SwiftFormat/Sources/Rules/SpaceAroundComments.swift

//
//  SpaceAroundComments.swift
//  SwiftFormat
//
//  Created by Nick Lockwood on 8/31/16.
//  Copyright © 2024 Nick Lockwood. All rights reserved.
//

import Foundation

public extension FormatRule {
    /// Add space around comments, except at the start or end of a line
    static let spaceAroundComments = FormatRule(
        help: "Add space before and/or after comments."
    ) { formatter in
        formatter.forEach(.startOfScope("//")) { i, _ in
            if let prevToken = formatter.token(at: i - 1), !prevToken.isSpaceOrLinebreak {
                formatter.insert(.space(" "), at: i)
            }
        }
        formatter.forEach(.endOfScope("*/")) { i, _ in
            guard let startIndex = formatter.index(of: .startOfScope("/*"), before: i),
                  case let .commentBody(commentStart)? = formatter.next(.nonSpaceOrLinebreak, after: startIndex),
                  case let .commentBody(commentEnd)? = formatter.last(.nonSpaceOrLinebreak, before: i),
                  !commentStart.hasPrefix("@"), !commentEnd.hasSuffix("@")
            else {
                return
            }
            if let nextToken = formatter.token(at: i + 1) {
                if !nextToken.isSpaceOrLinebreak {
                    if nextToken != .delimiter(",") {
                        formatter.insert(.space(" "), at: i + 1)
                    }
                } else if formatter.next(.nonSpace, after: i + 1) == .delimiter(",") {
                    formatter.removeToken(at: i + 1)
                }
            }
            if let prevToken = formatter.token(at: startIndex - 1), !prevToken.isSpaceOrLinebreak {
                if case let .commentBody(text) = prevToken, text.last?.unicodeScalars.last?.isSpace == true {
                    return
                }
                formatter.insert(.space(" "), at: startIndex)
            }
        }
    }
}