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672 BJavaScriptView Raw
1/**
2 * @fileoverview A rule to disallow negated left operands of the `in` operator
3 * @author Michael Ficarra
4 */
5
6"use strict";
7
8//------------------------------------------------------------------------------
9// Rule Definition
10//------------------------------------------------------------------------------
11
12module.exports = function(context) {
13
14 return {
15
16 "BinaryExpression": function(node) {
17 if (node.operator === "in" && node.left.type === "UnaryExpression" && node.left.operator === "!") {
18 context.report(node, "The 'in' expression's left operand is negated");
19 }
20 }
21 };
22
23};
24
25module.exports.schema = [];