ast-grep

The ast-grep skill enables users to perform advanced structural code searches by leveraging Abstract Syntax Tree (AST) patterns. Unlike traditional text-based search tools, ast-grep allows precise matching of code structures, making it possible to locate specific constructs, patterns, or behaviors across large codebases. This skill is designed to translate natural language queries into ast-grep rules, helping users define search criteria that reflect the actual structure of the code rather than relying solely on textual matches. It is particularly useful for developers, code reviewers, and analysts who need to understand code patterns in depth or identify potential issues that are not easily detectable through simple search methods.

Key capabilities of this skill include the ability to create example code snippets to model desired matches, define simple or complex ast-grep rules using patterns, kinds, and relational operators, and test these rules either inline or via rule files. Users can construct hierarchical queries using sub-rules with logical operators such as all, any, and not. The skill also provides guidance on debugging and refining rules, including the use of the `stopBy: end` directive to ensure accurate relational matching. This structured approach ensures that rules are both robust and adaptable to different programming languages and code structures.

Typical use cases for ast-grep include searching for all async functions that lack error handling, locating specific function calls with particular arguments, and performing complex queries that require understanding the underlying AST of code. The target users are developers, software engineers, and code auditors who need advanced code search capabilities, as well as teams performing code analysis or refactoring. This skill is suitable for projects where precise and structural code search can save time, improve code quality, and enhance maintainability.