Parameter is now required after upgrading to springdoc-openapi 2.8.10

[brunopereira7]

Describe the bug

I'm using springdoc-openapi in my Kotlin project. I've tried to upgrade from version 2.8.6 to 2.8.10, but I've noticed a change in the generated api-docs.

In version 2.8.6, the following parameters were generated as optional (required: false):

• filters.brand
• filters.service
• filters.productGroup

However, in version 2.8.10, these parameters are now generated as required (required: true).

Is it still related to #2978 ? I can have a workaround and explicitly force it as optional, but I would like to understand if it is a bug or why we have this change of behavior.

To Reproduce
Steps to reproduce the behavior:

• spring-boot version: 3.5.3
• spring-doc-openapi-webflux: 2.8.10

Code Snippet:

data class BaseSearchParameters(
    val filters: Filters = Filters()
)

@ParameterObject
data class Filters(
    @field:Parameter(
        description = "Description .",
        explode = FALSE,
        array = ArraySchema(schema = Schema(type = "string"))
    )
    var brand: Set<String> = emptySet(),

    @field:Parameter(
        description = "Description ..",
        explode = FALSE,
        array = ArraySchema(schema = Schema(type = "string"))
    )
    var service: Set<String> = emptySet(),

    @field:Parameter(
        description = "Description ...",
        explode = FALSE,
        array = ArraySchema(schema = Schema(type = "string"))
    )
    var productGroup: Set<String> = emptySet(),
)

This code is generating with version 2.8.10:

...
{
    "name": "filters.brand",
    "in": "query",
    "description": "Description .",
    "required": true,
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
},
{
    "name": "filters.service",
    "in": "query",
    "description": "Description ..",
    "required": true,
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
},
{
    "name": "filters.productGroup",
    "in": "query",
    "description": "Description ...",
    "required": true,
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
}
...

Expected behavior

Should we expect the same behavior of 2.8.6 version?

...
{
    "name": "filters.brand",
    "in": "query",
    "description": "Description .",
    "required": false,
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
},
{
    "name": "filters.service",
    "in": "query",
    "description": "Description ..",
    "required": false,
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
},
{
    "name": "filters.productGroup",
    "in": "query",
    "description": "Description ...",
    "required": false,
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
}
...

Thank you for your time and support.

[bnasslahsen]

@brunopereira7,

Not reproducible.
Feel free to provide a Minimal, Reproducible Example - with HelloController that reproduces the problem.

This ticket will be closed, but can be reopened if your provide the reproducible sample.

[brunopereira7]

Hi @bnasslahsen, I complemented the initial information with a HelloController, but basically all other information is already here:

package io.mb.controller

import jakarta.validation.Valid
import org.springframework.http.ResponseEntity
import org.springframework.web.bind.annotation.GetMapping
import org.springframework.web.bind.annotation.RestController

@RestController
class HelloController {
    @GetMapping("/hello")
    fun hello(@Valid baseSearchParameters: BaseSearchParameters) = ResponseEntity.ok("Hello, World!")
}

package io.mb.controller

@ParameterObject
data class BaseSearchParameters(
    val filters: Filters = Filters()
)

@ParameterObject
data class Filters(
    @field:Parameter(
        description = "Description .",
        explode = FALSE,
        array = ArraySchema(schema = Schema(type = "string"))
    )
    var brand: Set<String> = emptySet(),

    @field:Parameter(
        description = "Description ..",
        explode = FALSE,
        array = ArraySchema(schema = Schema(type = "string"))
    )
    var service: Set<String> = emptySet(),

    @field:Parameter(
        description = "Description ...",
        explode = FALSE,
        array = ArraySchema(schema = Schema(type = "string"))
    )
    var productGroup: Set<String> = emptySet(),
)

The api-docs generated by version 2.8.6 is:

...
{
    "name": "filters.brand",
    "in": "query",
    "description": "Description .",
    "required": false, <---------------
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
},
{
    "name": "filters.service",
    "in": "query",
    "description": "Description ..",
    "required": false, <---------------
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
},
{
    "name": "filters.productGroup",
    "in": "query",
    "description": "Description ...",
    "required": false, <------------------
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
}
...

with 2.8.10:

...
{
    "name": "filters.brand",
    "in": "query",
    "description": "Description .",
    "required": true, <---------------
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
},
{
    "name": "filters.service",
    "in": "query",
    "description": "Description ..",
    "required": true, <---------------
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
},
{
    "name": "filters.productGroup",
    "in": "query",
    "description": "Description ...",
    "required": true, <------------------
    "explode": false,
    "schema": {
        "type": "array",
        "items": {
            "type": "string"
        }
    }
}
...

[bnasslahsen]

@brunopereira7,

I see the root cause of your problem. Just pushed a fix for it.
Please feel free to test with the last SNAPSHOT.