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/**
* @fileoverview Rule to flag comparisons to the value NaN
* @author James Allardice
*/
"use strict";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
type: "problem",
docs: {
description: "require calls to `isNaN()` when checking for `NaN`",
category: "Possible Errors",
recommended: true,
url: "https://eslint.org/docs/rules/use-isnan"
},
schema: [],
messages: {
useIsNaN: "Use the isNaN function to compare with NaN."
}
},
create(context) {
return {
BinaryExpression(node) {
if (/^(?:[<>]|[!=]=)=?$/u.test(node.operator) && (node.left.name === "NaN" || node.right.name === "NaN")) {
context.report({ node, messageId: "useIsNaN" });
}
}
};
}
};