@Body() decorator with param broke swagger, swagger plugin auto @ApiProperty() doesn't work

I’m submitting a…

[ x ] Regression 
[ x ] Bug report
[ ] Feature request
[ ] Documentation issue or request
[ ] Support request => Please do not submit support request here, instead post your question on Stack Overflow.

Current behavior

I faced 2 issues when I use NestCLI to start my application with swagger plugin in nest-cli.json:

1. @Body('param') is not part of the request, I have to write wrapper DTO or use schema
2. The auto @ApiProperty() doesn’t work. I have to use @ApiProperty in all of my DTO files.

I tried to reproduce nest-example-cats-swagger in my own repository, but it doesn’t work like the Docs mentions here

Expected behavior

1. When I use @Body('param'), swagger maybe could wrap the type inside that parameter name.

  @Post('noDoc/param/scheme')
  @ApiBody({
    schema: {
      type: 'object',
      properties: {
        user: { // the `user` word comes from @Body('user')
          properties: { // these properties are coming from `UserDto`
            id: { type: 'number' },
            username: { type: 'string' },
            email: { type: 'string' },
          },
        },
      },
    },
  })
  async noDocParamScheme(@Body('user') user: UserDto) {
    return user;
  }

1. Swagger plugin should properly create @ApiProperty

Minimal reproduction of the problem with instructions

You can check it in my test-repository: https://github.com/PoOwAa/nestjs-swagger-body-param-bug

What is the motivation / use case for changing the behavior?

At least @Body() without params should work like in the documentation.

Environment

[System Information]
OS Version     : Linux 5.3
NodeJS Version : v12.16.1
NPM Version    : 6.14.4

[Nest CLI]
Nest CLI Version : 7.1.2

[Nest Platform Information]
platform-express version : 7.0.0
swagger version          : 4.5.1
common version           : 7.0.0
core version             : 7.0.0

[Akhouad]

@PoOwAa , i basically had this issue after trying to create a new decorator for a paginated response, following the steps in this docs page and the error I had was complaining about PaginatedDto schema which couldn’t be resolved, so I added the extraModels in swagger main configuration with PaginatedDto, it looked like this:

const document = SwaggerModule.createDocument(app, config, {
  extraModels: [PaginatedDto]
});

[Akhouad]

I had the same issue and could resolve it by including ExtraModels to swagger main configuration: docs