Better OpenAPI spec v3 support: allOf, anyOf, oneOf

[wing328]

PR checklist

• Read the contribution guidelines.
• Ran the shell script under ./bin/ to update Petstore sample so that CIs can verify the change. (For instance, only need to run ./bin/{LANG}-petstore.sh and ./bin/security/{LANG}-petstore.sh if updating the {LANG} (e.g. php, ruby, python, etc) code generator or {LANG} client's mustache templates). Windows batch files can be found in .\bin\windows\.
• Filed the PR against the correct branch: master, 3.4.x, 4.0.x. Default: master.
• Copied the technical committee to review the pull request if your PR is targeting a particular programming language.

Description of the PR

• fix composition
• fix inheritance support
• add mustache tags allOf, anyOf, oneOf
• add tests for discriminator, allOf, anyOf, etc in Rub client generator
• update Ruby templates to support inheritance, anyOf, oneOf, etc

Related issues/PRs

• [Java] "allOf" no longer supports inheritance AND composition #1358
• [PHP] Missing model inheritance in generated client when schema has both oneOf and properties #1206
• [typescript] allOf with multiple values is not handled properly #927
• [CSHARP] Multi Level inheritance is not building #1068
• [Python] Commenting supportsInheritance is enabling the model properties inhe… #1099
• [Java] Add proper support for allOf anyOf oneOf #634
• [Schema] Inline description and vendor extensions under allOf is not recognized #1125
• [C++][Pistache-server] "anyOf" keyword generates code that do not compile #537

cc @OpenAPITools/generator-core-team

[etherealjoy]

also this one #537?

[wing328]

@etherealjoy 👍 updated the list

[ybelenko]

Fix {{{#vars}{{{/vars}}} codegen array, please.

[mm-matthias]

FWIW, I tested with some simple specs using allOf using the python generator. It works really well so far. I ran into the limitation of "allOf"/ComposedSchemas not begin supported, but this is clearly logged.
I'm also writing my own codegen against the oas3-spec-support1 branch and things have worked out very nice as well.
Thanks for adding this sorely needed feature!

[wing328]

@mm-matthias thanks for reviewing the change. Can you ping me via https://gitter.im (ID: wing328) or Google hangout (email address in my Github profile page) for a quick chat?

[wing328]

Let's go with this PR to start with. If anyone encounters issues related to allOf/anyOf/oneOf, please open an issue with the details.

[hellboy81]

Waiting for anyOf, oneOf for Java as well.

+1000

[tomghyselinck]

I tried the latest build, but it looks like allOf is not supported for Python either yet.
We definitely need this too.

We get warnings like:

[main] INFO  o.o.codegen.DefaultCodegen - Composed schema not yet supported: class ComposedSchema {
...
}

[wing328]

@tomghyselinck do you mind opening an issue and share the spec so that we can reproduce the issue more easily?

[tomghyselinck]

@wing328 Thank you very much for your quick response!
I stripped down my pretty huge yaml file and file BUG report #1657

[marcelstoer]

I would love to give this a try. Is there a binary somewhere that includes this fix? Specifically I want to find out if this addresses the v2 Java multi-level hierarchy bug (not sure it was even reported) where it would not generate the correct Jackson @JsonSubTypes for

C allOf B allOf A

on A. That's the only reason I'm currently still stuck on Swagger gen 2.4; would love to migrate.

[jmini]

I would love to give this a try. Is there a binary somewhere that includes this fix?

We push SNAPSHOT releases on sonatype snapshot repository (sort of maven central for snapshots).
4.0.0-SNAPSHOT is available.

3 options:

1. You can use gradle/maven to get them, indicate that you want to consume binaries for:

https://oss.sonatype.org/content/repositories/snapshots/

With gradle/maven you can download the CLI jar and then use it from the command line or directly use the gradle/maven plugin.

2. If you want to download the all-in-one jar that we are producing manually, download the newest jar from this folder:
   https://oss.sonatype.org/content/repositories/snapshots/org/openapitools/openapi-generator-cli/4.0.0-SNAPSHOT/

3. @jimschubert has proposed a script that do the download for you:
   https://gist.github.com/jimschubert/ce241b0c78140e364f46914ef8ec4103
   Set OPENAPI_GENERATOR_VERSION to 4.0.0-SNAPSHOT and it should work.

---

Specifically I want to find out if this addresses the v2 Java multi-level hierarchy bug (not sure it was even reported)

Is it this #827 ?

If not please create a separated issue with a minimal spec to reproduce your issue...

[wing328]

@marcelstoer we only added the mustache tags for oneOf, anyOf and allOf but have not yet updated the templates for all the languages/generators to take advantage of these new features in OAS v3.

For Java client, please open a new issue with a spec and the current vs expected output for tracking.

[wing328]

@YeTingGe are you free for a quick chat via https://gitter.im (ID: wing328) about your use case?

[smasala]

@wing328 TypeScript generator has a weird side effect in which the interface property typing is prefixed with the word AnyOf or OneOf.

import {AnyOfMyType} from '../models/anyOfMyType.ts';   // doesn't exists. Only exists without the prefix
 
interface MyInt {
     myProp:  AnyOfMyType | null;
}

We need to define anyOf | oneOf so that we can use a $ref in conjunction with nullable: true OAI/OpenAPI-Specification#1368

[strobox]

I found interesting part in ReDoc petstore.yaml OpenAPI 3.0 sample:

  requestBodies:
    Pet:
      content:
        application/json:
          schema:
            allOf:
              - description: My Pet
                title: Pettie
              - $ref: '#/components/schemas/Pet'

I think it is some kind of inline overriding of default models using allOf notation

[spacether]

Fix {{{#vars}{{{/vars}}} codegen array, please.

#vars does not include inherited variables on 2019-01-23

[jakzal]

Am I right to think this has only been implemented for ruby?

[epark-brex]

@jazkal According to #10010, as of Jan 2022, it does seem like this is only solved for Ruby.

[spacether]

Composition in the root level or in deeper inline levels is working in python-experimental

Here is a PR that shows composition in inline schemas working #11420