Nest + Swagger not recognizing endpoints or parameters - swagger

Question

I'm having an issue with Nest + Swagger. When I open my swagger docs I see all of the endpoints I expect but am having two issues:
When I click on a method it expands all of the methods for that controller
The post method says No parameters despite having a DTO defined for the body
Ultimately I think the issue is: Swagger + Nest is not creating unique operationId's for each method. My understanding is that methods will only fail to get unique operationId's when they are not sufficiently unique: 2 methods with identical call signatures for example.
In the past when I've had issues like this it was either because I was missing the #ApiTags decorator, or I had accidentally included duplicate endpoints.
In general it feels like I missed a step in configuring Swagger, or I didn't set it up properly with Fastify. I installed fastify-swagger but I'm not actually using it anywhere, but according the docs on Nest's site the route for the swagger JSON should be /api/json when using Fastify, which it is for me.
Things that didn't work:
Annotating method with unique #ApiOperation
Adding a addTag to the DocumentBuilder chain
Deleting the swagger-ui-express and #nestjs/platform-express dependencies
Removing all of the Fastify deps and switching to the Express equivalents
Update:
Adding #ApiOperation({ operationId: 'test' }) to a method does fix this, but I was under impression that #nest/swagger did this automatically. Are my methods not unique enough?
main.ts
async function bootstrap() {
const app = await NestFactory.create<NestFastifyApplication>(
AppModule,
new FastifyAdapter(),
);
app.useGlobalPipes(
new ValidationPipe({
whitelist: true,
forbidNonWhitelisted: true,
transform: true,
}),
);
app.useGlobalInterceptors(new ClassSerializerInterceptor(app.get(Reflector))); // allows automatic serialization
app.enableCors();
const config = new DocumentBuilder().setTitle('PIM API').build();
const document = SwaggerModule.createDocument(app, config);
SwaggerModule.setup('docs', app, document);
await app.listen(process.env.APP_PORT || 3001);
}
bootstrap();
some controller
#ApiTags('chat-messages')
#Controller('chat-messages')
export class ChatMessagesController {
constructor(
private readonly service: ChatMessagesService,
) {}
#Post()
create(#Body() createChatMessageDto: CreateChatMessageDto) {
return this.service.create(createChatMessageDto);
}
#Get(':stream_id')
findByStreamId(#Param('stream_id') streamId: string) {
return this.service.findByStreamId(streamId);
}
ChatMessageDto
export class CreateChatMessageDto {
constructor(partial: Partial<CreateChatMessageDto>) {
Object.assign(this, partial);
}
#IsString()
value: string;
#IsRFC3339()
timestamp: Date;
#IsNotEmpty()
streamId: string;
}
Swagger JSON
{
"/chat-messages":{
"post":{
"operationId":"ChatMessagesController_",
"parameters":[
],
"responses":{
"201":{
"description":"",
"content":{
"application/json":{
"schema":{
"$ref":"#/components/schemas/ChatMessage"
}
}
}
}
},
"tags":[
"chat-messages"
]
}
},
"/chat-messages/{stream_id}":{
"get":{
"operationId":"ChatMessagesController_",
"parameters":[
],
"responses":{
"200":{
"description":"",
"content":{
"application/json":{
"schema":{
"type":"array",
"items":{
"$ref":"#/components/schemas/ChatMessage"
}
}
}
}
}
},
"tags":[
"chat-messages"
]
}
}
}

Answer 1

Did you try putting #ApiProperty in your dto ?
Like this:
export class CreateChatMessageDto {
constructor(partial: Partial<CreateChatMessageDto>) {
Object.assign(this, partial);
}
#ApiProperty()
#IsString()
value: string;
#ApiProperty()
#IsRFC3339()
timestamp: Date;
#ApiProperty()
#IsNotEmpty()
streamId: string;
}
This allows Swagger to see the properties.
This is what NestJs recommends in their documentation See here