node/tools/node_modules/eslint/lib/rules/no-eq-null.js
Rich Trott 0863a0e528 tools: update ESLint to 4.19.1
A few bug fixes result in more stringent linting rules.

PR-URL: https://github.com/nodejs/node/pull/19528
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: Daniel Bevenius <daniel.bevenius@gmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
Reviewed-By: Trivikram Kamat <trivikr.dev@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
2018-03-24 04:11:48 -07:00

45 lines
1.2 KiB
JavaScript

/**
* @fileoverview Rule to flag comparisons to null without a type-checking
* operator.
* @author Ian Christian Myers
*/
"use strict";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
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" });
}
}
};
}
};