| /** |
| * @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" }); |
| } |
| } |
| }; |
| |
| } |
| }; |