As an example the People context (contains User) has many other contexts depending upon it. I’m trying to avoid that context calling out to, or even knowing about, other contexts which depend upon it. There are schemas in other contexts that have a belongs_to association to User, but the User schema does not have a has_many to these resources.
Suppose I am archiving a user. There can be resources from various contexts that need to be removed or disabled and other shutdown operations, reporting, etc. This means calling out to contexts like Intercoms, Printers, Networking, etc. Currently that is happening in a module dedicated to that task, ArchiveUser. It mostly consists of a call function that contains a Multi that walks through the steps. These “cross-context” modules also sometimes have their own dedicated embedded schemas and changesets for custom workflow forms.
In some ways, these are just another context that happens to reach across multiple contexts, but they are smaller and typically only focused on one main operation so I dumped them into that “/services” directory. It was also just familiar to turn these into verb “use cases / services” because I did that quite a bit back in my Rails days.
Avoiding calling child contexts from a parent context is the only scenario where I’ve tried to be vigilant. Other than that, I’ve generally tried to limit the amount of dependencies between smaller contexts out on branches of the dependency tree. If I find that two otherwise independent contexts seem to need to be dependent upon each other, I take that as a sign that maybe they belong in the same context. This just happened recently where I merged the CRM and Leasing contexts into one.
I am also interested in trying your Boundary library to further enforce the dependency tree amongst contexts, but wonder if that would be a misuse of the intent of the library.
