[Java] Fix object defaults with enum properties generating invalid fluent builder expressions

[nh-ive]

Fixes #24298

Added an enum case for the if statement in the method toObjectDefaultValue of the class AbstractJavaCodegen so the Java fluent builder expression generates correctly when using object defaults on an object with enum properties.

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Summary by cubic

Fixes invalid Java fluent builder expressions for object defaults with enum properties by handling enums in AbstractJavaCodegen#toObjectDefaultValue and resolving enum class names via toEnumName. Removes a leftover debug print; generated models now reference the correct enum constants and compile.

^{Written for commit 4b87c8c. Summary will update on new commits.}

[cubic-dev-ai]

No issues found across 1 file

_{Re-trigger cubic}

[Chrimle]

This "Enum" looks out-of-place. There are some odd corner-cases where a "Enum"-suffix is added, but that is not the default naming convention AFAIK.

Might stem from not using the title-property, or perhaps because the schema name in #24298 is in lowercase?

[Mattias-Sehlstedt]

Might be taken from https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java#L1728 or similar. But if that is the case then it should of course be preferable to change it to a named variable (or that the method is used to some extent).

[nh-ive]

Updated to use the new toEnumName(String) helper instead of hardcoding the enum suffix

[Chrimle]

Great @nh-ive , thanks!

@Mattias-Sehlstedt I thought that suffix was added for edge-cases, like when using reserved keywords? 🤔 But maybe I am mistaken...

[nh-ive]

Just from a user perspective, it has always generated with the Enum suffix for me, but I haven't been using it for that long, so I might be missing some historical context

[Mattias-Sehlstedt]

To my knowledge the Enum suffix comes from when you have inline enum definitions. So when you have

properties:
  status:
    type: "string"
    description: "Order Status"
    enum:
      - "placed"
      - "approved"
      - "delivered"

rather than

properties:
  status:
    ref: '#/components/schemas/OrderStatus'

I.e., the Codegen will create a name for the enum structure for you.

I personally always prefer to have the enums be defined as refs, so that there are never duplicates, and their reuse is extremely clear.

[Chrimle]

Ah, that explains it! I always use $ref, so I didn't consider that - thanks for looking into it!

Okay, should a test-cases be added for both these scenarios, to ensure this is named correctly?

• Inline:
  private OutputFormat format = new OutputFormat().order(OutputFormat.OrderEnum.SIMILARITY).limit(10);
• Ref:
  private OutputFormat format = new OutputFormat().order(OutputFormat.Order.SIMILARITY).limit(10);