[BUG][JAXRS-spec] useOneOfInterfaces option causes compilation error

[jerui1]

Description

When using the useOneOfInterfaces option, the generated code does not compile.

Children classes are OK, but the generated parent is a class instead of an interface.

openapi-generator version

I've reproduces the issue with openapi-generator-maven-plugin :
7.0.1, 7.1.0
6.6.0

The option does not seem supported on previous releases.

OpenAPI declaration file content or url

OpenAPI spec :

https://gist.github.com/jerui1/da605832f67667e32a96f5c4d346640e

Sample maven project to reproduce :

openapigen-oneofbug.zip

Generation Details

mvn clean install

(I've tried using Java 17 or Java 21)

[mikeys]

Reproduced on openapi-generator v7.2.0

[parawanderer]

The issue still occurs with openapi-generator v7.3.0

[lucadirocco]

The same issue also occurs with jaxrs-resteasy generator (--additional-properties=useOneOfInterfaces=true).
The expected interface for the oneOf schema is not generated and a class with the same name is generated in its place.
However, the classes generated for the subschemas correctly implement the intended interface.

[jamfor999]

This has been open for 6 months without any resolution, is anyone maintaining this?

[magiusdarrigo]

This is still an issue in v7.8.0

[magiusdarrigo]

Likely root cause issue - #14166

[Nicklas2751]

#14166 doesn't look like the reason for this issue. The useOneOfInterface option works for Spring Server gen as well as for the java clients: feign, google-api-client, resteasy, resttemplate, webclient, restclient, rest-assured, retrofit2, vertx, apache-httpclient
Currently it doesn't work for the java clients: microprofile, jersey2, jersey3, native and okhttp-gson.

The issue is coming from the model.mustache file. The clients working don't override it or have the correct part. The clients not working are missing these part:

{{#vendorExtensions.x-is-one-of-interface}}{{>oneof_interface}}{{/vendorExtensions.x-is-one-of-interface}}

I'll provide a pr to fix this soon.

[agaidaichuk]

@Nicklas2751 , any chances to get this fix in the next release (7.13.0)?

[Nicklas2751]

@agaidaichuk I can't tell you if and when my PR (#20832) gets merged.