| /** | |
|  * @fileoverview Rule to forbid control characters from regular expressions. | |
|  * @author Nicholas C. Zakas | |
|  */ | |
| 
 | |
| "use strict"; | |
| 
 | |
| const RegExpValidator = require("@eslint-community/regexpp").RegExpValidator; | |
| const collector = new (class { | |
|     constructor() { | |
|         this._source = ""; | |
|         this._controlChars = []; | |
|         this._validator = new RegExpValidator(this); | |
|     } | |
| 
 | |
|     onPatternEnter() { | |
| 
 | |
|         /* | |
|          * `RegExpValidator` may parse the pattern twice in one `validatePattern`. | |
|          * So `this._controlChars` should be cleared here as well. | |
|          * | |
|          * For example, the `/(?<a>\x1f)/` regex will parse the pattern twice. | |
|          * This is based on the content described in Annex B. | |
|          * If the regex contains a `GroupName` and the `u` flag is not used, `ParseText` will be called twice. | |
|          * See https://tc39.es/ecma262/2023/multipage/additional-ecmascript-features-for-web-browsers.html#sec-parsepattern-annexb | |
|          */ | |
|         this._controlChars = []; | |
|     } | |
| 
 | |
|     onCharacter(start, end, cp) { | |
|         if (cp >= 0x00 && | |
|             cp <= 0x1F && | |
|             ( | |
|                 this._source.codePointAt(start) === cp || | |
|                 this._source.slice(start, end).startsWith("\\x") || | |
|                 this._source.slice(start, end).startsWith("\\u") | |
|             ) | |
|         ) { | |
|             this._controlChars.push(`\\x${`0${cp.toString(16)}`.slice(-2)}`); | |
|         } | |
|     } | |
| 
 | |
|     collectControlChars(regexpStr, flags) { | |
|         const uFlag = typeof flags === "string" && flags.includes("u"); | |
|         const vFlag = typeof flags === "string" && flags.includes("v"); | |
| 
 | |
|         this._controlChars = []; | |
|         this._source = regexpStr; | |
| 
 | |
|         try { | |
|             this._validator.validatePattern(regexpStr, void 0, void 0, { unicode: uFlag, unicodeSets: vFlag }); // Call onCharacter hook | |
|         } catch { | |
| 
 | |
|             // Ignore syntax errors in RegExp. | |
|         } | |
|         return this._controlChars; | |
|     } | |
| })(); | |
| 
 | |
| //------------------------------------------------------------------------------ | |
| // Rule Definition | |
| //------------------------------------------------------------------------------ | |
|  | |
| /** @type {import('../shared/types').Rule} */ | |
| module.exports = { | |
|     meta: { | |
|         type: "problem", | |
| 
 | |
|         docs: { | |
|             description: "Disallow control characters in regular expressions", | |
|             recommended: true, | |
|             url: "https://eslint.org/docs/latest/rules/no-control-regex" | |
|         }, | |
| 
 | |
|         schema: [], | |
| 
 | |
|         messages: { | |
|             unexpected: "Unexpected control character(s) in regular expression: {{controlChars}}." | |
|         } | |
|     }, | |
| 
 | |
|     create(context) { | |
| 
 | |
|         /** | |
|          * Get the regex expression | |
|          * @param {ASTNode} node `Literal` node to evaluate | |
|          * @returns {{ pattern: string, flags: string | null } | null} Regex if found (the given node is either a regex literal | |
|          * or a string literal that is the pattern argument of a RegExp constructor call). Otherwise `null`. If flags cannot be determined, | |
|          * the `flags` property will be `null`. | |
|          * @private | |
|          */ | |
|         function getRegExp(node) { | |
|             if (node.regex) { | |
|                 return node.regex; | |
|             } | |
|             if (typeof node.value === "string" && | |
|                 (node.parent.type === "NewExpression" || node.parent.type === "CallExpression") && | |
|                 node.parent.callee.type === "Identifier" && | |
|                 node.parent.callee.name === "RegExp" && | |
|                 node.parent.arguments[0] === node | |
|             ) { | |
|                 const pattern = node.value; | |
|                 const flags = | |
|                     node.parent.arguments.length > 1 && | |
|                     node.parent.arguments[1].type === "Literal" && | |
|                     typeof node.parent.arguments[1].value === "string" | |
|                         ? node.parent.arguments[1].value | |
|                         : null; | |
| 
 | |
|                 return { pattern, flags }; | |
|             } | |
| 
 | |
|             return null; | |
|         } | |
| 
 | |
|         return { | |
|             Literal(node) { | |
|                 const regExp = getRegExp(node); | |
| 
 | |
|                 if (regExp) { | |
|                     const { pattern, flags } = regExp; | |
|                     const controlCharacters = collector.collectControlChars(pattern, flags); | |
| 
 | |
|                     if (controlCharacters.length > 0) { | |
|                         context.report({ | |
|                             node, | |
|                             messageId: "unexpected", | |
|                             data: { | |
|                                 controlChars: controlCharacters.join(", ") | |
|                             } | |
|                         }); | |
|                     } | |
|                 } | |
|             } | |
|         }; | |
| 
 | |
|     } | |
| };
 |