.eslintrc

{
  "parser": "babel-eslint",
  "env": {
    "es6": true,
    "browser": true
  },
  "extends": "eslint:recommended",
  "ecmaFeatures": {
    "arrowFunctions": true,
    "binaryLiterals": true,
    "blockBindings": true,
    "classes": true,
    "defaultParams": true,
    "destructuring": true,
    "forOf": true,
    "generators": true,
    "modules": true,
    "objectLiteralComputedProperties": true,
    "objectLiteralDuplicateProperties": true,
    "objectLiteralShorthandMethods": true,
    "objectLiteralShorthandProperties": true,
    "octalLiterals": true,
    "regexUFlag": true,
    "regexYFlag": true,
    "spread": true,
    "superInFunctions": true,
    "templateStrings": true,
    "unicodeCodePointEscapes": true,
    "globalReturn": true,
    "jsx": true
  },
  "plugins": [
    "react"
  ],
  "rules": {
    "no-console": 0,
    // Possible errors
    "comma-dangle": [1, "always-multiline"], // Allow trailing commas in objects
    "no-cond-assign": 2, // disallow assignment in conditional expressions
    "no-dupe-args": 2, // disallow duplicate arguments in functions
    "no-dupe-keys": 2, // disallow duplicate keys when creating object literals
    "no-duplicate-case": 2, // disallow a duplicate case label.
    "no-empty": 2, // disallow empty statements
    "no-ex-assign": 2, // disallow assigning to the exception in a catch block
    "no-extra-semi": 2, // disallow unnecessary semicolons
    "no-func-assign": 2, // disallow overwriting functions written as function declarations
    "no-inner-declarations": 2, // disallow function or variable declarations in nested blocks
    "no-invalid-regexp": 2, // disallow invalid regular expression strings in the RegExp constructor
    "no-irregular-whitespace": 2, // disallow irregular whitespace outside of strings and comments
    "no-negated-in-lhs": 2, // disallow negation of the left operand of an in expression
    "no-obj-calls": 2, // disallow the use of object properties of the global object (Math and JSON) as functions
    "no-regex-spaces": 2, // disallow multiple spaces in a regular expression literal
    "no-sparse-arrays": 2, // disallow sparse arrays
    "no-unreachable": 2, // disallow unreachable statements after a return, throw, continue, or break statement
    "valid-typeof": 2, // Ensure that the results of typeof are compared against a valid string

    // Best Practices
    "semi": [2, "always"],
    "curly": 2, // specify curly brace conventions for all control statements
    "default-case": 2, // require default case in switch statements (off by default)
    "dot-notation": 2, // encourages use of dot notation whenever possible
    "eqeqeq": 2, // require the use of === and !==
    "no-extra-bind": 2, // disallow unnecessary function binding
    "no-lone-blocks": 2, // disallow unnecessary nested blocks
    "no-loop-func": 2, // disallow creation of functions within loops
    "no-multi-spaces": 2, // disallow use of multiple spaces
    "no-warning-comments": [0, {"terms": ["todo", "fixme"], "location": "start"}], // disallow usage of configurable warning terms in comments": 2, // e.g. TODO or FIXME (off by default)

    // Stylistic rules
    "indent": [2, 2, {"SwitchCase": 1}], // Set tabs to be 2 spaces
    "comma-spacing": [1, {"before": false, "after": true}], // enforce spacing before and after comma
    "comma-style": [1, "last"], // enforce one true comma style (off by default)
    "key-spacing": [1, {"beforeColon": false, "afterColon": true}], // enforces spacing between keys and values in object literal properties
    "no-mixed-spaces-and-tabs": 2, // Spaces only
    "no-multiple-empty-lines": [1, {"max": 2}], // max empty lines is 2
    "no-nested-ternary": 1, // warning if nested ternary
    "no-spaced-func": 1, // disallow space between function identifier and application
    "no-trailing-spaces": 1, // disallow trailing whitespace at the end of lines
    

    // ES6 Rules
    "no-var": 2,

    // For babel
    "strict": 0,

    // Variables
    "no-undef-init": 2, // disallow use of undefined when initializing variables
    "no-undefined": 2, // disallow use of undefined variable (off by default)
    "no-unused-vars": 2, // disallow declaration of variables that are not used in the code
    "no-use-before-define": 2, // disallow use of variables before they are defined


    // React rules
    "jsx-quotes": 2, // JSX Attributes must be double quotes
    "react/jsx-no-undef": 2, // Disallow undeclared variables in JSX
    "react/jsx-sort-props": 0, // Enforce props alphabetical sorting
    "react/jsx-uses-react": 2, // Prevent React to be incorrectly marked as unused
    "react/jsx-uses-vars": 2, // Prevent variables used in JSX to be incorrectly marked as unused
    "react/no-did-mount-set-state": 2, // Prevent usage of setState in componentDidMount
    "react/no-did-update-set-state": 2, // Prevent usage of setState in componentDidUpdate
    "react/no-multi-comp": 0, // Prevent multiple component definition per file
    "react/no-unknown-property": 2, // Prevent usage of unknown DOM property
    "react/prop-types": 2, // Prevent missing props validation in a React component definition
    "react/react-in-jsx-scope": 2, // Prevent missing React when using JSX
    "react/self-closing-comp": 1, // Prevent extra closing tags for components without children
    "react/wrap-multilines": 1, // Prevent missing parentheses around multilines JSX
  }
}