Question

I have an entity factory which requires access to the file system for construction of the object. I have created a IFileSystem interface, which is being injected into the factory.

Is the the correct way to use an infrastructure service? If so is it recommended to do the same for the entity itself, since important methods on the entity will be required to manipulate the file system also.

Answer 1

It is hard to answer this question without knowing what domain you are working on. It does not seem right though because this would be similar to injecting something like IDatabase. File system and database are persistence technologies and domain logic should be as persistent-agnostic as possible. So you might want to reevaluate this design if your Ubiquitous Language does not include the concept of ‘file system’. You can simply restate your intent in a more domain centric terms like ICustomerConstructionInfoProvider. And then inject this interface implementation similarly to how you would inject repositories implementation.