Using ast-grep for Code Refactoring in Elixir

The article introduces ast-grep, a powerful tool designed to enhance code refactoring by using abstract syntax trees (AST) rather than just plain text matching. It showcases how to use ast-grep to clean up an Elixir codebase, addressing various stylistic inconsistencies caused by multiple developers over the years. Through examples, it illustrates how to create rules for ast-grep to effectively refactor code by applying relational patterns, managing newlines, and parameterizing certain aspects to cover multiple scenarios. The use of multi meta variables and constraints for variable types is also discussed, emphasizing the tool's capabilities in automating code clean-ups across large codebases. The article concludes by encouraging developers to leverage ast-grep for structured code refactoring, highlighting available resources for further exploration.