func suffix()

in Sources/TSCBasic/Path.swift [735:768]

• 25 lines of code
• 7 McCabe index (conditional complexity)

    func suffix(withDot: Bool) -> String? {
#if os(Windows)
        return self.string.withCString(encodedAs: UTF16.self) {
          if let pointer = PathFindExtensionW($0) {
            let substring = String(decodingCString: pointer, as: UTF16.self)
            guard substring.length > 0 else { return nil }
            return withDot ? substring : String(substring.dropFirst(1))
          }
          return nil
        }
#else
        // FIXME: This method seems too complicated; it should be simplified,
        //        if possible, and certainly optimized (using UTF8View).
        // Find the last path separator, if any.
        let sIdx = string.lastIndex(of: "/")
        // Find the start of the basename.
        let bIdx = (sIdx != nil) ? string.index(after: sIdx!) : string.startIndex
        // Find the last `.` (if any), starting from the second character of
        // the basename (a leading `.` does not make the whole path component
        // a suffix).
        let fIdx = string.index(bIdx, offsetBy: 1, limitedBy: string.endIndex) ?? string.startIndex
        if let idx = string[fIdx...].lastIndex(of: ".") {
            // Unless it's just a `.` at the end, we have found a suffix.
            if string.distance(from: idx, to: string.endIndex) > 1 {
                let fromIndex = withDot ? idx : string.index(idx, offsetBy: 1)
                return String(string.suffix(from: fromIndex))
            } else {
                return nil
            }
        }
        // If we get this far, there is no suffix.
        return nil
#endif
    }