Update ContentView.swift

Author: stevapple

Examples/LocalDebugging/MyApp/MyApp/ContentView.swift

@@ -25,11 +25,12 @@ struct ContentView: View {
         VStack(alignment: .leading, spacing: 20) {
             TextField("Username", text: $name)
             SecureField("Password", text: $password)
-            let buttonDisabled = name.isEmpty || password.isEmpty
+            let inputIncomplete = name.isEmpty || password.isEmpty
             Button {
                 Task {
                     isLoading = true
-                    response = await self.register()
+                    do { response = try await self.register() }
+                    catch { response = error.localizedDescription }
                     isLoading = false
                 }
             } label: {
@@ -45,13 +46,13 @@ struct ContentView: View {
                         }
                     }
             }
-            .disabled(buttonDisabled || isLoading)
-            .opacity(buttonDisabled ? 0.5 : 1)
+            .disabled(inputIncomplete || isLoading)
+            .opacity(inputIncomplete ? 0.5 : 1)
             Text(response)
         }.padding(100)
     }
 
-    func register() async -> String {
+    func register() async throws -> String {
         guard let url = URL(string: "http://127.0.0.1:7000/invoke") else {
             fatalError("invalid url")
         }
@@ -63,21 +64,17 @@ struct ContentView: View {
         }
         request.httpBody = jsonRequest
 
-        do {
-            let (data, response) = try await URLSession.shared.data(for: request)
+        let (data, response) = try await URLSession.shared.data(for: request)
 
-            guard let httpResponse = response as? HTTPURLResponse else {
-                return "invalid response, expected HTTPURLResponse"
-            }
-            guard httpResponse.statusCode == 200 else {
-                return "invalid response code: \(httpResponse.statusCode)"
-            }
-
-            let jsonResponse = try JSONDecoder().decode(Response.self, from: data)
-            return jsonResponse.message
-        } catch {
-            return error.localizedDescription
+        guard let httpResponse = response as? HTTPURLResponse else {
+            throw CommunicationError(reason: "invalid response, expected HTTPURLResponse")
+        }
+        guard httpResponse.statusCode == 200 else {
+            throw CommunicationError(reason: "invalid response code: \(httpResponse.statusCode)")
         }
+
+        let jsonResponse = try JSONDecoder().decode(Response.self, from: data)
+        return jsonResponse.message
     }
 }
 
@@ -86,3 +83,10 @@ struct ContentView_Previews: PreviewProvider {
         ContentView()
     }
 }
+
+struct CommunicationError: Error, CustomStringConvertible {
+    let reason: String
+    var description: String {
+        self.reason
+    }
+}