StorageBackend: Remove recreate_user from _clear

[sphuber]

The _clear method on the StorageBackend deletes all data in the storage. This is used by the unit tests when a test requires a clean storage to test against. However, the ORM assumes that a User instance, designated by the profile as the default user, is always present. As soon as an ORM entity is stored that requires a user but that is not explicitly defined, the default user is retrieved.

When a new profile is configured, the setup command ensures that the default user is properly created. However, when the storage is cleared, the user is also deleted and so it needs to be recreated. This job had been assigned to the StorageBackend but really this should not be its responsibility. It is specific to the use case of the test cases that reset the storage and need to reconstruct the user, so it should take care of that.

The recreate_user argument is removed from StorageBackend._clear and the logic to recreate a user after storage reset is moved to the ProfileManager. The clear_profile method, which calls the storage clear, recreates the user at the end. The TemporaryProfileManager, which subclasses the ProfileManager does the same when a temporary test profile is created at the start of a test session.

[ltalirz]

Thanks @sphuber , makes sense.

This job had been assigned to the StorageBackend but really this should not be its responsibility. It is specific to the use case of the test cases that reset the storage and need to reconstruct the user, so it should take care of that.

Are there any other users of StorageBackend._clear besides the tests?

[sphuber]

Thanks @sphuber , makes sense.

This job had been assigned to the StorageBackend but really this should not be its responsibility. It is specific to the use case of the test cases that reset the storage and need to reconstruct the user, so it should take care of that.

Are there any other users of StorageBackend._clear besides the tests?

Currently not, but I imagine at some point this would become the generic entry point to clear a database when a profile is deleted. The profile delete functionality is currently still hardcoded to the psql-dos backend in aiida-core, but this should become generic at some point. But I think rather than _clear we would add a method like erase/destroy on the StorageBackend interface that all plugins should implemented. This could optionally call _clear internally of course if it first needs to drop the data manually before deleting tables/repo/whathaveyou.

[sphuber]

@ltalirz is there anything you still wanted to check here?

[ltalirz]

Currently not

Ok, just wanted to be sure that we're not changing behavior that some other place relies on. In that case, good to go!