escodegen VS openapi-preprocessor

What's cool about Esprima syntax is that there are tools that generate code based on their AST. An example is escodegen which takes Esprima AST as input and outputs JavaScript code. You can think that you can use just strings to generate code, but this solution will not scale. In this tutorial, I show only a single if statement but you will run into a lot of problems if you will have more complex code.

Unparse the modified AST back into Javascript: Escodegen

I use a mixed approach for OpenAPI, but not bidirectional.

I have OpenAPI pieces generated from my Go source code (comment, types, function signatures) as JSON.

I also have a manually-edited master YAML document that refers to generated bits via $ref links.

I then use openapi-preprocessor [1] (disclaimer: I wrote it) to produce a final openapi.json file which is committed in the repo.

When I want to extend the API in a spec-first process, I can add the new routes manually in the YAML file. When I do the implementation I replace the manual bits by the generated one when they are ready. When committing I can check the diff of openapi.json to verify I'm not losing in the process.

[1] https://github.com/dolmen-go/openapi-preprocessor

Bundling for OpenAPI specification has long been a need for authors to allow to reduce duplication, and to allow to split a big specification in multiples files, but publish a single one.

A few years ago I've written a tool to fit that niche: https://github.com/dolmen-go/openapi-preprocessor

https://github.com/dolmen-go/openapi-preprocessor

I have now to tweak it (well, it will be a major rewrite) to handle $ref relative to $id instead of the file location.