[BUG] Model inheritance in Java and Swift is broken in v6.0.0

[gereons]

Bug Report Checklist

• Have you provided a full/minimal spec to reproduce the issue?
• Have you validated the input using an OpenAPI validator (example)?
• Have you tested with the latest master to confirm the issue still exists?
• Have you searched for related issues/PRs?
• What's the actual output vs expected output?

Description

Installed v6.0.0, noticed that base class / derived class relationships no longer show up in generated Java and Swift models.

OpenAPI declaration file content or url

components:
  schemas:
    BaseClass:
      type: object
      properties:
        id:
          type: integer
        name:
          type: string
    DerivedClass:
      type: object
      allOf:
        - $ref: "#/components/schemas/BaseClass"
        - type: object
          properties:
            derivedData:
              type: string

Steps to reproduce

Generate models using openapi-generator generate -i spec.yml -g java and openapi-generator generate -i spec.yml -g swift5 --additional-properties=useClasses=true

The resulting Java code for DerivedClass looks like this:

public class DerivedClass {
  public static final String SERIALIZED_NAME_ID = "id";
  @SerializedName(SERIALIZED_NAME_ID)
  private Integer id;
  // ...
}

and the Swift version has

public final class DerivedClass: Codable, JSONEncodable, Hashable {
  // ...
}

i.e. in both cases, information about the inheritance is lost.

In the Swift case, the base class is erroneously generated as final,

public final class BaseClass: Codable, JSONEncodable, Hashable {
  // ...
}

which prohibits inheriance, even if the code for DerivedClass were generated correctly.

[valentin-braun]

We are facing the same issue for Swift. Is there a chance to get this fixed?

[wing328]

Hi all, I've filed #14172 to allow using $ref as parent in allOf with a new option called "openapi-normalizer".

Please give it a try as follows:

git clone --depth 1 -b allof-parent-type https://github.com/OpenAPITools/openapi-generator/
cd openapi-generator
mvn clean package -DskipTests -Dmaven.javadoc.skip=true
java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -g java -i /Users/williamcheng/Code/openapi-generator7/modules/openapi-generator/src/test/resources/3_0/allOf_extension_parent.yaml -o /tmp/java-okhttp/ --additional-properties hideGenerationTimestamp="true" --openapi-normalizer REF_AS_PARENT_IN_ALLOF=true

[gereons]

Thank you for looking at this, and sorry for the late reply!

Since your PR has already been merged I ran java -jar modules/openapi-generator-cli/target/openapi-generator-cli.jar generate -i spec.yml -o gen --openapi-normalizer REF_AS_PARENT_IN_ALLOF=true --skip-validate-spec -g swift5 --additional-properties=useClasses=true using the spec file I posted above using today's master (0b8c08c) and got the same result as initially reported for Swift (where my main focus lies):

public final class DerivedClass: Codable, JSONEncodable, Hashable { ... }
and
public final class BaseClass: Codable, JSONEncodable, Hashable { ... }

i.e. a base class that can't be inherited from and a derived class that doesn't inherit from anything.

Generating Java models actually produces public class DerivedClass extends BaseClass { ... } so this aspect of the regression appears to be fixed.

[gereons]

@valentin-braun if this is still relevant to you, we've finally decided to build a custom model generator from scratch: https://github.com/onvista-media/modelgen

[valentin-braun]

@gereons Thank you for the hint. In the meanwhile, I found SwagGen which works pretty well for most of my use cases. But it is written in Swift. I would better love to see a working Swift model generation in the openapi-generator project which is mainly based on a templating approach.