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

openapi-generator version

The bug appears with the OpenAPI generator versions 5.1.0, 5.1.1, 5.1.1-snapshot, 5.2.0-snapshot, 6.0.0-snapshot.

OpenAPI declaration file content or url

      "User": {
        "type": "object",
        "required": [
          "global_role"
        ],
          "global_role": {
            "$ref": "#/components/schemas/GlobalRole"
          },
        }
      },
      "GlobalRole": {
        "type": "string",
        "enum": [
          "SuperAdmin",
          "Auditor",
          "Employee"
        ]
      }

Description

Given the above schemata, the following dart code will be generated for updating a user in lib/src/models/user_update.dart:

  @override
  UserUpdate deserialize(Serializers serializers, Iterable<Object?> serialized,
      {FullType specifiedType = FullType.unspecified}) {
    final result = UserUpdateBuilder();

    final iterator = serialized.iterator;
    while (iterator.moveNext()) {
      final key = iterator.current as String;
      iterator.moveNext();
      final Object? value = iterator.current;
      switch (key) {
        case r'global_role':
          result.globalRole.replace(serializers.deserialize(value,
              specifiedType: const FullType(GlobalRole)) as GlobalRole);
          break;
      }
    }
    return result.build();
  }

And a lib/src/models/role.dart:

class GlobalRole extends EnumClass {
  @BuiltValueEnumConst(wireName: r'super_admin')
  static const GlobalRole superAdmin = _$superAdmin;
  @BuiltValueEnumConst(wireName: r'auditor')
  static const GlobalRole auditor = _$auditor;
  @BuiltValueEnumConst(wireName: r'employee')
  static const GlobalRole employee = _$employee;

  static Serializer<GlobalRole> get serializer => _$globalRoleSerializer;

  const GlobalRole._(String name) : super(name);

  static BuiltSet<GlobalRole> get values => _$values;
  static GlobalRole valueOf(String name) => _$valueOf(name);
}

This fails to build with the following Error:

lib/src/model/user_update.dart:96:29: Error: The method 'replace' isn't defined for the class 'GlobalRole?'.
 - 'GlobalRole' is from 'package:api/src/model/global_role.dart' ('api/lib/src/model/global_role.dart').
Try correcting the name to the name of an existing method, or defining a method named 'replace'.
          result.globalRole.replace(serializers.deserialize(value,
                            ^^^^^^^

Generation Details

generate -g dart-dio-next -o ./api -i openapi.yml -p pubName=api --enable-post-process-file

I'm using the dart-dio-next generator. Dart version is 2.12.3.

Steps to reproduce

1. Generate a client containing the schemata included above.
2. Include the generated api in a dart project.
3. compile the dart project.

Related issues/PRs

I have searched thoroughly for dart issues containing the keywords "enum" or "replace" but found nothing.

Suggest a fix

I've tried to locate the line responsible for the creating the generated code in question, but could not find it.