Nestjs/swagger: how to document the JWT payload? - swagger

Question

I have a controller's login() method that can return either 200 OK with JWT token fitted with Session payload or 451 Unavailable due to legal reasons with JWT token fitted with AcceptTerms payload if user trying to log in needs to agree to new version of terms&conditions.
#Nest.Post("login")
#ApiOperation({ title: 'Log in the user given email and password', operationId: 'userLogin'})
#Nest.UseFilters(UnavailableLegalReasonsExceptionFilter)
#ApiResponse({ status: HttpStatus.OK, description: "User was properly logged in", type: JwtToken})
#ApiResponse({ status: 451, description: "User haven't confirmed the latest version of Terms & Conditions", type: JwtToken})
async login(#Nest.Body() body: DTOs.LoginDto): Promise<JwtToken> {
...
}
Now, I'd like to document it with Swagger. JwtToken is defined as:
export class JwtToken {
#ApiModelProperty({enum: TOKEN})
type: TOKEN;
#ApiModelProperty({description: "Number of seconds"})
expiresIn: number;
#ApiModelProperty({ description: "Token", example: "eyJhb ... wWFQ"})
accessToken: string;
}
and TOKEN:
export enum TOKEN {
AcceptTerms = "AcceptTerms",
Session = "Session"
}
But writing that login() returns just a JwtToken is confusing as in case of 200 the type is Session and in case of 451 it is AcceptTerms. The payloads differ significantly too:
export class JwtPayload {
#ApiModelProperty({enum: TOKEN, description: "Token type"})
type: TOKEN;
#ApiModelProperty()
issuedAt: number;
}
export class LoginJwtPayload extends JwtPayload {
#ApiModelProperty()
name: string;
#ApiModelProperty({description: "T&C version accepted"})
tncAccepted: number;
}
export class AcceptTermsJwtPayload extends JwtPayload {
#ApiModelProperty({format: "email"})
email: string;
}
200's token uses LoginJwtPayload payload and 451's uses AcceptTermsJwtPayload.
How to document it using Nest's SwaggerModule?