implicit-param.scala

class HttpClient {
  def GET(url: String)(implicit context: ExecutionContext) = ???
}

class SomeService(http: HttpClient = new HttpClient) {
  def getSomething(implicit context: ExecutionContext) = ???
}

class ServiceB {
  def foo(arg: String)(implicit context: ExecutionContext) =
    someService.getSomething.map(???)
}

// --- VS ---

class HttpClient(implicit context: ExecutionContext){
  def GET(url: String)	
}

class SomeService {
  def getSomething(implicit client: HttpClient) = ???
}

class ServiceB {
  def foo(arg: String)(implicit client: HttpClient) =
    someService.getSomething.map(???)
}

// --- VS ---

class SomeService {
  def getSomething = (client: HttpClient) => ???
}

class ServiceB {
  def foo(arg: String) = someSerivce.getSomething.andThen(???)
}

class Controller {
  serviceB.foo("asdf")(client)
}