OpenAPI schema generates breaking change for enum type when migrating from Quarkus 3.16 to 3.17

[cristianonicolai]

Describe the bug

When migrating from Quarkus 3.16 to 3.17 using openapi version 3.0.3 the generated schema for an enum type creates a breaking change due to removing the type=string

Expected behavior

Generated schema is:

"status" : {
            "type" : "string",
            "allOf" : [ {
              "$ref" : "#/components/schemas/Status"
            } ],
            "nullable" : true
          }

Actual behavior

Field is annotated as:

@Schema(nullable = true) Status status

Generates:

"status" : {
            "allOf" : [ {
              "$ref" : "#/components/schemas/Status"
            } ],
            "nullable" : true
          }

How to Reproduce?

Created sample project with annotated POJOs here: https://github.com/cristianonicolai/quarkus-playground

Output of uname -a or ver

No response

Output of java -version

No response

Quarkus version or git rev

3.17.7

Build tool (ie. output of mvnw --version or gradlew --version)

Apache Maven 3.9.9

Additional information

No response

[quarkus-bot]

/cc @EricWittmann (openapi), @MikeEdgar (openapi), @phillip-kruger (openapi)

[MikeEdgar]

I'm curious if this one is causing an issue or it is just flagged as a change. The base schema should use the type from Status via the $ref.

[cristianonicolai]

Its been flagged as a breaking change since the type was dropped but indeed, it seems that the actual problem is that it should not be added at all in the first place by the previous SmallRye version. I tried annotating as @Schema(nullable = true, type = SchemaType.DEFAULT) but it still generates the String type on Quarkus 3.16

[MikeEdgar]

it seems that the actual problem is that it should not be added at all in the first place by the previous SmallRye version

Can we consider it fixed in 3.17 in that case?