.eslintrc.js

'use strict';

module.exports = {
  root: true,
  parser: '@typescript-eslint/parser',
  parserOptions: {
    ecmaVersion: 2018,
    sourceType: 'module',
  },
  plugins: ['ember', '@typescript-eslint', 'prettier'],
  extends: [
    'eslint:recommended',
    'plugin:ember/recommended',
    'plugin:@typescript-eslint/recommended',
    'plugin:prettier/recommended',
  ],
  env: {
    browser: true,
  },
  rules: {
    'prettier/prettier': 'error',
    'no-var': 'error',
    'prefer-const': 'off',
    'no-fallthrough': 'off', // this doesn't understand typescript's `never`
    '@typescript-eslint/explicit-module-boundary-types': 'off',
    '@typescript-eslint/no-non-null-assertion': 'off',
    '@typescript-eslint/no-explicit-any': 'off',
    '@typescript-eslint/no-empty-function': 'off',
    '@typescript-eslint/ban-ts-comment': 'off',
    '@typescript-eslint/no-unused-vars': ['error', { argsIgnorePattern: '^_' }],
  },
  overrides: [
    // node files
    {
      files: [
        'ember-cli-build.js',
        'index.js',
        'testem.js',
        'config/**/*.js',
        'tests/dummy/config/**/*.js',
        'lib/**/*.js',
        'fastboot-tests/**/*.js',
        'babel-plugin/**.js',
        '.eslintrc.js',
      ],
      excludedFiles: [
        'addon/**',
        'addon-test-support/**',
        'app/**',
        'tests/dummy/app/**',
      ],
      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
          'no-var': 'error',
          '@typescript-eslint/no-var-requires': 'off',
        }
      ),
    },
  ],
};