使用CacheModule.register集成Redis时NestJS出现类型错误

问题场景 #

使用CacheModule（来自@nestjs/common）和cache-manager-redis-store包在NestJS中集成Redis时，为CacheModule.register的store属性赋值redisStore出现类型错误。

报错代码 #

import { Module, CacheModule } from "@nestjs/common";
import { AuthModule } from "./auth/auth.module";
import { MongooseModule } from "@nestjs/mongoose";
import { EnvConfiguration } from "./config/env.config";
import { ConfigModule } from "@nestjs/config";
import { redisStore } from "cache-manager-redis-store";
@Module({
  imports: [
    ConfigModule.forRoot({
      load: [EnvConfiguration],
    }),
    MongooseModule.forRoot(process.env.MONGODB),
    AuthModule,
    CacheModule.register({
      store: redisStore, // 错误发生位置
      host: "localhost",
      port: 6379,
    }),
  ],
  controllers: [],
  providers: [],
})
export class AppModule {}

错误信息 #

(property) store: (string | CacheStoreFactory | CacheStore) & ((config: RedisClientOptions<RedisModules, RedisFunctions, RedisScripts> & Config) => Promise<...>)
Cache manager. The default value is 'memory' (memory storage). See Different Stores for more information.

Type '(config: RedisClientOptions<RedisModules, RedisFunctions, RedisScripts> & Config) => Promise<RedisStore>' cannot be assigned to type '(string | CacheStoreFactory | CacheStore) & ((config: RedisClientOptions<RedisModules, RedisFunctions, RedisScripts > & Configuration) => Promise<...>)'.
  Type '(config: RedisClientOptions<RedisModules, RedisFunctions, RedisScripts> & Config) => Promise<RedisStore>' cannot be assigned to type 'string & ((config: RedisClientOptions<RedisModules, RedisFunctions, RedisScripts> & Config) => Promise<...>)'.
    Type '(config: RedisClientOptions<RedisModules, RedisFunctions, RedisScripts> & Config) => Promise<RedisStore>' cannot be assigned to type 'string'.ts(2322)

解决办法 #

方法一：使用异步注册（推荐） #

redisStore返回的是一个Promise，同步的register方法无法正确处理异步的store工厂，改用CacheModule.registerAsync通过useFactory处理异步逻辑：

import { Module } from "@nestjs/common";
import { AuthModule } from "./auth/auth.module";
import { MongooseModule } from "@nestjs/mongoose";
import { EnvConfiguration } from "./config/env.config";
import { ConfigModule } from "@nestjs/config";
import { CacheModule } from "@nestjs/common";
import { redisStore } from "cache-manager-redis-store";

@Module({
  imports: [
    ConfigModule.forRoot({
      load: [EnvConfiguration],
    }),
    MongooseModule.forRoot(process.env.MONGODB),
    AuthModule,
    CacheModule.registerAsync({
      useFactory: async () => ({
        store: await redisStore({
          host: "localhost",
          port: 6379,
        }),
      }),
    }),
  ],
  controllers: [],
  providers: [],
})
export class AppModule {}

方法二：类型断言（临时方案） #

如果必须使用同步注册，可以通过类型断言强制转换redisStore的类型，不过这种方法可能隐藏真实类型问题，不推荐长期使用：

import { Module, CacheModule, CacheStoreFactory } from "@nestjs/common";
// 其他导入不变

CacheModule.register({
  store: redisStore as unknown as CacheStoreFactory,
  host: "localhost",
  port: 6379,
}),

方法三：升级到官方推荐的@nestjs/cache-manager模块 #

NestJS v10及以上版本推荐使用@nestjs/cache-manager模块（适配cache-manager v5+），步骤如下：

1. 安装依赖：

npm install @nestjs/cache-manager cache-manager cache-manager-redis-store

2. 修改代码：

import { Module } from "@nestjs/common";
import { AuthModule } from "./auth/auth.module";
import { MongooseModule } from "@nestjs/mongoose";
import { EnvConfiguration } from "./config/env.config";
import { ConfigModule } from "@nestjs/config";
import { CacheModule } from "@nestjs/cache-manager"; // 替换导入路径
import { redisStore } from "cache-manager-redis-store";

@Module({
  imports: [
    ConfigModule.forRoot({
      load: [EnvConfiguration],
    }),
    MongooseModule.forRoot(process.env.MONGODB),
    AuthModule,
    CacheModule.registerAsync({
      useFactory: async () => {
        const store = await redisStore({
          host: "localhost",
          port: 6379,
        });
        return {
          store: store,
        };
      },
    }),
  ],
  controllers: [],
  providers: [],
})
export class AppModule {}

错误原因 #

redisStore是一个返回Promise的异步函数，而同步的CacheModule.register期望的store类型是字符串、同步工厂函数或已实例化的store实例，无法直接兼容异步返回的函数，因此触发类型不匹配错误。

内容的提问来源于stack exchange，提问作者Luciano Pulido