"circular dependency" error when using object properties

[mamacdon-surveymonkey]

I'm submitting a...

Seems to be a regression of issue #502. Works in 4.8.2, fails in 5.0.0

[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

Nest crashes with this error:

(node:9740) UnhandledPromiseRejectionWarning: Error: A circular dependency has been detected (property key: "is_migrated"). Please, make sure that each side of a bidirectional relationships are using lazy resolvers ("type: () => ClassType").
    at SchemaObjectFactory.createNotBuiltInTypeReference (/Users/mmacdonald/Desktop/repro/myapp/node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:204:19)
    at SchemaObjectFactory.mergePropertyWithMetadata (/Users/mmacdonald/Desktop/repro/myapp/node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:141:25)
    at /Users/mmacdonald/Desktop/repro/myapp/node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:270:43
    at Array.forEach (<anonymous>)
    at SchemaObjectFactory.createFromObjectLiteral (/Users/mmacdonald/Desktop/repro/myapp/node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:254:24)
    at SchemaObjectFactory.mergePropertyWithMetadata (/Users/mmacdonald/Desktop/repro/myapp/node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:120:25)
    at /Users/mmacdonald/Desktop/repro/myapp/node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:79:35
    at Array.map (<anonymous>)
    at SchemaObjectFactory.extractPropertiesFromType (/Users/mmacdonald/Desktop/repro/myapp/node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:78:52)
    at SchemaObjectFactory.exploreModelSchema (/Users/mmacdonald/Desktop/repro/myapp/node_modules/@nestjs/swagger/dist/services/schema-object-factory.js:92:41)

If I downgrade to @nestjs/swagger@^4.8.2, the error goes away and Swagger works again.

Expected behavior

Expected it to work as it did in v4.8.2

Minimal reproduction of the problem with instructions

Repo is here, the important files are the DTO:

// user.dto.ts

export class UserDto {
  readonly user_id: string;

  readonly metadata: {
    readonly is_migrated: boolean;
  };
}

and the controller:

// users.controller.ts
@Controller()
@ApiTags('users')
export class UsersController {
  constructor(private readonly service: UserService) {}

  @Get()
  @HttpCode(200)
  async getUser(): Promise<UserDto> {
    return this.service.getUser();
  }
}

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

Allow object properties to work in DTO classes again.

Environment

[Nest Platform Information]
platform-express version : 8.0.0
swagger version          : 5.0.0
common version           : 8.0.0
core version             : 8.0.0

[System Information]
OS Version     : macOS Catalina
NodeJS Version : v14.15.3
NPM Version    : 6.14.5 

[Nest CLI]
Nest CLI Version : 8.0.2 

[kamilmysliwiec]

Thanks for reporting! Fixed in 5.0.1