Swiftformat: Update indent rule behavior to match Xcode 12

[nicklockwood]

Xcode 12 adds new alignment rules for wrapped expressions, e.g.

if let foo = bar,
    let baz = quux {

}

Now aligns the lets vertically:

if let foo = bar,
   let baz = quux {

}

Which means that the second line is actually indented exactly 3 spaces and not a multiple of the specified indent level.

SwiftFormat should probably adopt this, especially when using --xcodeindentation true. There's a question of whether this should have some way to retain the old behavior though for teams that haven't upgraded to Xcode 12.

@calda, any thoughts?

[calda]

I would love to see this be an option even for teams that aren't using --xcodeindentation true!

We use --indent 2 and --xcodeindentation disabled (I think we don't like how Xcode indents guard statements), but if there was a --multilineConditional alignKeywords option that works like this then I would totally lobby for us to adopt it.

[georgescumihai]

This is the same for guard, it will align it vertically

Xcode 12 indent

guard let foo = bar,
      let baz = quux else {
    return
}

swiftformat indent

guard let foo = bar,
    let baz = quux else {
        return
}

Also with swiftformat the return in case of guard is alligned at 8 spaces comparing to 4 with Xcode 12.
For if statement, both Xcode 12 and swiftformat allign the return at 4 spaces.

The above indentation was with the following command swiftformat . --rules indent --indent 4 --xcodeindentation enabled

[nicklockwood]

Implemented in 0.47.0

[georgescumihai]

Nice job, just tested it works, in most of the cases.
There are still situations where Xcode indentation is not following their own rules

Xcode

guard let value = foo
        .doSomething()
        .doSomethingElse() else {
    return
}

guard let x = x,
      let value = MyType(
        x: x,
        y: y,
        z: z
      ) else {
    return
}

Swiftformat

guard let value = foo
    .doSomething()
    .doSomethingElse() else {
    return
}

guard let x = x,
      let value = MyType(
          x: x,
          y: y,
          z: z
      ) else {
    return
}

Also } else if let does vertical aligning

Xcode

if foo {

} else if let bar = guas,
          let xuas = assas {

}

if foo ||
    bar &&
    asda {

} else if foo ||
            bar &&
            asda {

}

Swiftformat

if foo {

} else if let bar = guas,
    let xuas = assas {

}

if foo ||
    bar &&
    asda {

} else if foo ||
    bar &&
    asda {

}

[georgescumihai]

@nicklockwood maybe the thing that is missing is the vertical alignment for else if let

[nicklockwood]

@georgescumihai thanks, I'll fix these cases in the next update

[georgescumihai]

For my tests to check the differences I use SourceKitten to interact with SourceKit.

find . -type f -name "*.swift" | while read line; do
  sourcekitten format --file "$line";
done

[nicklockwood]

Fixed in 0.47.1