Mock Redis in Jest - NestJS

Question

I'm Using Redis cache for my nestjs Application and i'm maintaining redisCache.module.ts for Redis configuration.But my unit test has fail because,it's trying to connect into Redis server.How can i fix this issue?

redisCache.module.ts

import { Module, CacheModule } from '@nestjs/common';
import { ConfigModule, ConfigService } from '@nestjs/config';
import * as redisStore from 'cache-manager-redis-store';
import { RedisCacheService } from './redisCache.service';

@Module({
  imports: [
    CacheModule.registerAsync({
      imports: [ConfigModule],
      inject: [ConfigService],
      useFactory: async (configService: ConfigService) => ({
        store:redisStore, 
        host: configService.get('REDIS_HOST'),
        port: configService.get('REDIS_PORT'),
        ttl: configService.get('REDIS_CACHE_TTL'),
      }),
    }),
  ],
  providers: [RedisCacheService],
  exports: [RedisCacheService]
})
export class RedisCacheModule {}

redisCache.module.spec.ts

import { CacheModule, CACHE_MANAGER } from '@nestjs/common';
import { Test, TestingModule } from '@nestjs/testing';
import { RedisCacheService } from './redisCache.service';
import { RedisCacheModule } from './redisCache.module';
import { Cache } from 'cache-manager';

describe('RedisCacheModule', () => {
  let redisCacheService: RedisCacheService;
  let redisCacheModule: RedisCacheModule;
  let cache: Cache;

  beforeEach(async () => {
    const module: TestingModule = await Test.createTestingModule({
      providers: [RedisCacheService],
      imports: [CacheModule.register({}),RedisCacheModule],
    }).compile();

    redisCacheService = module.get(RedisCacheService);
    redisCacheModule = module.get(RedisCacheModule);
    cache = module.get(CACHE_MANAGER);
  });

  it('RedisCacheService should be defined', () => {
    expect(redisCacheService).toBeDefined();
  });

  it('RedisCacheModule should be defined', () => {
    expect(redisCacheModule).toBeDefined();
  });
});

Error

user_19258691 · Answer

I mocked this by overriding the CACHE_MODULE_OPTIONS.

Here is an example from one of my e2e tests:

const moduleFixture: TestingModule = await Test.createTestingModule({
  imports: [AppModule], // or whatever imports you need for your service/etc
})
  .overrideProvider(CACHE_MODULE_OPTIONS)
  .useValue({
    // your options go here (minus host and port and store), or you can leave as an empty object
  })
  .compile();

I got this answer from here when trying to figure out this same thing: https://github.com/nestjs/docs.nestjs.com/issues/681#issuecomment-1096939527

Mock Redis in Jest - NestJS

1 Answers