Move search users into a dedicated service (#789)

* add users provider with test

* add ui test for search users

* add changelog

* Update ElementX/Sources/Services/Users/UsersProvider.swift

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>

* add error handling in usersprovider

* remove empty section

* add search in invite users

* add CancellableTask, add setup App Settings in UnitTest, screenshots

* rename of UserDiscoveryService

* Update ElementX/Sources/Other/Extensions/Publisher.swift

Co-authored-by: Doug <6060466+pixlwave@users.noreply.github.com>

* new error management for User Discovery Service

* Update ElementX/Sources/Other/CancellableTask.swift

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>

* Update ElementX/Sources/Services/Users/UserDiscoveryService.swift

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>

* fix invite users and start chat errors

* use only one task to fetch user profile

---------

Co-authored-by: Alfonso Grillo <alfogrillo@gmail.com>
Co-authored-by: Doug <6060466+pixlwave@users.noreply.github.com>

ElementX/Sources/Mocks/Generated/GeneratedMocks.swift

@@ -874,4 +874,45 @@ class SessionVerificationControllerProxyMock: SessionVerificationControllerProxy
         }
     }
 }
+class UserDiscoveryServiceMock: UserDiscoveryServiceProtocol {
+
+    //MARK: - searchProfiles
+
+    var searchProfilesWithCallsCount = 0
+    var searchProfilesWithCalled: Bool {
+        return searchProfilesWithCallsCount > 0
+    }
+    var searchProfilesWithReceivedSearchQuery: String?
+    var searchProfilesWithReceivedInvocations: [String] = []
+    var searchProfilesWithReturnValue: Result<[UserProfile], UserDiscoveryErrorType>!
+    var searchProfilesWithClosure: ((String) async -> Result<[UserProfile], UserDiscoveryErrorType>)?
+
+    func searchProfiles(with searchQuery: String) async -> Result<[UserProfile], UserDiscoveryErrorType> {
+        searchProfilesWithCallsCount += 1
+        searchProfilesWithReceivedSearchQuery = searchQuery
+        searchProfilesWithReceivedInvocations.append(searchQuery)
+        if let searchProfilesWithClosure = searchProfilesWithClosure {
+            return await searchProfilesWithClosure(searchQuery)
+        } else {
+            return searchProfilesWithReturnValue
+        }
+    }
+    //MARK: - fetchSuggestions
+
+    var fetchSuggestionsCallsCount = 0
+    var fetchSuggestionsCalled: Bool {
+        return fetchSuggestionsCallsCount > 0
+    }
+    var fetchSuggestionsReturnValue: Result<[UserProfile], UserDiscoveryErrorType>!
+    var fetchSuggestionsClosure: (() async -> Result<[UserProfile], UserDiscoveryErrorType>)?
+
+    func fetchSuggestions() async -> Result<[UserProfile], UserDiscoveryErrorType> {
+        fetchSuggestionsCallsCount += 1
+        if let fetchSuggestionsClosure = fetchSuggestionsClosure {
+            return await fetchSuggestionsClosure()
+        } else {
+            return fetchSuggestionsReturnValue
+        }
+    }
+}
 // swiftlint:enable all

ElementX/Sources/Mocks/UserProfile+Mock.swift

@@ -26,6 +26,10 @@ extension UserProfile {
         .init(userID: "@bob:matrix.org", displayName: "Bob", avatarURL: nil)
     }
 
+    static var mockBobby: UserProfile {
+        .init(userID: "@bobby:matrix.org", displayName: "Bobby", avatarURL: nil)
+    }
+
     static var mockCharlie: UserProfile {
         .init(userID: "@charlie:matrix.org", displayName: "Charlie", avatarURL: nil)
     }

ElementX/Sources/Other/CancellableTask.swift

@@ -0,0 +1,35 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+@propertyWrapper
+struct CancellableTask<S: Sendable, F: Error> {
+    private var storedValue: Task<S, F>?
+    
+    init(_ value: Task<S, F>? = nil) {
+        storedValue = value
+    }
+    
+    var wrappedValue: Task<S, F>? {
+        get {
+            storedValue
+        } set {
+            storedValue?.cancel()
+            storedValue = newValue
+        }
+    }
+}

ElementX/Sources/Other/Extensions/Publisher.swift

@@ -15,6 +15,7 @@
 //
 
 import Combine
+import Foundation
 
 extension Publisher where Self.Failure == Never {
     func weakAssign<Root: AnyObject>(to keyPath: ReferenceWritableKeyPath<Root, Self.Output>, on object: Root) -> AnyCancellable {
@@ -23,3 +24,17 @@ extension Publisher where Self.Failure == Never {
         }
     }
 }
+
+extension Publisher where Output == String, Failure == Never {
+    /// Debounce text queries and remove duplicates.
+    /// Clearing the text publishes the update immediately.
+    func debounceAndRemoveDuplicates() -> AnyPublisher<String, Never> {
+        map { query in
+            let milliseconds = query.isEmpty ? 0 : 500
+            return Just(query).delay(for: .milliseconds(milliseconds), scheduler: DispatchQueue.main)
+        }
+        .switchToLatest()
+        .removeDuplicates()
+        .eraseToAnyPublisher()
+    }
+}

ElementX/Sources/Screens/InviteUsers/InviteUsersCoordinator.swift

@@ -19,6 +19,7 @@ import SwiftUI
 
 struct InviteUsersCoordinatorParameters {
     let userSession: UserSessionProtocol
+    let userDiscoveryService: UserDiscoveryServiceProtocol
 }
 
 enum InviteUsersCoordinatorAction {
@@ -38,7 +39,7 @@ final class InviteUsersCoordinator: CoordinatorProtocol {
     init(parameters: InviteUsersCoordinatorParameters) {
         self.parameters = parameters
         
-        viewModel = InviteUsersViewModel(userSession: parameters.userSession)
+        viewModel = InviteUsersViewModel(userSession: parameters.userSession, userDiscoveryService: parameters.userDiscoveryService)
     }
     
     func start() {

ElementX/Sources/Screens/InviteUsers/InviteUsersModels.swift

@@ -16,6 +16,10 @@
 
 import Foundation
 
+enum InviteUsersErrorType: Error {
+    case unknown
+}
+
 enum InviteUsersViewModelAction {
     case close
 }
@@ -23,7 +27,7 @@ enum InviteUsersViewModelAction {
 struct InviteUsersViewState: BindableState {
     var bindings = InviteUsersViewStateBindings()
     
-    var usersSection: SearchUsersSection = .init(type: .empty, users: [])
+    var usersSection: UserDiscoverySection = .init(type: .suggestions, users: [])
     var selectedUsers: [UserProfile] = []
     
     var isSearching: Bool {
@@ -45,7 +49,7 @@ struct InviteUsersViewStateBindings {
     var searchQuery = ""
     
     /// Information describing the currently displayed alert.
-    var alertInfo: AlertInfo<ClientProxyError>?
+    var alertInfo: AlertInfo<InviteUsersErrorType>?
 }
 
 enum InviteUsersViewAction {

ElementX/Sources/Screens/InviteUsers/InviteUsersViewModel.swift

@@ -21,17 +21,19 @@ typealias InviteUsersViewModelType = StateStoreViewModel<InviteUsersViewState, I
 
 class InviteUsersViewModel: InviteUsersViewModelType, InviteUsersViewModelProtocol {
     private let userSession: UserSessionProtocol
+    private let userDiscoveryService: UserDiscoveryServiceProtocol
     private let actionsSubject: PassthroughSubject<InviteUsersViewModelAction, Never> = .init()
     
     var actions: AnyPublisher<InviteUsersViewModelAction, Never> {
         actionsSubject.eraseToAnyPublisher()
     }
     
-    init(userSession: UserSessionProtocol) {
+    init(userSession: UserSessionProtocol, userDiscoveryService: UserDiscoveryServiceProtocol) {
         self.userSession = userSession
+        self.userDiscoveryService = userDiscoveryService
         super.init(initialViewState: InviteUsersViewState(), imageProvider: userSession.mediaProvider)
         
-        fetchSuggestions()
+        setupSubscriptions()
     }
     
     // MARK: - Public
@@ -65,11 +67,53 @@ class InviteUsersViewModel: InviteUsersViewModelType, InviteUsersViewModelProtoc
 
     // MARK: - Private
     
-    private func fetchSuggestions() {
-        guard ServiceLocator.shared.settings.startChatUserSuggestionsEnabled else {
-            state.usersSection = .init(type: .empty, users: [])
+    private func setupSubscriptions() {
+        context.$viewState
+            .map(\.bindings.searchQuery)
+            .debounceAndRemoveDuplicates()
+            .sink { [weak self] _ in
+                self?.fetchUsers()
+            }
+            .store(in: &cancellables)
+    }
+    
+    @CancellableTask
+    private var fetchUsersTask: Task<Void, Never>?
+    
+    private func fetchUsers() {
+        guard searchQuery.count >= 3 else {
+            fetchSuggestions()
             return
         }
-        state.usersSection = .init(type: .suggestions, users: [.mockAlice, .mockBob, .mockCharlie])
+        fetchUsersTask = Task {
+            let result = await userDiscoveryService.searchProfiles(with: searchQuery)
+            guard !Task.isCancelled else { return }
+            handleResult(for: .searchResult, result: result)
+        }
+    }
+    
+    private func fetchSuggestions() {
+        guard ServiceLocator.shared.settings.startChatUserSuggestionsEnabled else {
+            state.usersSection = .init(type: .suggestions, users: [])
+            return
+        }
+        fetchUsersTask = Task {
+            let result = await userDiscoveryService.fetchSuggestions()
+            guard !Task.isCancelled else { return }
+            handleResult(for: .suggestions, result: result)
+        }
+    }
+    
+    private func handleResult(for sectionType: UserDiscoverySectionType, result: Result<[UserProfile], UserDiscoveryErrorType>) {
+        switch result {
+        case .success(let users):
+            state.usersSection = .init(type: sectionType, users: users)
+        case .failure:
+            break
+        }
+    }
+    
+    private var searchQuery: String {
+        context.searchQuery
     }
 }

ElementX/Sources/Screens/InviteUsers/View/InviteUsersScreen.swift

@@ -44,10 +44,10 @@ struct InviteUsersScreen: View {
     /// The content shown in the form when a search query has been entered.
     @ViewBuilder
     private var searchContent: some View {
-        if context.viewState.hasEmptySearchResults {
-            noResultsContent
-        } else {
-            Form {
+        Form {
+            if context.viewState.hasEmptySearchResults {
+                noResultsContent
+            } else {
                 usersSection
             }
         }
@@ -72,7 +72,7 @@ struct InviteUsersScreen: View {
                 .buttonStyle(FormButtonStyle(accessory: .selection(isSelected: context.viewState.isUserSelected(user))))
             }
         } header: {
-            if let title = context.viewState.usersSection.type.title {
+            if let title = context.viewState.usersSection.title {
                 Text(title)
             }
         }
@@ -120,7 +120,10 @@ struct InviteUsersScreen_Previews: PreviewProvider {
     static let viewModel = {
         let userSession = MockUserSession(clientProxy: MockClientProxy(userID: "@userid:example.com"),
                                           mediaProvider: MockMediaProvider())
-        return InviteUsersViewModel(userSession: userSession)
+        let userDiscoveryService = UserDiscoveryServiceMock()
+        userDiscoveryService.fetchSuggestionsReturnValue = .success([.mockAlice])
+        userDiscoveryService.searchProfilesWithReturnValue = .success([.mockAlice])
+        return InviteUsersViewModel(userSession: userSession, userDiscoveryService: userDiscoveryService)
     }()
     
     static var previews: some View {

ElementX/Sources/Screens/StartChat/StartChatCoordinator.swift

@@ -21,6 +21,7 @@ struct StartChatCoordinatorParameters {
     let userSession: UserSessionProtocol
     weak var userIndicatorController: UserIndicatorControllerProtocol?
     let navigationStackCoordinator: NavigationStackCoordinator?
+    let userDiscoveryService: UserDiscoveryServiceProtocol
 }
 
 enum StartChatCoordinatorAction {
@@ -41,7 +42,7 @@ final class StartChatCoordinator: CoordinatorProtocol {
     init(parameters: StartChatCoordinatorParameters) {
         self.parameters = parameters
         
-        viewModel = StartChatViewModel(userSession: parameters.userSession, userIndicatorController: parameters.userIndicatorController)
+        viewModel = StartChatViewModel(userSession: parameters.userSession, userIndicatorController: parameters.userIndicatorController, userDiscoveryService: parameters.userDiscoveryService)
     }
     
     func start() {
@@ -69,7 +70,7 @@ final class StartChatCoordinator: CoordinatorProtocol {
     // MARK: - Private
     
     private func presentInviteUsersScreen() {
-        let inviteParameters = InviteUsersCoordinatorParameters(userSession: parameters.userSession)
+        let inviteParameters = InviteUsersCoordinatorParameters(userSession: parameters.userSession, userDiscoveryService: parameters.userDiscoveryService)
         let coordinator = InviteUsersCoordinator(parameters: inviteParameters)
         coordinator.actions.sink { [weak self] result in
             switch result {

ElementX/Sources/Screens/StartChat/StartChatModels.swift

@@ -16,6 +16,11 @@
 
 import Foundation
 
+enum StartChatErrorType: Error {
+    case failedCreatingRoom
+    case unknown
+}
+
 enum StartChatViewModelAction {
     case close
     case createRoom
@@ -24,7 +29,7 @@ enum StartChatViewModelAction {
 
 struct StartChatViewState: BindableState {
     var bindings = StartChatScreenViewStateBindings()
-    var usersSection: SearchUsersSection = .init(type: .empty, users: [])
+    var usersSection: UserDiscoverySection = .init(type: .suggestions, users: [])
 
     var isSearching: Bool {
         !bindings.searchQuery.isEmpty
@@ -39,7 +44,7 @@ struct StartChatScreenViewStateBindings {
     var searchQuery = ""
     
     /// Information describing the currently displayed alert.
-    var alertInfo: AlertInfo<ClientProxyError>?
+    var alertInfo: AlertInfo<StartChatErrorType>?
 }
 
 enum StartChatViewAction {

ElementX/Sources/Screens/StartChat/StartChatViewModel.swift

@@ -22,6 +22,7 @@ typealias StartChatViewModelType = StateStoreViewModel<StartChatViewState, Start
 class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
     private let userSession: UserSessionProtocol
     private let actionsSubject: PassthroughSubject<StartChatViewModelAction, Never> = .init()
+    private let userDiscoveryService: UserDiscoveryServiceProtocol
     
     var actions: AnyPublisher<StartChatViewModelAction, Never> {
         actionsSubject.eraseToAnyPublisher()
@@ -29,13 +30,13 @@ class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
     
     weak var userIndicatorController: UserIndicatorControllerProtocol?
     
-    init(userSession: UserSessionProtocol, userIndicatorController: UserIndicatorControllerProtocol?) {
+    init(userSession: UserSessionProtocol, userIndicatorController: UserIndicatorControllerProtocol?, userDiscoveryService: UserDiscoveryServiceProtocol) {
         self.userSession = userSession
         self.userIndicatorController = userIndicatorController
+        self.userDiscoveryService = userDiscoveryService
         super.init(initialViewState: StartChatViewState(), imageProvider: userSession.mediaProvider)
         
         setupBindings()
-        fetchSuggestions()
     }
     
     // MARK: - Public
@@ -70,87 +71,61 @@ class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
     
     private func displayError(_ type: ClientProxyError) {
         switch type {
-        case .failedRetrievingDirectRoom:
-            state.bindings.alertInfo = AlertInfo(id: type,
-                                                 title: L10n.commonError,
-                                                 message: L10n.screenStartChatErrorStartingChat)
-        case .failedCreatingRoom:
-            state.bindings.alertInfo = AlertInfo(id: type,
+        case .failedCreatingRoom, .failedRetrievingDirectRoom:
+            state.bindings.alertInfo = AlertInfo(id: .failedCreatingRoom,
                                                  title: L10n.commonError,
                                                  message: L10n.screenStartChatErrorStartingChat)
+        case .failedSearchingUsers:
+            state.bindings.alertInfo = AlertInfo(id: .unknown)
         default:
-            state.bindings.alertInfo = AlertInfo(id: type)
+            break
         }
     }
     
     private func setupBindings() {
         context.$viewState
             .map(\.bindings.searchQuery)
-            .map { query in
-                // debounce search queries but make sure clearing the search updates immediately
-                let milliseconds = query.isEmpty ? 0 : 500
-                return Just(query).delay(for: .milliseconds(milliseconds), scheduler: DispatchQueue.main)
-            }
-            .switchToLatest()
-            .removeDuplicates()
+            .debounceAndRemoveDuplicates()
             .sink { [weak self] _ in
-                self?.fetchData()
+                self?.fetchUsers()
             }
             .store(in: &cancellables)
     }
     
-    private func fetchData() {
+    @CancellableTask
+    private var fetchUsersTask: Task<Void, Never>?
+    
+    private func fetchUsers() {
         guard searchQuery.count >= 3 else {
             fetchSuggestions()
             return
         }
-        
-        Task {
-            await searchProfiles()
+        fetchUsersTask = Task {
+            let result = await userDiscoveryService.searchProfiles(with: searchQuery)
+            guard !Task.isCancelled else { return }
+            handleResult(for: .searchResult, result: result)
         }
     }
     
-    private func searchProfiles() async {
-        // copies the current query to check later if fetched data must be shown or not
-        let committedQuery = searchQuery
-        
-        async let queriedProfile = getProfileIfPossible()
-        async let searchedUsers = clientProxy.searchUsers(searchTerm: committedQuery, limit: 5)
-        
-        await updateState(committedQuery: committedQuery,
-                          queriedProfile: queriedProfile,
-                          searchResults: try? searchedUsers.get())
-    }
-    
-    private func updateState(committedQuery: String, queriedProfile: UserProfile?, searchResults: SearchUsersResults?) {
-        guard committedQuery == searchQuery else {
-            return
-        }
-        
-        let localProfile = queriedProfile ?? UserProfile(searchQuery: searchQuery)
-        let allResults = merge(localProfile: localProfile, searchResults: searchResults?.results)
-        
-        state.usersSection = .init(type: .searchResult, users: allResults)
-    }
-    
-    private func merge(localProfile: UserProfile?, searchResults: [UserProfile]?) -> [UserProfile] {
-        guard let localProfile else {
-            return searchResults ?? []
-        }
-        
-        let filteredSearchResult = searchResults?.filter {
-            $0.userID != localProfile.userID
-        } ?? []
-
-        return [localProfile] + filteredSearchResult
-    }
-    
     private func fetchSuggestions() {
         guard ServiceLocator.shared.settings.startChatUserSuggestionsEnabled else {
-            state.usersSection = .init(type: .empty, users: [])
+            state.usersSection = .init(type: .suggestions, users: [])
             return
         }
-        state.usersSection = .init(type: .suggestions, users: [.mockAlice, .mockBob, .mockCharlie])
+        fetchUsersTask = Task {
+            let result = await userDiscoveryService.fetchSuggestions()
+            guard !Task.isCancelled else { return }
+            handleResult(for: .suggestions, result: result)
+        }
+    }
+    
+    private func handleResult(for sectionType: UserDiscoverySectionType, result: Result<[UserProfile], UserDiscoveryErrorType>) {
+        switch result {
+        case .success(let users):
+            state.usersSection = .init(type: sectionType, users: users)
+        case .failure:
+            break
+        }
     }
     
     private func createDirectRoom(with user: UserProfile) async {
@@ -165,14 +140,6 @@ class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
         }
     }
     
-    private func getProfileIfPossible() async -> UserProfile? {
-        guard searchQuery.isMatrixIdentifier else {
-            return nil
-        }
-        
-        return try? await clientProxy.getProfile(for: searchQuery).get()
-    }
-    
     private var clientProxy: ClientProxyProtocol {
         userSession.clientProxy
     }
@@ -196,18 +163,3 @@ class StartChatViewModel: StartChatViewModelType, StartChatViewModelProtocol {
         userIndicatorController?.retractIndicatorWithId(Self.loadingIndicatorIdentifier)
     }
 }
-
-private extension String {
-    var isMatrixIdentifier: Bool {
-        MatrixEntityRegex.isMatrixUserIdentifier(self)
-    }
-}
-
-private extension UserProfile {
-    init?(searchQuery: String) {
-        guard searchQuery.isMatrixIdentifier else {
-            return nil
-        }
-        self.init(userID: searchQuery)
-    }
-}

ElementX/Sources/Screens/StartChat/View/StartChatScreen.swift

@@ -92,7 +92,7 @@ struct StartChatScreen: View {
                     .buttonStyle(FormButtonStyle())
                 }
             } header: {
-                if let title = context.viewState.usersSection.type.title {
+                if let title = context.viewState.usersSection.title {
                     Text(title)
                 }
             }
@@ -131,12 +131,19 @@ struct StartChatScreen: View {
 // MARK: - Previews
 
 struct StartChat_Previews: PreviewProvider {
-    static var previews: some View {
+    static let viewModel = {
         let userSession = MockUserSession(clientProxy: MockClientProxy(userID: "@userid:example.com"),
                                           mediaProvider: MockMediaProvider())
-        let regularViewModel = StartChatViewModel(userSession: userSession, userIndicatorController: nil)
+        let userDiscoveryService = UserDiscoveryServiceMock()
+        userDiscoveryService.fetchSuggestionsReturnValue = .success([.mockAlice])
+        userDiscoveryService.searchProfilesWithReturnValue = .success([.mockAlice])
+        let viewModel = StartChatViewModel(userSession: userSession, userIndicatorController: nil, userDiscoveryService: userDiscoveryService)
+        return viewModel
+    }()
+    
+    static var previews: some View {
         NavigationView {
-            StartChatScreen(context: regularViewModel.context)
+            StartChatScreen(context: viewModel.context)
                 .tint(.element.accent)
         }
     }

ElementX/Sources/Screens/UserDiscoverySection/SearchUsersSection.swift

@@ -16,22 +16,21 @@
 
 import Foundation
 
-struct SearchUsersSection {
-    let type: SearchUserSectionType
+struct UserDiscoverySection {
+    let type: UserDiscoverySectionType
     let users: [UserProfile]
-}
-
-enum SearchUserSectionType: Equatable {
-    case searchResult
-    case suggestions
-    case empty
     
     var title: String? {
-        switch self {
-        case .searchResult, .empty:
+        switch type {
+        case .searchResult:
             return nil
         case .suggestions:
-            return L10n.commonSuggestions
+            return users.isEmpty ? nil : L10n.commonSuggestions
         }
     }
 }
+
+enum UserDiscoverySectionType: Equatable {
+    case searchResult
+    case suggestions
+}

ElementX/Sources/Services/Client/ClientProxy.swift

@@ -262,7 +262,7 @@ class ClientProxy: ClientProxyProtocol {
         }
     }
     
-    func getProfile(for userID: String) async -> Result<UserProfile, ClientProxyError> {
+    func profile(for userID: String) async -> Result<UserProfile, ClientProxyError> {
         await Task.dispatch(on: clientQueue) {
             do {
                 return try .success(.init(sdkUserProfile: self.client.getProfile(userId: userID)))

ElementX/Sources/Services/Client/ClientProxyProtocol.swift

@@ -98,5 +98,5 @@ protocol ClientProxyProtocol: AnyObject, MediaLoaderProtocol {
     
     func searchUsers(searchTerm: String, limit: UInt) async -> Result<SearchUsersResults, ClientProxyError>
     
-    func getProfile(for userID: String) async -> Result<UserProfile, ClientProxyError>
+    func profile(for userID: String) async -> Result<UserProfile, ClientProxyError>
 }

ElementX/Sources/Services/Client/MockClientProxy.swift

@@ -125,7 +125,7 @@ class MockClientProxy: ClientProxyProtocol {
     
     var getProfileResult: Result<UserProfile, ClientProxyError> = .success(.init(userID: "@a:b.com", displayName: "Some user"))
     private(set) var getProfileCalled = false
-    func getProfile(for userID: String) async -> Result<UserProfile, ClientProxyError> {
+    func profile(for userID: String) async -> Result<UserProfile, ClientProxyError> {
         getProfileCalled = true
         return getProfileResult
     }

ElementX/Sources/Services/UserSession/UserSessionFlowCoordinator.swift

@@ -287,8 +287,8 @@ class UserSessionFlowCoordinator: CoordinatorProtocol {
         let startChatNavigationStackCoordinator = NavigationStackCoordinator()
         
         let userIndicatorController = UserIndicatorController(rootCoordinator: startChatNavigationStackCoordinator)
-        
-        let parameters = StartChatCoordinatorParameters(userSession: userSession, userIndicatorController: userIndicatorController, navigationStackCoordinator: startChatNavigationStackCoordinator)
+        let userDiscoveryService = UserDiscoveryService(clientProxy: userSession.clientProxy)
+        let parameters = StartChatCoordinatorParameters(userSession: userSession, userIndicatorController: userIndicatorController, navigationStackCoordinator: startChatNavigationStackCoordinator, userDiscoveryService: userDiscoveryService)
         let coordinator = StartChatCoordinator(parameters: parameters)
         coordinator.actions.sink { [weak self] action in
             guard let self else { return }

ElementX/Sources/Services/Users/UserDiscoveryService.swift

@@ -0,0 +1,77 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+final class UserDiscoveryService: UserDiscoveryServiceProtocol {
+    private let clientProxy: ClientProxyProtocol
+    
+    init(clientProxy: ClientProxyProtocol) {
+        self.clientProxy = clientProxy
+    }
+    
+    func fetchSuggestions() async -> Result<[UserProfile], UserDiscoveryErrorType> {
+        .success([.mockAlice, .mockBob, .mockCharlie])
+    }
+    
+    func searchProfiles(with searchQuery: String) async -> Result<[UserProfile], UserDiscoveryErrorType> {
+        do {
+            async let queriedProfile = try? profileIfPossible(with: searchQuery).get()
+            async let searchedUsers = clientProxy.searchUsers(searchTerm: searchQuery, limit: 5)
+            let users = try await merge(searchQuery: searchQuery, queriedProfile: queriedProfile, searchResults: searchedUsers.get())
+            return .success(users)
+        } catch {
+            return .failure(.failedSearchingUsers)
+        }
+    }
+    
+    private func merge(searchQuery: String, queriedProfile: UserProfile?, searchResults: SearchUsersResults) -> [UserProfile] {
+        let localProfile = queriedProfile ?? UserProfile(searchQuery: searchQuery)
+        let searchResults = searchResults.results
+        guard let localProfile else {
+            return searchResults
+        }
+        
+        let filteredSearchResult = searchResults.filter {
+            $0.userID != localProfile.userID
+        }
+
+        return [localProfile] + filteredSearchResult
+    }
+    
+    private func profileIfPossible(with searchQuery: String) async -> Result<UserProfile, ClientProxyError> {
+        guard searchQuery.isMatrixIdentifier else {
+            return .failure(.failedGettingUserProfile)
+        }
+        
+        return await clientProxy.profile(for: searchQuery)
+    }
+}
+
+private extension String {
+    var isMatrixIdentifier: Bool {
+        MatrixEntityRegex.isMatrixUserIdentifier(self)
+    }
+}
+
+private extension UserProfile {
+    init?(searchQuery: String) {
+        guard searchQuery.isMatrixIdentifier else {
+            return nil
+        }
+        self.init(userID: searchQuery)
+    }
+}

ElementX/Sources/Services/Users/UserDiscoveryServiceProtocol.swift

@@ -0,0 +1,28 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+enum UserDiscoveryErrorType: Error {
+    case failedSearchingUsers
+    case failedFetchingSuggestedUsers
+}
+
+// sourcery: AutoMockable
+protocol UserDiscoveryServiceProtocol {
+    func searchProfiles(with searchQuery: String) async -> Result<[UserProfile], UserDiscoveryErrorType>
+    func fetchSuggestions() async -> Result<[UserProfile], UserDiscoveryErrorType>
+}

ElementX/Sources/UITests/UITestsAppCoordinator.swift

@@ -315,23 +315,24 @@ class MockScreen: Identifiable {
             navigationStackCoordinator.setRootCoordinator(coordinator)
             return navigationStackCoordinator
         case .startChat:
+            ServiceLocator.shared.settings.startChatUserSuggestionsEnabled = true
             let navigationStackCoordinator = NavigationStackCoordinator()
-            let coordinator = StartChatCoordinator(parameters: .init(userSession: MockUserSession(clientProxy: MockClientProxy(userID: "@mock:client.com"), mediaProvider: MockMediaProvider()), navigationStackCoordinator: navigationStackCoordinator))
+            let userDiscoveryMock = UserDiscoveryServiceMock()
+            userDiscoveryMock.fetchSuggestionsReturnValue = .success([.mockAlice, .mockBob, .mockCharlie])
+            userDiscoveryMock.searchProfilesWithReturnValue = .success([])
+            let userSession = MockUserSession(clientProxy: MockClientProxy(userID: "@mock:client.com"), mediaProvider: MockMediaProvider())
+            let parameters: StartChatCoordinatorParameters = .init(userSession: userSession, navigationStackCoordinator: navigationStackCoordinator, userDiscoveryService: userDiscoveryMock)
+            let coordinator = StartChatCoordinator(parameters: parameters)
             navigationStackCoordinator.setRootCoordinator(coordinator)
             return navigationStackCoordinator
         case .startChatWithSearchResults:
             let navigationStackCoordinator = NavigationStackCoordinator()
             let clientProxy = MockClientProxy(userID: "@mock:client.com")
-            clientProxy.searchUsersResult = .success(.init(results: [.mockAlice], limited: true))
-            let coordinator = StartChatCoordinator(parameters: .init(userSession: MockUserSession(clientProxy: clientProxy, mediaProvider: MockMediaProvider()), navigationStackCoordinator: navigationStackCoordinator))
-            navigationStackCoordinator.setRootCoordinator(coordinator)
-            return navigationStackCoordinator
-        case .startChatSearchingNonexistentID:
-            let navigationStackCoordinator = NavigationStackCoordinator()
-            let clientProxy = MockClientProxy(userID: "@mock:client.com")
-            clientProxy.searchUsersResult = .success(.init(results: [.mockAlice], limited: true))
-            clientProxy.getProfileResult = .failure(.failedGettingUserProfile)
-            let coordinator = StartChatCoordinator(parameters: .init(userSession: MockUserSession(clientProxy: clientProxy, mediaProvider: MockMediaProvider()), navigationStackCoordinator: navigationStackCoordinator))
+            let userDiscoveryMock = UserDiscoveryServiceMock()
+            userDiscoveryMock.fetchSuggestionsReturnValue = .success([])
+            userDiscoveryMock.searchProfilesWithReturnValue = .success([.mockBob, .mockBobby])
+            let userSession = MockUserSession(clientProxy: clientProxy, mediaProvider: MockMediaProvider())
+            let coordinator = StartChatCoordinator(parameters: .init(userSession: userSession, navigationStackCoordinator: navigationStackCoordinator, userDiscoveryService: userDiscoveryMock))
             navigationStackCoordinator.setRootCoordinator(coordinator)
             return navigationStackCoordinator
         case .roomMemberDetailsAccountOwner:
@@ -381,8 +382,12 @@ class MockScreen: Identifiable {
             navigationStackCoordinator.setRootCoordinator(coordinator)
             return navigationStackCoordinator
         case .inviteUsers:
+            ServiceLocator.shared.settings.startChatUserSuggestionsEnabled = true
             let navigationStackCoordinator = NavigationStackCoordinator()
-            let coordinator = InviteUsersCoordinator(parameters: .init(userSession: MockUserSession(clientProxy: MockClientProxy(userID: "@mock:client.com"), mediaProvider: MockMediaProvider())))
+            let userDiscoveryMock = UserDiscoveryServiceMock()
+            userDiscoveryMock.fetchSuggestionsReturnValue = .success([.mockAlice, .mockBob, .mockCharlie])
+            userDiscoveryMock.searchProfilesWithReturnValue = .success([])
+            let coordinator = InviteUsersCoordinator(parameters: .init(userSession: MockUserSession(clientProxy: MockClientProxy(userID: "@mock:client.com"), mediaProvider: MockMediaProvider()), userDiscoveryService: userDiscoveryMock))
             navigationStackCoordinator.setRootCoordinator(coordinator)
             return navigationStackCoordinator
         }

ElementX/Sources/UITests/UITestsScreenIdentifier.swift

@@ -51,7 +51,6 @@ enum UITestsScreenIdentifier: String {
     case reportContent
     case startChat
     case startChatWithSearchResults
-    case startChatSearchingNonexistentID
     case invites
     case invitesNoInvites
     case inviteUsers