Swagger / OpenAPI documentation trong NestJS — setup và các annotations phổ biến?

NestJS tích hợp Swagger qua @nestjs/swagger. Setup trong main.ts: DocumentBuilder cấu hình title/description/version/auth, SwaggerModule.createDocument() tạo document, SwaggerModule.setup('api/docs', app, document) serve UI.

Annotations trên DTO: @ApiProperty({ example, description }) cho required fields, @ApiPropertyOptional() cho optional fields. Hỗ trợ enum, type, minLength, maxLength, default.

Annotations trên Controller: @ApiTags('GroupName') nhóm endpoints trong Swagger UI, @ApiBearerAuth() chỉ định cần JWT, @ApiOperation({ summary }) mô tả endpoint, @ApiResponse({ status, type, description }) document các response codes. Param annotations: @ApiParam() cho route params, @ApiQuery() cho query params. PickType, OmitType, PartialType từ @nestjs/swagger để tạo derived DTOs tái sử dụng schema.

NestJS integrates Swagger via @nestjs/swagger. Setup in main.ts: use DocumentBuilder to configure title/description/version/auth, SwaggerModule.createDocument() to build the document, SwaggerModule.setup('api/docs', app, document) to serve the UI.

DTO annotations: @ApiProperty({ example, description }) for required fields, @ApiPropertyOptional() for optional fields. Supports enum, type, minLength, maxLength, default.

Controller annotations: @ApiTags('GroupName') groups endpoints in the Swagger UI, @ApiBearerAuth() marks JWT requirement, @ApiOperation({ summary }) describes the endpoint, @ApiResponse({ status, type, description }) documents response codes. Param annotations: @ApiParam() for route params, @ApiQuery() for query params. Use PickType, OmitType, PartialType from @nestjs/swagger to create derived DTOs that reuse the schema.