NestJs Questions

NestJS provides ValidationPipe, ParseIntPipe, and DefaultValuePipe as built-in solutions. There's no built-in 'TransformationPipe.'

Models in Mongoose are constructed from Schemas and provide an interface for interacting with a specific collection in your MongoDB database. They offer methods for querying, creating, updating, and deleting documents.

The ICanActivate interface requires a single method, canActivate, which contains the core logic of your guard. This method returns a boolean or a Promise resolving to a boolean, indicating whether the request is allowed.

After Passport.js successfully authenticates a request, it typically attaches the user object to the request object. You can access this object as req.user within your controller methods.

Schemas in Mongoose define the structure of documents within a MongoDB collection. They specify the fields, data types, validation rules, and other properties for each document, providing a layer of organization and consistency.

In NestJS, logging interceptors implement the NestInterceptor interface. This interface provides two methods: intercept() for intercepting incoming requests and modifying responses, and catch() for handling any exceptions that occur during the interception process.

Using interceptors in NestJS for tasks like logging, caching, and transformation brings multiple benefits, including improved code organization, reduced code duplication, and potentially enhanced performance due to their centralized nature.

The @UseInterceptors(CacheInterceptor) decorator is used to register a caching interceptor globally in a NestJS application, allowing it to intercept requests and responses for all controllers and routes.

NestJS itself doesn't directly manage database connections. However, its modular design and decorators (like @InjectRepository) make it easy to integrate ORMs like TypeORM or ODMs like Mongoose, allowing you to seamlessly connect to and work with your chosen database.

CQRS optimizes event-driven systems by dividing operations into distinct commands (for changing state) and queries (for reading state), allowing for independent scaling and optimization.