: 'module',
    babelOptions: {
      babelrc: false,
      configFile: false,
      presets: ['@babel/preset-env'],
      plugins: [
        [
          '@babel/plugin-proposal-decorators',
          { decoratorsBeforeExport: false }
        ],
      ],
    },
  },
  plugins: [
    'ember',
    'es'
  ],
  extends: [
    'eslint:recommended',
    'plugin:ember/recommended'
  ],
  env: {
    browser: true,
    es6: true
  },
  rules: {
  },
  overrides: [
    // node files
    {
      files: [
        '.eslintrc.js',
        '.template-lintrc.js',
        'ember-cli-build.js',
        'index.js',
        'testem.js',
        'blueprints/*/index.js',
        'config/**/*.js',
        'tests/dummy/config/**/*.js'
      ],
      excludedFiles: [
        'addon/**',
        'addon-test-support/**',
        'app/**',
        'tests/dummy/app/**'
      ],
      parserOptions: {
        sourceType: 'script',
      },
      env: {
        browser: false,
        node: true
      },
      plugins: ['node'],
      rules: {}
    }
  ]
};