.eslintrc.js

module.exports = {
  parser: '@typescript-eslint/parser',
  extends: [
    'plugin:@typescript-eslint/recommended',
    'prettier',
    'prettier/@typescript-eslint'
  ],
  plugins: ['jest', '@typescript-eslint'],
  parserOptions: {
    ecmaVersion: 2018,
    sourceType: 'module'
  },
  env: {
    node: true,
    jest: true,
    es6: true
  },
  rules: {
    '@typescript-eslint/no-unused-vars': [
      'error',
      {
        argsIgnorePattern: '^_',
        varsIgnorePattern: '^_',
        args: 'after-used',
        ignoreRestSiblings: true
      }
    ],
    'no-unused-expressions': [
      'error',
      {
        allowTernary: true
      }
    ],
    'no-console': 0,
    'no-confusing-arrow': 0,
    'no-else-return': 0,
    'no-return-assign': [2, 'except-parens'],
    'no-underscore-dangle': 0,
    'jest/no-focused-tests': 2,
    'jest/no-identical-title': 2,
    camelcase: 0,
    'prefer-arrow-callback': [
      'error',
      {
        allowNamedFunctions: true
      }
    ],
    'class-methods-use-this': 0,
    'no-restricted-syntax': 0,
    'no-param-reassign': [
      'error',
      {
        props: false
      }
    ],

    'import/no-extraneous-dependencies': 0,

    'arrow-body-style': 0,
    'no-nested-ternary': 0
  },
  overrides: [
    {
      files: ['src/**/*.d.ts'],
      rules: {
        '@typescript-eslint/triple-slash-reference': 0
      }
    }
  ]
}