Add conditional compilation directive

Sources/WebSocketKit/WebSocket+Connect.swift

@@ -20,6 +20,7 @@ extension WebSocket {
         on eventLoopGroup: EventLoopGroup,
         onUpgrade: @Sendable @escaping (WebSocket) -> ()
     ) -> EventLoopFuture<Void> {
+        #if canImport(Foundation)
         let optionalURL: URL?
         if #available(iOS 17.0, macOS 14.0, tvOS 17.0, watchOS 10.0, *) {
             optionalURL = URL(string: url, encodingInvalidCharacters: false)
@@ -37,8 +38,20 @@ extension WebSocket {
             on: eventLoopGroup,
             onUpgrade: onUpgrade
         )
+        #else
+        guard let url = URL(string: url) else {
+            return eventLoopGroup.any().makeFailedFuture(WebSocketClient.Error.invalidURL)
+        }
+        return self.connect(
+            to: url,
+            headers: headers,
+            configuration: configuration,
+            on: eventLoopGroup,
+            onUpgrade: onUpgrade
+        )
+        #endif
     }
-
+    
     /// Establish a WebSocket connection.
     ///
     /// - Parameters:
@@ -69,7 +82,7 @@ extension WebSocket {
             onUpgrade: onUpgrade
         )
     }
-
+    
     /// Establish a WebSocket connection.
     ///
     /// - Parameters:
@@ -108,7 +121,7 @@ extension WebSocket {
             onUpgrade: onUpgrade
         )
     }
-
+    
     /// Establish a WebSocket connection via a proxy server.
     ///
     /// - Parameters:
@@ -159,8 +172,8 @@ extension WebSocket {
             onUpgrade: onUpgrade
         )
     }
-
-
+    
+    
     /// Description
     /// - Parameters:
     ///   - url: URL for the origin server.