Disable yaml aliases for generateschema

[ghost]

@carltongibson as requested in #7096

when objects are reused in a structure, yaml creates aliases for those objects.

• makes the schema harder to read with only alias tags like &id001 instead of proper names
• usage of advanced yaml feature possibly not supported everywhere
• the openapi client generators also chokes on that feature

(will push fix once test fails)

[kevin-brown]

Is it possible to do this without overriding ignore_aliases on the Dumper class? I'm wondering what the interaction is for anyone else who wishes to use yaml.dump after this call.

[carltongibson]

the openapi client generators also chokes on that feature

(Just checking) but it is valid yaml being generated yes? So surely this last is a bug in whatever yaml parser these generators are using?

[ghost]

The generator i use for testing is https://github.com/OpenAPITools/openapi-generator, which i believe is the defacto standard besides the swagger one. it will choke with errors like:

attribute paths.'/api/users/password/'(post).requestBody.content.schema is not of type `object`

because it does not recognize the alias labels:

        content:
          application/json:
           schema: &id017
             $ref: '#/components/schemas/SetPassword'
           application/x-www-form-urlencoded:
             schema: *id017
           multipart/form-data:
             schema: *id017

As the yaml is valid i think (no expert on that), you could say it is an upstream bug. So we can either do a upstream PR to fix this or only use the most common set of yaml features. In my opinion the aliases add complexity, non-descript names without much of a benefit except slightly lower schema file size.

@kevin-brown Absolutely. Unfortunately there was no option for that. The last time i tried with an explicit Dumper it had no effect. Maybe i had an old pyyaml version. It works now.

yaml/pyyaml#103
https://stackoverflow.com/questions/13518819/avoid-references-in-pyyaml

[carltongibson]

@tfranzel-cashlink Can you open an issue on openapi-generator to at least see what they say?

[ghost]

Actually there is: OpenAPITools/openapi-generator#1593
there is also this: https://stackoverflow.com/questions/46689801/yaml-jackson-anchor-keys-of-array

apparently the problem lies deeper (openapig-generator -> Jackson lib -> SnakeYaml lib)

Nonetheless, i have not seen any openapi spec yet that uses aliases. Upstream bug or not, it will not go through the de-facto standard generator, which makes the generated schema rather pointless to begin with.

[carltongibson]

I´m not sure I´m convinced by the de facto here. There are lots of tools out there. However...

Thanks for the extra references. I need to look into those and OpenAPI Generator but the immediate work-around is to use a custom renderer with your fix in place. That gets you going at least.

[carltongibson]

@tfranzel-cashlink It looks like you´ve resolved @kevin-brown´s worry so let´s have this. Thanks for the effort.

[adnathanail]

Would you be able to release a version with this change in?

[carltongibson]

We're working on 3.12 currently. It'll be in that.

Pip can help you if you're in a rush...