UITests and Mock Screens

Adds the test targets for Unit and UI tests
Adds mock screen data and utilities to render each mock screen for previews/ui tests.
Changes Published property in the service to CurrentValueSubject. we don't need the synthesized aspect of Published and property wrappers cannot be included in protocols.

RiotSwiftUI/Modules/Template/SimpleUserProfileExample/Test/Unit/TemplateUserProfileViewModelTests.swift

@@ -0,0 +1,54 @@
+// 
+// Copyright 2021 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 XCTest
+import Combine
+
+@testable import RiotSwiftUI
+
+@available(iOS 14.0, *)
+class TemplateUserProfileViewModelTests: XCTestCase {
+    private enum Constants {
+        static let presenceInitialValue: TemplateUserProfilePresence = .offline
+        static let displayName = "Alice"
+    }
+    var service: MockTemplateUserProfileService!
+    var viewModel: TemplateUserProfileViewModel!
+    var cancellables = Set<AnyCancellable>()
+    override func setUpWithError() throws {
+        service = MockTemplateUserProfileService(displayName: Constants.displayName, presence: Constants.presenceInitialValue)
+        viewModel = TemplateUserProfileViewModel(userService: service)
+    }
+    
+    func testInitialState() {
+        XCTAssertEqual(viewModel.viewState.displayName, Constants.displayName)
+        XCTAssertEqual(viewModel.viewState.presence, Constants.presenceInitialValue)
+    }
+
+    func testFirstPresenceRecieved() throws {
+        let presencePublisher = viewModel.$viewState.map(\.presence).removeDuplicates().collect(1).first()
+        XCTAssertEqual(try xcAwait(presencePublisher), [Constants.presenceInitialValue])
+    }
+    
+    func testPresenceUpdatesRecieved() throws {
+        let presencePublisher = viewModel.$viewState.map(\.presence).removeDuplicates().collect(3).first()
+        let newPresenceValue1: TemplateUserProfilePresence = .online
+        let newPresenceValue2: TemplateUserProfilePresence = .idle
+        service.simulateUpdate(presence: newPresenceValue1)
+        service.simulateUpdate(presence: newPresenceValue2)
+        XCTAssertEqual(try xcAwait(presencePublisher), [Constants.presenceInitialValue, newPresenceValue1, newPresenceValue2])
+    }
+}