| /** |
| * @fileoverview Rule to flag bitwise identifiers |
| * @author Nicholas C. Zakas |
| */ |
| |
| "use strict"; |
| |
| /* |
| * |
| * Set of bitwise operators. |
| * |
| */ |
| const BITWISE_OPERATORS = [ |
| "^", "|", "&", "<<", ">>", ">>>", |
| "^=", "|=", "&=", "<<=", ">>=", ">>>=", |
| "~" |
| ]; |
| |
| //------------------------------------------------------------------------------ |
| // Rule Definition |
| //------------------------------------------------------------------------------ |
| |
| module.exports = { |
| meta: { |
| type: "suggestion", |
| |
| docs: { |
| description: "disallow bitwise operators", |
| category: "Stylistic Issues", |
| recommended: false, |
| url: "https://eslint.org/docs/rules/no-bitwise" |
| }, |
| |
| schema: [ |
| { |
| type: "object", |
| properties: { |
| allow: { |
| type: "array", |
| items: { |
| enum: BITWISE_OPERATORS |
| }, |
| uniqueItems: true |
| }, |
| int32Hint: { |
| type: "boolean", |
| default: false |
| } |
| }, |
| additionalProperties: false |
| } |
| ], |
| |
| messages: { |
| unexpected: "Unexpected use of '{{operator}}'." |
| } |
| }, |
| |
| create(context) { |
| const options = context.options[0] || {}; |
| const allowed = options.allow || []; |
| const int32Hint = options.int32Hint === true; |
| |
| /** |
| * Reports an unexpected use of a bitwise operator. |
| * @param {ASTNode} node Node which contains the bitwise operator. |
| * @returns {void} |
| */ |
| function report(node) { |
| context.report({ node, messageId: "unexpected", data: { operator: node.operator } }); |
| } |
| |
| /** |
| * Checks if the given node has a bitwise operator. |
| * @param {ASTNode} node The node to check. |
| * @returns {boolean} Whether or not the node has a bitwise operator. |
| */ |
| function hasBitwiseOperator(node) { |
| return BITWISE_OPERATORS.indexOf(node.operator) !== -1; |
| } |
| |
| /** |
| * Checks if exceptions were provided, e.g. `{ allow: ['~', '|'] }`. |
| * @param {ASTNode} node The node to check. |
| * @returns {boolean} Whether or not the node has a bitwise operator. |
| */ |
| function allowedOperator(node) { |
| return allowed.indexOf(node.operator) !== -1; |
| } |
| |
| /** |
| * Checks if the given bitwise operator is used for integer typecasting, i.e. "|0" |
| * @param {ASTNode} node The node to check. |
| * @returns {boolean} whether the node is used in integer typecasting. |
| */ |
| function isInt32Hint(node) { |
| return int32Hint && node.operator === "|" && node.right && |
| node.right.type === "Literal" && node.right.value === 0; |
| } |
| |
| /** |
| * Report if the given node contains a bitwise operator. |
| * @param {ASTNode} node The node to check. |
| * @returns {void} |
| */ |
| function checkNodeForBitwiseOperator(node) { |
| if (hasBitwiseOperator(node) && !allowedOperator(node) && !isInt32Hint(node)) { |
| report(node); |
| } |
| } |
| |
| return { |
| AssignmentExpression: checkNodeForBitwiseOperator, |
| BinaryExpression: checkNodeForBitwiseOperator, |
| UnaryExpression: checkNodeForBitwiseOperator |
| }; |
| |
| } |
| }; |