Add support of trailing commas in all cases containing round parentheses in Swift 6.1

[kfamyn]

Overview

This PR adds support of trailing commas in all cases containing round parentheses () in Swift 6.1

Implemented earlier

Trailing commas were already supported in:

• Multi-line collections
• Parameter or argument lists
• Enum cases with associated values

New features

Trailing commas are now added (or removed) for multi-line lists in the following contexts:

• Array and dictionary literals
• Function and initializer parameters and arguments
• Enum case associated values
• Tuple literals, including in return, switch, case let, let
• Parenthesized single expressions (e.g., throw (error,), if (true,), guard (true,), while (true,))
• Attribute arguments (e.g. @Attribute(...))
• Macro arguments (e.g. #macro(...))
• String interpolation expressions (when custom interpolation methods allow multiple arguments)

Trailing commas are not added in:

• Empty parentheses ()
• Type annotations (e.g. let x: (Int, String))

Future plans

I'm planning to add trailing commas in the following contexts in the next PR:

• Subscripts, including key path subscripts
• Closure capture lists
• Generic parameters

In addition to this, I'm planning to debug and fix failing tests in TrailingCommasTests

Testing info

To test String interpolation, use this extension:

extension String.StringInterpolation {
    
    mutating func appendInterpolation(_ a: Int, _ b: Int) {
        appendLiteral("\(a)\(b)")
    }
}

[codecov]

Codecov Report

Attention: Patch coverage is 93.93939% with 2 lines in your changes missing coverage. Please review.

Project coverage is 95.79%. Comparing base (eb81f2f) to head (aab424f).
Report is 4 commits behind head on develop.

Files with missing lines	Patch %	Lines
Sources/Rules/TrailingCommas.swift	93.93%	2 Missing ⚠️

Additional details and impacted files

@@             Coverage Diff             @@
##           develop    #2008      +/-   ##
===========================================
+ Coverage    95.51%   95.79%   +0.27%     
===========================================
  Files          141      141              
  Lines        25982    26010      +28     
===========================================
+ Hits         24817    24916      +99     
+ Misses        1165     1094      -71     

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[calda]

Thanks!

[KonDouvris]

Hello @nicklockwood ! Is this released in the latest 0.55.6 version?

[nicklockwood]

@KonDouvris no, 0.55.6 is just bug fixes. This will be included in the 0.56 release