.eslintrc.js

module.exports = {
  extends: ['eslint:recommended', 'plugin:@typescript-eslint/recommended', 'prettier', 'plugin:cypress/recommended'],

  parserOptions: {
    ecmaVersion: 6,
    sourceType: 'module',
    ecmaFeatures: {
      impliedStrict: true,
      jsx: true,
    },
  },

  env: {
    browser: true,
    node: true,
    es6: true,
    mocha: true,
    jquery: true,
  },

  plugins: ['@typescript-eslint', 'react', 'react-hooks', 'import', 'cypress', 'mocha'],

  globals: {
    RequestInfo: true,
    RequestInit: true,
    ServiceWorkerGlobalScope: true,
    beforeAll: true,
    cy: true,
    define: true,
    describe: true,
    expect: true,
    globalThis: true,
    it: true,
    jest: true,
  },

  overrides: [
    {
      files: ['*.ts', '*.tsx'],
      parser: '@typescript-eslint/parser',
      rules: {
        'react/prop-types': 'off',
        'no-unused-vars': 'off',
        '@typescript-eslint/no-unused-vars': [
          'error',
          {
            argsIgnorePattern: '^_',
          },
        ],
        'no-shadow': 'off',
        '@typescript-eslint/no-shadow': ['error'],
      },
    },

    {
      files: ['*.test.ts', '*.test.tsx'],
      rules: {
        '@typescript-eslint/no-non-null-assertion': 'off',
      },
    },

    {
      files: ['*.spec.cy.ts'],
      rules: {
        'max-statements': 'off',
      },
    },
  ],

  settings: {
    react: {
      version: '17',
    },
    'import/extensions': ['.js', '.jsx', '.ts', '.tsx'],
    'import/parsers': {
      '@typescript-eslint/parser': ['.ts', '.tsx'],
    },
  },

  rules: {
    'import/default': 'error',
    'import/no-absolute-path': 'error',
    'import/no-cycle': 'error',
    'import/no-dynamic-require': 'error',
    'import/order': [
      'error',
      {
        alphabetize: {
          order: 'asc',
          caseInsensitive: true,
        },
        groups: [['builtin', 'external'], 'internal', 'parent', 'sibling', 'index'],
        'newlines-between': 'always',
      },
    ],
    'import/newline-after-import': 'error',

    // Possible Errors
    'comma-dangle': ['error', 'always-multiline'],
    'no-cond-assign': 'error',
    'no-console': 'warn',
    'no-constant-condition': 'error',
    'no-control-regex': 'error',
    'no-debugger': 'warn',
    'no-dupe-args': 'error',
    'no-dupe-keys': 'error',
    'no-duplicate-case': 'error',
    'no-empty': 'error',
    'no-empty-character-class': 'error',
    'no-ex-assign': 'error',
    'no-extra-boolean-cast': 'error',
    'no-extra-parens': 'off',
    'no-extra-semi': 'error',
    'no-func-assign': 'error',
    'no-inner-declarations': 'error',
    'no-invalid-regexp': 'error',
    'no-irregular-whitespace': [
      'error',
      {
        skipStrings: true,
        skipTemplates: true,
      },
    ],
    'no-negated-in-lhs': 'error',
    'no-obj-calls': 'error',
    'no-regex-spaces': 'error',
    'no-sparse-arrays': 'error',
    'no-template-curly-in-string': 'off',
    'no-unexpected-multiline': 'error',
    'no-unreachable': 'error',
    'no-unsafe-finally': 'error',
    'use-isnan': 'error',
    'valid-jsdoc': 'off',
    'valid-typeof': 'error',

    // Best Practices
    'accessor-pairs': 'error',
    'array-callback-return': 'error',
    'block-scoped-var': 'error',
    complexity: 'off',
    'consistent-return': 'error',
    curly: ['error', 'all'],
    'default-case': 'error',
    'dot-location': ['error', 'property'],
    'dot-notation': 'error',
    eqeqeq: 'error',
    'guard-for-in': 'error',
    'no-alert': 'error',
    'no-caller': 'error',
    'no-case-declarations': 'error',
    'no-div-regex': 'error',
    'no-else-return': 'error',
    'no-empty-function': 'error',
    'no-empty-pattern': 'error',
    'no-eq-null': 'error',
    'no-eval': 'error',
    'no-extend-native': 'error',
    'no-extra-bind': 'error',
    'no-extra-label': 'error',
    'no-fallthrough': 'error',
    'no-floating-decimal': 'error',
    'no-implicit-coercion': 'error',
    'no-implicit-globals': 'error',
    'no-implied-eval': 'error',
    'no-invalid-this': 'off',
    'no-iterator': 'error',
    'no-labels': 'error',
    'no-lone-blocks': 'error',
    'no-loop-func': 'error',
    'no-magic-numbers': [
      'off',
      {
        enforceConst: true,
        detectObjects: true,
      },
    ],
    'no-multi-spaces': 'error',
    'no-multi-str': 'error',
    'no-native-reassign': 'error',
    'no-new': 'error',
    'no-new-func': 'error',
    'no-new-wrappers': 'error',
    'no-octal': 'error',
    'no-octal-escape': 'error',
    'no-param-reassign': 'error',
    'no-proto': 'error',
    'no-redeclare': 'error',
    'no-return-assign': 'error',
    'no-script-url': 'error',
    'no-self-assign': 'error',
    'no-self-compare': 'error',
    'no-sequences': 'error',
    'no-throw-literal': 'off',
    'no-unmodified-loop-condition': 'error',
    'no-unused-expressions': 'error',
    'no-unused-labels': 'error',
    'no-useless-call': 'error',
    'no-useless-concat': 'error',
    'no-useless-escape': 'error',
    'no-void': 'error',
    'no-warning-comments': 'warn',
    'no-with': 'error',
    radix: 'error',
    'vars-on-top': 'error',
    'wrap-iife': 'error',
    yoda: ['error', 'never'],

    // Strict Mode
    strict: ['error', 'never'],

    // Variables
    'init-declarations': ['off', 'always'],
    'no-catch-shadow': 'error',
    'no-delete-var': 'error',
    'no-label-var': 'error',
    'no-restricted-globals': 'error',
    'no-shadow': 'error',
    'no-shadow-restricted-names': 'error',
    'no-undef': 'error',
    'no-undef-init': 'error',
    'no-undefined': 'off',
    'no-unused-vars': 'error',
    'no-use-before-define': 'off',

    // Node.js and CommonJS
    'callback-return': 'off',
    'global-require': 'off',
    'handle-callback-err': 'off',
    'no-mixed-requires': 'off',
    'no-new-require': 'off',
    'no-path-concat': 'off',
    'no-process-env': 'off',
    'no-process-exit': 'error',
    'no-restricted-modules': 'off',
    'no-sync': 'off',

    // Stylistic Issues
    'array-bracket-spacing': ['error', 'never'],
    'block-spacing': ['error', 'always'],
    'brace-style': ['error', '1tbs'],
    camelcase: [
      'error',
      {
        properties: 'always',
      },
    ],
    'comma-spacing': [
      'error',
      {
        before: false,
        after: true,
      },
    ],
    'comma-style': ['error', 'last'],
    'computed-property-spacing': ['error', 'never'],
    'consistent-this': ['error', 'this'],
    'eol-last': 'error',
    'func-names': ['error', 'never'],
    'func-style': 'off',
    'id-blacklist': 'off',
    'id-length': [
      'off',
      {
        min: 3,
        exceptions: ['_', 'id', 'to', 'x', 'y'],
      },
    ],
    'id-match': 'off',
    indent: ['error', 2],
    'jsx-quotes': ['error', 'prefer-double'],
    'key-spacing': [
      'error',
      {
        beforeColon: false,
        afterColon: true,
        mode: 'strict',
      },
    ],
    'keyword-spacing': [
      'error',
      {
        before: true,
        after: true,
      },
    ],
    'linebreak-style': ['error', 'unix'],
    'lines-around-comment': 'off',
    'max-depth': ['error', 4],
    'max-len': ['error', 120],
    'max-lines': ['warn', 200],
    'max-nested-callbacks': ['error', 4],
    'max-params': ['error', 4],
    'max-statements': ['warn', 20],
    'max-statements-per-line': [
      'error',
      {
        max: 1,
      },
    ],
    'new-cap': [
      'error',
      {
        newIsCap: true,
        capIsNew: false,
        properties: true,
      },
    ],
    'new-parens': 'error',
    'newline-after-var': 'off',
    'newline-before-return': 'off',
    'newline-per-chained-call': 'off',
    'no-array-constructor': 'error',
    'no-bitwise': 'error',
    'no-continue': 'off',
    'no-inline-comments': 'off',
    'no-lonely-if': 'error',
    'no-mixed-operators': 'off',
    'no-mixed-spaces-and-tabs': 'error',
    'no-multiple-empty-lines': 'error',
    'no-negated-condition': 'error',
    'no-nested-ternary': 'error',
    'no-new-object': 'error',
    'no-plusplus': 'off',
    'no-restricted-syntax': ['error', 'WithStatement'],
    'no-spaced-func': 'off', // deprecated
    'func-call-spacing': ['error', 'never'],
    'no-ternary': 'off',
    'no-trailing-spaces': 'error',
    'no-underscore-dangle': [
      'error',
      {
        allow: ['_'],
      },
    ],
    'no-unneeded-ternary': 'error',
    'no-whitespace-before-property': 'error',
    'object-curly-newline': 'off',
    'object-curly-spacing': ['error', 'always'],
    'object-property-newline': [
      'error',
      {
        allowMultiplePropertiesPerLine: true,
      },
    ],
    'one-var': ['error', 'never'],
    'one-var-declaration-per-line': ['error', 'always'],
    'operator-assignment': ['error', 'always'],
    'operator-linebreak': [
      'off',
      'none',
      {
        overrides: {
          '?': 'before',
          ':': 'before',
        },
      },
    ],
    'padded-blocks': ['error', 'never'],
    'quote-props': ['error', 'as-needed'],
    quotes: [
      'error',
      'single',
      {
        allowTemplateLiterals: true,
        avoidEscape: true,
      },
    ],
    'require-jsdoc': 'off',
    semi: ['error', 'always'],
    'semi-spacing': [
      'error',
      {
        before: false,
        after: true,
      },
    ],
    'sort-vars': 'error',
    'space-before-blocks': ['error', 'always'],
    'space-before-function-paren': [
      'error',
      {
        anonymous: 'never',
        named: 'never',
        asyncArrow: 'always',
      },
    ],
    'space-in-parens': ['error', 'never'],
    'space-infix-ops': 'error',
    'space-unary-ops': 'error',
    'spaced-comment': 'off',
    'unicode-bom': ['error', 'never'],
    'wrap-regex': 'off',

    // ECMAScript 6
    'arrow-body-style': 'off',
    'arrow-parens': ['error', 'always'],
    'arrow-spacing': [
      'error',
      {
        before: true,
        after: true,
      },
    ],
    'constructor-super': 'error',
    'generator-star-spacing': [
      'error',
      {
        before: false,
        after: true,
      },
    ],
    'no-class-assign': 'error',
    'no-confusing-arrow': 'off',
    'no-const-assign': 'error',
    'no-dupe-class-members': 'error',
    'no-duplicate-imports': 'error',
    'no-new-symbol': 'error',
    'no-restricted-imports': 'off',
    'no-this-before-super': 'error',
    'no-useless-computed-key': 'error',
    'no-useless-constructor': 'error',
    'no-useless-rename': 'error',
    'no-var': 'error',
    'object-shorthand': [
      'error',
      'always',
      {
        avoidQuotes: true,
      },
    ],
    'prefer-arrow-callback': 'error',
    'prefer-const': 'error',
    'prefer-reflect': 'error',
    'prefer-rest-params': 'error',
    'prefer-spread': 'error',
    'prefer-template': 'error',
    'require-yield': 'error',
    'rest-spread-spacing': ['error', 'never'],
    'sort-imports': 'off',
    'template-curly-spacing': ['error', 'never'],
    'yield-star-spacing': [
      'error',
      {
        before: false,
        after: true,
      },
    ],

    // React
    'react/display-name': 'off',
    'react/forbid-prop-types': [
      'off',
      {
        forbid: ['any'],
      },
    ],
    'react/jsx-no-comment-textnodes': 'error',
    'react/no-danger': 'error',
    'react/no-deprecated': 'error',
    'react/no-did-mount-set-state': 'error',
    'react/no-did-update-set-state': 'error',
    'react/no-direct-mutation-state': 'error',
    'react/no-is-mounted': 'error',
    'react/no-multi-comp': [
      'error',
      {
        ignoreStateless: true,
      },
    ],
    'react/no-render-return-value': 'error',
    // 'react/no-set-state': 'error',
    'react/no-string-refs': 'error',
    'react/no-unknown-property': 'error',
    'react/prefer-es6-class': 'error',
    // 'react/prefer-stateless-function': 'error',
    'react/prop-types': 'error',
    'react/react-in-jsx-scope': 'off',
    // 'react/require-optimization': 'error',
    'react/require-render-return': 'error',
    'react/self-closing-comp': 'error',
    'react/sort-comp': [
      'error',
      {
        order: [
          'static-methods',
          'instance-variables',
          'lifecycle',
          '/^on.+$/',
          'everything-else',
          'render',
          '/^render.+/',
        ],
      },
    ],
    'react/sort-prop-types': [
      'error',
      {
        ignoreCase: true,
        callbacksLast: true,
      },
    ],
    'react/no-unused-prop-types': 'error',
    'react/jsx-wrap-multilines': 'error',

    // JSX-specific rules
    'react/jsx-boolean-value': ['error', 'never'],
    'react/jsx-closing-bracket-location': [
      'error',
      {
        nonEmpty: 'tag-aligned',
        selfClosing: 'tag-aligned',
      },
    ],
    'react/jsx-curly-spacing': ['error', 'never'],
    'react/jsx-equals-spacing': ['error', 'never'],
    'react/jsx-filename-extension': [
      'error',
      {
        extensions: ['.js', '.jsx', '.ts', '.tsx'],
      },
    ],
    'react/jsx-first-prop-new-line': ['error', 'multiline'],
    'react/jsx-handler-names': [
      'error',
      {
        eventHandlerPrefix: 'on',
        eventHandlerPropPrefix: 'on',
      },
    ],
    'react/jsx-indent': ['error', 2],
    'react/jsx-indent-props': ['error', 2],
    'react/jsx-key': 'error',
    'react/jsx-max-props-per-line': 'off',
    'react/jsx-no-bind': 'off',
    'react/jsx-no-duplicate-props': 'error',
    'react/jsx-no-literals': 'off',
    'react/jsx-no-target-blank': 'error',
    'react/jsx-no-undef': 'error',
    'react/jsx-pascal-case': 'error',
    'react/jsx-sort-props': 'off',
    'react/jsx-tag-spacing': [
      'error',
      {
        closingSlash: 'never',
        beforeSelfClosing: 'always',
        afterOpening: 'never',
        beforeClosing: 'never',
      },
    ],
    'react/jsx-uses-react': 'error',
    'react/jsx-uses-vars': 'error',

    'mocha/no-exclusive-tests': 'error',
    'mocha/no-skipped-tests': 'error',
  },
};