ast-grep vs CodART

ast-grep is a free, open-source tool for structural code search, linting, and rewriting. It matches patterns against syntax-tree nodes, helping developers locate and change code across a codebase rather than searching plain text. Its CLI can preview and apply rewrites interactively, and scan configurable YAML rules with error, warning, info, or hint severity. Rules can combine pattern, kind, regex, relational, and composite conditions, and CLI commands help create and snapshot-test them. The project says it supports more than 20 languages and can load custom languages. JavaScript and WebAssembly APIs allow programmatic syntax-tree work; a browser playground offers a way to try patterns without local installation. Editor options include a VS Code extension and language-server setups, including for Vim and Neovim. The tool is free, has a web interface, and is distributed through package managers or built from source. Its FAQ notes that some advanced static-analysis information is unsupported, and one rule cannot target multiple languages at once.

CodART is a toolkit for automated refactoring and multi-objective optimization of Java source code. It documents 47 refactoring operations, including Extract Class, Move Method, and Encapsulate Field, and supports project-level and batch work. Its optimization uses NSGA-II and NSGA-III across eight QMOOD quality metrics. The toolkit also includes PPO-based generation of refactoring sequences and models that predict testability from source code metrics. PMD integration with custom rulesets supports code smell detection, while SciTools Understand handles code parsing and metric computation. The documented interfaces are a React web interface and a FastAPI REST API, and Docker Compose instructions explain how to run the services locally. CodART is free under an MIT License, which permits use, copying, modification, distribution, sublicensing, and sale subject to its conditions. The setup requires a separate SciTools Understand professional license; academic licenses are available for research purposes. The quick-start calls for at least 8 GB RAM and 4 CPU cores, with 12 GB or more recommended for large projects. Java is its listed supported language.