Insert a space before colon in ternary expression in Fix-It

[gibachan]

This pull request addresses #1607

[kimdv]

@swift-ci please test

[ahoppen]

@gibachan, welcome to SwiftSyntax’s development.

I would prefer to adjust the formatting in BasicFormat instead of ParseDiagnsoticsGenerator because that way we also get the correct formatting you you are constructing a ternary operator e.g. from SwiftSyntaxBuilder, which is what people will do when writing macros.

In that case, it should work both when the operators are folded and when they haven’t been folded yet (see https://swiftpackageindex.com/apple/swift-syntax/main/documentation/swiftoperators).

An unfolded ternary operator would be the following

SequenceExprSyntax {
  BooleanLiteralExprSyntax(true)
  UnresolvedTernaryExprSyntax(firstChoice: IntegerLiteralExprSyntax(1))
  IntegerLiteralExprSyntax(0)
}

and a folded ternary operator would be

TernaryExprSyntax(
  conditionExpression: BooleanLiteralExprSyntax(true),
  firstChoice: IntegerLiteralExprSyntax(1),
  secondChoice: IntegerLiteralExprSyntax(0)
)

The code that you’d like to change is most likely in here https://github.com/apple/swift-syntax/blob/cecb0340a95f00f8f2725c912b494266ed7b4a80/Sources/SwiftBasicFormat/BasicFormat.swift#L177

[gibachan]

Thank you for your feedback. I'll take a look into it!

[ahoppen]

Thanks. This looks great! I’ve got one slight comment on how to improve implementation, otherwise this is ready to be merged. 👍🏽

[ahoppen]

Thank you for your contribution, @gibachan. This looks good to me. Once CI passes, I’ll merge the PR.

[ahoppen]

@swift-ci Please test

[ahoppen]

@swift-ci Please test Windows

[ahoppen]

@swift-ci Please test Windows