no-eq-null.js
1.21 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
/**
* @fileoverview Rule to flag comparisons to null without a type-checking
* operator.
* @author Ian Christian Myers
*/
"use strict";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
type: "suggestion",
docs: {
description: "disallow `null` comparisons without type-checking operators",
category: "Best Practices",
recommended: false,
url: "https://eslint.org/docs/rules/no-eq-null"
},
schema: [],
messages: {
unexpected: "Use '===' to compare with null."
}
},
create(context) {
return {
BinaryExpression(node) {
const badOperator = node.operator === "==" || node.operator === "!=";
if (node.right.type === "Literal" && node.right.raw === "null" && badOperator ||
node.left.type === "Literal" && node.left.raw === "null" && badOperator) {
context.report({ node, messageId: "unexpected" });
}
}
};
}
};