How to ignore global cache on some routes in NestJs

Question

I activate the global cache by APP_INTERCEPTOR in my NestJS app. But now, I need to ignore it on some routes. How can I do that?

Answer 1

I found the solution. Before all, I made a CustomHttpCacheInterceptor that extends the CacheInterceptor :

@Injectable()
export default class CustomHttpCacheInterceptor extends CacheInterceptor {
  httpServer: any;
  trackBy(context: ExecutionContext): string | undefined {
    const request = context.switchToHttp().getRequest();
    const isGetRequest = request.method === 'GET';
    const requestURl = request.path;
    const excludePaths = ['/my/custom/route'];

    if (
      !isGetRequest ||
      (isGetRequest && excludePaths.some(url => requestURl.includes(url)))
    ) {
      return undefined;
    }
    return requestURl;
  }
}

and then I add it as a global cache interceptor in app.module

//...
  providers: [
    AppService,
    {
      provide: APP_INTERCEPTOR,
      useClass: CustomHttpCacheInterceptor,
    },
  ],
//...

Answer 2

A different take on what Sadra suggested, instead of the trackBy() method you can override the isRequestCacheable() method on the CacheInterceptor class. It is a little easier.

@Injectable()
export class CustomCacheInterceptor extends CacheInterceptor {

  excludePaths = ["/my/custom/route"];

  isRequestCacheable(context: ExecutionContext): boolean {
    const req = context.switchToHttp().getRequest();
    return (
      this.allowedMethods.includes(req.method) &&
      !this.excludePaths.includes(req.url)
    );
  }
}