NestJS Communication & Stakeholder Relations 2

Question 1

Which NestJS transport layer is best suited for real-time bidirectional communication with browser clients?

Accepted Answer

WebSockets

Answer

NestJS WebSockets adapter enables full-duplex, real-time communication between server and browser clients.

Question 2

In a NestJS microservices architecture, what is the role of the @MessagePattern() decorator?

Accepted Answer

It maps a message pattern to a handler method

Answer

@MessagePattern() maps an incoming message pattern string to the controller method that should handle it.

Question 3

A stakeholder asks for API documentation that can be tested interactively. Which NestJS tool satisfies this requirement?

Accepted Answer

Swagger/OpenAPI via @nestjs/swagger

Answer

@nestjs/swagger generates an interactive Swagger UI that lets stakeholders explore and test API endpoints.

Question 4

When using NestJS Server-Sent Events (SSE), what return type must a controller method use?

Accepted Answer

Observable<MessageEvent>

Answer

SSE endpoints must return an Observable<MessageEvent> so NestJS can stream events to the client.

Question 5

Which decorator in @nestjs/swagger marks a DTO property as required in the generated API schema?

Accepted Answer

@ApiProperty({ required: true })

Answer

@ApiProperty({ required: true }) tells Swagger to flag the property as required in the OpenAPI schema.

NestJS Practice Test