Better error message

Sources/Parsers/ColorsFileParser.swift

@@ -10,17 +10,17 @@ import PathKit
 public enum ColorsParserError: Error, CustomStringConvertible {
   case invalidHexColor(string: String, key: String?)
   case invalidFile(reason: String)
-  case unsupportedFileType
+  case unsupportedFileType(supported: [String])
 
   public var description: String {
     switch self {
-    case .invalidHexColor(string: let string, key: let key):
+    case .invalidHexColor(let string, let key):
       let keyInfo = key.flatMap { " for key \"\($0)\"" } ?? ""
       return "error: Invalid hex color \"\(string)\" found\(keyInfo)."
-    case .invalidFile(reason: let reason):
+    case .invalidFile(let reason):
       return "error: Unable to parse file. \(reason)"
-    case .unsupportedFileType:
-      return "error: Unsupported file type. The supported file types are CLR, TXT, XML and JSON"
+    case .unsupportedFileType(let supported):
+      return "error: Unsupported file type. The supported file types are: \(supported.joined(separator: ", "))"
     }
   }
 }
@@ -45,7 +45,7 @@ public final class ColorsFileParser {
 
   public func parseFile(at path: Path) throws {
     guard let parserType = parsers[path.extension?.lowercased() ?? ""] else {
-      throw ColorsParserError.unsupportedFileType
+      throw ColorsParserError.unsupportedFileType(supported: Array(parsers.keys))
     }
 
     let parser = parserType.init()