afv-library/skills/dx-code-analyzer-custom-rule-create/references/eslint-tier2-configurable.md

ESLint Tier 2: Configurable Rules

← Back to ESLint Rules Discovery

Tier 2: Configurable Rules

When no built-in rule exists but the pattern is generic (ban a function, ban a property, ban a syntax construct):

Option A: no-restricted-globals

Ban specific global functions or variables.

Example: Ban setTimeout/setInterval

// eslint.config.js
module.exports = [
  {
    files: ["**/lwc/**/*.js"],
    rules: {
      "no-restricted-globals": ["error",
        {
          name: "setTimeout",
          message: "Use LWC lifecycle hooks instead of setTimeout"
        },
        {
          name: "setInterval",
          message: "Use LWC lifecycle hooks instead of setInterval"
        }
      ]
    }
  }
];

Example: Ban window.localStorage

rules: {
  "no-restricted-globals": ["error",
    {
      name: "localStorage",
      message: "Use Salesforce state management instead of localStorage"
    }
  ]
}

Option B: no-restricted-syntax

Ban specific AST patterns using ESLint selectors.

Example: Ban eval() calls

rules: {
  "no-restricted-syntax": ["error",
    {
      selector: "CallExpression[callee.name='eval']",
      message: "eval() is forbidden for security reasons"
    }
  ]
}

Example: Ban innerHTML property access

rules: {
  "no-restricted-syntax": ["error",
    {
      selector: "MemberExpression[property.name='innerHTML']",
      message: "innerHTML is forbidden - use textContent or render() for XSS prevention"
    }
  ]
}

Example: Ban for-in loops

rules: {
  "no-restricted-syntax": ["error",
    {
      selector: "ForInStatement",
      message: "for-in loops are forbidden - use for-of or Object.keys()"
    }
  ]
}

ESLint Selector Syntax Cheat Sheet

Pattern	Selector	Example
Function call	CallExpression[callee.name='functionName']	eval(), alert()
Property access	MemberExpression[property.name='propName']	obj.innerHTML
Statement type	ForInStatement, WithStatement	for-in, with statements
Operator	BinaryExpression[operator='==']	== instead of ===
Literal value	Literal[value='string']	Specific string literals

Full selector docs: https://eslint.org/docs/latest/extend/selectors

Option C: no-restricted-properties

Ban specific object properties.

Example: Ban Object.prototype methods

rules: {
  "no-restricted-properties": ["error",
    {
      object: "Object",
      property: "setPrototypeOf",
      message: "setPrototypeOf is forbidden for performance reasons"
    }
  ]
}