[BUG] [JAVA] regressions introduced by #17622 (lombok)

[jpfinne]

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?
• [Optional] Sponsorship to speed up the bug fix or feature request (example)

Description

#17622 allows the use of lombok. It works for simple cases but I don't think it is production ready.

There are multiple regressions

• contraints not generated
• JsonProperty gone even if the property name is different than the field name
• javadoc not generated
• incorrect constructors and builders for inheritance
• toString is different (minor)
• x-setter-extra-annotation ignored ( x-extra-field-annotation works)
• probably other missing features : Optional, @Valid...

openapi-generator version

7.3.0-SNAPHOT

OpenAPI declaration file content or url

openapi: 3.0.1
info:
  title: lombok issues
  description: lombok issues
  version: 1.0.0
paths:
  /testLombok:
    get:
      description: test
      responses:
        200:
          description: 'response'
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/LombokData'
components:
  schemas:
    ParentData:
      type: object
      properties:
        type:
          type: string
      discriminator:
        propertyName: type
    LombokData:
      allOf:
        - $ref: '#/components/schemas/ParentData'
        - type: object
          properties:
            extra-data:
              description: 'This is an extra-data'
              type: string
              minLength: 10

Here the generated LombokData.java

@lombok.Data
@lombok.NoArgsConstructor
@lombok.AllArgsConstructor
@lombok.Builder
public class LombokData extends ParentData {
  private String extraData;
}

compared to the non lombok version:

  /**
   * This is an extra-data
   * @return extraData
  */
  @Size(min = 10) 
  @Schema(name = "extra-data", description = "This is an extra-data", requiredMode = Schema.RequiredMode.NOT_REQUIRED)
  @JsonProperty("extra-data")
  public String getExtraData() {
    return extraData;
  }

Generation Details

java -jar openapi-generator-cli.jar generate -g spring -i issue_lombok.yaml -p additionalModelTypeAnnotations='@lombok.Data;@lombok.NoArgsConstructor;@lombok.AllArgsConstructor;@lombok.Builder'

Steps to reproduce

Build with 7.3.0-SNAPSHOT with lombok additionalModelTypeAnnotations
java -jar openapi-generator-cli.jar generate -g spring -i issue_lombok.yaml -p additionalModelTypeAnnotations='@lombok.Data;@lombok.NoArgsConstructor;@lombok.AllArgsConstructor;@lombok.Builder'

Related issues/PRs

#17622

Suggest a fix

Fix the different pojo.mustache with

• Constraints on the field

• lombok superBuilder for inheritance

• javadoc on the field

• @JsonProperty on the field (using @Getter(onMethod=@__({@JsonProperty("extra-data")})))

General question: Do we really need a openapi generator that needs lombok to create java classes?
pojo.mustache is already complex.
Configuring lombok is also complex. How to generate for example @Builder(toBuilder=true)?

Lombok is nice when writing code. Here the openapi generator does the job.

The only valid reason I see is the lack of the builder pattern in the current pojo.mustache.
It can be introduced. The generated code can be equivalent or better than a lombok annotated class.

IMHO it will be easier to implements new features without the extra lombok handling (immutability, records, genericity, merging the different java generators...)

[dabdirb]

@jpfinne thanks for you comments.
Why we need lombok models, if we just run a fresh generated program, it just provide rest api, there is business logic here, if i implement the database entity by using lombok, i will found the rest api models are not consistent. adding the lombok support also provide a work around to current implementation, such as constructor issue #15796, #15827.
I think the bean validation constraint is mandatory, should be added.
jackson @JsonProperty should be a optional, only exist when the field name not same as property name.
SuperBuilder support is simple, just add additionalModelTypeAnnotations @lombok.experimental.SuperBuilder
java doc and x-setter-extra-annotation, if we make the model support both lombok and all legacy features, the implementation will too complex to maintain, especially mustache template file.

[jpfinne]

So we agree that the generated java code should behave the same as some hand written pojo annotated with lombok.
ie: all arguments constructor + builder pattern.

IMHO it is better to add these 2 features in mustache code.

[EladShechter]

The story of constraints that are not generated when using data is disturbing. I hope it will be fixed as soon as possible