.eslintrc.js

module.exports = {
  root: true,
  parser: 'babel-eslint',
  parserOptions: {
    ecmaVersion: 2018,
    sourceType: 'module',
  },
  plugins: ['ember', 'prettier'],
  extends: ['eslint:recommended', 'plugin:ember/recommended', 'plugin:prettier/recommended'],
  env: {
    browser: true,
  },
  rules: {
    'ember/no-classic-components': 'off',
    'ember/no-classic-classes': 'off',
    'ember/require-tagless-components': 'off',
  },
  overrides: [
    // node files
    {
      files: [
        './.eslintrc.js',
        './.prettierrc.js',
        './.template-lintrc.js',
        'colocated-broccoli-plugin.js',
        './ember-cli-build.js',
        'lib/**/*.js',
        './testem.js',
        './blueprints/*/index.js',
        './config/**/*.js',
        './tests/dummy/config/**/*.js',
        'tests/dummy/lib/**/*.js',
      ],
      parserOptions: {
        sourceType: 'script',
        ecmaVersion: 2018,
      },
      env: {
        browser: false,
        node: true,
      },
      plugins: ['node'],
      rules: Object.assign({}, require('eslint-plugin-node').configs.recommended.rules, {
        // add your custom rules and overrides for node files here
      }),
    },

    // node files
    {
      files: ['node-tests/**/*.js'],
      parserOptions: {
        sourceType: 'script',
        ecmaVersion: 2018,
      },
      env: {
        browser: false,
        node: true,
        mocha: true,
      },
      plugins: ['node', 'mocha'],
      rules: Object.assign({}, require('eslint-plugin-node').configs.recommended.rules, {
        // add your custom rules and overrides for node files here
      }),
    },
    {
      // Test files:
      files: ['tests/**/*-test.{js,ts}'],
      extends: ['plugin:qunit/recommended'],
    },
  ],
};