Fix CodeGenerationFormat to correctly handle trailing trivia when formatting list elements

[roopekv]

This fixes 2 issues with how CodeGenerationFormat handles trailing trivia when formatting lists to be separated by a newline. These issues don't manifest in the current codebase, but the fixes in this PR will prevent them from appearing in the future. Examples are provided below.

Change CodeGenerationFormat to keep whitespace after comma if it precedes other trivia on the same line

Example

DeclSyntax(
  """
  public static func \(tokenSpec.funcDeclName)(
    _ value: Keyword, // EXAMPLE <--
    leadingTrivia: Trivia = [],
    trailingTrivia: Trivia = [],
    presence: SourcePresence = .present
  ) -> TokenSyntax {
    // ...
  }
  """
)

Before (missing space between , and //)

public static func keyword(
  _ value: Keyword,// EXAMPLE <--
  leadingTrivia: Trivia = [],
  trailingTrivia: Trivia = [],
  presence: SourcePresence = .present
) -> TokenSyntax {
  // ...
}

After

public static func keyword(
  _ value: Keyword, // EXAMPLE <--
  leadingTrivia: Trivia = [],
  trailingTrivia: Trivia = [],
  presence: SourcePresence = .present
) -> TokenSyntax {
  // ...
}

Another example

DeclSyntax(
  """
  func verify<Node: RawSyntaxNodeProtocol>(_ raw: RawSyntax?, /* EXAMPLE <-- */ as _: Node.Type, file: StaticString = #fileID, line: UInt = #line) -> ValidationError? {
    // ...
  }
  """
)

Before (missing space between , and /*)

func verify<Node: RawSyntaxNodeProtocol>(
  _ raw: RawSyntax?,/* EXAMPLE <-- */ 
  as _: Node.Type,
  file: StaticString = #fileID,
  line: UInt = #line
) -> ValidationError? {
  // ...
}

After

func verify<Node: RawSyntaxNodeProtocol>(
  _ raw: RawSyntax?, /* EXAMPLE <-- */ 
  as _: Node.Type,
  file: StaticString = #fileID,
  line: UInt = #line
) -> ValidationError? {
  // ...
}

Fix CodeGenerationFormat to keep existing trailing trivia when adding a newline after the last element of a list

Example

DeclSyntax(
  """
  func verify<Node: RawSyntaxNodeProtocol>(_ raw: RawSyntax?, as _: Node.Type, file: StaticString = #fileID, line: UInt = #line /* EXAMPLE <-- */) -> ValidationError? {
    // ...
  }
  """
)

Before (missing /* EXAMPLE <-- */)

func verify<Node: RawSyntaxNodeProtocol>(
  _ raw: RawSyntax?,
  as _: Node.Type,
  file: StaticString = #fileID,
  line: UInt = #line
) -> ValidationError? {
  // ...
}

After

func verify<Node: RawSyntaxNodeProtocol>(
  _ raw: RawSyntax?,
  as _: Node.Type,
  file: StaticString = #fileID,
  line: UInt = #line /* EXAMPLE <-- */
) -> ValidationError? {
  // ...
}

[ahoppen]

@swift-ci Please test

[roopekv]

Could this be merged?

[ahoppen]

Thanks for the ping and sorry, I forgot about this PR. I’m not sure why CI failed and we don’t have the logs anymore. Let me re-trigger it and then we can see.

@swift-ci Please test

[roopekv]

No problem, anything I can do to get that Windows test to pass?

[ahoppen]

Looks like the Windows failure was because it picked up swiftlang/swift#77149 but not #2859. Let’s try again.

@swift-ci Please test Windows

[ahoppen]

@swift-ci Please test Windows