.eslintrc

{
    "parser": "babel-eslint",
    "parserOptions": {
      "ecmaVersion": 8,
      "sourceType": "module",
      "ecmaFeatures": {
        "jsx": true,
        "experimentalObjectRestSpread": true
      }
    },
    "plugins": ["jest", "react"],
    "extends": ["plugin:jest/recommended"],
    "env": {
      "browser": false,
      "node": true,
      "commonjs": true,
      "es6": true
    },
    "rules": {
      "comma-dangle": ["error", "never"],
      "no-cond-assign": ["error", "always"],
      "no-control-regex": "error",
      "no-debugger": "error",
      "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": ["warn", "all"],
      "no-extra-semi": "error",
      "no-func-assign": "error",
      "no-inner-declarations": ["error", "functions"],
      "no-invalid-regexp": "error",
      "no-irregular-whitespace": "error",
      "no-negated-in-lhs": "error",
      "no-obj-calls": "error",
      "no-prototype-builtins": "warn",
      "no-regex-spaces": "error",
      "no-sparse-arrays": "error",
      "no-unexpected-multiline": "error",
      "no-unreachable": "error",
      "use-isnan": "error",
      "valid-jsdoc": "warn",
      "valid-typeof": "error",
  
      "accessor-pairs": "warn",
      "array-callback-return": "error",
      "block-scoped-var": "error",
      "complexity": "off",
      "curly": ["error", "all"],
      "default-case": "warn",
      "dot-location": ["error", "property"],
      "dot-notation": "warn",
      "eqeqeq": ["error", "smart"],
      "no-alert": "error",
      "no-caller": "error",
      "no-case-declarations": "error",
      "no-div-regex": "error",
      "no-else-return": "warn",
      "no-empty-function": "off",
      "no-empty-pattern": "error",
      "no-eq-null": "off",
      "no-eval": "error",
      "no-extend-native": "error",
      "no-extra-bind": "error",
      "no-extra-label": "error",
      "no-fallthrough": "warn",
      "no-floating-decimal": "error",
      "no-implicit-coercion": "error",
      "no-implicit-globals": "error",
      "no-implied-eval": "error",
      "no-invalid-this": "error",
      "no-iterator": "error",
      "no-labels": "error",
      "no-lone-blocks": "error",
      "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-proto": "error",
      "no-redeclare": ["warn", { "builtinGlobals": true }],
      "no-return-assign": ["error", "always"],
      "no-script-url": "error",
      "no-self-compare": "error",
      "no-sequences": "error",
      "no-throw-literal": "error",
      "no-unmodified-loop-condition": "warn",
      "no-unused-expressions": ["error", { "allowShortCircuit": true, "allowTernary": true }],
      "no-unused-labels": "warn",
      "no-useless-call": "warn",
      "no-useless-concat": "warn",
      "no-useless-escape": "warn",
      "no-void": "warn",
      "no-warning-comments": ["warn", { "terms": ["todo", "fixme"], "location": "anywhere" }],
      "no-with": "error",
      "radix": "error",
      "vars-on-top": "warn",
      "wrap-iife": ["error", "any"],
      "yoda": "off",
  
      "strict": ["error", "function"],
  
      "init-declarations": "off",
      "no-catch-shadow": "error",
      "no-delete-var": "error",
      "no-label-var": "error",
      "no-restricted-globals": "error",
      "no-shadow-restricted-names": "error",
      "no-undef": "error",
      "no-undef-init": "error",
      "no-undefined": "error",
      "no-unused-vars": "error",  
      "callback-return": ["warn", ["callback", "cb", "next"]],
      "handle-callback-err": "error",
      "no-mixed-requires": "warn",
      "no-new-require": "error",
      "no-path-concat": "error",
      "no-process-exit": "warn",
      "no-restricted-modules": "off",
      "no-sync": "off",
      "no-console": "off",
      "array-bracket-spacing": ["error", "always"],
      "block-spacing": ["error", "always"],
      "comma-spacing": ["error", { "before": false, "after": true }],
      "comma-style": ["error", "last"],
      "computed-property-spacing": ["error", "never"],
      "eol-last": "error",
      "func-style": "off",
      "id-blacklist": "off",
      "id-match": "off",
      "indent": ["error", 4],
      "jsx-quotes": ["error", "prefer-double"],
      "key-spacing": ["error", { "beforeColon": false, "afterColon": true }],
      "keyword-spacing": ["error", { "before": true, "after": true }],
      "linebreak-style": ["error", "unix"],
      "max-depth": "off",
      "max-nested-callbacks": ["warn", 3],
      "max-params": "off",
      "max-statements": "off",
      "max-statements-per-line": "off",
      "new-parens": "error",
      "newline-after-var": ["error", "always"],
      "newline-before-return": "warn",
      "no-array-constructor": "error",
      "no-lonely-if": "warn",
      "no-mixed-spaces-and-tabs": "error",
      "no-nested-ternary": "error",
      "no-new-object": "error",
      "no-plusplus": "off",
      "no-restricted-syntax": "off",
      "no-spaced-func": "error",
      "no-ternary": "off",
      "no-trailing-spaces": "error",
      "no-underscore-dangle": "warn",
      "no-unneeded-ternary": "error",
      "no-whitespace-before-property": "error",
      "object-curly-spacing": ["error", "always"],
      "object-property-newline": "off",
      "one-var": "off",
      "one-var-declaration-per-line": "warn",
      "operator-assignment": "off",
      "operator-linebreak": ["error", "after"],
      "padded-blocks": ["error", "never"],
      "quote-props": "off",
      "quotes": ["error", "single", "avoid-escape"],
      "require-jsdoc": "off",
      "semi-spacing": ["error", { "before": false, "after": true }],
      "sort-vars": "off",
      "space-infix-ops": ["error", { "int32Hint": false }],
      "space-unary-ops": ["warn", { "words": true, "nonwords": false }],
      "unicode-bom": "off",
      "wrap-regex": "warn",
      "constructor-super": "error",
      "generator-star-spacing": ["error", { "before": false, "after": true }],
      "no-class-assign": "error",
      "no-confusing-arrow": "warn",
      "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": "warn",
      "no-var": "error",
      "object-shorthand": "warn",
      "prefer-arrow-callback": "warn",
      "prefer-const": "error",
      "prefer-rest-params": "warn",
      "prefer-spread": "warn",
      "prefer-template": "warn",
      "require-yield": "error",
      "sort-imports": "off",
      "template-curly-spacing": ["error", "never"],
      "yield-star-spacing": ["error", "after"]
    }
  }