.eslintrc.json

{
    "extends": "airbnb",
    "parser": "babel-eslint",
    "env": {
        "browser": true,
        "webextensions": true
    },
    "rules": {
        "arrow-parens": [
            "error",
            "always"
        ],
        "quotes": [
            2,
            "single",
            "avoid-escape"
        ],
        "indent": [
            "error",
            4
        ],
        "no-extend-native": [
            "error", 
            { 
                "exceptions": [
                    "Date"
                ] 
            }
        ],
        "implicit-arrow-linebreak": [
            0,
            "below"
        ],       
        "object-shorthand": [
            "warn"
        ],
        "consistent-return": [
            "warn"
        ],        
        "object-curly-newline": [
            "error",
            {
                "multiline": true
            }
        ],
        "max-len": [
            "warn",
            120
        ]
    }
}