.eslintrc.js

module.exports = {
  root: true,
  parser: '@typescript-eslint/parser',
  plugins: ['@typescript-eslint', 'jest', 'import'],

  env: {
    browser: true,
    commonjs: true,
    es6: true,
    jest: true,
    node: true,
    'jest/globals': true,
    mocha: true,
  },

  extends: [
    'eslint:recommended',
    'plugin:@typescript-eslint/recommended',
    'prettier',
  ],

  settings: {
    'import/resolver': {
      node: {
        extensions: ['.js', '.ts', '.json'],
      },
    },
  },

  parserOptions: {
    ecmaVersion: 6,
    sourceType: 'module',
    ecmaFeatures: {
      generators: true,
      experimentalObjectRestSpread: true,
    },
  },

  rules: {
    eqeqeq: ['error', 'allow-null'],
    'guard-for-in': 'error',
    'no-array-constructor': 'error',
    'no-caller': 'error',
    'no-cond-assign': ['error', 'always'],
    'no-const-assign': 'error',
    'no-control-regex': 'error',
    'no-debugger': 'error',
    'no-delete-var': 'error',
    'no-dupe-args': 'error',
    'no-dupe-class-members': 'error',
    'no-dupe-keys': 'error',
    'no-duplicate-case': 'error',
    'no-empty-character-class': 'error',
    'no-empty-pattern': 'error',
    'no-eval': 'error',
    'no-ex-assign': 'error',
    'no-extend-native': 'error',
    'no-extra-bind': 'error',
    'no-extra-label': 'error',
    'no-fallthrough': 'error',
    'no-func-assign': 'error',
    'no-implied-eval': 'error',
    'no-invalid-regexp': 'error',
    'no-iterator': 'error',
    'no-label-var': 'error',
    'no-labels': ['error', {allowLoop: false, allowSwitch: false}],
    'no-lone-blocks': 'error',
    'no-loop-func': 'error',
    'no-mixed-operators': [
      'error',
      {
        groups: [
          ['&', '|', '^', '~', '<<', '>>', '>>>'],
          ['==', '!=', '===', '!==', '>', '>=', '<', '<='],
          ['&&', '||'],
          ['in', 'instanceof'],
        ],
        allowSamePrecedence: false,
      },
    ],
    'no-multi-str': 'error',
    'no-native-reassign': 'error',
    'no-negated-in-lhs': 'error',
    'no-new-func': 'error',
    'no-new-object': 'error',
    'no-new-symbol': 'error',
    'no-new-wrappers': 'error',
    'no-obj-calls': 'error',
    'no-octal': 'error',
    'no-octal-escape': 'error',
    'no-redeclare': 'off',
    '@typescript-eslint/no-redeclare': ['error'],
    'no-regex-spaces': 'error',
    'no-restricted-imports': [
      'error',
      {
        paths: [
          {
            name: 'd3',
            message: 'Import specific d3-* module(s) (e.g., d3-scale) instead',
          },
        ],
        patterns: ['*/dist/*'],
      },
    ],
    'no-restricted-syntax': ['error', 'LabeledStatement', 'WithStatement'],
    'no-script-url': 'error',
    'no-self-assign': 'error',
    'no-self-compare': 'error',
    'no-sequences': 'error',
    'no-shadow-restricted-names': 'error',
    'no-sparse-arrays': 'error',
    'no-this-before-super': 'error',
    'no-unexpected-multiline': 'error',
    'no-unreachable': 'error',
    'no-unused-expressions': [
      'error',
      {
        allowShortCircuit: true,
        allowTernary: true,
      },
    ],
    'no-unused-labels': 'error',
    'no-useless-computed-key': 'error',
    'no-useless-concat': 'error',
    'no-useless-rename': [
      'error',
      {
        ignoreDestructuring: false,
        ignoreImport: false,
        ignoreExport: false,
      },
    ],
    'no-with': 'error',
    'one-var': ['error', 'never'],
    'operator-assignment': ['error', 'always'],
    radix: 'error',
    strict: ['error', 'never'],
    'use-isnan': 'error',
    'valid-typeof': 'error',
    'import/no-restricted-paths': [
      'error',
      {
        zones: [
          {target: './src/client', from: './src/gateway'},
          {target: './src/gateway', from: './src/client'},
          {target: './src/shared', from: './src/client'},
          {target: './src/shared', from: './src/gateway'},
        ],
      },
    ],
    'prefer-const': ['error', {destructuring: 'all'}],
    'object-shorthand': 'error',
    '@typescript-eslint/no-unused-vars': [
      'error',
      {
        ignoreRestSiblings: true,
        varsIgnorePattern: '[iI]gnored',
        argsIgnorePattern: '[iI]gnored',
      },
    ],
  },
};