.eslintrc.json

{
  "root": true,
  "extends": ["eslint:recommended"],
  "rules": {
    "curly": "error",
    "no-restricted-syntax": [
      "error",
      {
        "selector": "SequenceExpression",
        "message": "The comma operator is confusing and a common mistake. Don’t use it!"
      }
    ]
  },
  "overrides": [
    {
      "files": ["*.js"],
      "excludedFiles": ["patch.js"],
      "env": {
        "node": true,
        "es2020": true
      },
      "rules": {
        "no-var": "error",
        "object-shorthand": "error",
        "one-var": ["error", "never"],
        "prefer-arrow-callback": "error",
        "prefer-const": "error",
        "prefer-destructuring": [
          "error",
          {
            "object": true,
            "array": false
          }
        ],
        "prefer-exponentiation-operator": "error",
        "prefer-numeric-literals": "error",
        "prefer-object-spread": "error",
        "prefer-promise-reject-errors": "error",
        "prefer-regex-literals": "error",
        "prefer-rest-params": "error",
        "prefer-spread": "error",
        "prefer-template": "error"
      }
    },
    {
      "files": ["patch.js"],
      "env": {
        "browser": true
      },
      "rules": {
        "one-var": [
          "error",
          {
            "var": "always",
            "separateRequires": true
          }
        ]
      }
    },
    {
      "files": "tests/**/*.js",
      "extends": ["plugin:jest/recommended", "plugin:jest/style"],
      "env": {
        "browser": true
      }
    }
  ]
}