[BUG] CodegenParameter.baseType is different than CodegenProperty.baseType

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

When generating specs with a container type, the behavior of CodegenParameter and CodegenProperty is inconsistent.

• in CodegenParameter the baseType refers to the items type
• in CodegenProperty the baseType refers to the container type (the correct behavior)

e.g. generating modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml with any generator (tested with csharp and dart-dio-next)

• operation createUsersWithArrayInput has array of User as body parameter when debugging this:

  "bodyParam" : {
        "dataType" : "BuiltList<User>",
        "baseType" : "User",
  ...
  }
  

• Model NullableClass has property array_nullable_prop which is a list of objects when debugging this:

  {
      "dataType" : "BuiltList<JsonObject>",
      "datatypeWithEnum" : "BuiltList<JsonObject>",
      "baseType" : "BuiltList", 
  ...
  }
  

openapi-generator version

5.2.1 (latest master commit a7de7095a7bfb6f84f8a7115b009db612db24a26)

Generation Details

for dart-dio-next: ./bin/generate-samples.sh bin/configs/dart-dio-next* -- --global-property debugOperations,debugModels > log.txt for csharp: ./bin/generate-samples.sh bin/configs/other/openapi3/csharp-OpenAPIClientNetStandard.yaml -- --global-property debugOperations,debugModels > log_cs.txt

cc @wing328 @kuhnroyal @agilob

[ahmednfwela]

yes, the problem is there is no way to get the list type alone in the operation parameters

[kuhnroyal]

Yea, not sure where this is handled. You can try to rewrite the baseType similar to the handling here: https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/DartDioNextClientCodegen.java#L294

All the information needed (container type, unique items) should be available.