format code

Implementation/Peered.xcodeproj/project.pbxproj

@@ -6,8 +6,19 @@
 	objectVersion = 77;
 	objects = {
 
+/* Begin PBXContainerItemProxy section */
+		47D771C32FC2141600C4C002 /* PBXContainerItemProxy */ = {
+			isa = PBXContainerItemProxy;
+			containerPortal = 479E819F2DD09F9400B82386 /* Project object */;
+			proxyType = 1;
+			remoteGlobalIDString = 479E81A62DD09F9400B82386;
+			remoteInfo = Peered;
+		};
+/* End PBXContainerItemProxy section */
+
 /* Begin PBXFileReference section */
 		479E81A72DD09F9400B82386 /* Peered.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Peered.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		47D771BF2FC2141600C4C002 /* PeeredTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = PeeredTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
 /* End PBXFileReference section */
 
 /* Begin PBXFileSystemSynchronizedBuildFileExceptionSet section */
@@ -29,6 +40,11 @@
 			path = Peered;
 			sourceTree = "<group>";
 		};
+		47D771C02FC2141600C4C002 /* PeeredTests */ = {
+			isa = PBXFileSystemSynchronizedRootGroup;
+			path = PeeredTests;
+			sourceTree = "<group>";
+		};
 /* End PBXFileSystemSynchronizedRootGroup section */
 
 /* Begin PBXFrameworksBuildPhase section */
@@ -39,6 +55,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		47D771BC2FC2141600C4C002 /* Frameworks */ = {
+			isa = PBXFrameworksBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
@@ -46,6 +69,7 @@
 			isa = PBXGroup;
 			children = (
 				479E81A92DD09F9400B82386 /* Peered */,
+				47D771C02FC2141600C4C002 /* PeeredTests */,
 				479E81A82DD09F9400B82386 /* Products */,
 			);
 			sourceTree = "<group>";
@@ -54,6 +78,7 @@
 			isa = PBXGroup;
 			children = (
 				479E81A72DD09F9400B82386 /* Peered.app */,
+				47D771BF2FC2141600C4C002 /* PeeredTests.xctest */,
 			);
 			name = Products;
 			sourceTree = "<group>";
@@ -83,6 +108,29 @@
 			productReference = 479E81A72DD09F9400B82386 /* Peered.app */;
 			productType = "com.apple.product-type.application";
 		};
+		47D771BE2FC2141600C4C002 /* PeeredTests */ = {
+			isa = PBXNativeTarget;
+			buildConfigurationList = 47D771C52FC2141600C4C002 /* Build configuration list for PBXNativeTarget "PeeredTests" */;
+			buildPhases = (
+				47D771BB2FC2141600C4C002 /* Sources */,
+				47D771BC2FC2141600C4C002 /* Frameworks */,
+				47D771BD2FC2141600C4C002 /* Resources */,
+			);
+			buildRules = (
+			);
+			dependencies = (
+				47D771C42FC2141600C4C002 /* PBXTargetDependency */,
+			);
+			fileSystemSynchronizedGroups = (
+				47D771C02FC2141600C4C002 /* PeeredTests */,
+			);
+			name = PeeredTests;
+			packageProductDependencies = (
+			);
+			productName = PeeredTests;
+			productReference = 47D771BF2FC2141600C4C002 /* PeeredTests.xctest */;
+			productType = "com.apple.product-type.bundle.unit-test";
+		};
 /* End PBXNativeTarget section */
 
 /* Begin PBXProject section */
@@ -90,12 +138,16 @@
 			isa = PBXProject;
 			attributes = {
 				BuildIndependentTargetsInParallel = 1;
-				LastSwiftUpdateCheck = 1630;
+				LastSwiftUpdateCheck = 2650;
 				LastUpgradeCheck = 1640;
 				TargetAttributes = {
 					479E81A62DD09F9400B82386 = {
 						CreatedOnToolsVersion = 16.3;
 					};
+					47D771BE2FC2141600C4C002 = {
+						CreatedOnToolsVersion = 26.5;
+						TestTargetID = 479E81A62DD09F9400B82386;
+					};
 				};
 			};
 			buildConfigurationList = 479E81A22DD09F9400B82386 /* Build configuration list for PBXProject "Peered" */;
@@ -113,6 +165,7 @@
 			projectRoot = "";
 			targets = (
 				479E81A62DD09F9400B82386 /* Peered */,
+				47D771BE2FC2141600C4C002 /* PeeredTests */,
 			);
 		};
 /* End PBXProject section */
@@ -125,6 +178,13 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		47D771BD2FC2141600C4C002 /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXResourcesBuildPhase section */
 
 /* Begin PBXSourcesBuildPhase section */
@@ -135,8 +195,23 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		47D771BB2FC2141600C4C002 /* Sources */ = {
+			isa = PBXSourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXSourcesBuildPhase section */
 
+/* Begin PBXTargetDependency section */
+		47D771C42FC2141600C4C002 /* PBXTargetDependency */ = {
+			isa = PBXTargetDependency;
+			target = 479E81A62DD09F9400B82386 /* Peered */;
+			targetProxy = 47D771C32FC2141600C4C002 /* PBXContainerItemProxy */;
+		};
+/* End PBXTargetDependency section */
+
 /* Begin XCBuildConfiguration section */
 		479E81C72DD09F9500B82386 /* Debug */ = {
 			isa = XCBuildConfiguration;
@@ -364,6 +439,58 @@
 			};
 			name = Release;
 		};
+		47D771C62FC2141600C4C002 /* Debug */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				BUNDLE_LOADER = "$(TEST_HOST)";
+				CODE_SIGN_STYLE = Automatic;
+				CURRENT_PROJECT_VERSION = 1;
+				DEVELOPMENT_TEAM = LTFJ368N25;
+				GENERATE_INFOPLIST_FILE = YES;
+				IPHONEOS_DEPLOYMENT_TARGET = 26.5;
+				MACOSX_DEPLOYMENT_TARGET = 26.5;
+				MARKETING_VERSION = 1.0;
+				PRODUCT_BUNDLE_IDENTIFIER = me.oschly.PeeredTests;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SDKROOT = auto;
+				STRING_CATALOG_GENERATE_SYMBOLS = NO;
+				SUPPORTED_PLATFORMS = "iphoneos iphonesimulator macosx xros xrsimulator";
+				SWIFT_APPROACHABLE_CONCURRENCY = YES;
+				SWIFT_EMIT_LOC_STRINGS = NO;
+				SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2,7";
+				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/Peered.app/$(BUNDLE_EXECUTABLE_FOLDER_PATH)/Peered";
+				XROS_DEPLOYMENT_TARGET = 26.5;
+			};
+			name = Debug;
+		};
+		47D771C72FC2141600C4C002 /* Release */ = {
+			isa = XCBuildConfiguration;
+			buildSettings = {
+				BUNDLE_LOADER = "$(TEST_HOST)";
+				CODE_SIGN_STYLE = Automatic;
+				CURRENT_PROJECT_VERSION = 1;
+				DEVELOPMENT_TEAM = LTFJ368N25;
+				GENERATE_INFOPLIST_FILE = YES;
+				IPHONEOS_DEPLOYMENT_TARGET = 26.5;
+				MACOSX_DEPLOYMENT_TARGET = 26.5;
+				MARKETING_VERSION = 1.0;
+				PRODUCT_BUNDLE_IDENTIFIER = me.oschly.PeeredTests;
+				PRODUCT_NAME = "$(TARGET_NAME)";
+				SDKROOT = auto;
+				STRING_CATALOG_GENERATE_SYMBOLS = NO;
+				SUPPORTED_PLATFORMS = "iphoneos iphonesimulator macosx xros xrsimulator";
+				SWIFT_APPROACHABLE_CONCURRENCY = YES;
+				SWIFT_EMIT_LOC_STRINGS = NO;
+				SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
+				SWIFT_VERSION = 5.0;
+				TARGETED_DEVICE_FAMILY = "1,2,7";
+				TEST_HOST = "$(BUILT_PRODUCTS_DIR)/Peered.app/$(BUNDLE_EXECUTABLE_FOLDER_PATH)/Peered";
+				XROS_DEPLOYMENT_TARGET = 26.5;
+			};
+			name = Release;
+		};
 /* End XCBuildConfiguration section */
 
 /* Begin XCConfigurationList section */
@@ -385,6 +512,15 @@
 			defaultConfigurationIsVisible = 0;
 			defaultConfigurationName = Release;
 		};
+		47D771C52FC2141600C4C002 /* Build configuration list for PBXNativeTarget "PeeredTests" */ = {
+			isa = XCConfigurationList;
+			buildConfigurations = (
+				47D771C62FC2141600C4C002 /* Debug */,
+				47D771C72FC2141600C4C002 /* Release */,
+			);
+			defaultConfigurationIsVisible = 0;
+			defaultConfigurationName = Release;
+		};
 /* End XCConfigurationList section */
 	};
 	rootObject = 479E819F2DD09F9400B82386 /* Project object */;

Implementation/Peered/AllNotesScreen.swift

@@ -8,70 +8,70 @@
 import SwiftUI
 
 struct AllNotesScreen: View {
-	@AppStorage("peered_username") private var username: String?
-	@State private var notes = [Note]()
-	@State private var notesClient: NoteEditingSessionClient?
-	@State private var ownPeer: OwnPeer?
-	
-	var isUsernameValid: Bool {
-		!(username.map(\.isEmpty) ?? true)
-	}
-	
-	var body: some View {
-		NavigationStack {
-			List {
-				Section("Your notes") {
-					ForEach(notes) { note in
-						NavigationLink(note.name) {
-							if let ownPeer {
-								NoteEditorScreen(note: note, peer: ownPeer)
-							}
-						}
-					}
-				}
-				
-				if let notesClient {
-					Section("External notes") {
-						ForEach(notesClient.invitations) { invitation in
-							NavigationLink(invitation.noteName) {
-								SharedNoteEditor(invitation: invitation, noteClient: notesClient)
-							}
-						}
-					}
-				}
-			}
-			.navigationTitle("Peered")
-			.toolbar {
-				Button("Create note") {
-					NotesStorage().createNote(name: "New Note")
-					notes = NotesStorage().loadNotes()
-				}
-			}
-		}
-		.onAppear {
-			notes = NotesStorage().loadNotes()
-			if let username, isUsernameValid {
-				setupSession(username: username)
-			}
-		}
-		.onChange(of: username) { _, newUsername in
-			guard let newUsername, isUsernameValid else { return }
-			setupSession(username: newUsername)
-		}
-		.sheet(isPresented: .constant(!isUsernameValid)) {
-			SetUserNameBottomSheetView(username: $username)
-		}
-	}
-	
-	private func setupSession(username: String) {
-		notesClient?.stopBrowsingForNotes()
-		let peer = OwnPeer(peer: .init(displayName: username))
-		ownPeer = peer
-		notesClient = .init(peer: peer.peer)
-		notesClient?.startBrowsingForNotes()
-	}
+  @AppStorage("peered_username") private var username: String?
+  @State private var notes = [Note]()
+  @State private var notesClient: NoteEditingSessionClient?
+  @State private var ownPeer: OwnPeer?
+
+  var isUsernameValid: Bool {
+    !(username.map(\.isEmpty) ?? true)
+  }
+
+  var body: some View {
+    NavigationStack {
+      List {
+        Section("Your notes") {
+          ForEach(notes) { note in
+            NavigationLink(note.name) {
+              if let ownPeer {
+                NoteEditorScreen(note: note, peer: ownPeer)
+              }
+            }
+          }
+        }
+
+        if let notesClient {
+          Section("External notes") {
+            ForEach(notesClient.invitations) { invitation in
+              NavigationLink(invitation.noteName) {
+                SharedNoteEditor(invitation: invitation, noteClient: notesClient)
+              }
+            }
+          }
+        }
+      }
+      .navigationTitle("Peered")
+      .toolbar {
+        Button("Create note") {
+          NotesStorage().createNote(name: "New Note")
+          notes = NotesStorage().loadNotes()
+        }
+      }
+    }
+    .onAppear {
+      notes = NotesStorage().loadNotes()
+      if let username, isUsernameValid {
+        setupSession(username: username)
+      }
+    }
+    .onChange(of: username) { _, newUsername in
+      guard let newUsername, isUsernameValid else { return }
+      setupSession(username: newUsername)
+    }
+    .sheet(isPresented: .constant(!isUsernameValid)) {
+      SetUserNameBottomSheetView(username: $username)
+    }
+  }
+
+  private func setupSession(username: String) {
+    notesClient?.stopBrowsingForNotes()
+    let peer = OwnPeer(peer: .init(displayName: username))
+    ownPeer = peer
+    notesClient = .init(peer: peer.peer)
+    notesClient?.startBrowsingForNotes()
+  }
 }
 
 #Preview {
-	AllNotesScreen()
+  AllNotesScreen()
 }

Implementation/Peered/NoteEditor/ManageMembersScreen.swift

@@ -7,22 +7,22 @@
 import SwiftUI
 
 struct ManageMembersScreen: View {
-	@Bindable var noteAdvertiser: NoteEditingSessionServer
-	let noteTitle: String
-	@Binding var noteContent: String
-	
-	var body: some View {
-		List(noteAdvertiser.visiblePeers) { peer in
-			HStack {
-				Text(peer.id)
-				
-				Spacer()
-				
-					PeerStateButton(peerState: peer.state) {
-						noteAdvertiser.invite(peer: peer, to: .init(title: noteTitle, noteSnapshot: noteContent))
-					}
-			}
-		}
-		.navigationTitle("Visible users")
-	}
+  @Bindable var noteAdvertiser: NoteEditingSessionServer
+  let noteTitle: String
+  @Binding var noteContent: String
+
+  var body: some View {
+    List(noteAdvertiser.visiblePeers) { peer in
+      HStack {
+        Text(peer.id)
+
+        Spacer()
+
+        PeerStateButton(peerState: peer.state) {
+          noteAdvertiser.invite(peer: peer, to: .init(title: noteTitle, noteSnapshot: noteContent))
+        }
+      }
+    }
+    .navigationTitle("Visible users")
+  }
 }

Implementation/Peered/NoteEditor/NoteEditingSessionServer.swift

@@ -1,126 +1,142 @@
-import MultipeerConnectivity
-import Foundation
 import Combine
+import Foundation
+import MultipeerConnectivity
 
 struct OwnPeer {
-	let peer: MCPeerID
+  let peer: MCPeerID
 }
 
 struct Peer: Identifiable {
-	enum ConnectionState {
-		case available
-		case joined
-		case rejected
-		case invitationPending
-	}
-	
-	var id: String { mcPeer.displayName }
-	let mcPeer: MCPeerID
-	var state: ConnectionState
+  enum ConnectionState {
+    case available
+    case joined
+    case rejected
+    case invitationPending
+  }
+
+  var id: String { mcPeer.displayName }
+  let mcPeer: MCPeerID
+  var state: ConnectionState
 }
 
 @Observable
 final class NoteEditingSessionServer: NSObject {
-	private let session: MCSession
-	private let browser: MCNearbyServiceBrowser
-	private(set) var ownPeer: OwnPeer
-	
-	var visiblePeers: [Peer] = []
-	let noteChangesEmitter = PassthroughSubject<NoteMessage, Never>()
-	
-	init(peer: OwnPeer) {
-		ownPeer = peer
-		browser = .init(peer: peer.peer, serviceType: "peered")
-		session = .init(peer: peer.peer, securityIdentity: nil, encryptionPreference: .required)
-		super.init()
-		browser.delegate = self
-		session.delegate = self
-	}
-	
-	func startServer() {
-		browser.startBrowsingForPeers()
-	}
-	
-	func stopServer() {
-		browser.stopBrowsingForPeers()
-		session.disconnect()
-	}
-	
-	func invite(peer: Peer, to note: NoteInvitation.NoteContent) {
-		guard peer.state == .available, let note = try? JSONEncoder().encode(note) else { return }
-		browser.invitePeer(
-			peer.mcPeer,
-			to: session,
-			withContext: note,
-			timeout: 600
-		)
-		guard let idxToUpdate = visiblePeers.firstIndex(where: { $0.mcPeer == peer.mcPeer }) else { return }
-		visiblePeers[idxToUpdate].state = .invitationPending
-	}
-	
-	func send(note: String, to peers: [MCPeerID]) {
-		let message = NoteMessage(senderID: ownPeer.peer.displayName, content: note)
-		guard !peers.isEmpty, let data = try? JSONEncoder().encode(message) else { return }
-		try? session.send(data, toPeers: peers, with: .reliable)
-	}
+  private let session: MCSession
+  private let browser: MCNearbyServiceBrowser
+  private(set) var ownPeer: OwnPeer
+
+  var visiblePeers: [Peer] = []
+  let noteChangesEmitter = PassthroughSubject<NoteMessage, Never>()
+
+  init(peer: OwnPeer) {
+    ownPeer = peer
+    browser = .init(peer: peer.peer, serviceType: "peered")
+    session = .init(peer: peer.peer, securityIdentity: nil, encryptionPreference: .required)
+    super.init()
+    browser.delegate = self
+    session.delegate = self
+  }
+
+  func startServer() {
+    browser.startBrowsingForPeers()
+  }
+
+  func stopServer() {
+    browser.stopBrowsingForPeers()
+    session.disconnect()
+  }
+
+  func invite(peer: Peer, to note: NoteInvitation.NoteContent) {
+    guard peer.state == .available, let note = try? JSONEncoder().encode(note) else { return }
+    browser.invitePeer(
+      peer.mcPeer,
+      to: session,
+      withContext: note,
+      timeout: 600
+    )
+    guard let idxToUpdate = visiblePeers.firstIndex(where: { $0.mcPeer == peer.mcPeer }) else {
+      return
+    }
+    visiblePeers[idxToUpdate].state = .invitationPending
+  }
+
+  func send(note: String, to peers: [MCPeerID]) {
+    let message = NoteMessage(senderID: ownPeer.peer.displayName, content: note)
+    guard !peers.isEmpty, let data = try? JSONEncoder().encode(message) else { return }
+    try? session.send(data, toPeers: peers, with: .reliable)
+  }
 }
 
 extension NoteEditingSessionServer: MCNearbyServiceBrowserDelegate {
-	func browser(
-		_ browser: MCNearbyServiceBrowser,
-		foundPeer peerID: MCPeerID,
-		withDiscoveryInfo info: [String: String]?
-	) {
-		guard !visiblePeers.contains(where: { $0.mcPeer == peerID }) && peerID.displayName != ownPeer.peer.displayName else { return }
-		DispatchQueue.main.async {
-			self.visiblePeers.append(Peer(mcPeer: peerID, state: .available))
-		}
-	}
-	
-	func browser(_ browser: MCNearbyServiceBrowser, lostPeer peerID: MCPeerID) {
-		DispatchQueue.main.async {
-			guard let peerIdx = self.visiblePeers.firstIndex(where: { $0.mcPeer == peerID }) else { return }
-			self.visiblePeers.remove(at: peerIdx)
-		}
-	}
+  func browser(
+    _ browser: MCNearbyServiceBrowser,
+    foundPeer peerID: MCPeerID,
+    withDiscoveryInfo info: [String: String]?
+  ) {
+    guard
+      !visiblePeers.contains(where: { $0.mcPeer == peerID })
+        && peerID.displayName != ownPeer.peer.displayName
+    else { return }
+    DispatchQueue.main.async {
+      self.visiblePeers.append(Peer(mcPeer: peerID, state: .available))
+    }
+  }
+
+  func browser(_ browser: MCNearbyServiceBrowser, lostPeer peerID: MCPeerID) {
+    DispatchQueue.main.async {
+      guard let peerIdx = self.visiblePeers.firstIndex(where: { $0.mcPeer == peerID }) else {
+        return
+      }
+      self.visiblePeers.remove(at: peerIdx)
+    }
+  }
 }
 
 extension NoteEditingSessionServer: MCSessionDelegate {
-	func session(
-		_ session: MCSession,
-		peer peerID: MCPeerID,
-		didChange state: MCSessionState
-	) {
-		DispatchQueue.main.async {
-			guard let idx = self.visiblePeers.firstIndex(where: { $0.mcPeer == peerID }) else { return }
-			switch state {
-			case .connected:
-				self.visiblePeers[idx].state = .joined
-			case .notConnected:
-				let currentState = self.visiblePeers[idx].state
-				if currentState == .invitationPending || currentState == .joined {
-					self.visiblePeers[idx].state = .rejected
-				}
-			default:
-				break
-			}
-		}
-	}
-	
-	func session(_ session: MCSession, didReceive data: Data, fromPeer peerID: MCPeerID) {
-		guard let message = try? JSONDecoder().decode(NoteMessage.self, from: data) else { return }
-		
-		let otherPeers = session.connectedPeers.filter { $0 != peerID }
-		if !otherPeers.isEmpty {
-			try? session.send(data, toPeers: otherPeers, with: .reliable)
-		}
-		
-		DispatchQueue.main.async {
-			self.noteChangesEmitter.send(message)
-		}
-	}
-	
-	func session(_ session: MCSession, didReceive stream: InputStream, withName streamName: String, fromPeer peerID: MCPeerID) {}
-	func session(_ session: MCSession, didStartReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, with progress: Progress) {}
-	func session(_ session: MCSession, didFinishReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, at localURL: URL?, withError error: (any Error)?) {}
+  func session(
+    _ session: MCSession,
+    peer peerID: MCPeerID,
+    didChange state: MCSessionState
+  ) {
+    DispatchQueue.main.async {
+      guard let idx = self.visiblePeers.firstIndex(where: { $0.mcPeer == peerID }) else { return }
+      switch state {
+      case .connected:
+        self.visiblePeers[idx].state = .joined
+      case .notConnected:
+        let currentState = self.visiblePeers[idx].state
+        if currentState == .invitationPending || currentState == .joined {
+          self.visiblePeers[idx].state = .rejected
+        }
+      default:
+        break
+      }
+    }
+  }
+
+  func session(_ session: MCSession, didReceive data: Data, fromPeer peerID: MCPeerID) {
+    guard let message = try? JSONDecoder().decode(NoteMessage.self, from: data) else { return }
+
+    let otherPeers = session.connectedPeers.filter { $0 != peerID }
+    if !otherPeers.isEmpty {
+      try? session.send(data, toPeers: otherPeers, with: .reliable)
+    }
+
+    DispatchQueue.main.async {
+      self.noteChangesEmitter.send(message)
+    }
+  }
+
+  func session(
+    _ session: MCSession, didReceive stream: InputStream, withName streamName: String,
+    fromPeer peerID: MCPeerID
+  ) {}
+  func session(
+    _ session: MCSession, didStartReceivingResourceWithName resourceName: String,
+    fromPeer peerID: MCPeerID, with progress: Progress
+  ) {}
+  func session(
+    _ session: MCSession, didFinishReceivingResourceWithName resourceName: String,
+    fromPeer peerID: MCPeerID, at localURL: URL?, withError error: (any Error)?
+  ) {}
 }

Implementation/Peered/NoteEditor/NoteEditorScreen.swift

@@ -5,69 +5,69 @@
 //  Created by Oskar Chybowski on 25/09/2025.
 //
 
-import SwiftUI
 import MultipeerConnectivity
+import SwiftUI
 
 struct NoteEditorScreen: View {
-	let note: Note
-	@State private var noteAdvertiser: NoteEditingSessionServer
-	@State private var noteContent: String = ""
-	@State private var remoteNoteContent: String? = nil
-	@State private var timer = Timer.publish(every: 5, on: .current, in: .common)
-		.autoconnect()
-	@State private var showManageMembers = false
+  let note: Note
+  @State private var noteAdvertiser: NoteEditingSessionServer
+  @State private var noteContent: String = ""
+  @State private var remoteNoteContent: String? = nil
+  @State private var timer = Timer.publish(every: 5, on: .current, in: .common)
+    .autoconnect()
+  @State private var showManageMembers = false
 
-	init(note: Note, peer: OwnPeer) {
-		self.note = note
-		self._noteAdvertiser = .init(initialValue: .init(peer: peer))
-	}
+  init(note: Note, peer: OwnPeer) {
+    self.note = note
+    self._noteAdvertiser = .init(initialValue: .init(peer: peer))
+  }
 
-	var body: some View {
-		NoteTextEditor(text: $noteContent, remoteText: remoteNoteContent)
-			.toolbar {
-				ToolbarItem(placement: .primaryAction) {
-					Button("Manage members") {
-						showManageMembers = true
-					}
-				}
-			}
-			.sheet(isPresented: $showManageMembers) {
-				NavigationStack {
-					ManageMembersScreen(
-						noteAdvertiser: noteAdvertiser,
-						noteTitle: note.name,
-						noteContent: $noteContent
-					)
-				}
-			}
-			.onReceive(noteAdvertiser.noteChangesEmitter) { message in
-				guard message.senderID != noteAdvertiser.ownPeer.peer.displayName else { return }
-				remoteNoteContent = message.content
-			}
-			.task(id: noteContent) {
-				if noteContent == remoteNoteContent { return }
-				let connectedPeers = noteAdvertiser.visiblePeers
-					.filter { $0.state == .joined }
-					.map(\.mcPeer)
-				guard !connectedPeers.isEmpty else { return }
-				try? await Task.sleep(nanoseconds: 500_000_000)
-				guard !Task.isCancelled else { return }
-				noteAdvertiser.send(note: noteContent, to: connectedPeers)
-			}
-			.onAppear {
-				noteContent = (try? String(contentsOf: note.path, encoding: .utf8)) ?? ""
-				noteAdvertiser.startServer()
-			}
-			.onDisappear {
-				noteAdvertiser.stopServer()
-				saveNote()
-			}
-			.onReceive(timer) { _ in
-				saveNote()
-			}
-	}
+  var body: some View {
+    NoteTextEditor(text: $noteContent, remoteText: remoteNoteContent)
+      .toolbar {
+        ToolbarItem(placement: .primaryAction) {
+          Button("Manage members") {
+            showManageMembers = true
+          }
+        }
+      }
+      .sheet(isPresented: $showManageMembers) {
+        NavigationStack {
+          ManageMembersScreen(
+            noteAdvertiser: noteAdvertiser,
+            noteTitle: note.name,
+            noteContent: $noteContent
+          )
+        }
+      }
+      .onReceive(noteAdvertiser.noteChangesEmitter) { message in
+        guard message.senderID != noteAdvertiser.ownPeer.peer.displayName else { return }
+        remoteNoteContent = message.content
+      }
+      .task(id: noteContent) {
+        if noteContent == remoteNoteContent { return }
+        let connectedPeers = noteAdvertiser.visiblePeers
+          .filter { $0.state == .joined }
+          .map(\.mcPeer)
+        guard !connectedPeers.isEmpty else { return }
+        try? await Task.sleep(nanoseconds: 500_000_000)
+        guard !Task.isCancelled else { return }
+        noteAdvertiser.send(note: noteContent, to: connectedPeers)
+      }
+      .onAppear {
+        noteContent = (try? String(contentsOf: note.path, encoding: .utf8)) ?? ""
+        noteAdvertiser.startServer()
+      }
+      .onDisappear {
+        noteAdvertiser.stopServer()
+        saveNote()
+      }
+      .onReceive(timer) { _ in
+        saveNote()
+      }
+  }
 
-	func saveNote() {
-		try? noteContent.write(to: note.path, atomically: true, encoding: .utf8)
-	}
+  func saveNote() {
+    try? noteContent.write(to: note.path, atomically: true, encoding: .utf8)
+  }
 }

Implementation/Peered/NoteEditor/NoteTextEditor.swift

@@ -1,16 +1,16 @@
 import SwiftUI
 
 struct NoteTextEditor: View {
-    @Binding var text: String
-	let remoteText: String?
-	@State private var selection: TextSelection? = nil
-	
-	var body: some View {
-		TextEditor(text: $text, selection: $selection)
-			.onChange(of: remoteText) { oldValue, newValue in
-				guard let newValue, newValue != text else { return }
-				// Apply remote text first
-				text = newValue
-			}
-	}
+  @Binding var text: String
+  let remoteText: String?
+  @State private var selection: TextSelection? = nil
+
+  var body: some View {
+    TextEditor(text: $text, selection: $selection)
+      .onChange(of: remoteText) { oldValue, newValue in
+        guard let newValue, newValue != text else { return }
+        // Apply remote text first
+        text = newValue
+      }
+  }
 }

Implementation/Peered/NoteEditor/PeerStateButton.swift

@@ -8,19 +8,19 @@
 import SwiftUI
 
 struct PeerStateButton: View {
-	let peerState: Peer.ConnectionState
-	let onTap: () -> Void
-	
-	var body: some View {
-		switch peerState {
-		case .available:
-			Button("Invite", action: onTap)
-		case .joined:
-			Text("Joined")
-		case .rejected:
-			Text("Rejected")
-		case .invitationPending:
-			Text("Invitation pending")
-		}
-	}
+  let peerState: Peer.ConnectionState
+  let onTap: () -> Void
+
+  var body: some View {
+    switch peerState {
+    case .available:
+      Button("Invite", action: onTap)
+    case .joined:
+      Text("Joined")
+    case .rejected:
+      Text("Rejected")
+    case .invitationPending:
+      Text("Invitation pending")
+    }
+  }
 }

Implementation/Peered/NoteEditor/SharedNoteEditor.swift

@@ -7,41 +7,41 @@
 import SwiftUI
 
 struct SharedNoteEditor: View {
-	@State var note: String?
-	@State var remoteNote: String? = nil
-	@State var invitation: NoteInvitation
-	@Bindable var noteClient: NoteEditingSessionClient
+  @State var note: String?
+  @State var remoteNote: String? = nil
+  @State var invitation: NoteInvitation
+  @Bindable var noteClient: NoteEditingSessionClient
 
-	init(
-		invitation: NoteInvitation,
-		noteClient: NoteEditingSessionClient
-	) {
-		self._invitation = .init(initialValue: invitation)
-		self._noteClient = .init(noteClient)
-	}
+  init(
+    invitation: NoteInvitation,
+    noteClient: NoteEditingSessionClient
+  ) {
+    self._invitation = .init(initialValue: invitation)
+    self._noteClient = .init(noteClient)
+  }
 
-	var body: some View {
-		ZStack {
-			if let note = Binding($note) {
-				NoteTextEditor(text: note, remoteText: remoteNote)
-			} else {
-				ProgressView {
-					Text("Fetching note...")
-				}
-			}
-		}
-		.onReceive(noteClient.noteChangesEmitter) { message in
-			guard message.senderID != noteClient.ownPeer.displayName else { return }
-			remoteNote = message.content
-		}
-		.task(id: note) {
-			try? await Task.sleep(nanoseconds: 500_000_000)
-			guard !Task.isCancelled, let note else { return }
-			noteClient.send(note: note, to: invitation.invitatorID)
-		}
-		.onAppear {
-			invitation.accept()
-			note = invitation.note.noteSnapshot
-		}
-	}
+  var body: some View {
+    ZStack {
+      if let note = Binding($note) {
+        NoteTextEditor(text: note, remoteText: remoteNote)
+      } else {
+        ProgressView {
+          Text("Fetching note...")
+        }
+      }
+    }
+    .onReceive(noteClient.noteChangesEmitter) { message in
+      guard message.senderID != noteClient.ownPeer.displayName else { return }
+      remoteNote = message.content
+    }
+    .task(id: note) {
+      try? await Task.sleep(nanoseconds: 500_000_000)
+      guard !Task.isCancelled, let note else { return }
+      noteClient.send(note: note, to: invitation.invitatorID)
+    }
+    .onAppear {
+      invitation.accept()
+      note = invitation.note.noteSnapshot
+    }
+  }
 }

Implementation/Peered/NotesList/Note.swift

@@ -8,8 +8,8 @@
 import Foundation
 
 struct Note: Identifiable {
-	var id: URL { path }
+  var id: URL { path }
 
-	let name: String
-	let path: URL
+  let name: String
+  let path: URL
 }

Implementation/Peered/NotesList/NoteEditingSessionClient.swift

@@ -1,131 +1,140 @@
-import MultipeerConnectivity
-import Foundation
 import Combine
+import Foundation
+import MultipeerConnectivity
 
 struct NoteInvitation: Identifiable {
-	struct NoteContent: Codable {
-		let title: String
-		let noteSnapshot: String
-	}
-	
-	var id: MCPeerID { invitatorID }
-	var noteName: String { note.title }
-	let invitatorID: MCPeerID
-	let note: NoteContent
-	private var invitationHandler: ((Bool) -> Void)?
-	
-	init(
-		invitatorID: MCPeerID,
-		note: NoteContent,
-		invitationHandler: ((Bool) -> Void)? = nil
-	) {
-		self.invitatorID = invitatorID
-		self.note = note
-		self.invitationHandler = invitationHandler
-	}
-	
-	mutating func accept() {
-		invitationHandler?(true)
-		invitationHandler = nil
-	}
-	
-	mutating func decline() {
-		invitationHandler?(false)
-		invitationHandler = nil
-	}
+  struct NoteContent: Codable {
+    let title: String
+    let noteSnapshot: String
+  }
+
+  var id: MCPeerID { invitatorID }
+  var noteName: String { note.title }
+  let invitatorID: MCPeerID
+  let note: NoteContent
+  private var invitationHandler: ((Bool) -> Void)?
+
+  init(
+    invitatorID: MCPeerID,
+    note: NoteContent,
+    invitationHandler: ((Bool) -> Void)? = nil
+  ) {
+    self.invitatorID = invitatorID
+    self.note = note
+    self.invitationHandler = invitationHandler
+  }
+
+  mutating func accept() {
+    invitationHandler?(true)
+    invitationHandler = nil
+  }
+
+  mutating func decline() {
+    invitationHandler?(false)
+    invitationHandler = nil
+  }
 }
 
 @Observable
 final class NoteEditingSessionClient: NSObject {
-	private let session: MCSession
-	private let advertiser: MCNearbyServiceAdvertiser
-	private(set) var ownPeer: MCPeerID
-	
-	var invitations: [NoteInvitation] = []
-	let noteChangesEmitter = PassthroughSubject<NoteMessage, Never>()
+  private let session: MCSession
+  private let advertiser: MCNearbyServiceAdvertiser
+  private(set) var ownPeer: MCPeerID
 
-	init(peer: MCPeerID) {
-		ownPeer = peer
-		session = MCSession(
-			peer: peer,
-			securityIdentity: nil,
-			encryptionPreference: .required
-		)
-		advertiser = MCNearbyServiceAdvertiser(
-			peer: peer,
-			discoveryInfo: [:],
-			serviceType: "peered"
-		)
-		super.init()
-		advertiser.delegate = self
-		session.delegate = self
-	}
-	
-	func startBrowsingForNotes() {
-		advertiser.startAdvertisingPeer()
-	}
-	
-	func stopBrowsingForNotes() {
-		advertiser.stopAdvertisingPeer()
-		session.disconnect()
-	}
-	
-	func send(note: String, to peer: MCPeerID) {
-		let message = NoteMessage(senderID: ownPeer.displayName, content: note)
-		guard let data = try? JSONEncoder().encode(message) else { return }
-		try? session.send(data, toPeers: [peer], with: .reliable)
-	}
+  var invitations: [NoteInvitation] = []
+  let noteChangesEmitter = PassthroughSubject<NoteMessage, Never>()
+
+  init(peer: MCPeerID) {
+    ownPeer = peer
+    session = MCSession(
+      peer: peer,
+      securityIdentity: nil,
+      encryptionPreference: .required
+    )
+    advertiser = MCNearbyServiceAdvertiser(
+      peer: peer,
+      discoveryInfo: [:],
+      serviceType: "peered"
+    )
+    super.init()
+    advertiser.delegate = self
+    session.delegate = self
+  }
+
+  func startBrowsingForNotes() {
+    advertiser.startAdvertisingPeer()
+  }
+
+  func stopBrowsingForNotes() {
+    advertiser.stopAdvertisingPeer()
+    session.disconnect()
+  }
+
+  func send(note: String, to peer: MCPeerID) {
+    let message = NoteMessage(senderID: ownPeer.displayName, content: note)
+    guard let data = try? JSONEncoder().encode(message) else { return }
+    try? session.send(data, toPeers: [peer], with: .reliable)
+  }
 }
 
 extension NoteEditingSessionClient: MCNearbyServiceAdvertiserDelegate {
-	func advertiser(
-		_ advertiser: MCNearbyServiceAdvertiser,
-		didReceiveInvitationFromPeer peerID: MCPeerID,
-		withContext context: Data?,
-		invitationHandler: @escaping (Bool, MCSession?) -> Void
-	) {
-		guard
-			let context,
-			let noteContent = try? JSONDecoder().decode(NoteInvitation.NoteContent.self, from: context)
-		else { return }
-		
-		DispatchQueue.main.async {
-			self.invitations.append(
-				.init(
-					invitatorID: peerID,
-					note: noteContent,
-					invitationHandler: { [weak self, invitationHandler] accepted in
-						guard let self else { return }
-						invitationHandler(accepted, self.session)
-						DispatchQueue.main.async {
-							self.invitations.removeAll { $0.id == peerID }
-						}
-					}
-				)
-			)
-		}
-	}
+  func advertiser(
+    _ advertiser: MCNearbyServiceAdvertiser,
+    didReceiveInvitationFromPeer peerID: MCPeerID,
+    withContext context: Data?,
+    invitationHandler: @escaping (Bool, MCSession?) -> Void
+  ) {
+    guard
+      let context,
+      let noteContent = try? JSONDecoder().decode(NoteInvitation.NoteContent.self, from: context)
+    else { return }
+
+    DispatchQueue.main.async {
+      self.invitations.append(
+        .init(
+          invitatorID: peerID,
+          note: noteContent,
+          invitationHandler: { [weak self, invitationHandler] accepted in
+            guard let self else { return }
+            invitationHandler(accepted, self.session)
+            DispatchQueue.main.async {
+              self.invitations.removeAll { $0.id == peerID }
+            }
+          }
+        )
+      )
+    }
+  }
 }
 
 extension NoteEditingSessionClient: MCSessionDelegate {
-	func session(
-		_ session: MCSession,
-		peer peerID: MCPeerID,
-		didChange state: MCSessionState
-	) {}
-	
-	func session(
-		_ session: MCSession,
-		didReceive data: Data,
-		fromPeer peerID: MCPeerID
-	) {
-		guard let message = try? JSONDecoder().decode(NoteMessage.self, from: data) else { return }
-		DispatchQueue.main.async {
-			self.noteChangesEmitter.send(message)
-		}
-	}
-	
-	func session(_ session: MCSession, didReceive stream: InputStream, withName streamName: String, fromPeer peerID: MCPeerID) {}
-	func session(_ session: MCSession, didStartReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, with progress: Progress) {}
-	func session(_ session: MCSession, didFinishReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, at localURL: URL?, withError error: (any Error)?) {}
+  func session(
+    _ session: MCSession,
+    peer peerID: MCPeerID,
+    didChange state: MCSessionState
+  ) {}
+
+  func session(
+    _ session: MCSession,
+    didReceive data: Data,
+    fromPeer peerID: MCPeerID
+  ) {
+    guard let message = try? JSONDecoder().decode(NoteMessage.self, from: data) else { return }
+    DispatchQueue.main.async {
+      self.noteChangesEmitter.send(message)
+    }
+  }
+
+  func session(
+    _ session: MCSession, didReceive stream: InputStream, withName streamName: String,
+    fromPeer peerID: MCPeerID
+  ) {}
+  func session(
+    _ session: MCSession, didStartReceivingResourceWithName resourceName: String,
+    fromPeer peerID: MCPeerID, with progress: Progress
+  ) {}
+  func session(
+    _ session: MCSession, didFinishReceivingResourceWithName resourceName: String,
+    fromPeer peerID: MCPeerID, at localURL: URL?, withError error: (any Error)?
+  ) {}
 }

Implementation/Peered/NotesList/NoteInvitationView.swift

@@ -1,14 +1,14 @@
 import SwiftUI
 
 struct NoteInvitationView: View {
-	@Binding var invitation: NoteInvitation
-	let joinTapped: () -> Void
-	
-	var body: some View {
-		HStack {
-			Text(invitation.noteName)
-			Spacer()
-			Button("Join", action: joinTapped)
-		}
-	}
+  @Binding var invitation: NoteInvitation
+  let joinTapped: () -> Void
+
+  var body: some View {
+    HStack {
+      Text(invitation.noteName)
+      Spacer()
+      Button("Join", action: joinTapped)
+    }
+  }
 }

Implementation/Peered/NotesList/NoteMessage.swift

@@ -1,4 +1,4 @@
 struct NoteMessage: Codable {
-	let senderID: String
-	let content: String
+  let senderID: String
+  let content: String
 }

Implementation/Peered/NotesList/NotesStorage.swift

@@ -7,48 +7,77 @@
 
 import Foundation
 
-struct NotesStorage {
-	let storageProvider: FileManager = FileManager.default
-	
-	func loadNotes() -> [Note] {
-		let files = try! storageProvider
-			.contentsOfDirectory(atPath: URL.documentsDirectory.path)
-		var notes = [Note]()
-		
-		for file in files.compactMap({
-			URL(
-				filePath: $0,
-				directoryHint: .notDirectory,
-				relativeTo: URL.documentsDirectory
-			)
-		}) {
-			let name = file.lastPathComponent
-			let note = Note(
-				name: name,
-				path: file
-			)
-			
-			notes.append(note)
-		}
-		
-		return notes
-	}
-	
-	func createNote(name: String) {
-		let currentNotes = loadNotes()
-		var index: Int? = nil
-		var proposedName: String {
-			index.map { name + " \($0)" } ?? name
-		}
-		
-		while currentNotes.contains(where: { $0.name == proposedName }) {
-			if let _index = index {
-				index = _index + 1
-			} else {
-				index = 1
-			}
-		}
-		let pathToWrite = URL.documentsDirectory.appendingPathComponent(proposedName).appendingPathExtension(for: .text)
-		try! String().write(to: pathToWrite, atomically: true, encoding: .utf8)
-	}
+protocol StorageProvider {
+  func contentsOfDirectory(atPath path: String) throws -> [String]
+
+  @discardableResult
+  func createFile(
+    atPath path: String, contents data: Data?, attributes attr: [FileAttributeKey: Any]?
+  ) -> Bool
+}
+
+extension FileManager: StorageProvider {}
+
+struct NotesStorage {
+  let storageProvider: StorageProvider
+  let rootDirectory: URL
+
+  init(
+    storageProvider: StorageProvider = FileManager.default,
+    rootDirectory: URL = .documentsDirectory
+  ) {
+    self.storageProvider = storageProvider
+    self.rootDirectory = rootDirectory
+  }
+
+  func loadNotes() -> [Note] {
+    let files =
+      try! storageProvider
+      .contentsOfDirectory(atPath: rootDirectory.path)
+    var notes = [Note]()
+
+    for file in files.compactMap({
+      URL(
+        filePath: $0,
+        directoryHint: .notDirectory,
+        relativeTo: rootDirectory
+      )
+    }) {
+      let name = file.lastPathComponent
+      let note = Note(
+        name: name,
+        path: file
+      )
+      notes.append(note)
+    }
+
+    return notes
+  }
+
+  func createNote(name: String) {
+    let currentNotes = loadNotes()
+    var index: Int? = nil
+    var proposedName: String {
+      index.map { name + " \($0)" } ?? name
+    }
+
+    while currentNotes.contains(where: { $0.name == proposedName }) {
+      if let _index = index {
+        index = _index + 1
+      } else {
+        index = 1
+      }
+    }
+
+    let pathToWrite =
+      rootDirectory
+      .appendingPathComponent(proposedName)
+      .appendingPathExtension(for: .text)
+
+    storageProvider.createFile(
+      atPath: pathToWrite.path,
+      contents: Data(),
+      attributes: nil
+    )
+  }
 }

Implementation/PeeredTests/Helpers/InMemoryStorageProvider.swift

@@ -0,0 +1,27 @@
+import Foundation
+
+@testable import Peered
+
+final class InMemoryStorageProvider: StorageProvider {
+  private(set) var files: [String: Data] = [:]
+
+  func contentsOfDirectory(atPath path: String) throws -> [String] {
+    return files.keys.compactMap { filePath -> String? in
+      guard filePath.hasPrefix(path) else { return nil }
+      let remainder = String(filePath.dropFirst(path.count))
+      let stripped = remainder.hasPrefix("/") ? String(remainder.dropFirst()) : remainder
+      guard !stripped.isEmpty, !stripped.contains("/") else { return nil }
+      return stripped
+    }
+  }
+
+  @discardableResult
+  func createFile(
+    atPath path: String,
+    contents data: Data?,
+    attributes attr: [FileAttributeKey: Any]?
+  ) -> Bool {
+    files[path] = data ?? Data()
+    return true
+  }
+}

Implementation/PeeredTests/NoteContentCodableTests.swift

@@ -0,0 +1,28 @@
+import Foundation
+import Testing
+
+@testable import Peered
+
+@Suite
+struct NoteContentCodableTests {
+  @Test("encode → decode")
+  func coding() throws {
+    let original = NoteInvitation.NoteContent(
+      title: "My note", noteSnapshot: "Note Sample Snapshot")
+    let data = try JSONEncoder().encode(original)
+    let decoded = try JSONDecoder().decode(NoteInvitation.NoteContent.self, from: data)
+
+    #expect(decoded.title == original.title)
+    #expect(decoded.noteSnapshot == original.noteSnapshot)
+  }
+
+  @Test
+  func containsExpectedKeys() throws {
+    let content = NoteInvitation.NoteContent(title: "Titlee", noteSnapshot: "Snapshott")
+    let data = try JSONEncoder().encode(content)
+    let json = try #require(try? JSONSerialization.jsonObject(with: data) as? [String: String])
+
+    #expect(json["title"] == "Titlee")
+    #expect(json["noteSnapshot"] == "Snapshott")
+  }
+}

Implementation/PeeredTests/NoteInvitationTests.swift

@@ -0,0 +1,88 @@
+import MultipeerConnectivity
+import Testing
+
+@testable import Peered
+
+extension NoteInvitation {
+  fileprivate init(handler: @escaping (Bool) -> Void) {
+    self.init(
+      invitatorID: .init(
+        displayName: "host"
+      ),
+      note: .init(title: "Shared note", noteSnapshot: "Snapshot"),
+      invitationHandler: handler
+    )
+  }
+}
+
+@Suite
+struct NoteInvitationTests {
+  @Test
+  func acceptCallsHandlerWithTrue() {
+    var received: Bool? = nil
+    var invitation = NoteInvitation { received = $0 }
+
+    invitation.accept()
+
+    #expect(received == true)
+  }
+
+  @Test
+  func declineCallsHandlerWithFalse() {
+    var received: Bool? = nil
+    var invitation = NoteInvitation { received = $0 }
+
+    invitation.decline()
+
+    #expect(received == false)
+  }
+
+  @Test
+  func acceptIsIdempotent() {
+    var callCount = 0
+    var invitation = NoteInvitation { _ in callCount += 1 }
+
+    invitation.accept()
+    invitation.accept()
+
+    #expect(callCount == 1)
+  }
+
+  @Test
+  func declineIsIdempotent() {
+    var callCount = 0
+    var invitation = NoteInvitation { _ in callCount += 1 }
+
+    invitation.decline()
+    invitation.decline()
+
+    #expect(callCount == 1)
+  }
+
+  @Test
+  func declineAfterAcceptIsNoOp() {
+    var callCount = 0
+    var invitation = NoteInvitation { _ in callCount += 1 }
+
+    invitation.accept()
+    invitation.decline()
+
+    #expect(callCount == 1)
+  }
+
+  @Test
+  func noteNameReturnsTitle() {
+    let invitation = NoteInvitation { _ in }
+    #expect(invitation.noteName == "Shared note")
+  }
+
+  @Test
+  func idIsInvitatorPeerID() {
+    let peerID = MCPeerID(displayName: "host")
+    let invitation = NoteInvitation(
+      invitatorID: peerID,
+      note: .init(title: "T", noteSnapshot: "S")
+    )
+    #expect(invitation.id == peerID)
+  }
+}

Implementation/PeeredTests/NoteMessageCodableTests.swift

@@ -0,0 +1,37 @@
+import Foundation
+import Testing
+
+@testable import Peered
+
+@Suite
+struct NoteMessageCodableTests {
+  @Test
+  func encodesToJSON() throws {
+    let message = NoteMessage(senderID: "host", content: "Content")
+    let data = try JSONEncoder().encode(message)
+    let json = try #require(try? JSONSerialization.jsonObject(with: data) as? [String: String])
+
+    #expect(json["senderID"] == "host")
+    #expect(json["content"] == "Content")
+  }
+
+  @Test
+  func decodesFromJSON() throws {
+    let json = #"{"senderID":"host","content":"contentt"}"#
+    let data = try #require(json.data(using: .utf8))
+    let message = try JSONDecoder().decode(NoteMessage.self, from: data)
+
+    #expect(message.senderID == "host")
+    #expect(message.content == "contentt")
+  }
+
+  @Test("encode → decode")
+  func coding() throws {
+    let original = NoteMessage(senderID: "host", content: "coding test")
+    let data = try JSONEncoder().encode(original)
+    let decoded = try JSONDecoder().decode(NoteMessage.self, from: data)
+
+    #expect(decoded.senderID == original.senderID)
+    #expect(decoded.content == original.content)
+  }
+}

Implementation/PeeredTests/NotesStorageTests.swift

@@ -0,0 +1,74 @@
+import Foundation
+import Testing
+
+@testable import Peered
+
+@Suite
+struct NotesStorageTests {
+  private func makeStorage(root: URL = URL(filePath: "/test")) -> (
+    NotesStorage, InMemoryStorageProvider
+  ) {
+    let provider = InMemoryStorageProvider()
+    let storage = NotesStorage(storageProvider: provider, rootDirectory: root)
+    return (storage, provider)
+  }
+
+  @Test
+  func loadNotesReturnsEmptyArrayWhenNoFiles() {
+    let (storage, _) = makeStorage()
+    let notes = storage.loadNotes()
+    #expect(notes.isEmpty)
+  }
+
+  @Test
+  func createNoteCreatesFile() {
+    let root = URL(filePath: "/test")
+    let (storage, provider) = makeStorage(root: root)
+
+    storage.createNote(name: "My note")
+
+    #expect(!provider.files.isEmpty)
+  }
+
+  @Test
+  func loadNotesReturnCreatedNote() {
+    let root = URL(filePath: "/test")
+    let (storage, provider) = makeStorage(root: root)
+
+    let filePath = root.appendingPathComponent("Note").path
+    provider.createFile(atPath: filePath, contents: Data(), attributes: nil)
+
+    let notes = storage.loadNotes()
+
+    #expect(notes.count == 1)
+    #expect(notes.first?.name == "Note")
+  }
+
+  @Test
+  func createNoteDeduplicatesNames() {
+    let root = URL(filePath: "/test")
+    let (storage, provider) = makeStorage(root: root)
+
+    let existingPath = root.appendingPathComponent("Note").path
+    provider.createFile(atPath: existingPath, contents: Data(), attributes: nil)
+
+    storage.createNote(name: "Note")
+
+    #expect(provider.files.count == 2)
+
+    let paths = provider.files.keys
+    #expect(paths.contains(where: { $0.contains("Note 1") }))
+  }
+
+  @Test
+  func createNoteTwiceCreatesTwoFiles() {
+    let root = URL(filePath: "/test")
+    let (storage, _) = makeStorage(root: root)
+
+    storage.createNote(name: "Note")
+    storage.createNote(name: "Note")
+
+    let notes = storage.loadNotes()
+    #expect(notes.count == 2)
+  }
+}