.eslintrc.json

{
    "extends": "eslint:recommended",
    "parserOptions": {
        "ecmaVersion": 2018,
        "ecmaFeatures": {
            "jsx": false
        }
    },
    "env": {
        "node": true,
        "mocha": true,
        "es6": true
    },
    "globals": {
        "expect": false
    },
    "plugins": [
        "chai-expect"
    ],
    "settings": {
    },
    "rules": {
        "curly": ["error", "all"],
        "no-var": "error",
        "indent": ["error", 4, { "SwitchCase": 1 }],
        "semi": ["error", "always"],
        "object-curly-spacing": ["error", "always"],
        "comma-dangle": ["error", "only-multiline"],
        "space-before-function-paren": [
            "error",
            {
                "anonymous": "always",
                "named": "never",
                "asyncArrow": "always"
            }
        ],
        "padding-line-between-statements": [
            "error",
            {
                "blankLine": "always",
                "prev": ["directive", "import", "const", "let", "block-like"],
                "next": "*"
            },
            {
                "blankLine": "always",
                "prev": "*",
                "next": ["export", "return", "throw", "block-like"]
            },
            {
                "blankLine": "any",
                "prev": "import",
                "next": "import"
            },
            {
                "blankLine": "any",
                "prev": "const",
                "next": "const"
            },
            {
                "blankLine": "any",
                "prev": "let",
                "next": "let"
            }
        ],
        "padded-blocks": ["error", "never"],
        "prefer-rest-params": "error",
        "prefer-spread": "error",
        "prefer-const": "error",
        "chai-expect/terminating-properties": 1,
        "no-unused-expressions": "off"
    }
}