Generate plumber stub file from openapi yaml

[schloerke]

cc @krlmlr

• Given a full kitchen sink plumber file, be able to produce open api yaml file
• produce a stub plumber file given the open api file. (No true functionality, but can be plumbed. )
• Verify the open api yaml produced from the stub file is equivalent to the original open api spec produced.

Related: #354

[mcjudd]

Hello, just curious as to if/where you're tracking progress on the second task above (i.e., "produce a stub plumber file given the open api file"). Would love to see plumber support a workflow where the OpenAPI spec is designed first, then plumber server stubs are generated a la Swagger Codegen. Many thanks!

[schloerke]

cc @blairj09

[schloerke]

@mcjudd Last time I looked at the Swagger Codegen, they were producing functions via R6.

Integrating with Swagger Codegen would introduce a very external dependency. I am hoping we will be able to produce this within plumber with native R.

[meztez]

A reverse parseBlock? I'll think about it while generalizing lines parsing. So each block (endpoint) has a from and to open api definition. What I am afraid is that plumber does not fully support openapi entire definition. You would obviously lose some details if you used unsupported tags. Also types are not quite the same.

I agree it should be done internally. Now comes the hardest part. Pick a function name

I kind of like jsonlite naming.

fromOpenAPI({openapi.json})
toOpenAPI({router})

[schloerke]

@meztez fromOpenAPI and toOpenAPI sound great to me!

Goal:

1. Start with a fully defined plumber.R
2. Produce an openapi spec
3. Produce a shell plumber.R file
4. Produce the same openapi spec as in step 2

If we can loop back between steps 3 and 4, I'd call it a success

[meztez]

@blairj09 I'm stuck on this one trying to dereference input OpenApi specification. https://swagger.io/docs/specification/using-ref/. Is it something you have tackled before?

I'm not sure this should be a problem solved by plumber as it a more general feature.