Fix empty host name resolving

Author: ivan.kishchenko

Sources/AsposeWordsCloud/Api/Configuration.swift

@@ -75,8 +75,13 @@ public class Configuration : Codable {
     }
 
     // Returns URL to Aspose Cloud API with remote API version
-    public func getApiRootUrl() -> URL {
-        return URL(string: self.getBaseUrl())!.appendingPathComponent(self.getApiVersion());
+    public func getApiRootUrl() throws -> URL {
+        let url = URL(string: self.getBaseUrl());
+        if (url == nil) {
+            throw WordsApiError.badHostAddress(hostName: self.getBaseUrl());
+        }
+        
+        return url!.appendingPathComponent(self.getApiVersion());
     }
 
     // Returns SDK name for using in statistics headers

Sources/AsposeWordsCloud/Api/WordsApiError.swift

@@ -31,6 +31,7 @@ public enum WordsApiError : LocalizedError {
     case requestError(errorCode: Int, message: String?)
     case requiredArgumentError(argumentName: String)
     case invalidTypeSerialization(typeName: String)
+    case badHostAddress(hostName: String)
 
     public var errorDescription: String? {
         switch self {
@@ -40,6 +41,8 @@ public enum WordsApiError : LocalizedError {
                 return "Required argument \(argumentName) not present.";
             case let .invalidTypeSerialization(typeName):
                 return "Failed to serialize type '\(typeName)'.";
+            case let .badHostAddress(hostName):
+                return "Unable to resolve hostname address '\(hostName)' as url.";
         }
     }
 }