87 lines
2.8 KiB
JavaScript
87 lines
2.8 KiB
JavaScript
/**
|
|
* @fileoverview Rule to disallow negating the left operand of relational operators
|
|
* @author Toru Nagashima
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Requirements
|
|
//------------------------------------------------------------------------------
|
|
|
|
const astUtils = require("../util/ast-utils");
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Helpers
|
|
//------------------------------------------------------------------------------
|
|
|
|
/**
|
|
* Checks whether the given operator is a relational operator or not.
|
|
*
|
|
* @param {string} op - The operator type to check.
|
|
* @returns {boolean} `true` if the operator is a relational operator.
|
|
*/
|
|
function isRelationalOperator(op) {
|
|
return op === "in" || op === "instanceof";
|
|
}
|
|
|
|
/**
|
|
* Checks whether the given node is a logical negation expression or not.
|
|
*
|
|
* @param {ASTNode} node - The node to check.
|
|
* @returns {boolean} `true` if the node is a logical negation expression.
|
|
*/
|
|
function isNegation(node) {
|
|
return node.type === "UnaryExpression" && node.operator === "!";
|
|
}
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Rule Definition
|
|
//------------------------------------------------------------------------------
|
|
|
|
module.exports = {
|
|
meta: {
|
|
type: "problem",
|
|
|
|
docs: {
|
|
description: "disallow negating the left operand of relational operators",
|
|
category: "Possible Errors",
|
|
recommended: true,
|
|
url: "https://eslint.org/docs/rules/no-unsafe-negation"
|
|
},
|
|
|
|
schema: [],
|
|
fixable: "code",
|
|
messages: {
|
|
unexpected: "Unexpected negating the left operand of '{{operator}}' operator."
|
|
}
|
|
},
|
|
|
|
create(context) {
|
|
const sourceCode = context.getSourceCode();
|
|
|
|
return {
|
|
BinaryExpression(node) {
|
|
if (isRelationalOperator(node.operator) &&
|
|
isNegation(node.left) &&
|
|
!astUtils.isParenthesised(sourceCode, node.left)
|
|
) {
|
|
context.report({
|
|
node,
|
|
loc: node.left.loc,
|
|
messageId: "unexpected",
|
|
data: { operator: node.operator },
|
|
|
|
fix(fixer) {
|
|
const negationToken = sourceCode.getFirstToken(node.left);
|
|
const fixRange = [negationToken.range[1], node.range[1]];
|
|
const text = sourceCode.text.slice(fixRange[0], fixRange[1]);
|
|
|
|
return fixer.replaceTextRange(fixRange, `(${text})`);
|
|
}
|
|
});
|
|
}
|
|
}
|
|
};
|
|
}
|
|
};
|