Refactor and fixes for Vapor integration

Author: Fernando Fernandes

Sources/SwiftTrader/Extensions/Decodable+String.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 /// A **request** for an overview of a Kucoin Futures account.
 ///
@@ -50,7 +53,7 @@ public struct KucoinAccountOverviewRequest: NetworkRequest {
 
 public extension KucoinAccountOverviewRequest {
 
-    func decode(_ data: Data) throws -> KucoinFuturesAccountOverviewResponse {
+    func decode(_ data: Data) throws -> DecodableModel {
         try JSONDecoder().decode(KucoinFuturesAccountOverviewResponse.self, from: data)
     }
 }

Sources/SwiftTrader/Network/Kucoin/AccountOverview/KucoinAccountOverviewRequest.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 /// Holds logic to set values for default HTTP header fields common to all Kucoin APIs requests.
 extension KucoinAPI {

Sources/SwiftTrader/Network/Kucoin/KucoinAPI+Header.swift

@@ -19,6 +19,9 @@ public enum NetworkRequestError: Error {
     /// Could not cast response to `HTTPURLResponse`.
     case invalidResponse
 
+    /// Could not instantiate a valid `URLRequest` (e.g.: `NetworkRequest.getter:request`).
+    case invalidRequest(error: Error)
+    
     /// Could not instantiate a `URLComponents` struct using the given `String` URL.
     case invalidURLString(urlString: String)
 

Sources/SwiftTrader/Network/NetworkRequest/NetworkRequestError.swift

@@ -22,21 +22,45 @@ public extension NetworkRequest {
     /// - Parameter request: `URLRequest` containing the target `URL`.
     /// - Returns: `NetworkRequestResult`.
     func execute() async -> NetworkRequestResult {
+        let req: URLRequest
+        do {
+            req = try request
+        } catch {
+            return .failure(.invalidRequest(error: error))
+        }
 #if os(macOS) || os(iOS)
+        return await runOnApplePlatforms(request: req)
+#elseif canImport(FoundationNetworking)
+        return await runOnLinux(request: req)
+#endif
+    }
+}
+
+#warning("TODO: retry mechanism, at least 3 times")
+
+// MARK: - Private
+
+private extension NetworkRequest {
+
+#if os(macOS) || os(iOS)
+    /// macOS and iOS.
+    func runOnApplePlatforms(request: URLRequest) async -> NetworkRequestResult {
         do {
             let (data, response) = try await session.data(for: request)
             return handleResult(data: data, response: response)
         } catch {
-            return handleResult(data: nil, response: nil, error: error)
+            return .failure(.requestFailed(error: error))
         }
-#elseif canImport(FoundationNetworking)
-        // `async/await` isn't fully ported to Linux; use "withCheckedContinuation(function:_:)" instead.
-        let (data, response, error) = await  withCheckedContinuation { continuation in
+    }
+#endif
+
+    /// `async/await` isn't fully ported to Linux; use "withCheckedContinuation(function:_:)" instead.
+    func runOnLinux(request: URLRequest) async -> NetworkRequestResult {
+        let (data, response, error) = await withCheckedContinuation { continuation in
             session.dataTask(with: request) { data, response, error in
                 continuation.resume(returning: (data, response, error))
             }.resume()
-            return handleResult(data: data, response: response, error: error)
         }
-#endif
+        return handleResult(data: data, response: response, error: error)
     }
 }

Sources/SwiftTrader/Network/NetworkRequest/NetworkRequestProtocol+Execution.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 /// Holds logic to parse and return results of type `NetworkRequestResult`.
 public extension NetworkRequest {

Sources/SwiftTrader/Network/NetworkRequest/NetworkRequestProtocol+Result.swift

@@ -6,6 +6,9 @@
 //
 
 import Foundation
+#if canImport(FoundationNetworking)
+import FoundationNetworking
+#endif
 
 public typealias NetworkRequestResult = Result<Decodable, NetworkRequestError>
 

Sources/SwiftTrader/Network/NetworkRequest/NetworkRequestProtocol.swift

@@ -30,8 +30,7 @@ public extension SwiftTrader {
         switch await request.execute() {
         case .success(let model):
             guard let accountOverview = model as? KucoinFuturesAccountOverviewResponse else {
-                let modelString = model.toString()
-                return .failure(.unexpectedResponse(modelString: modelString))
+                return .failure(.unexpectedResponse(modelString: "\(model)"))
             }
             return .success(accountOverview)
         case .failure(let error):