Merge pull request #11 from etempls/endpoint-publisher

Add Endpoint publisher, powered by Combine

Sources/TinyNetworking/Endpoint.swift

@@ -240,3 +240,31 @@ extension URLSession {
     }
 }
 
+#if canImport(Combine)
+import Combine
+
+@available(iOS 13, macOS 10.15, watchOS 6, tvOS 13, *)
+extension URLSession {
+    /// Returns a publisher that wraps a URL session data task for a given Endpoint.
+    ///
+    /// - Parameters:
+    ///   - e: The endpoint.
+    /// - Returns: The publisher of a dataTask.
+    public func load<A>(_ e: Endpoint<A>) -> AnyPublisher<A, Error> {
+        let r = e.request
+        return dataTaskPublisher(for: r)
+            .tryMap { data, resp in
+                guard let h = resp as? HTTPURLResponse else {
+                    throw UnknownError()
+                }
+
+                guard e.expectedStatusCode(h.statusCode) else {
+                    throw WrongStatusCodeError(statusCode: h.statusCode, response: h)
+                }
+
+                return try e.parse(data, resp).get()
+        }
+        .eraseToAnyPublisher()
+    }
+}
+#endif