.eslintrc.json

{
    "env": {
        "browser": true,
        "es6": true,
        "webextensions": true
    },
    "extends": ["eslint:recommended"],
    "globals": {
        "Atomics": "readonly",
        "SharedArrayBuffer": "readonly"
    },
    "parserOptions": {
        "ecmaVersion": 2017
    },
    "rules": {
        "block-spacing": ["error"],
        "brace-style": ["error"],
        "camelcase": ["error"],
        "comma-spacing": ["error"],
        "curly": ["error"],
        "eqeqeq": ["error"],
        "func-call-spacing": ["error"],
        "indent": ["error", 2],
        "key-spacing": ["error"],
        "keyword-spacing": ["error"],
        "new-parens": ["error"],
        "no-eval": ["error"],
        "no-extra-parens": ["error"],
        "no-multi-spaces": ["error"],
        "no-multiple-empty-lines": ["error"],
        "no-trailing-spaces": ["error"],
        "no-useless-rename": ["error"],
        "no-var": ["error"],
        "no-whitespace-before-property": ["error"],
        "object-property-newline": ["error", {
            "allowAllPropertiesOnSameLine": true
        }],
        "object-shorthand": ["error"],
        "one-var": ["error", "never"],
        "operator-linebreak": ["error"],
        "padded-blocks": ["error", "never"],
        "quotes": ["error", "single"],
        "semi": ["error", "never"],
        "space-infix-ops": ["error"]
    },
    "overrides": [
        {
            "files": ["./web-ext-config.js"],
            "env": {
                "node": true
            }
        }
    ]
}