source: imaps-frontend/node_modules/eslint/lib/rules/no-unsafe-negation.js

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Last change on this file was d565449, checked in by stefan toskovski <stefantoska84@…>, 4 weeks ago

Update repo after prototype presentation

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1/**
2 * @fileoverview Rule to disallow negating the left operand of relational operators
3 * @author Toru Nagashima
4 */
5
6"use strict";
7
8//------------------------------------------------------------------------------
9// Requirements
10//------------------------------------------------------------------------------
11
12const astUtils = require("./utils/ast-utils");
13
14//------------------------------------------------------------------------------
15// Helpers
16//------------------------------------------------------------------------------
17
18/**
19 * Checks whether the given operator is `in` or `instanceof`
20 * @param {string} op The operator type to check.
21 * @returns {boolean} `true` if the operator is `in` or `instanceof`
22 */
23function isInOrInstanceOfOperator(op) {
24 return op === "in" || op === "instanceof";
25}
26
27/**
28 * Checks whether the given operator is an ordering relational operator or not.
29 * @param {string} op The operator type to check.
30 * @returns {boolean} `true` if the operator is an ordering relational operator.
31 */
32function isOrderingRelationalOperator(op) {
33 return op === "<" || op === ">" || op === ">=" || op === "<=";
34}
35
36/**
37 * Checks whether the given node is a logical negation expression or not.
38 * @param {ASTNode} node The node to check.
39 * @returns {boolean} `true` if the node is a logical negation expression.
40 */
41function isNegation(node) {
42 return node.type === "UnaryExpression" && node.operator === "!";
43}
44
45//------------------------------------------------------------------------------
46// Rule Definition
47//------------------------------------------------------------------------------
48
49/** @type {import('../shared/types').Rule} */
50module.exports = {
51 meta: {
52 type: "problem",
53
54 docs: {
55 description: "Disallow negating the left operand of relational operators",
56 recommended: true,
57 url: "https://eslint.org/docs/latest/rules/no-unsafe-negation"
58 },
59
60 hasSuggestions: true,
61
62 schema: [
63 {
64 type: "object",
65 properties: {
66 enforceForOrderingRelations: {
67 type: "boolean",
68 default: false
69 }
70 },
71 additionalProperties: false
72 }
73 ],
74
75 fixable: null,
76
77 messages: {
78 unexpected: "Unexpected negating the left operand of '{{operator}}' operator.",
79 suggestNegatedExpression: "Negate '{{operator}}' expression instead of its left operand. This changes the current behavior.",
80 suggestParenthesisedNegation: "Wrap negation in '()' to make the intention explicit. This preserves the current behavior."
81 }
82 },
83
84 create(context) {
85 const sourceCode = context.sourceCode;
86 const options = context.options[0] || {};
87 const enforceForOrderingRelations = options.enforceForOrderingRelations === true;
88
89 return {
90 BinaryExpression(node) {
91 const operator = node.operator;
92 const orderingRelationRuleApplies = enforceForOrderingRelations && isOrderingRelationalOperator(operator);
93
94 if (
95 (isInOrInstanceOfOperator(operator) || orderingRelationRuleApplies) &&
96 isNegation(node.left) &&
97 !astUtils.isParenthesised(sourceCode, node.left)
98 ) {
99 context.report({
100 node,
101 loc: node.left.loc,
102 messageId: "unexpected",
103 data: { operator },
104 suggest: [
105 {
106 messageId: "suggestNegatedExpression",
107 data: { operator },
108 fix(fixer) {
109 const negationToken = sourceCode.getFirstToken(node.left);
110 const fixRange = [negationToken.range[1], node.range[1]];
111 const text = sourceCode.text.slice(fixRange[0], fixRange[1]);
112
113 return fixer.replaceTextRange(fixRange, `(${text})`);
114 }
115 },
116 {
117 messageId: "suggestParenthesisedNegation",
118 fix(fixer) {
119 return fixer.replaceText(node.left, `(${sourceCode.getText(node.left)})`);
120 }
121 }
122 ]
123 });
124 }
125 }
126 };
127 }
128};
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