Cache interceptor in NestJS - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a Cache Interceptor in NestJS?

A Cache Interceptor in NestJS is a tool that automatically stores the response of a request so that future requests can get the stored response quickly without running the full logic again.

intermediate

How do you enable caching globally in a NestJS application?

You enable caching globally by importing and configuring CacheModule in the root module's imports array, and providing { provide: APP_INTERCEPTOR, useClass: CacheInterceptor } in the providers array.

intermediate

Which decorator is used to disable caching on a specific route in NestJS?

The @CacheKey() decorator sets a custom cache key, but to disable caching on a route, you use the @CacheTTL(0) decorator or avoid applying the CacheInterceptor on that route.

beginner

What is the role of CacheModule in NestJS caching?

CacheModule provides the caching functionality and configuration, like setting the store type (memory, redis), default TTL (time to live), and other options for caching in NestJS.

intermediate

How does CacheInterceptor decide when to return cached data?

CacheInterceptor checks if a cached response exists for the request key. If yes, it returns the cached data immediately. If not, it runs the handler, caches the response, then returns it.

What does CacheInterceptor do in NestJS?

A Stores and returns cached responses automatically

B Handles user authentication

C Manages database connections

D Formats HTTP responses

CacheInterceptor automatically caches responses to speed up repeated requests.

Which module must be imported to use caching in NestJS?

A HttpModule

B CacheModule

C ConfigModule

D AuthModule

CacheModule provides caching features and configuration in NestJS.

How do you apply CacheInterceptor globally in NestJS?

A Use @GlobalCache() decorator

B Add CacheInterceptor in controller constructor

C Set cache: true in main.ts

D Provide { provide: APP_INTERCEPTOR, useClass: CacheInterceptor } in AppModule providers

You apply CacheInterceptor globally by providing it with the APP_INTERCEPTOR token in the root module's providers array.

What happens if CacheInterceptor finds no cached data for a request?

A Returns an error

B Skips the request

C Executes the handler and caches the response

D Returns null

If no cached data exists, CacheInterceptor runs the handler, caches the result, then returns it.

Which decorator can set a custom cache key in NestJS?

A @CacheKey()

B @CacheTTL()

C @CacheDisable()

D @CacheControl()

@CacheKey() sets a custom key for caching responses.

Explain how CacheInterceptor works in NestJS and how it improves application performance.

Think about how saving answers helps you avoid repeating work.

Describe the steps to enable caching globally in a NestJS app using CacheModule and CacheInterceptor.

Remember the setup involves both module import and interceptor application.