Nest 无法解析 MailerService 的依赖项（？）

Question

I'm trying to configure this module .

The full error message reads as follows:

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

I keep getting this error out of nowhere, what MAILER_OPTIONS? Where are those options? Nothing is said in the documentation in this respect. Absolutely no idea what's going on.

Here is my AppModule:

@Module({
  imports: [
    MailerModule.forRoot({
      defaults: {
        from: '"No Reply" <noreply@example.com>',
      },
      template: {
        dir: path.join(process.env.PWD, 'templates/pages'),
        adapter: new HandlebarsAdapter(),
        options: {
          strict: true,
        },
      },
      options: {
        partials: {
          dir: path.join(process.env.PWD, 'templates/partials'),
          options: {
            strict: true,
          },
        },
      },
    }),
  ],
  controllers: [AppController],
  providers: [
    AppService,
    MailerService,
  ],
})
export class AppModule {}

Any ideas?

Here is the service I'm using:

@Injectable()
export class AppService {
  constructor(
    private readonly mailerService: MailerService,
  ) {}

  public async sendEmail(): Promise<any> {
    const mailDetail: ISendMailOptions = {
      to: 'gutgesagt@yahoo.co.uk',
      from: 'noreply@nestjs.com',
      subject: 'testing Nest MailerModule',
      text: 'test test?!',
      html: '<b>Yahooooo</b>',
    };

    return this.mailerService.sendMail(mailDetail);
  }
}

Answer 1

You have to remove the imported MailerService from the providers array of your AppModule . Only declare providers that are part of the module itself; you would never declare an imported provider (service).

  providers: [
    AppService,
  ],