In model/business logic returning collections, returning nonoptional collection types simplifies consumer logic, and throwing errors clearly communicates failure modes.

returning-nonoptional-collections-and-throwing.swift

func modelLayerFunction() throws -> [Any] { /* ... */ }

func controllerFunction() throws -> [Any] {
  let models = try modelLayerFunction()
  // ...
  return models
}

do {
  let results = try controllerFunction()
  // work with result
} catch {
  // log error and/or show alert 
}