1 | /**
|
2 | * @fileoverview Rule to flag bitwise identifiers
|
3 | * @author Nicholas C. Zakas
|
4 | */
|
5 |
|
6 | ;
|
7 |
|
8 | /*
|
9 | *
|
10 | * Set of bitwise operators.
|
11 | *
|
12 | */
|
13 | const BITWISE_OPERATORS = [
|
14 | "^", "|", "&", "<<", ">>", ">>>",
|
15 | "^=", "|=", "&=", "<<=", ">>=", ">>>=",
|
16 | "~"
|
17 | ];
|
18 |
|
19 | //------------------------------------------------------------------------------
|
20 | // Rule Definition
|
21 | //------------------------------------------------------------------------------
|
22 |
|
23 | module.exports = {
|
24 | meta: {
|
25 | docs: {
|
26 | description: "disallow bitwise operators",
|
27 | category: "Stylistic Issues",
|
28 | recommended: false,
|
29 | url: "https://eslint.org/docs/rules/no-bitwise"
|
30 | },
|
31 |
|
32 | schema: [
|
33 | {
|
34 | type: "object",
|
35 | properties: {
|
36 | allow: {
|
37 | type: "array",
|
38 | items: {
|
39 | enum: BITWISE_OPERATORS
|
40 | },
|
41 | uniqueItems: true
|
42 | },
|
43 | int32Hint: {
|
44 | type: "boolean"
|
45 | }
|
46 | },
|
47 | additionalProperties: false
|
48 | }
|
49 | ],
|
50 |
|
51 | messages: {
|
52 | unexpected: "Unexpected use of '{{operator}}'."
|
53 | }
|
54 | },
|
55 |
|
56 | create(context) {
|
57 | const options = context.options[0] || {};
|
58 | const allowed = options.allow || [];
|
59 | const int32Hint = options.int32Hint === true;
|
60 |
|
61 | /**
|
62 | * Reports an unexpected use of a bitwise operator.
|
63 | * @param {ASTNode} node Node which contains the bitwise operator.
|
64 | * @returns {void}
|
65 | */
|
66 | function report(node) {
|
67 | context.report({ node, messageId: "unexpected", data: { operator: node.operator } });
|
68 | }
|
69 |
|
70 | /**
|
71 | * Checks if the given node has a bitwise operator.
|
72 | * @param {ASTNode} node The node to check.
|
73 | * @returns {boolean} Whether or not the node has a bitwise operator.
|
74 | */
|
75 | function hasBitwiseOperator(node) {
|
76 | return BITWISE_OPERATORS.indexOf(node.operator) !== -1;
|
77 | }
|
78 |
|
79 | /**
|
80 | * Checks if exceptions were provided, e.g. `{ allow: ['~', '|'] }`.
|
81 | * @param {ASTNode} node The node to check.
|
82 | * @returns {boolean} Whether or not the node has a bitwise operator.
|
83 | */
|
84 | function allowedOperator(node) {
|
85 | return allowed.indexOf(node.operator) !== -1;
|
86 | }
|
87 |
|
88 | /**
|
89 | * Checks if the given bitwise operator is used for integer typecasting, i.e. "|0"
|
90 | * @param {ASTNode} node The node to check.
|
91 | * @returns {boolean} whether the node is used in integer typecasting.
|
92 | */
|
93 | function isInt32Hint(node) {
|
94 | return int32Hint && node.operator === "|" && node.right &&
|
95 | node.right.type === "Literal" && node.right.value === 0;
|
96 | }
|
97 |
|
98 | /**
|
99 | * Report if the given node contains a bitwise operator.
|
100 | * @param {ASTNode} node The node to check.
|
101 | * @returns {void}
|
102 | */
|
103 | function checkNodeForBitwiseOperator(node) {
|
104 | if (hasBitwiseOperator(node) && !allowedOperator(node) && !isInt32Hint(node)) {
|
105 | report(node);
|
106 | }
|
107 | }
|
108 |
|
109 | return {
|
110 | AssignmentExpression: checkNodeForBitwiseOperator,
|
111 | BinaryExpression: checkNodeForBitwiseOperator,
|
112 | UnaryExpression: checkNodeForBitwiseOperator
|
113 | };
|
114 |
|
115 | }
|
116 | };
|