feat: add factory to cache-key

Added factory to 'CacheKey' decorator and use it in interceptor

Author: ivanfmn

lib/decorators/cache-key.decorator.ts

@@ -1,5 +1,6 @@
-import { SetMetadata } from '@nestjs/common';
+import { ExecutionContext, SetMetadata } from '@nestjs/common';
 import { CACHE_KEY_METADATA } from '../cache.constants';
+export type CacheKeyFactory = (ctx: ExecutionContext) => string;
 
 /**
  * Decorator that sets the caching key used to store/retrieve cached items for
@@ -14,4 +15,5 @@ import { CACHE_KEY_METADATA } from '../cache.constants';
  *
  * @publicApi
  */
-export const CacheKey = (key: string) => SetMetadata(CACHE_KEY_METADATA, key);
+export const CacheKey = (key: string | CacheKeyFactory) =>
+  SetMetadata(CACHE_KEY_METADATA, key);

lib/decorators/cache-ttl.decorator.ts

@@ -1,5 +1,8 @@
 import { ExecutionContext, SetMetadata } from '@nestjs/common';
 import { CACHE_TTL_METADATA } from '../cache.constants';
+export type CacheTTLFactory = (
+  ctx: ExecutionContext,
+) => Promise<number> | number;
 
 /**
  * Decorator that sets the cache ttl setting the duration for cache expiration.
@@ -12,6 +15,5 @@ import { CACHE_TTL_METADATA } from '../cache.constants';
  *
  * @publicApi
  */
-type CacheTTLFactory = (ctx: ExecutionContext) => Promise<number> | number;
 export const CacheTTL = (ttl: number | CacheTTLFactory) =>
   SetMetadata(CACHE_TTL_METADATA, ttl);

lib/interceptors/cache.interceptor.ts

@@ -17,6 +17,7 @@ import {
   CACHE_MANAGER,
   CACHE_TTL_METADATA,
 } from '../cache.constants';
+import { CacheKeyFactory, CacheTTLFactory } from '../decorators';
 
 /**
  * @see [Caching](https://docs.nestjs.com/techniques/caching)
@@ -41,7 +42,7 @@ export class CacheInterceptor implements NestInterceptor {
     next: CallHandler,
   ): Promise<Observable<any>> {
     const key = this.trackBy(context);
-    const ttlValueOrFactory =
+    const ttlValueOrFactory: number | CacheTTLFactory | null =
       this.reflector.get(CACHE_TTL_METADATA, context.getHandler()) ??
       this.reflector.get(CACHE_TTL_METADATA, context.getClass()) ??
       null;
@@ -90,13 +91,13 @@ export class CacheInterceptor implements NestInterceptor {
   protected trackBy(context: ExecutionContext): string | undefined {
     const httpAdapter = this.httpAdapterHost.httpAdapter;
     const isHttpApp = httpAdapter && !!httpAdapter.getRequestMethod;
-    const cacheMetadata = this.reflector.get(
-      CACHE_KEY_METADATA,
-      context.getHandler(),
-    );
+    const cacheMetadataOrFactory: string | CacheKeyFactory | null =
+      this.reflector.get(CACHE_KEY_METADATA, context.getHandler()) ?? null;
 
-    if (!isHttpApp || cacheMetadata) {
-      return cacheMetadata;
+    if (!isHttpApp || cacheMetadataOrFactory) {
+      return isFunction(cacheMetadataOrFactory)
+        ? cacheMetadataOrFactory(context)
+        : cacheMetadataOrFactory;
     }
 
     const request = context.getArgByIndex(0);