Revisiting Interface Segregation in Go(rednafi.com)

    // embedded S3Client not properly initialized
    mock := mockS3{}
    // somewhere inside the business logic
    s3.UploadReport(...) // surprise

    type myDependencies interface {
        services.UsesDB
        services.UsesLogging
    }

    func init() {
        services.Register(func(in myDependencies) error {
             // init here
        }
    }

    type myDependencies interface {
        services.UsesLogging
        services.UsesCaching
        services.UsesWebCrawler
    }

    // func init() { etc. }

  // The HandlerFunc type is an adapter to allow the use of
  // ordinary functions as HTTP handlers. If f is a function
  // with the appropriate signature, HandlerFunc(f) is a
  // [Handler] that calls f.
  type HandlerFunc func(ResponseWriter, *Request)
  
  // ServeHTTP calls f(w, r).
  func (f HandlerFunc) ServeHTTP(w ResponseWriter, r *Request) {
      f(w, r)
  }