.eslintrc-base.json

{
  "rules": {
    // Rules are divided into sections from http://eslint.org/docs/rules/

    // Possible errors
    "comma-dangle": ["error", "never"],
    "no-cond-assign": ["error", "except-parens"],
    "no-constant-condition": ["error", {"checkLoops": false}],
    "no-control-regex": "error",
    "no-debugger": "error",
    "no-dupe-args": "error",
    "no-dupe-keys": "error",
    "no-duplicate-case": "error",
    "no-empty-character-class": "error",
    "no-empty": "error",
    "no-ex-assign": "error",
    "no-extra-boolean-cast": "error",
    "no-extra-semi": "error",
    "no-func-assign": "error",
    "no-inner-declarations": "error",
    "no-invalid-regexp": "error",
    "no-irregular-whitespace": "error",
    "no-negated-in-lhs": "error",
    "no-obj-calls": "error",
    "no-regex-spaces": "error",
    "no-sparse-arrays": "error",
    "no-unreachable": "error",
    "use-isnan": "error",
    "no-unsafe-finally": "error",
    "valid-typeof": "error",
    "no-unexpected-multiline": "error",

    // Best practices
    "accessor-pairs": "error",
    "array-callback-return": "error",
    "eqeqeq": ["error", "allow-null"],
    "no-alert": "error",
    "no-caller": "error",
    "no-case-declarations": "error",
    "no-eval": "error",
    "no-extend-native": "error",
    "no-extra-bind": "error",
    "no-extra-label": "error",
    "no-fallthrough": "error",
    "no-floating-decimal": "error",
    "no-implied-eval": "error",
    "no-invalid-this": "error",
    "no-iterator": "error",
    "no-multi-str": "error",
    "no-new-func": "error",
    "no-new-wrappers": "error",
    "no-new": "error",
    "no-octal-escape": "error",
    "no-octal": "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": "error",
    "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-with": "error",
    "radix": "error",
    "wrap-iife": ["error", "inside"],

    // Strict mode
    "strict": ["error", "global"],

    // Variables
    "no-delete-var": "error",
    "no-label-var": "error",
    "no-restricted-globals": ["error", "event"],
    "no-shadow-restricted-names": "error",
    "no-undef-init": "error",
    "no-undef": "error",
    "no-unused-vars": ["error", { "vars": "local", "args": "none" }],

    // Node.js
    "handle-callback-err": "error",

    // Stylistic issues
    "array-bracket-spacing": ["error", "never"],
    "brace-style": ["error", "1tbs", { "allowSingleLine": true }],
    "comma-style": ["error", "last"],
    "eol-last": "error",
    "keyword-spacing": "error",
    "linebreak-style": ["error", "unix"],
    "max-len": ["error", { "code": 200, "ignoreComments": true, "ignoreUrls": true }],
    "new-cap": "error",
    "new-parens": "error",
    "no-array-constructor": "error",
    "no-bitwise": "error",
    "no-mixed-spaces-and-tabs": "error",
    "no-multiple-empty-lines": ["error", { "max": 3, "maxEOF": 1 }],
    "no-whitespace-before-property": "error",
    "no-spaced-func": "error",
    "no-trailing-spaces": "error",
    "no-unneeded-ternary": "error",
    "quotes": ["error", "single"],
    "semi-spacing": "error",
    "semi": "error",
    "space-before-blocks": ["error", "always"],
    "space-before-function-paren": ["error", "never"],
    "space-in-parens": ["error", "never"],
    "space-infix-ops": "error",
    "space-unary-ops": ["error", { "words": true, "nonwords": false }],
    "unicode-bom": ["error", "never"]
  }
}