242

0242-reliably-testing-async-pt5/README.md

@@ -0,0 +1,5 @@
+## [Point-Free](https://www.pointfree.co)
+
+> #### This directory contains code from Point-Free Episode: [Reliable Async Tests: The Point](https://www.pointfree.co/episodes/ep242-reliable-async-tests-the-point)
+>
+> What’s the point of the work we did to make async testing reliable and deterministic, and are we even testing reality anymore? We conclude our series by rewriting our feature and tests using Combine instead of async-await, and comparing both approaches.

0242-reliably-testing-async-pt5/ReliablyTestingAsync/ReliablyTestingAsync.xcodeproj/project.xcworkspace/xcshareddata/IDEWorkspaceChecks.plist

@@ -0,0 +1,8 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>IDEDidComputeMac32BitWarning</key>
+	<true/>
+</dict>
+</plist>

0242-reliably-testing-async-pt5/ReliablyTestingAsync/ReliablyTestingAsync.xcodeproj/xcshareddata/xcschemes/ReliablyTestingAsync.xcscheme

@@ -0,0 +1,106 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<Scheme
+   LastUpgradeVersion = "1500"
+   version = "1.7">
+   <BuildAction
+      parallelizeBuildables = "YES"
+      buildImplicitDependencies = "YES">
+      <BuildActionEntries>
+         <BuildActionEntry
+            buildForTesting = "YES"
+            buildForRunning = "YES"
+            buildForProfiling = "YES"
+            buildForArchiving = "YES"
+            buildForAnalyzing = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "CAC2DD7C2A30B827007675BD"
+               BuildableName = "ReliablyTestingAsync.app"
+               BlueprintName = "ReliablyTestingAsync"
+               ReferencedContainer = "container:ReliablyTestingAsync.xcodeproj">
+            </BuildableReference>
+         </BuildActionEntry>
+      </BuildActionEntries>
+   </BuildAction>
+   <TestAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      shouldUseLaunchSchemeArgsEnv = "YES">
+      <TestPlans>
+         <TestPlanReference
+            reference = "container:ReliablyTestingAsyncTests/ReliablyTestingAsync.xctestplan"
+            default = "YES">
+         </TestPlanReference>
+      </TestPlans>
+      <Testables>
+         <TestableReference
+            skipped = "NO"
+            parallelizable = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "CAC2DD8C2A30B829007675BD"
+               BuildableName = "ReliablyTestingAsyncTests.xctest"
+               BlueprintName = "ReliablyTestingAsyncTests"
+               ReferencedContainer = "container:ReliablyTestingAsync.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
+         <TestableReference
+            skipped = "NO"
+            parallelizable = "YES">
+            <BuildableReference
+               BuildableIdentifier = "primary"
+               BlueprintIdentifier = "CAC2DD962A30B829007675BD"
+               BuildableName = "ReliablyTestingAsyncUITests.xctest"
+               BlueprintName = "ReliablyTestingAsyncUITests"
+               ReferencedContainer = "container:ReliablyTestingAsync.xcodeproj">
+            </BuildableReference>
+         </TestableReference>
+      </Testables>
+   </TestAction>
+   <LaunchAction
+      buildConfiguration = "Debug"
+      selectedDebuggerIdentifier = "Xcode.DebuggerFoundation.Debugger.LLDB"
+      selectedLauncherIdentifier = "Xcode.DebuggerFoundation.Launcher.LLDB"
+      launchStyle = "0"
+      useCustomWorkingDirectory = "NO"
+      ignoresPersistentStateOnLaunch = "NO"
+      debugDocumentVersioning = "YES"
+      debugServiceExtension = "internal"
+      allowLocationSimulation = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "CAC2DD7C2A30B827007675BD"
+            BuildableName = "ReliablyTestingAsync.app"
+            BlueprintName = "ReliablyTestingAsync"
+            ReferencedContainer = "container:ReliablyTestingAsync.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </LaunchAction>
+   <ProfileAction
+      buildConfiguration = "Release"
+      shouldUseLaunchSchemeArgsEnv = "YES"
+      savedToolIdentifier = ""
+      useCustomWorkingDirectory = "NO"
+      debugDocumentVersioning = "YES">
+      <BuildableProductRunnable
+         runnableDebuggingMode = "0">
+         <BuildableReference
+            BuildableIdentifier = "primary"
+            BlueprintIdentifier = "CAC2DD7C2A30B827007675BD"
+            BuildableName = "ReliablyTestingAsync.app"
+            BlueprintName = "ReliablyTestingAsync"
+            ReferencedContainer = "container:ReliablyTestingAsync.xcodeproj">
+         </BuildableReference>
+      </BuildableProductRunnable>
+   </ProfileAction>
+   <AnalyzeAction
+      buildConfiguration = "Debug">
+   </AnalyzeAction>
+   <ArchiveAction
+      buildConfiguration = "Release"
+      revealArchiveInOrganizer = "YES">
+   </ArchiveAction>
+</Scheme>

0242-reliably-testing-async-pt5/ReliablyTestingAsync/ReliablyTestingAsync/App.swift

@@ -0,0 +1,12 @@
+import SwiftUI
+
+@main
+struct ReliablyTestingAsyncApp: App {
+  var body: some Scene {
+    WindowGroup {
+      if NSClassFromString("XCTestCase") == nil {
+        ContentView(model: CombineNumberFactModel())
+      }
+    }
+  }
+}

0242-reliably-testing-async-pt5/ReliablyTestingAsync/ReliablyTestingAsync/Assets.xcassets/AccentColor.colorset/Contents.json

@@ -0,0 +1,11 @@
+{
+  "colors" : [
+    {
+      "idiom" : "universal"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

0242-reliably-testing-async-pt5/ReliablyTestingAsync/ReliablyTestingAsync/Assets.xcassets/AppIcon.appiconset/Contents.json

@@ -0,0 +1,13 @@
+{
+  "images" : [
+    {
+      "idiom" : "universal",
+      "platform" : "ios",
+      "size" : "1024x1024"
+    }
+  ],
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

0242-reliably-testing-async-pt5/ReliablyTestingAsync/ReliablyTestingAsync/Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}

0242-reliably-testing-async-pt5/ReliablyTestingAsync/ReliablyTestingAsync/ConcurrencyExtras.swift

@@ -0,0 +1,13 @@
+import Darwin
+
+typealias Original = @convention(thin) (UnownedJob) -> Void
+typealias Hook = @convention(thin) (UnownedJob, Original) -> Void
+
+var swift_task_enqueueGlobal_hook: Hook? {
+  get { _swift_task_enqueueGlobal_hook.pointee }
+  set { _swift_task_enqueueGlobal_hook.pointee = newValue }
+}
+
+private let _swift_task_enqueueGlobal_hook =
+  dlsym(dlopen(nil, RTLD_LAZY), "swift_task_enqueueGlobal_hook")
+    .assumingMemoryBound(to: Hook?.self)

0242-reliably-testing-async-pt5/ReliablyTestingAsync/ReliablyTestingAsync/ContentView.swift

@@ -0,0 +1,172 @@
+import Combine
+import Dependencies
+import SwiftUI
+
+struct NumberFactClient {
+  var fact: @Sendable (Int) async throws -> String
+  var factPublisher: @Sendable (Int) -> AnyPublisher<String, Error>
+}
+
+extension NumberFactClient: DependencyKey {
+  static let liveValue = Self { number in
+    try await Task.sleep(for: .seconds(1))
+    return try await String(
+      decoding: URLSession.shared.data(from: URL(string: "http://numbersapi.com/\(number)")!).0,
+      as: UTF8.self
+    )
+  } factPublisher: { number in
+    URLSession.shared.dataTaskPublisher(for: URL(string: "http://numbersapi.com/\(number)")!)
+//      .delay(for: 1, scheduler: DispatchQueue.main)
+      .map { data, _ in String(decoding: data, as: UTF8.self) }
+      .mapError { $0 as Error }
+      .eraseToAnyPublisher()
+  }
+}
+
+extension DependencyValues {
+  var numberFact: NumberFactClient {
+    get { self[NumberFactClient.self] }
+    set { self[NumberFactClient.self] = newValue }
+  }
+}
+
+@MainActor
+class CombineNumberFactModel: ObservableObject {
+  @Dependency(\.mainQueue) var mainQueue
+  @Dependency(\.numberFact) var numberFact
+
+  @Published var count = 0
+  @Published var fact: String?
+  @Published var factCancellable: AnyCancellable?
+  var isLoading: Bool { self.factCancellable != nil }
+
+  func incrementButtonTapped() {
+    self.fact = nil
+    self.factCancellable?.cancel()
+    self.factCancellable = nil
+    self.count += 1
+  }
+  func decrementButtonTapped() {
+    self.fact = nil
+    self.factCancellable?.cancel()
+    self.factCancellable = nil
+    self.count -= 1
+  }
+  func getFactButtonTapped() {
+    self.factCancellable?.cancel()
+
+    self.fact = nil
+    self.factCancellable = self.numberFact.factPublisher(self.count)
+      .receive(on: self.mainQueue)
+      .sink(
+        receiveCompletion: { [weak self] _ in
+          // TODO: Handle error
+          self?.factCancellable = nil
+        },
+        receiveValue: { [weak self] fact in
+          self?.fact = fact
+        }
+      )
+  }
+  func cancelButtonTapped() {
+    self.factCancellable?.cancel()
+    self.factCancellable = nil
+  }
+  var notificationCancellable: AnyCancellable?
+  func onTask() {
+    self.notificationCancellable = NotificationCenter.default.publisher(for:  UIApplication.userDidTakeScreenshotNotification)
+      .sink { [weak self] _ in
+        self?.count += 1
+      }
+  }
+}
+@MainActor
+class NumberFactModel: ObservableObject {
+  @Dependency(\.numberFact) var numberFact
+
+  @Published var count = 0
+  @Published var fact: String?
+  @Published var factTask: Task<String, Error>?
+  var isLoading: Bool { self.factTask != nil }
+
+  func incrementButtonTapped() {
+    self.fact = nil
+    self.factTask?.cancel()
+    self.factTask = nil
+    self.count += 1
+  }
+  func decrementButtonTapped() {
+    self.fact = nil
+    self.factTask?.cancel()
+    self.factTask = nil
+    self.count -= 1
+  }
+  func getFactButtonTapped() async {
+    self.factTask?.cancel()
+
+    self.fact = nil
+    self.factTask = Task {
+      try await self.numberFact.fact(self.count)
+    }
+    defer { self.factTask = nil }
+    do {
+      self.fact = try await self.factTask?.value
+    } catch {
+      // TODO: handle error
+    }
+  }
+  func cancelButtonTapped() {
+    self.factTask?.cancel()
+    self.factTask = nil
+  }
+  func onTask() async {
+    for await _ in NotificationCenter.default.notifications(named: UIApplication.userDidTakeScreenshotNotification) {
+      self.count += 1
+    }
+  }
+}
+
+struct ContentView: View {
+  @ObservedObject var model: CombineNumberFactModel
+
+  var body: some View {
+    Form {
+      Section {
+        HStack {
+          Button("-") { self.model.decrementButtonTapped() }
+          Text("\(self.model.count)")
+          Button("+") { self.model.incrementButtonTapped() }
+        }
+      }
+      .buttonStyle(.plain)
+
+      Section {
+        if self.model.isLoading {
+          HStack(spacing: 4) {
+            Button("Cancel") {
+              self.model.cancelButtonTapped()
+            }
+            Spacer()
+            ProgressView()
+              .id(UUID())
+          }
+        } else {
+          Button("Get fact") {
+            Task { await self.model.getFactButtonTapped() }
+          }
+        }
+      }
+
+      if let fact = self.model.fact {
+        Text(fact)
+      }
+    }
+    .task { await self.model.onTask() }
+  }
+}
+
+struct ContentPreviews: PreviewProvider {
+  static var previews: some View {
+    ContentView(model: CombineNumberFactModel())
+  }
+}