error-pattern-safety

Infinite loops in regex occur when zero-width matches advance without consuming input. Prevent them by ensuring your patterns consume at least one character per match, using possessive quantifiers, or adding iteration caps. This Skill provides validation tests and safe pattern guidelines for error matching in AI agents.

Zero-width matches are regex patterns that succeed without advancing the input position, like lookaheads or anchors. In loops, they repeat infinitely because the engine retries the same position. This Skill teaches detection and safety rules to identify and eliminate zero-width hazards in JavaScript and Go regex.

Yes. This Skill is designed specifically for developers building or extending AI agent engines. It provides error pattern matching guidelines that prevent system hangs, ensuring agents remain stable and operational without freezing on malformed input patterns.

Use built-in validation tests and safety checks to verify pattern safety. This Skill documents mechanisms in validate_errors.cjs and related unit tests that implement zero-width progression checks and iteration caps to catch dangerous patterns before deployment.

Dangerous patterns use unanchored quantifiers on zero-width assertions like `(?=.*)*` which repeat infinitely. Safe alternatives constrain matches to consume input or use bounded repetition. This Skill contrasts both types with examples specific to error pattern matching in agent systems.

Yes. This Skill covers zero-width match safety and validation for both JavaScript and Go regex implementations used in error pattern testing, with language-specific safety rules and guidelines for each.