Configure the AuthenticationService later now that we have 2 flows on the start screen. (#3316)

* Don't query the homeserver until confirming it (or selecting a different one).

* Setup the infrastructure to test AuthenticationService.

Implement basic tests for configuration & password login.

* Use the real AuthenticationService with a mock Client in all of the tests.

* Add tests for the ServerConfirmationScreenViewModel.

* Remove redundant view state and test for it.

UnitTests/Sources/ServerConfirmationScreenViewModelTests.swift

@@ -11,5 +11,117 @@ import XCTest
 
 @MainActor
 class ServerConfirmationScreenViewModelTests: XCTestCase {
-    // Nothing to test, the view model has no mutable state.
+    var clientBuilderFactory: AuthenticationClientBuilderFactoryMock!
+    var service: AuthenticationServiceProtocol!
+    
+    var viewModel: ServerConfirmationScreenViewModel!
+    var context: ServerConfirmationScreenViewModel.Context { viewModel.context }
+    
+    func testConfirmLoginWithoutConfiguration() async throws {
+        // Given a view model for login using a service that hasn't been configured.
+        setupViewModel(authenticationFlow: .login)
+        XCTAssertEqual(service.homeserver.value.loginMode, .unknown)
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 0)
+        
+        // When continuing from the confirmation screen.
+        let deferred = deferFulfillment(viewModel.actions) { $0 == .confirm }
+        context.send(viewAction: .confirm)
+        try await deferred.fulfill()
+        
+        // Then a call to configure service should be made.
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 1)
+        XCTAssertNotEqual(service.homeserver.value.loginMode, .unknown)
+    }
+    
+    func testConfirmLoginAfterConfiguration() async throws {
+        // Given a view model for login using a service that has already been configured (via the server selection screen).
+        setupViewModel(authenticationFlow: .login)
+        guard case .success = await service.configure(for: viewModel.state.homeserverAddress, flow: .login) else {
+            XCTFail("The configuration should succeed.")
+            return
+        }
+        XCTAssertNotEqual(service.homeserver.value.loginMode, .unknown)
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 1)
+        
+        // When continuing from the confirmation screen.
+        let deferred = deferFulfillment(viewModel.actions) { $0 == .confirm }
+        context.send(viewAction: .confirm)
+        try await deferred.fulfill()
+        
+        // Then the configured homeserver should be used and no additional call should be made to the service.
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 1)
+    }
+    
+    func testConfirmRegisterWithoutConfiguration() async throws {
+        // Given a view model for registration using a service that hasn't been configured.
+        setupViewModel(authenticationFlow: .register)
+        XCTAssertEqual(service.homeserver.value.loginMode, .unknown)
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 0)
+        
+        // When continuing from the confirmation screen.
+        let deferred = deferFulfillment(viewModel.actions) { $0 == .confirm }
+        context.send(viewAction: .confirm)
+        try await deferred.fulfill()
+        
+        // Then a call to configure service should be made.
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 1)
+        XCTAssertNotEqual(service.homeserver.value.loginMode, .unknown)
+    }
+    
+    func testConfirmRegisterAfterConfiguration() async throws {
+        // Given a view model for registration using a service that has already been configured (via the server selection screen).
+        setupViewModel(authenticationFlow: .register)
+        guard case .success = await service.configure(for: viewModel.state.homeserverAddress, flow: .register) else {
+            XCTFail("The configuration should succeed.")
+            return
+        }
+        XCTAssertNotEqual(service.homeserver.value.loginMode, .unknown)
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 1)
+        
+        // When continuing from the confirmation screen.
+        let deferred = deferFulfillment(viewModel.actions) { $0 == .confirm }
+        context.send(viewAction: .confirm)
+        try await deferred.fulfill()
+        
+        // Then the configured homeserver should be used and no additional call should be made to the service.
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 1)
+    }
+    
+    func testRegistrationNotSupportedAlert() async throws {
+        // Given a view model for registration using a service that hasn't been configured and the default server doesn't support registration.
+        setupViewModel(authenticationFlow: .register, elementWellKnown: false)
+        XCTAssertEqual(service.homeserver.value.loginMode, .unknown)
+        XCTAssertFalse(service.homeserver.value.supportsRegistration)
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 0)
+        XCTAssertNil(context.alertInfo)
+        
+        // When continuing from the confirmation screen.
+        let deferred = deferFulfillment(context.$viewState) { $0.bindings.alertInfo != nil }
+        context.send(viewAction: .confirm)
+        try await deferred.fulfill()
+        
+        // Then the configured homeserver should be used and no additional call should be made to the service.
+        XCTAssertEqual(clientBuilderFactory.makeBuilderSessionDirectoriesPassphraseClientSessionDelegateAppSettingsAppHooksCallsCount, 1)
+        XCTAssertEqual(context.alertInfo?.id, .registration)
+    }
+    
+    // MARK: - Helpers
+    
+    private func setupViewModel(authenticationFlow: AuthenticationFlow, elementWellKnown: Bool = true) {
+        let client = ClientSDKMock(configuration: elementWellKnown ? .init() : .init(elementWellKnown: ""))
+        let configuration = AuthenticationClientBuilderMock.Configuration(homeserverClients: ["matrix.org": client],
+                                                                          qrCodeClient: client)
+        
+        clientBuilderFactory = AuthenticationClientBuilderFactoryMock(configuration: .init(builderConfiguration: configuration))
+        service = AuthenticationService(userSessionStore: UserSessionStoreMock(configuration: .init()),
+                                        encryptionKeyProvider: EncryptionKeyProvider(),
+                                        clientBuilderFactory: clientBuilderFactory,
+                                        appSettings: ServiceLocator.shared.settings,
+                                        appHooks: AppHooks())
+        
+        viewModel = ServerConfirmationScreenViewModel(authenticationService: service,
+                                                      authenticationFlow: authenticationFlow,
+                                                      slidingSyncLearnMoreURL: ServiceLocator.shared.settings.slidingSyncLearnMoreURL,
+                                                      userIndicatorController: UserIndicatorControllerMock())
+    }
 }