[Config] Group.__call__() has same behaviour as Group.all()

[Tobotimus]

Type

• Bugfix

Description of the changes

This modifies config.Group.__call__ to now have the same behaviour of config.Group.all(), and in fact all() is now simply an alias for __call__. Both of these functions are able to be used as a context manager as well.

Furthermore, to match the new behaviour of __call__, get_raw will mix in defaults when a sub-group is being retrieved by it.

[Tobotimus]

Notes about breaking changes

The situations where these changes could be breaking are where you are retrieving data whose default type is a dict, by either calling a config.Group object, or using get_raw() to retrieve a dict. Previously, these functions would not return defaults mixed into the returned dict - the new behaviour is that they do.

As an example:

# old behaviour

config.register_global(foo={'bar': True})
await config.foo()  # -> {}

# new behaviour

config.register_global(foo={'bar': True})
await config.foo()  # -> {'bar': True}

And an example with get_raw():

# old behaviour

config.register_global(foo={'bar': True, 'baz': False})
await config.foo.baz.set(True)
await config.get_raw('foo')  # -> {'baz': True}

# new behaviour

config.register_global(foo={'bar': True, 'baz': False})
await config.foo.baz.set(True)
await config.get_raw('foo')  # -> {'bar': True, 'baz': True}

Concerns

If you have any concerns about how you will update to account for these changes, let us know (in #coding perhaps) and we will do our best to assist you.

[mikeshardmind]

A slight clarification, this is only a breaking change in those cases if you were using that behavior as a method for checking that no value was set. In most cases, registering a default should indicate that you have a default value and do not care if one is not already set, however, if you do care, there are a few ways to handle this.

• Sentinel Values which will never exist in normal operation as defaults. (None for a value which can't normally be None as an example)
• Checking the all_members, all_roles, all_guilds (etc) method for their existence.

[mikeshardmind]

This looks solid and appears to be behaving with the new intended behavior. I've left a comment about a particular refactor option in the bank, but it's not a necessity to change the way this was handled, just an option for discussion.

[mikeshardmind]

Would it make more sense to use a context manager with a sentinel value default for account creation which would be impossible? It's not a required change, but it should simplify the new user case significantly.

[Tobotimus]

That's true. For now this works so I'm going to leave it as it is, however sentinel values are possible as defaults... You just need to be careful whether you specify a sentinel value as an empty dict, or None.

When using a NoneType sentinel value, that value will not be treated as a config.Group, even if a dict later replaces it. Using an empty dict instead, the value will be treated as a config.Group, and programmers can utilise the extra methods of this object.