.eslintrc.js

module.exports = {
    // start with google standard style
    //     https://github.com/google/eslint-config-google/blob/master/index.js
    "extends": ["eslint:recommended", "google"],
    "env": {
        "node": true,
        "es6": true
    },
    "rules": {
        // 2 == error, 1 == warning, 0 == off
        "indent": [2, 4, {
            "SwitchCase": 1,
            "VariableDeclarator": 2
        }],
        "max-len": [2, 140, {
            "ignoreComments": true,
            "ignoreUrls": true,
            "tabWidth": 2
        }],
        "no-empty": [2, {
            "allowEmptyCatch": true
        }],
        "no-implicit-coercion": [2, {
            "boolean": false,
            "number": true,
            "string": true
        }],
        "no-unused-expressions": [2, {
            "allowShortCircuit": true,
            "allowTernary": false
        }],
        "no-unused-vars": [2, {
            "vars": "all",
            "args": "after-used",
            "argsIgnorePattern": "(^reject$|^_$)",
            "varsIgnorePattern": "(^_$)"
        }],
        "quotes": [2, "double"],
        "strict": [2, "global"],
        "prefer-const": 2,

        // Disabled rules
        "require-jsdoc": 0,
        "valid-jsdoc": 0,
        "comma-dangle": 0,
        "arrow-parens": 0,
        "no-console": 0,
        // Compat: support for rest params is behind a flag for node v5.x
        "prefer-rest-params": 0,
    },
    "parserOptions": {
        "ecmaVersion": 6,
        "ecmaFeatures": {
            "globalReturn": true,
            "jsx": false,
            "experimentalObjectRestSpread": false
        },
        "sourceType": "module"
    }
}