How to avoid dependency injection in Scala?

Question

I read Dependency Injection Without the Gymnastics PDF which indicates there\'s no need for any fancy DI framework, but it\'s beyond my grasp (at least without concrete examples

Answer 1

Implicit parameters are completely sufficient for the use case you're describing.

case class A(implicit b: B, c: C)
case class B(implicit d: D)
case class C(implicit d: D)
class D { /* ... */ }

implicit val theD = new D
implicit val theB = B()
implicit val theC = C()

Now you can ask for an A just by:

val a = A()