specifying `rules` in `.swift-format` file seems to change the default value for some rules

[DetachHead]

// foo.swift
enum Foo {
  case foo
}

with the following .swift-format config file:

// .swift-format
{}

i get this error:

Sources/project/foo.swift:6:8: error: [AlwaysUseLowerCamelCase] rename the enum case 'x86_64' using lowerCamelCase

when i add an empty rules object to it, the error goes away:

// .swift-format
{
    "rules": {}
}

[allevato]

This is a somewhat known issue but I don't remember if we have an issue for it already, so thanks for filing it.

The problem is a little bit more subtle: if the rules dictionary is completely omitted, then we apply the default settings because we see that the entire field is nil and we bring in that other dictionary. But if rules is empty, then we never apply the defaults, even for rules that aren't listed in the user's configuration.

I think it's possible to rationalize both behaviors, and I fear that changing it now without some other flag to control it would impact users who may be depending on that behavior (and may not realize it).

[DetachHead]

I think it's possible to rationalize both behaviors, and I fear that changing it now without some other flag to control it would impact users who may be depending on that behavior (and may not realize it).

in my experience with other linters/formatters, this behavior is definitely surprising. i feel like there's probably more people completely unaware of this behavior and therefore unknowingly disabling certain rules when they aren't intending to - than there are people intentionally relying on it