no-negated-in-lhs.js
672 Bytes
/**
* @fileoverview A rule to disallow negated left operands of the `in` operator
* @author Michael Ficarra
*/
"use strict";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = function(context) {
return {
"BinaryExpression": function(node) {
if (node.operator === "in" && node.left.type === "UnaryExpression" && node.left.operator === "!") {
context.report(node, "The `in` expression's left operand is negated");
}
}
};
};
module.exports.schema = [];