@drejc thanks for the PR. Can you please run ./bin/kotlin-springboot-petstore-server.sh to update the Kotlin samples so that the CI can verify the result?

cc @jimschubert (2017/09), @dr4ke616 (2018/08) @karismann (2019/03) @Zomzog (2019/04)

I have run the ./bin/kotlin-springboot-petstore-server.sh and the newly generated files are "broken" due to missing success response definitions in /2_0/petstore.yaml file.

Where for instance there is the following definition:

delete:
      tags:
        - user
      summary: Delete user
      description: This can only be done by the logged in user.
      operationId: deleteUser
      produces:
        - application/xml
        - application/json
      parameters:
        - name: username
          in: path
          description: The name that needs to be deleted
          required: true
          type: string
      responses:
        '400':
          description: Invalid username supplied
        '404':
          description: User not found

The generated code is:

@ApiOperation(
           value = "Deletes a pet",
           nickname = "deletePet",
           notes = "",
           authorizations = [Authorization(value = "petstore_auth", scopes = [AuthorizationScope(scope = "write:pets", description = "modify pets in your account"), AuthorizationScope(scope = "read:pets", description = "read your pets")])])
   @ApiResponses(
           value = [ApiResponse(code = 400, message = "Invalid pet value")])
   @RequestMapping(
           value = ["/pet/{petId}"],
           method = [RequestMethod.DELETE])
   fun deletePet(@ApiParam(value = "Pet id to delete", required=true) @PathVariable("petId") petId: Long
,@ApiParam(value = "" ) @RequestHeader(value="api_key", required=false) apiKey: String?
): ResponseEntity<Unit> {
       return ResponseEntity(service.deletePet(petId, apiKey), HttpStatus.valueOf(400))
   }

Previously it was: HttpStatus.OK

Now I didn't dive into swagger definition details if 200 is by default the expected default response, nevertheless either:

• the definition must be updated
• or a default response 200 as the first response added (if no 2** code present) to model prior to generating

Now I didn't dive into swagger definition details if 200 is by default the expected default response, nevertheless either:

I've seen many spec without 200 response defined in the endpoints so I think we need a better way to handle this.

Yes I agree ... and I have seen a similar approach in /JavaSpring/api.mustache

where response codes are generated:

@ApiResponses(value = { {{#responses}}
        @ApiResponse(code = {{{code}}}, message = "{{{message}}}"{{#baseType}}, response = {{{baseType}}}.class{{/baseType}}{{#containerType}}, responseContainer = "{{{containerType}}}"{{/containerType}}){{#hasMore}},{{/hasMore}}{{/responses}} })
    {{#implicitHeaders}}

And the generated code:

@ApiOperation(value = "Delete purchase order by ID", nickname = "deleteOrder", notes = "For valid response try integer IDs with value < 1000. Anything above 1000 or nonintegers will generate API errors", tags={ "store", })
    @ApiResponses(value = { 
        @ApiResponse(code = 400, message = "Invalid ID supplied"),
        @ApiResponse(code = 404, message = "Order not found") })
    @RequestMapping(value = "/store/order/{order_id}",
        method = RequestMethod.DELETE)
    default ResponseEntity<Void> deleteOrder(@ApiParam(value = "ID of the order that needs to be deleted",required=true) @PathVariable("order_id") String orderId) {
        return new ResponseEntity<>(HttpStatus.NOT_IMPLEMENTED);
    }

I would suggest to manually add the 200 response as the first default response in case there is no other non-error response definition, as this is the expected behaviour.

This allows for customisation of 2** responses, and will not break existing APIs

FIY https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.2.md#responsesObject

The documentation is not necessarily expected to cover all possible HTTP response codes because they may not be known in advance. However, documentation is expected to cover a successful operation response and any known errors.

I'm agree that petstore spec need to be improved to cover at least one successful status code for each operation. I will try to fill a PR for this purpose.

@karismann please ping me via Gitter to have a chat on this before filing a PR.