[CLI] Generating an empty object using swagger:type object does not work as expected.

[adam-debkowski]

Problem statement

I'm trying to generate an OpenAPI spec from code that skips the additionalProperties when generating spec based on a map[string]interface{} type.
So I want a definition of:

type CustomMetadata map[string]interface{}

To generate:

  CustomMetadata:
    type: object

As far as I observed, the additionalProperties property comes from using a map[string]interface{}, since when using a simple interface{}, it generates the expected output. A definition:

type CustomMetadata interface{}

Generates:

  CustomMetadata:
    type: object

I have tried to achieve that using swagger:format. I expected a definition of:

// swagger:type object
type CustomMetadata map[string]interface{}

To generate:

  CustomMetadata:
    type: object

so without the additionalProperties field. But it is not the case and the // swagger:type object seems to be ignored. The same happens with a type definition of type CustomMetadata interface{}: no matter the swagger:type, the type definitions based on a map or interface always generate their respective OpenAPI specs disregarding a swagger:type.

I've also checked other types, and so for example:

// swagger:type object
type CustomMetadata string

Generates:

  CustomMetadata: {}

This is still not ideal, since as far as I know, the {} in Swagger 2.0 means "any type", and not an object specifically. But it shows that the swagger:type is taken into account in this case.

The current solution is to use interface{} instead of map[string]interface{} which generates expected output, but is not ideal since it requires a lot of changes in the actual application code.

Swagger specification

definitions:
  CustomMetadata:
    additionalProperties:
      type: object
    type: object
info:
  description: Test description
  title: Test
  version: 1.2.3
paths:
  /pets:
    get:
      operationId: listPets
      responses:
        "200":
          $ref: '#/responses/someResponse'
responses:
  someResponse:
    description: ""
    schema:
      properties:
        CustomMetadata:
          $ref: '#/definitions/CustomMetadata'
      type: object
swagger: "2.0"

Steps to reproduce

// Test
//
// Test description
//
//     Version: 1.2.3
//
// swagger:meta
package main

// swagger:route GET /pets listPets
//
//     Responses:
//       200: someResponse

// swagger:response someResponse
type SomeResponse struct {
	// in: body
	Body struct {
		CustomMetadata CustomMetadata
	}
}

// swagger:type object
type CustomMetadata map[string]interface{}

Run:

swagger generate spec -o api.yml

Environment

swagger version:

version: v0.29.0
commit: 09ae1192ca9a941bbb534aca09e6bdc562c95ef3

go version: go version go1.17.2 linux/amd64
OS: Ubuntu 18.04.6 LTS

[adam-debkowski]

It seems that the #2776 fixes this issue so I'm closing this one.