.eslintrc.json

{
  "env": {
    "browser": false,
    "commonjs": true,
    "es6": true,
    "node": true,
    "mocha": true
  },
  "parserOptions": {
    "ecmaVersion": 2018,
    "ecmaFeatures": {
      "jsx": true
    },
    "sourceType": "module"
  },
  "rules": {
    "constructor-super": "warn",
    "no-const-assign": "warn",
    "no-this-before-super": "warn",
    "no-undef": "warn",
    "no-unreachable": "warn",
    "no-unused-vars": "warn",
    "prefer-arrow-callback": "error",
    "prefer-const": "error",
    "prefer-destructuring": [
      "error",
      {
        "AssignmentExpression": {
          "array": false,
          "object": false
        },
        "VariableDeclarator": {
          "array": false,
          "object": true
        }
      }
    ],
    "prefer-exponentiation-operator": "error",
    "prefer-numeric-literals": "error",
    "prefer-object-spread": "error",
    "prefer-template": "error",
    "valid-typeof": "warn"
  }
}