在TypeORMModule.forRootAsync中使用connectionName时NestJS抛出依赖异常

问题 #

在TypeORM.forRootAsync中添加name: 'psql'属性后，NestJS应用启动抛出依赖解析异常，提示AccountRepository无法获取DataSource。

相关代码 #

AppModule #

@Module({
    imports: [
        UsersModule,
        TypeOrmModule.forRootAsync({
            name: 'psql',  // 添加此行后报错
            useFactory: () => {
                return {
                    type: 'postgres',
                    host: process.env.POSTGRES_DATABASE_HOST,
                    port: parseInt(process.env.POSTGRES_DATABASE_PORT),
                    username: process.env.POSTGRES_DATABASE_USERNAME,
                    password: process.env.POSTGRES_DATABASE_PASSWORD,
                    database: process.env.POSTGRES_DATABASE_NAME,
                    logging: false,
                    autoLoadEntities: true,
                    synchronize: false,
                };
            },
        }),
        GroupsModule,
        EventsModule,
        AccountsModule,
        ConfigModule.forRoot({ isGlobal: true }),
        AuthModule,
        IntegrationsModule,
        MailModule,
    ],
    controllers: [AppController],
    providers: [AppService],
    exports: [TypeOrmModule],
})
export class AppModule {}

AccountsModule #

@Module({
    imports: [
        TypeOrmModule.forFeature([Account, Project, ApiKey, Operator, ProjectRole, Session], 'psql'),
        CqrsModule,
        ConfigModule,
        MailModule,
        BullModule.registerQueue({
            name: 'projects',
        }),
        JwtModule.register({
            secret: process.env.JWT_SECRET,
            signOptions: { expiresIn: '30d' },
        }),
    ],
    controllers: [AccountsController, ApikeysController, ProjectsController, OperatorsController],
    exports: [ApikeysService, ApiKeyRepository, AccountRepository, ProjectRepository, OperatorsService],
    providers: [...],
})
export class AccountsModule {}

AccountRepository #

import { AggregateRoot, EventBus } from '@nestjs/cqrs';
import { v4 as uuidv4 } from 'uuid';
import { HttpException, HttpStatus, Logger } from '@nestjs/common';
import { Account } from '../entities/account.entity';
import { AccountCreatedEvent } from '../events/account-created.event';
import { InjectRepository } from '@nestjs/typeorm';
import { Repository } from 'typeorm';

export class AccountRepository extends AggregateRoot {
    private readonly logger = new Logger('Account Repository');
    constructor(private eventBus: EventBus, @InjectRepository(Account) private readonly accountRepository: Repository<Account>) {
        super();
    }

    async create(name: string, slug: string): Promise<Account> {
        this.logger.debug(`Checking if account exists`);
        if (await this.get({ slug })) {
            throw new HttpException('Account slug already exists', HttpStatus.BAD_REQUEST);
        }

        const id = uuidv4();
        const createdAt = new Date();

        const account: Account = this.accountRepository.create({ id, name, slug, createdAt });
        await this.accountRepository.save(account);

        this.logger.debug(`Posting AccountCreatedEvent`);
        this.eventBus.publish(new AccountCreatedEvent(id));

        return { id, slug, name, createdAt };
    }
}

错误信息 #

Nest can't resolve dependencies of the AccountRepository (?). Please make sure that the argument DataSource at index [0] is available in the TypeOrmModule context.

Potential solutions:
- If DataSource is a provider, is it part of the current TypeOrmModule?
- If DataSource is exported from a separate @Module, is that module imported within TypeOrmModule?
  @Module({
    imports: [ /* the Module containing DataSource */ ]
  })

解决方案 #

1. 注入Repository时指定数据源名称 #

配置命名数据源后，@InjectRepository必须明确指定数据源名称，否则Nest会默认查找未命名的默认数据源（当前仅配置了psql命名数据源）。修改AccountRepository的构造函数：

constructor(
    private eventBus: EventBus, 
    @InjectRepository(Account, 'psql') // 添加第二个参数指定数据源名称
    private readonly accountRepository: Repository<Account>
) {
    super();
}

2. 调整ConfigModule加载顺序 #

AppModule中ConfigModule.forRoot在TypeOrmModule之后加载，会导致TypeOrm的useFactory执行时环境变量未初始化，可能引发配置读取错误。将ConfigModule.forRoot移到imports数组最前面：

@Module({
    imports: [
        ConfigModule.forRoot({ isGlobal: true }), // 移到最顶部
        UsersModule,
        TypeOrmModule.forRootAsync({
            name: 'psql',
            useFactory: () => {
                // ... 原有配置
            },
        }),
        // ... 其他模块
    ],
    // ... 其他配置
})
export class AppModule {}

3. 统一所有关联Repository的数据源配置 #

如果其他自定义Repository（如ApiKeyRepository、ProjectRepository等）也注入了实体Repository，同样需要在@InjectRepository中添加'psql'参数，确保所有操作都指向同一命名数据源。

内容的提问来源于stack exchange，提问作者Luis Novo