602.0.0 and 603.0.0 produce different output with the same configuration

[davidkoski]

See attached config -- this is the dump from 603 with a few custom settings at the top:

swift-format.txt

Consider this swift file:

import Foundation
import MLX
@_spi(Testing) @testable import MLXLMCommon
import MLXNN
import Testing

struct Test {
}

Test.swift.txt

602 gives this output:

[dkoski@dkoski-m5 swift-format-602 (602.0.0)]$ swift run swift-format /tmp/Test.swift
import Foundation
import MLX
@_spi(Testing) @testable import MLXLMCommon
import MLXNN
import Testing

struct Test {
}

while 603 gives this output:

[dkoski@dkoski-m5 swift-format (603.0.0 ✗)]$ swift run swift-format /tmp/Test.swift
import Foundation
import MLX
import MLXNN
import Testing

@_spi(Testing) @testable import MLXLMCommon

struct Test {
}

The new configuration in 603 is:

  "indentBlankLines" : false,
  "orderedImports" : {
    "includeConditionalImports" : true
  },

and no setting on those will produce the 602 output. This makes it hard to use in CI -- do I pin a version of swift-format? Ideally no, because people might use different versions for various reasons. Can I just use config to make all the versions do the same thing? Ideally yes -- this would be stable. You just need a version later than the one it is based on.

[davidkoski]

It looks like this is introduced with #1013. I am not sure this sorting is an intended consequence of that, but that change isn't controlled by configuration.

Perhaps a larger question is: should I expect consistent formatting over versions if I hold the configuration constant (adjusting for new versions with their configuration set to match the old behavior)?

[allevato]

Yeah, this was an unintentional side effect from #1013. We do strive to keep the formatting stable from version to version without configuration changes, but we clearly dropped the ball on this one.

Given that, I'd be comfortable with introducing a new configuration option to return to the previous behavior (only @testable being treated special), so that we could at least fix it in 604.

[davidkoski]

That sounds fine -- we will keep the CI pinned to 602 for now and pick up 604 + appropriate config when it is available. Thanks for the response!