recipe-writer

OpenRewrite recipes use declarative YAML, Refaster templates, or imperative Java to automate code migrations and refactoring. Test-first development—writing test cases before implementing the recipe logic—ensures reliability. Plan your recipe type based on complexity, implement visitor patterns or JavaTemplate usage, and validate with RewriteTest coverage before deployment.

Use test-first development: define test cases covering your migration scenarios, implement the recipe (YAML for simple transforms, Java for complex LST manipulation), apply preconditions to target the right code, then validate across your full codebase. This RED-GREEN-REFACTOR workflow catches edge cases early and produces production-ready recipes.

Yes. OpenRewrite recipes handle Java code refactoring, YAML transformations, Kubernetes manifests, GitHub Actions, and related declarative formats. Choose YAML recipes for straightforward structural changes or Java recipes for complex logic involving visitor patterns and LST traversal.

Not always. Declarative YAML recipes suit simple transformations. Refaster templates offer a middle ground for templated replacements. Only complex migrations requiring visitor pattern logic, JavaTemplate usage, and precondition scanning demand imperative Java—test-first practices help validate either approach.

Production recipes require comprehensive RewriteTest coverage, proper visitor pattern implementation or JavaTemplate usage, preconditions to scope transformations, robust documentation, and validated packaging for distribution. Test-first development ensures functional requirements are met and edge cases in code migrations are handled correctly.

Use RewriteTest to write test cases covering before-and-after code transformations, edge cases, and precondition scenarios. Test-first development means writing these tests before recipe logic, running the RED-GREEN-REFACTOR cycle, and validating that your recipe produces the expected refactored output reliably.