/** * @fileoverview Rule to flag for-in loops without if statements inside * @author Nicholas C. Zakas */ "use strict"; //------------------------------------------------------------------------------ // Rule Definition //------------------------------------------------------------------------------ module.exports = { meta: { docs: { description: "require `for-in` loops to include an `if` statement", category: "Best Practices", recommended: false }, schema: [] }, create: function(context) { return { ForInStatement: function(node) { /* * If the for-in statement has {}, then the real body is the body * of the BlockStatement. Otherwise, just use body as provided. */ var body = node.body.type === "BlockStatement" ? node.body.body[0] : node.body; if (body && body.type !== "IfStatement") { context.report(node, "The body of a for-in should be wrapped in an if statement to filter unwanted properties from the prototype."); } } }; } };