Should be able through injector instantiate a class that depends on the class being instantiated

[pavelgj]

class ParentDynamicallyInstantiatingChild {
  ParentDynamicallyInstantiatingChild(Injector injector) {
    injector.get(ChildDependingOnParent);
  }
}

class ChildDependingOnParent {
  ChildDependingOnParent(ParentDynamicallyInstantiatingChild _);
}

it('should be able through injector instantiate a class that depends on the class being instantiated', () {
  var injector = new Injector();
  expect(() {
    injector.get(ParentDynamicallyInstantiatingChild);
  }, not(throwsA(anything)));
});

throws
Cannot resolve a circular dependency! (resolving ParentDynamicallyInstantiatingChild -> ChildDependingOnParent -> ParentDynamicallyInstantiatingChild)

[pavelgj]

I think I want to withdraw this one... it is a circular dependency, instantiation of ParentDynamicallyInstantiatingChild is not complete at that point.

[vojtajina]

Well, this IS a circular dependency.

In general, I think we should try to avoid it, often it's possible http://misko.hevery.com/2008/08/01/circular-dependency-in-constructors-and-dependency-injection/

Workaround can be using a setter:

• A depends on B, B depends on A
• we make A on B dependency "setter" (instead of passed into the constructor)

module.factory('B', (A a) {
  var b = new B(a);

  // set manually the back-ref
  a.b = b;

  return b;
});