I just created a global module to work with Redis. At first it just provided the client:
// redis.module.ts import { Global, Module } from '@nestjs/common' import { createClient } from 'redis' import { RedisMutex } from './redis-mutex.service' export const REDIS = 'redis' @Global() @Module({ providers: [ { provide: REDIS, useFactory: async () => { const client = createClient() await client.connect() return client }, }, ], exports: [REDIS], }) export class RedisModule {} It worked well, I could inject it everywhere with no issue at all. Next, I created a class to implement mutex with this client under the same module:
// redis-mutex.service.ts import { Inject, Injectable } from '@nestjs/common' import { randomBytes } from 'crypto' import { RedisClientType } from 'redis' import { REDIS } from './redis.module' @Injectable() export class RedisMutex { constructor(@Inject(REDIS) private redis: RedisClientType) {} async lock(lockName: string): Promise<() => void> { // ...code } } Add it as a provider to the module and export:
// redis.module.ts import { Global, Module } from '@nestjs/common' import { createClient } from 'redis' import { RedisMutex } from './redis-mutex.service' export const REDIS = 'redis' @Global() @Module({ providers: [ { provide: REDIS, useFactory: async () => { const client = createClient() await client.connect() return client }, }, RedisMutex, ], exports: [REDIS, RedisMutex], }) export class RedisModule {} Everything's still fine. Then I injected RedisMutex into 2 other providers in outside modules. Those other modules don't explicitly import RedisModule and they don't inject REDIS, only RedisMutex. RedisModule is only added to the imports of AppModule.
At this point Nest starts reporting a circular dependency, but without its trace:
Error: A circular dependency has been detected. Please, make sure that each side of a bidirectional relationships are decorated with "forwardRef()". at NestContainer.addProvider (/home/andrey/Code/cashflowio/node_modules/@nestjs/core/injector/container.js:107:19) at DependenciesScanner.insertProvider (/home/andrey/Code/cashflowio/node_modules/@nestjs/core/scanner.js:201:35) at /home/andrey/Code/cashflowio/node_modules/@nestjs/core/scanner.js:105:18 at Array.forEach (<anonymous>) at DependenciesScanner.reflectProviders (/home/andrey/Code/cashflowio/node_modules/@nestjs/core/scanner.js:104:19) at DependenciesScanner.scanModulesForDependencies (/home/andrey/Code/cashflowio/node_modules/@nestjs/core/scanner.js:85:18) at DependenciesScanner.scan (/home/andrey/Code/cashflowio/node_modules/@nestjs/core/scanner.js:29:9) at /home/andrey/Code/cashflowio/node_modules/@nestjs/core/nest-factory.js:95:17 at Function.asyncRun (/home/andrey/Code/cashflowio/node_modules/@nestjs/core/errors/exceptions-zone.js:22:13) at NestFactoryStatic.initialize (/home/andrey/Code/cashflowio/node_modules/@nestjs/core/nest-factory.js:94:13) So I don't know what's causing it. I went as far as to wrap every single new injection that I just wrote in forwardRef, but that didn't help. How do I find out what dependencies is Nest referencing here?
