Polymorphism - documentation not generated for subtypes when using JsonTypeInfo.As.WRAPPER_OBJECT and JsonTypeInfo.Id.NAME

[didjoman]

Describe the bug

If a controller returning a response containing an interface or class that is annotated with:

@JsonTypeInfo(include= JsonTypeInfo.As.WRAPPER_OBJECT, use=JsonTypeInfo.Id.NAME)
@JsonSubTypes({
    @JsonSubTypes.Type(value = Dog.class, name = "dog"),
})

Then, the documentation generated does not contain the schemas of child classes.

How to reproduce

git clone https://github.com/didjoman/springdoc-polymorphism-issue-v1.6.10
Run the application (spring boot).
Run curl --location --request GET 'http://localhost:8080/doc' --header 'Content-Type: application/json'

Expected behavior

The json representation of the Cat and Dog (subtypes of Animal class) schemas should be returned:

{
    "openapi": "3.0.1",
    "info": {
        "title": "OpenAPI definition",
        "version": "v0"
    },
    "servers": [
        {
            "url": "http://localh",
            "description": "Generated server url"
        }
    ],
    "paths": {
        "/test": {
            "get": {
                "tags": [
                    "basic-controller"
                ],
                "summary": "get",
                "description": "Provides an animal.",
                "operationId": "get",
                "responses": {
                    "200": {
                        "description": "OK",
                        "content": {
                            "*/*": {
                                "schema": {
                                    "oneOf": [
                                        {
                                            "$ref": "#/components/schemas/Cat"
                                        },
                                        {
                                            "$ref": "#/components/schemas/Dog"
                                        }
                                    ]
                                }
                            }
                        }
                    }
                }
            }
        }
    },
    "components": {
        "schemas": {
            "Animal": {
                "type": "object",
                "description": "Represents an Animal class."
            },
            "Cat": {
                "type": "object",
                "description": "Represents a Cat class.",
                "allOf": [
                    {
                        "$ref": "#/components/schemas/Animal"
                    },
                    {
                        "type": "object",
                        "properties": {
                            "speed": {
                                "type": "integer",
                                "format": "int32"
                            }
                        }
                    }
                ]
            },
            "Dog": {
                "type": "object",
                "description": "Represents a Dog class.",
                "allOf": [
                    {
                        "$ref": "#/components/schemas/Animal"
                    },
                    {
                        "type": "object",
                        "properties": {
                            "name": {
                                "type": "string"
                            },
                            "age": {
                                "type": "integer",
                                "format": "int32"
                            }
                        }
                    }
                ]
            }
        }
    }
}

Actual behavior

Only the Animal (parent class) schema is described:

{
    "openapi": "3.0.1",
    "info": {
        "title": "OpenAPI definition",
        "version": "v0"
    },
    "servers": [
        {
            "url": "http://localh",
            "description": "Generated server url"
        }
    ],
    "paths": {
        "/test": {
            "get": {
                "tags": [
                    "basic-controller"
                ],
                "summary": "get",
                "description": "Provides an animal.",
                "operationId": "get",
                "responses": {
                    "200": {
                        "description": "OK",
                        "content": {
                            "*/*": {
                                "schema": {
                                    "oneOf": [
                                        {
                                            "$ref": "#/components/schemas/Cat"
                                        },
                                        {
                                            "$ref": "#/components/schemas/Dog"
                                        }
                                    ]
                                }
                            }
                        }
                    }
                }
            }
        }
    },
    "components": {
        "schemas": {
            "Animal": {
                "type": "object",
                "description": "Represents an Animal class."
            },
            "Cat": {
                "type": "object",
                "description": "Represents a Cat class.",
                "allOf": [
                    {
                        "$ref": "#/components/schemas/Animal"
                    },
                    {
                        "type": "object",
                        "properties": {
                            "speed": {
                                "type": "integer",
                                "format": "int32"
                            }
                        }
                    }
                ]
            },
            "Dog": {
                "type": "object",
                "description": "Represents a Dog class.",
                "allOf": [
                    {
                        "$ref": "#/components/schemas/Animal"
                    },
                    {
                        "type": "object",
                        "properties": {
                            "name": {
                                "type": "string"
                            },
                            "age": {
                                "type": "integer",
                                "format": "int32"
                            }
                        }
                    }
                ]
            }
        }
    }
}

Additional context

The issue started to occur from version 1.5.8 onwards. From 1.5.8 to 1.6.9 (inlcuded) there was a nullPointer in the logs.
Since 1.6.10, the NullPointerException is fixed, but the documentation is still incorrect (not generating subtypes documentation).

See also the same demo using SpringDoc 1.5.7 that worked: https://github.com/didjoman/springdoc-no-polymorphism-issue-v1.5.7

[DVD27]

Hello,

I have the same issue but I success to get arround using this annotation :

@Schema(type = "object", oneOf = { Dog.class, Cat.class })

But It will be great to fix this bug ;)

[ruckc]

Running into this today. I have the issue even with @Schema on my interface.

@JsonTypeInfo(use = JsonTypeInfo.Id.NAME, include = JsonTypeInfo.As.WRAPPER_OBJECT)
@JsonSubTypes({
    @JsonSubTypes.Type(value = A.class, name = "a"),
    @JsonSubTypes.Type(value = B.class, name = "b"),
    @JsonSubTypes.Type(value = C.class, name = "c"),})
@Schema(type = "object", oneOf = {A.class, B.class, C.class})
public interface SomeInterface extends Serializable {

}

Initially my annotations looked like this, which also resulted in the error, using CUSTOM with a TypeIdResolver implementation.

@JsonTypeInfo(use = JsonTypeInfo.Id.CUSTOM, include = JsonTypeInfo.As.WRAPPER_OBJECT)
@JsonTypeIdResolver(MyResolver.class)
public interface SomeInterface extends Serializable {

}