@ifc-lite/regex-guard

Dependency-free validation for regular-expression patterns supplied by users or model files. Shared by IFC pattern-validation and editing tools.

Usage

import { compileGuardedRegex } from '@ifc-lite/regex-guard';

const pattern = compileGuardedRegex('^Wall-[0-9]+$', 'i');
console.log(pattern.test('Wall-42')); // true

compileGuardedRegex(pattern, flags?, { maxLength? }?) validates the pattern before constructing a JavaScript RegExp. Rejected patterns throw UnsafeRegexPatternError, which exposes pattern and reason. A malformed pattern that passes the guard can still throw the native SyntaxError.

Other exports:

• compileNameMatcher(pattern) / isNamePattern(pattern): cached exact-or-/regex/flags name matching shared by Lists and Rules; guarded patterns retain the Lists API behavior.
• unsafeNamePatternReason(pattern): inspect a name-pattern rejection without compiling it.
• assertGuardedRegexPattern(pattern, { maxLength? }?): validate without compiling.
• hasCatastrophicBacktrackingShape(pattern): detect the nested-quantifier shapes covered by the heuristic.
• MAX_GUARDED_REGEX_PATTERN_LENGTH: the default limit of 256 characters.

Limits

This is a heuristic, not a guarantee of bounded execution time. It rejects known nested-quantifier patterns such as (a+)+ and caps pattern length, but it does not analyze every possible backtracking shape. It does not move matches to a worker, enforce a match timeout, or replace JavaScript's regex engine.

License

MPL-2.0.