PageableObject and SortObject are called Pageablenull and Sortnull in v2.8.0 and v2.8.1

[mgansler]

Describe the bug

When upgrading "org.springdoc:springdoc-openapi-starter-webmvc-api from 2.7.0 to 2.8.1 the generated openapi-spec accessable via http://localhost:8080/v3/api-docs contains a bug where PagableObject and SortObject are called Pageablenull and Sortnull.

To Reproduce

Given the simple controller:

import org.springframework.data.domain.Page;
import org.springframework.http.HttpStatus;
import org.springframework.http.ResponseEntity;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;

@RestController
@RequestMapping("/api")
public class DemoController {
    @GetMapping("/test")
    public ResponseEntity<Page<String>> test() {
        return new ResponseEntity<>(HttpStatus.OK);
    }
}

The generated openapi-spec looks like this:

{
  "openapi": "3.1.0",
  "info": {
    "title": "OpenAPI definition",
    "version": "v0"
  },
  "servers": [
    {
      "url": "http://localhost:8080",
      "description": "Generated server url"
    }
  ],
  "paths": {
    "/api/test": {
      "get": {
        "tags": [
          "demo-controller"
        ],
        "operationId": "test",
        "responses": {
          "200": {
            "description": "OK",
            "content": {
              "*/*": {
                "schema": {
                  "$ref": "#/components/schemas/PageString"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "PageString": {
        "type": "object",
        "properties": {
          "totalElements": {
            "type": "integer",
            "format": "int64"
          },
          "totalPages": {
            "type": "integer",
            "format": "int32"
          },
          "first": {
            "type": "boolean"
          },
          "last": {
            "type": "boolean"
          },
          "size": {
            "type": "integer",
            "format": "int32"
          },
          "content": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "number": {
            "type": "integer",
            "format": "int32"
          },
          "sort": {
            "$ref": "#/components/schemas/Sortnull"
          },
          "numberOfElements": {
            "type": "integer",
            "format": "int32"
          },
          "pageable": {
            "$ref": "#/components/schemas/Pageablenull"
          },
          "empty": {
            "type": "boolean"
          }
        }
      },
      "Pageablenull": {
        "type": "object",
        "properties": {
          "offset": {
            "type": "integer",
            "format": "int64"
          },
          "sort": {
            "$ref": "#/components/schemas/Sortnull"
          },
          "paged": {
            "type": "boolean"
          },
          "unpaged": {
            "type": "boolean"
          },
          "pageNumber": {
            "type": "integer",
            "format": "int32"
          },
          "pageSize": {
            "type": "integer",
            "format": "int32"
          }
        }
      },
      "Sortnull": {
        "type": "object",
        "properties": {
          "empty": {
            "type": "boolean"
          },
          "sorted": {
            "type": "boolean"
          },
          "unsorted": {
            "type": "boolean"
          }
        }
      }
    }
  }
}

Expected behavior

The generated openapi-spec should look like this:

{
  "openapi": "3.0.1",
  "info": {
    "title": "OpenAPI definition",
    "version": "v0"
  },
  "servers": [
    {
      "url": "http://localhost:8080",
      "description": "Generated server url"
    }
  ],
  "paths": {
    "/api/test": {
      "get": {
        "tags": [
          "demo-controller"
        ],
        "operationId": "test",
        "responses": {
          "200": {
            "description": "OK",
            "content": {
              "*/*": {
                "schema": {
                  "$ref": "#/components/schemas/PageString"
                }
              }
            }
          }
        }
      }
    }
  },
  "components": {
    "schemas": {
      "PageString": {
        "type": "object",
        "properties": {
          "totalElements": {
            "type": "integer",
            "format": "int64"
          },
          "totalPages": {
            "type": "integer",
            "format": "int32"
          },
          "first": {
            "type": "boolean"
          },
          "last": {
            "type": "boolean"
          },
          "size": {
            "type": "integer",
            "format": "int32"
          },
          "content": {
            "type": "array",
            "items": {
              "type": "string"
            }
          },
          "number": {
            "type": "integer",
            "format": "int32"
          },
          "sort": {
            "$ref": "#/components/schemas/SortObject"
          },
          "pageable": {
            "$ref": "#/components/schemas/PageableObject"
          },
          "numberOfElements": {
            "type": "integer",
            "format": "int32"
          },
          "empty": {
            "type": "boolean"
          }
        }
      },
      "PageableObject": {
        "type": "object",
        "properties": {
          "offset": {
            "type": "integer",
            "format": "int64"
          },
          "sort": {
            "$ref": "#/components/schemas/SortObject"
          },
          "paged": {
            "type": "boolean"
          },
          "unpaged": {
            "type": "boolean"
          },
          "pageNumber": {
            "type": "integer",
            "format": "int32"
          },
          "pageSize": {
            "type": "integer",
            "format": "int32"
          }
        }
      },
      "SortObject": {
        "type": "object",
        "properties": {
          "empty": {
            "type": "boolean"
          },
          "sorted": {
            "type": "boolean"
          },
          "unsorted": {
            "type": "boolean"
          }
        }
      }
    }
  }
}

[bnasslahsen]

@mgansler,

should be fixed by #2849

[mgansler]

Thank you