| /** | |
|  * @fileoverview The rule should warn against code that tries to compare against -0. | |
|  * @author Aladdin-ADD <hh_2013@foxmail.com> | |
|  */ | |
| "use strict"; | |
| 
 | |
| //------------------------------------------------------------------------------ | |
| // Rule Definition | |
| //------------------------------------------------------------------------------ | |
|  | |
| /** @type {import('../shared/types').Rule} */ | |
| module.exports = { | |
|     meta: { | |
|         type: "problem", | |
| 
 | |
|         docs: { | |
|             description: "Disallow comparing against -0", | |
|             recommended: true, | |
|             url: "https://eslint.org/docs/latest/rules/no-compare-neg-zero" | |
|         }, | |
| 
 | |
|         fixable: null, | |
|         schema: [], | |
| 
 | |
|         messages: { | |
|             unexpected: "Do not use the '{{operator}}' operator to compare against -0." | |
|         } | |
|     }, | |
| 
 | |
|     create(context) { | |
| 
 | |
|         //-------------------------------------------------------------------------- | |
|         // Helpers | |
|         //-------------------------------------------------------------------------- | |
|  | |
|         /** | |
|          * Checks a given node is -0 | |
|          * @param {ASTNode} node A node to check. | |
|          * @returns {boolean} `true` if the node is -0. | |
|          */ | |
|         function isNegZero(node) { | |
|             return node.type === "UnaryExpression" && node.operator === "-" && node.argument.type === "Literal" && node.argument.value === 0; | |
|         } | |
|         const OPERATORS_TO_CHECK = new Set([">", ">=", "<", "<=", "==", "===", "!=", "!=="]); | |
| 
 | |
|         return { | |
|             BinaryExpression(node) { | |
|                 if (OPERATORS_TO_CHECK.has(node.operator)) { | |
|                     if (isNegZero(node.left) || isNegZero(node.right)) { | |
|                         context.report({ | |
|                             node, | |
|                             messageId: "unexpected", | |
|                             data: { operator: node.operator } | |
|                         }); | |
|                     } | |
|                 } | |
|             } | |
|         }; | |
|     } | |
| };
 |