75 lines
1.6 KiB
JavaScript
75 lines
1.6 KiB
JavaScript
/**
|
|
* @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('../types').Rule.RuleModule} */
|
|
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 },
|
|
});
|
|
}
|
|
}
|
|
},
|
|
};
|
|
},
|
|
};
|