如何使用Macwire注入特征

Question

我有Scala特质

trait UserRepository {
  def findByEmail(email: String): User
}

我想将其注入MacWire服务中

class AccountService(){
  val userRepo = wire[UserRepository]
}

然后在测试或课程中使用它

class AccountServiceSpec {
  val userRepo = new UserRepositoryImpl()
  val accountSvc = new AccountService() //<--not manually injecting repo in service constructor
}

但是我在服务类中遇到了编译错误

找不到accounts.repository.UserRepository的公共构造函数或伴随对象

Answer 1

您可以尝试将userRepo转换为类参数，该参数允许macwire自动提供其用于服务的值：

import com.softwaremill.macwire._

case class User(email: String)

trait UserRepository {
  def findByEmail(email: String): User
}

class AccountService(val userRepo: UserRepository)

class UserRepositoryImpl extends UserRepository{
  def findByEmail(email: String): User = new User(email)
}

class AccountServiceSpec {
  val userRepo = new UserRepositoryImpl()
  val accountSvc = wire[AccountService] //<--not manually injecting repo in service constructor
}