Cache interceptor

cache.interceptor.ts

import {Injectable, NestInterceptor, ExecutionContext, CallHandler, Inject, Logger} from '@nestjs/common'
import {map, Observable, tap} from 'rxjs'
import {RedisService} from './redis.service'

@Injectable()
export class CacheInterceptor implements NestInterceptor {
    @Inject() redisService: RedisService

    async intercept(context: ExecutionContext, next: CallHandler): Promise<Observable<any>> {
        if (process.env.NODE_ENV.includes('development')) {
            Logger.log('CACHE WONT WORK IN DEV MODE')
            return next.handle()
        }

        const request = context.switchToHttp().getRequest()
        const key = request._parsedOriginalUrl?.path || request.path
        const data = await this.redisService.get(key)
        if (data) {
            Logger.log('from cache')
            return next.handle().pipe(map(() => data))
        }
        Logger.log('from db')
        return next.handle().pipe(
            tap(value => {
                if (value) {
                    this.redisService.save(key, value)
                }
            }),
        )
    }
}