Updates following self review.

RiotSwiftUI/Modules/Onboarding/DisplayName/Coordinator/OnboardingDisplayNameCoordinator.swift

@@ -84,13 +84,8 @@ final class OnboardingDisplayNameCoordinator: Coordinator, Presentable {
         waitingIndicator = indicatorPresenter.present(.loading(label: VectorL10n.saving, isInteractionBlocking: true))
     }
     
-    private func stopWaiting(error: Error? = nil) {
-        waitingIndicator?.cancel()
+    private func stopWaiting() {
         waitingIndicator = nil
-        
-        if let error = error {
-            onboardingDisplayNameViewModel.update(with: error)
-        }
     }
     
     private func setDisplayName(_ displayName: String) {
@@ -102,7 +97,8 @@ final class OnboardingDisplayNameCoordinator: Coordinator, Presentable {
             self.completion?(self.parameters.userSession)
         } failure: { [weak self] error in
             guard let self = self else { return }
-            self.stopWaiting(error: error)
+            self.stopWaiting()
+            self.onboardingDisplayNameViewModel.processError(error as NSError?)
         }
     }
 }

RiotSwiftUI/Modules/Onboarding/DisplayName/OnboardingDisplayNameViewModel.swift

@@ -52,14 +52,13 @@ class OnboardingDisplayNameViewModel: OnboardingDisplayNameViewModelType, Onboar
         }
     }
     
-    func update(with error: Error) {
-        if let error = error as NSError? {
-            state.bindings.alertInfo = AlertInfo(error: error)
-        }
+    func processError(_ error: NSError?) {
+        state.bindings.alertInfo = AlertInfo(error: error)
     }
     
     // MARK: - Private
     
+    /// Checks for a display name that exceeds 256 characters and updates the footer error if needed.
     private func validateDisplayName() {
         if state.bindings.displayName.count > 256 {
             guard state.validationErrorMessage == nil else { return }

RiotSwiftUI/Modules/Onboarding/DisplayName/OnboardingDisplayNameViewModelProtocol.swift

@@ -22,5 +22,7 @@ protocol OnboardingDisplayNameViewModelProtocol {
     @available(iOS 14, *)
     var context: OnboardingDisplayNameViewModelType.Context { get }
     
-    func update(with error: Error)
+    /// Update the view model to show that an error has occurred.
+    /// - Parameter error: The error to be displayed or `nil` to display a generic alert.
+    func processError(_ error: NSError?)
 }

RiotSwiftUI/Modules/Onboarding/DisplayName/Test/UI/OnboardingDisplayNameUITests.swift

@@ -49,6 +49,10 @@ class OnboardingDisplayNameUITests: MockScreenTest {
         let footer = app.staticTexts["textFieldFooter"]
         XCTAssertTrue(footer.exists, "The textfield's footer should always be shown.")
         XCTAssertEqual(footer.label, VectorL10n.onboardingDisplayNameHint, "The footer should display a hint when no text is set.")
+        
+        let saveButton = app.buttons["saveButton"]
+        XCTAssertTrue(saveButton.exists, "There should be a save button.")
+        XCTAssertFalse(saveButton.isEnabled, "The save button should not be enabled.")
     }
 
     func verifyDisplayName(displayName: String) {
@@ -57,6 +61,10 @@ class OnboardingDisplayNameUITests: MockScreenTest {
         XCTAssertEqual(textField.value as? String, displayName, "When a name has been set, it should show in the textfield.")
         XCTAssertEqual(textField.placeholderValue, VectorL10n.onboardingDisplayNamePlaceholder, "The textfield's placeholder should be set.")
         
+        let saveButton = app.buttons["saveButton"]
+        XCTAssertTrue(saveButton.exists, "There should be a save button.")
+        XCTAssertTrue(saveButton.isEnabled, "The save button should be enabled.")
+        
         let footer = app.staticTexts["textFieldFooter"]
         XCTAssertTrue(footer.exists, "The textfield's footer should always be shown.")
         XCTAssertEqual(footer.label, VectorL10n.onboardingDisplayNameHint, "The footer should display a hint when an acceptable name is entered.")
@@ -71,5 +79,9 @@ class OnboardingDisplayNameUITests: MockScreenTest {
         let footer = app.staticTexts["textFieldFooter"]
         XCTAssertTrue(footer.exists, "The textfield's footer should always be shown.")
         XCTAssertEqual(footer.label, VectorL10n.onboardingDisplayNameMaxLength, "The footer should display an error when the display name is too long.")
+        
+        let saveButton = app.buttons["saveButton"]
+        XCTAssertTrue(saveButton.exists, "There should be a save button.")
+        XCTAssertFalse(saveButton.isEnabled, "The save button should not be enabled.")
     }
 }

RiotSwiftUI/Modules/Onboarding/DisplayName/Test/Unit/OnboardingDisplayNameViewModelTests.swift

@@ -21,10 +21,6 @@ import Combine
 
 @available(iOS 14.0, *)
 class OnboardingDisplayNameViewModelTests: XCTestCase {
-    private enum Constants {
-        static let displayName = "Alice"
-    }
-    
     var viewModel: OnboardingDisplayNameViewModel!
     var context: OnboardingDisplayNameViewModelType.Context!
     

RiotSwiftUI/Modules/Onboarding/DisplayName/View/OnboardingDisplayNameScreen.swift

@@ -111,7 +111,8 @@ struct OnboardingDisplayNameScreen: View {
                 viewModel.send(viewAction: .save)
             }
             .buttonStyle(PrimaryActionButtonStyle())
-            .disabled(viewModel.displayName.isEmpty)
+            .disabled(viewModel.displayName.isEmpty || viewModel.viewState.validationErrorMessage != nil)
+            .accessibilityIdentifier("saveButton")
             
             Button { viewModel.send(viewAction: .skip) } label: {
                 Text(VectorL10n.onboardingPersonalizationSkip)