How to unbind @Singleton

[TheDeadOne]

I have a monolithic application with a huge ammount of classes annotated with @Singleton. Their automatic loading, without the need to write walls of bind().to() in modules, is convenient until the need for integration tests arises. In a test, I don't need all the components of the application, only dependencies of this particular test. How to prevent binding of annotated classes into the context or unbind unnecessary ones?

[TheDeadOne]

I found part of the answer, implicit binding needs to be disabled. But now I get errors like

Explicit bindings are required and controllers.Application is not explicitly bound.
  while locating controllers.Application
    for the 2nd parameter of router.Routes.<init>(Routes.scala:312)
  at play.api.inject.RoutesProvider$.bindingsFromConfiguration(BuiltinModule.scala:129):
Binding(class router.Routes to self) (via modules: com.google.inject.util.Modules$OverrideModule ->
  play.api.inject.guice.GuiceableModuleConversions$$anon$4)

I can't replace the routes using the play.http.router parameter because the code has too much reverse routing and it won't compile. Is it possible to compile the router but not load it into the Guice context?

[TheDeadOne]

I copied source of the BuiltinModule module, replace the call to the RoutesProvider.bindingsFromConfiguration method with FakeRouterProvider.bindingStub, which returns an empty router, disabled the original module in the configuration and enabled patched one. I don’t know if this is right or if it can’t be done better, but it works.

[ihostage]

Hi, Sergey!
Did you try this override approach?

[TheDeadOne]

Yes, but without success. BuiltinModule creates an instance of GeneratedRouted using reflection and then adds the instance to the Guice context, and GeneratedRouter calls the constructors of all controllers that have routes. So it cannot be overridden in GuiceApplicationBuilder, as I see.