Disable the next button whilst loading a server.

Add tests for login screen.
Self review.

RiotSwiftUI/Modules/Authentication/Common/Service/MatrixSDK/AuthenticationService.swift

@@ -84,7 +84,7 @@ class AuthenticationService: NSObject {
     }
     
     func startFlow(_ flow: AuthenticationFlow, for homeserverAddress: String) async throws {
-        var (client, state) = try await loginFlow(for: homeserverAddress)
+        var (client, homeserver) = try await loginFlow(for: homeserverAddress)
         
         let loginWizard = LoginWizard(client: client)
         self.loginWizard = loginWizard
@@ -92,18 +92,19 @@ class AuthenticationService: NSObject {
         if flow == .register {
             do {
                 let registrationWizard = RegistrationWizard(client: client)
-                state.homeserver.registrationFlow = try await registrationWizard.registrationFlow()
-                state.flow = .register
+                homeserver.registrationFlow = try await registrationWizard.registrationFlow()
                 self.registrationWizard = registrationWizard
             } catch {
-                guard state.homeserver.preferredLoginMode.hasSSO, error as? RegistrationError == .registrationDisabled else {
+                guard homeserver.preferredLoginMode.hasSSO, error as? RegistrationError == .registrationDisabled else {
                     throw error
                 }
                 // Continue without throwing when registration is disabled but SSO is available.
             }
         }
         
-        self.state = state
+        // The state and client are set after trying the registration flow to
+        // ensure the existing state isn't wiped out when an error occurs.
+        self.state = AuthenticationState(flow: flow, homeserver: homeserver)
         self.client = client
     }
     
@@ -165,10 +166,11 @@ class AuthenticationService: NSObject {
     
     // MARK: - Private
     
-    /// Request the supported login flows for this homeserver.
+    /// Query the supported login flows for the supplied homeserver.
     /// This is the first method to call to be able to get a wizard to login or to create an account
     /// - Parameter homeserverAddress: The homeserver string entered by the user.
-    private func loginFlow(for homeserverAddress: String) async throws -> (AuthenticationRestClient, AuthenticationState) {
+    /// - Returns: A tuple containing the REST client for the server along with the homeserver state containing the login flows.
+    private func loginFlow(for homeserverAddress: String) async throws -> (AuthenticationRestClient, AuthenticationState.Homeserver) {
         let homeserverAddress = HomeserverAddress.sanitized(homeserverAddress)
         
         guard var homeserverURL = URL(string: homeserverAddress) else {
@@ -186,16 +188,16 @@ class AuthenticationService: NSObject {
         
         let loginFlow = try await getLoginFlowResult(client: client)
         
-        let state = AuthenticationState(flow: .login, homeserver: .init(address: loginFlow.homeserverAddress,
-                                                                        addressFromUser: homeserverAddress,
-                                                                        preferredLoginMode: loginFlow.loginMode))
-        return (client, state)
+        let homeserver = AuthenticationState.Homeserver(address: loginFlow.homeserverAddress,
+                                                        addressFromUser: homeserverAddress,
+                                                        preferredLoginMode: loginFlow.loginMode)
+        return (client, homeserver)
     }
     
     /// Request the supported login flows for the corresponding session.
     /// This method is used to get the flows for a server after a soft-logout.
     /// - Parameter session: The MXSession where a soft-logout has occurred.
-    private func loginFlow(for session: MXSession) async throws -> (AuthenticationRestClient, AuthenticationState) {
+    private func loginFlow(for session: MXSession) async throws -> (AuthenticationRestClient, AuthenticationState.Homeserver) {
         guard let client = session.matrixRestClient else {
             MXLog.error("[AuthenticationService] loginFlow called on a session that doesn't have a matrixRestClient.")
             throw AuthenticationError.missingMXRestClient
@@ -203,9 +205,9 @@ class AuthenticationService: NSObject {
         
         let loginFlow = try await getLoginFlowResult(client: session.matrixRestClient)
         
-        let state = AuthenticationState(flow: .login, homeserver: .init(address: loginFlow.homeserverAddress,
-                                                                        preferredLoginMode: loginFlow.loginMode))
-        return (client, state)
+        let homeserver = AuthenticationState.Homeserver(address: loginFlow.homeserverAddress,
+                                                        preferredLoginMode: loginFlow.loginMode)
+        return (client, homeserver)
     }
     
     private func getLoginFlowResult(client: MXRestClient) async throws -> LoginFlowResult {

RiotSwiftUI/Modules/Authentication/Common/Service/MatrixSDK/AuthenticationState.swift

@@ -58,6 +58,7 @@ struct AuthenticationState {
             return url.host == "matrix.org" || url.host == "matrix-client.matrix.org"
         }
         
+        /// The homeserver mapped into view data that is ready for display.
         var viewData: AuthenticationHomeserverViewData {
             AuthenticationHomeserverViewData(address: displayableAddress,
                                              isMatrixDotOrg: isMatrixDotOrg,