The fastapi-mvc update command will update any already generated project (fastapi-mvc new ...) with changes from the new template (copier-project) version. The correctness of this process is being tested the following way:

1. Generate a project from each copier-project release (except the latest).
2. Generate reference project from the latest release
3. For each generated project from point no. 1, run fastapi-mvc update
4. Compare directory checksums for updated and reference projects. If the checksums are the same, the update succeeded up to a single bit.

However, there are some corner cases where the update will not work as expected. I'm planning on improving/fixing that. But first, I'll need to discuss a few behaviors with the upstream project (copier).

Regarding functions defined in the Generator class. Each custom or built-in generator depends on fastapi-mvc package (needs Generator class). This provides two things. First, standardizing usage across all implementations, two providing common utilities/methods for the user. For an instance method for ensuring correct permissions to a given path, or validating fastapi-mvc project. However, now that you mentioned this, insert_router_import method feels more specific to the controller generator rather than something common. Also, there is a small difference between built-ins and custom generators. For the builtins, interface implementation is separated from the copier template. Example for controller generator:

• Template: https://github.com/fastapi-mvc/copier-controller
• Interface implementation: https://github.com/fastapi-mvc/fastapi-mvc/blob/master/fastapi_mvc/generators/controller.py

Maybe for builtins, this should not be separated too? But then is the question of testing and packaging the implementation for fastapi-mvc. Do you have any suggestions on this?

Lastly, any generator can be updated with the changes from the upstream (copier-generator), example:

• https://github.com/fastapi-mvc/copier-controller#updating Update generator copier-controller#2

But this action will not update/override your template and its configuration but rather generators common files like dotfiles, environment definition, etc. I've tested this recently, and it works well.

Yeah, I think it comes down to having the base template and generators modifying the same files. There should be a way to create an intermittent template and supplement with the updated generator template., You might need to keep track of the order the generators were applied.