.eslintrc.js

'use strict';

module.exports = {
  root: true,
  parser: '@typescript-eslint/parser',
  parserOptions: {
    ecmaVersion: 'latest',
  },
  plugins: ['ember', '@typescript-eslint', 'unicorn'],
  extends: [
    'eslint:recommended',
    'plugin:ember/recommended',
    'plugin:unicorn/all',
    'prettier',
  ],
  env: {
    browser: true,
  },
  rules: {
    'unicorn/no-null': 'off',
    'unicorn/prefer-module': 'off',
    'unicorn/prevent-abbreviations': 'off',
  },
  overrides: [
    // ts files
    {
      files: ['**/*.ts'],
      parserOptions: {
        project: ['./tsconfig.json', './lib/tsconfig.json'],
      },
      extends: [
        'plugin:@typescript-eslint/recommended-requiring-type-checking',
      ],
      rules: {
        'no-unused-vars': 'off',
        // START rules from 'plugin:@typescript-eslint/strict' but with 'warn' --> 'error'
        '@typescript-eslint/array-type': ['error', { default: 'array-simple' }],
        '@typescript-eslint/ban-tslint-comment': 'error',
        '@typescript-eslint/class-literal-property-style': 'error',
        '@typescript-eslint/consistent-generic-constructors': 'error',
        '@typescript-eslint/consistent-indexed-object-style': 'error',
        '@typescript-eslint/consistent-type-assertions': 'error',
        '@typescript-eslint/consistent-type-definitions': 'error',
        'dot-notation': 'off',
        '@typescript-eslint/dot-notation': 'error',
        '@typescript-eslint/no-base-to-string': 'error',
        '@typescript-eslint/no-confusing-non-null-assertion': 'error',
        '@typescript-eslint/no-duplicate-enum-values': 'error',
        '@typescript-eslint/no-dynamic-delete': 'error',
        '@typescript-eslint/no-extraneous-class': 'error',
        '@typescript-eslint/no-invalid-void-type': 'error',
        '@typescript-eslint/no-meaningless-void-operator': 'error',
        '@typescript-eslint/no-mixed-enums': 'error',
        '@typescript-eslint/no-non-null-asserted-nullish-coalescing': 'error',
        'no-throw-literal': 'off',
        '@typescript-eslint/no-throw-literal': 'error',
        '@typescript-eslint/no-unnecessary-boolean-literal-compare': 'error',
        '@typescript-eslint/no-unnecessary-condition': 'error',
        '@typescript-eslint/no-unnecessary-type-arguments': 'error',
        '@typescript-eslint/no-unsafe-declaration-merging': 'error',
        'no-useless-constructor': 'off',
        '@typescript-eslint/no-useless-constructor': 'error',
        '@typescript-eslint/non-nullable-type-assertion-style': 'error',
        '@typescript-eslint/prefer-for-of': 'error',
        '@typescript-eslint/prefer-function-type': 'error',
        '@typescript-eslint/prefer-includes': 'error',
        '@typescript-eslint/prefer-literal-enum-member': 'error',
        '@typescript-eslint/prefer-nullish-coalescing': 'error',
        '@typescript-eslint/prefer-optional-chain': 'error',
        '@typescript-eslint/prefer-reduce-type-parameter': 'error',
        '@typescript-eslint/prefer-return-this-type': 'error',
        '@typescript-eslint/prefer-string-starts-ends-with': 'error',
        '@typescript-eslint/prefer-ts-expect-error': 'error',
        '@typescript-eslint/unified-signatures': 'error',
        // END rules from 'plugin:@typescript-eslint/strict'
        '@typescript-eslint/consistent-type-exports': [
          'error',
          { fixMixedExportsWithInlineTypeSpecifier: true },
        ],
        '@typescript-eslint/consistent-type-imports': [
          'error',
          { fixStyle: 'inline-type-imports' },
        ],
        '@typescript-eslint/explicit-function-return-type': [
          'error',
          { allowTypedFunctionExpressions: true },
        ],
        '@typescript-eslint/method-signature-style': 'error',
        '@typescript-eslint/no-confusing-void-expression': 'error',
        '@typescript-eslint/no-useless-empty-export': 'error',
        '@typescript-eslint/prefer-enum-initializers': 'error',
        '@typescript-eslint/prefer-readonly': 'error',
        '@typescript-eslint/prefer-regexp-exec': 'error',
        '@typescript-eslint/promise-function-async': 'error',
        '@typescript-eslint/require-array-sort-compare': 'error',
        '@typescript-eslint/switch-exhaustiveness-check': 'error',
        // This rule is not very useful in TS
        'unicorn/no-array-callback-reference': 'off',
      },
    },
    // node files
    {
      files: [
        './.eslintrc.js',
        './.prettierrc.js',
        './.template-lintrc.js',
        './ember-cli-build.js',
        './index.js',
        './testem.js',
        './blueprints/*/index.js',
        './config/**/*.js',
        './tests/dummy/config/**/*.js',
        // In addition to what ember-cli adds above:
        './jest.config.js',
      ],
      env: {
        browser: false,
        node: true,
      },
      extends: ['plugin:n/recommended'],
      rules: {
        'n/no-missing-require': [
          'error',
          {
            tryExtensions: ['.js', '.json', '.ts'],
          },
        ],
      },
    },
    {
      // test files
      files: ['tests/**/*-test.{js,ts}'],
      extends: ['plugin:qunit/recommended'],
    },
  ],
};