Commit `872583eca8`

872583eca8b4e7ae6ef85917604d4a5257b9d125

parent: d3af0e7d51

Unsigned

cmc <hello@cleberg.net> · 2026-07-23 02:43 UTC

fix: adopt Swift 6 language mode; resolve all concurrency issues (#27)

All three product targets (app, widget, share extension) now build under
SWIFT_VERSION = 6.0 with zero errors and zero warnings. The UITests
target stays on 5.0: XCTestCase's nonisolated setUp/init overrides
conflict with the target's MainActor default isolation under 6, and test
tooling is not shipping code.

The original seven diagnostics, plus the layers Swift 6 mode surfaced
once those cleared:

- SMTPChannel is an actor. It was implicitly MainActor while running its
  receive loop on a background queue, so parsedLines/lineWaiters/
  receiveBuffer were declared main-actor-protected and mutated off it —
  concurrent mutation while resuming a CheckedContinuation can
  double-resume, which traps. The actor serialises all state; Network
  callbacks hop in via Task. The start() continuation also gains an
  OSAllocatedUnfairLock resume-once guard: the state handler can fire
  .ready and later .failed, and resuming twice was a pre-existing trap of
  the same family.
- CachedLookupResult is nonisolated (a value pair built inside actor
  LookupRuntime cannot have a MainActor-bound memberwise init) with
  conditional Sendable — opting out of MainActor isolation also opted out
  of the implicit Sendable that globally-isolated types get.
- PortScanService.printableBanner is nonisolated: a pure transformation
  called from the connection's queue.
- SweepActivityController stores the activity's Sendable id instead of
  the non-Sendable Activity, re-resolving via Activity.activities inside
  each fire-and-forget task, so nothing non-Sendable crosses isolation.
- App Intents' static title/description/openAppWhenRun become lets
  (get-only protocol requirements; static var is shared mutable global
  state), and the summary helpers are @MainActor to match the model
  properties they read and the perform() implementations that call them.
- ExternalDataService's ISO8601DateFormatter is nonisolated(unsafe),
  citing Apple's documented thread-safety, rather than risking a parser
  behaviour change by switching APIs with no test coverage.
- TaskMetricsDelegate.metrics is nonisolated(unsafe): written on the
  session's delegate queue, read only after the request completes, and
  URLSession guarantees didFinishCollecting precedes task completion.
- The share extension extracts the host via async/withCheckedContinuation
  instead of sending a non-Sendable completion into loadItem's @Sendable
  handler; Task inherits the view controller's MainActor so the manual
  DispatchQueue.main hop goes too.

Validated: clean Swift 6 build of all product targets, and the full
enforced 11-test audit suite green on the floor runtime — Swift 6's
runtime isolation checks ran the app through every screen without a
trap.

Layout: unified · split

DomainDig.xcodeproj/project.pbxproj +6 −6

		@@ -591,7 +591,7 @@
591	591	SWIFT_DEFAULT_ACTOR_ISOLATION = MainActor;
592	592	SWIFT_EMIT_LOC_STRINGS = YES;
593	593	SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
594		SWIFT_VERSION = 5.0;
	594	SWIFT_VERSION = 6.0;
595	595	TARGETED_DEVICE_FAMILY = "1,2";
596	596	};
597	597	name = Debug;
		@@ -628,7 +628,7 @@
628	628	SWIFT_DEFAULT_ACTOR_ISOLATION = MainActor;
629	629	SWIFT_EMIT_LOC_STRINGS = YES;
630	630	SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
631		SWIFT_VERSION = 5.0;
	631	SWIFT_VERSION = 6.0;
632	632	TARGETED_DEVICE_FAMILY = "1,2";
633	633	};
634	634	name = Release;
		@@ -657,7 +657,7 @@
657	657	SWIFT_APPROACHABLE_CONCURRENCY = YES;
658	658	SWIFT_EMIT_LOC_STRINGS = YES;
659	659	SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
660		SWIFT_VERSION = 5.0;
	660	SWIFT_VERSION = 6.0;
661	661	TARGETED_DEVICE_FAMILY = "1,2";
662	662	};
663	663	name = Debug;
		@@ -686,7 +686,7 @@
686	686	SWIFT_APPROACHABLE_CONCURRENCY = YES;
687	687	SWIFT_EMIT_LOC_STRINGS = YES;
688	688	SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
689		SWIFT_VERSION = 5.0;
	689	SWIFT_VERSION = 6.0;
690	690	TARGETED_DEVICE_FAMILY = "1,2";
691	691	};
692	692	name = Release;
		@@ -715,7 +715,7 @@
715	715	SWIFT_APPROACHABLE_CONCURRENCY = YES;
716	716	SWIFT_EMIT_LOC_STRINGS = YES;
717	717	SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
718		SWIFT_VERSION = 5.0;
	718	SWIFT_VERSION = 6.0;
719	719	TARGETED_DEVICE_FAMILY = "1,2";
720	720	};
721	721	name = Debug;
		@@ -744,7 +744,7 @@
744	744	SWIFT_APPROACHABLE_CONCURRENCY = YES;
745	745	SWIFT_EMIT_LOC_STRINGS = YES;
746	746	SWIFT_UPCOMING_FEATURE_MEMBER_IMPORT_VISIBILITY = YES;
747		SWIFT_VERSION = 5.0;
	747	SWIFT_VERSION = 6.0;
748	748	TARGETED_DEVICE_FAMILY = "1,2";
749	749	};
750	750	name = Release;

DomainDig/DomainDigIntents.swift +11 −9

		@@ -6,13 +6,13 @@ import Foundation
6	6	/// `DomainReportBuilder`) and returns a concise summary. Usable from
7	7	/// Shortcuts, Spotlight, the Action button, and Siri.
8	8	struct InspectDomainIntent: AppIntent {
9		static var title: LocalizedStringResource = "Inspect Domain"
10		static var description = IntentDescription(
	9	static let title: LocalizedStringResource = "Inspect Domain"
	10	static let description = IntentDescription(
11	11	"Run a DomainDig inspection and return a summary of availability, risk, TLS, email security, and certificate health."
12	12	)
13	13
14	14	// Read-only inspection; no need to foreground the app.
15		static var openAppWhenRun = false
	15	static let openAppWhenRun = false
16	16
17	17	@Parameter(
18	18	title: "Domain",
		@@ -44,6 +44,7 @@ struct InspectDomainIntent: AppIntent {
44	44	}
45	45
46	46	/// Multi-line summary suitable for a returned Shortcuts text value.
	47	@MainActor
47	48	static func summaryText(for report: DomainReport) -> String {
48	49	let dnssec: String
49	50	switch report.dns.dnssecSigned {
		@@ -68,6 +69,7 @@ struct InspectDomainIntent: AppIntent {
68	69	}
69	70
70	71	/// Short spoken/dialog line for Siri and the Shortcuts result banner.
	72	@MainActor
71	73	static func spokenSummary(for report: DomainReport) -> String {
72	74	"\(report.domain) is \(report.availability.rawValue). Risk \(report.riskAssessment.level.title.lowercased()), health \(report.health.title.lowercased())."
73	75	}
		@@ -89,12 +91,12 @@ enum InspectDomainError: Error, CustomLocalizedStringResourceConvertible {
89	91	/// existing view-model path (premium limits, monitoring, history linking,
90	92	/// cloud-sync recording, and the paywall when over the free limit).
91	93	struct AddToWatchlistIntent: AppIntent {
92		static var title: LocalizedStringResource = "Add Domain to Watchlist"
93		static var description = IntentDescription(
	94	static let title: LocalizedStringResource = "Add Domain to Watchlist"
	95	static let description = IntentDescription(
94	96	"Open DomainDig and add a domain to your watchlist."
95	97	)
96	98
97		static var openAppWhenRun = true
	99	static let openAppWhenRun = true
98	100
99	101	@Parameter(
100	102	title: "Domain",
		@@ -128,12 +130,12 @@ struct AddToWatchlistIntent: AppIntent {
128	130	/// through the existing view-model batch path (`refreshAllTrackedDomains`), which
129	131	/// enforces the batch feature gate and surfaces the paywall when needed.
130	132	struct RunSweepIntent: AppIntent {
131		static var title: LocalizedStringResource = "Run Watchlist Sweep"
132		static var description = IntentDescription(
	133	static let title: LocalizedStringResource = "Run Watchlist Sweep"
	134	static let description = IntentDescription(
133	135	"Open DomainDig and re-inspect every domain on your watchlist."
134	136	)
135	137
136		static var openAppWhenRun = true
	138	static let openAppWhenRun = true
137	139
138	140	@MainActor
139	141	func perform() async throws -> some IntentResult {

DomainDig/ExternalDataService.swift +4 −1

		@@ -738,7 +738,10 @@ actor ExternalDataService {
738	738	}
739	739	}
740	740
741		private static let iso8601DateFormatter: ISO8601DateFormatter = {
	741	// ISO8601DateFormatter is documented thread-safe ("ISO8601DateFormatter is
	742	// thread-safe" — Apple docs), so sharing one instance across contexts is
	743	// sound; the annotation records that the compiler cannot see it. (#27)
	744	private nonisolated(unsafe) static let iso8601DateFormatter: ISO8601DateFormatter = {
742	745	let formatter = ISO8601DateFormatter()
743	746	formatter.formatOptions = [.withInternetDateTime, .withFractionalSeconds]
744	747	return formatter

DomainDig/HTTPHeadersService.swift +4 −1

		@@ -103,7 +103,10 @@ struct HTTPHeadersService {
103	103	}
104	104
105	105	private final class TaskMetricsDelegate: NSObject, URLSessionTaskDelegate {
106		private(set) var metrics: URLSessionTaskMetrics?
	106	// Written from the session's delegate queue, read only after the request
	107	// has completed — URLSession guarantees didFinishCollecting is delivered
	108	// before the task finishes, so the accesses are sequenced. (#27)
	109	nonisolated(unsafe) private(set) var metrics: URLSessionTaskMetrics?
107	110
108	111	func urlSession(
109	112	_ _: URLSession,

DomainDig/IntegrationService.swift +49 −25

		@@ -1,5 +1,6 @@
1	1	import Foundation
2	2	import Network
	3	import os
3	4	import Observation
4	5	import Security
5	6
		@@ -749,11 +750,17 @@ private enum SMTPClient {
749	750	try await channel.sendRaw(body + "\r\n.\r\n")
750	751	_ = try await channel.readResponse(expecting: [250])
751	752	_ = try await channel.sendCommand("QUIT", expecting: [221])
752		channel.cancel()
	753	await channel.cancel()
753	754	}
754	755	}
755	756
756		private final class SMTPChannel {
	757	/// An actor, not a MainActor class. The previous shape inherited the project's
	758	/// MainActor default while running its receive loop on a background dispatch
	759	/// queue, so `parsedLines`/`lineWaiters`/`receiveBuffer` were declared
	760	/// main-actor-protected and mutated off it — concurrent mutation while resuming
	761	/// a `CheckedContinuation` can double-resume, which traps. The actor serialises
	762	/// all of it and forces the Network callbacks to hop in explicitly. (Issue #27.)
	763	private actor SMTPChannel {
757	764	private let connection: NWConnection
758	765	private var parsedLines: [String] = []
759	766	private var lineWaiters: [CheckedContinuation<String, Error>] = []
		@@ -765,25 +772,35 @@ private final class SMTPChannel {
765	772
766	773	func start() async throws {
767	774	try await withCheckedThrowingContinuation { (continuation: CheckedContinuation<Void, Error>) in
768		connection.stateUpdateHandler = { [weak self] state in
	775	// The state handler can fire `.ready` and later `.failed` (or
	776	// `.failed` twice); resuming a continuation twice traps. The lock
	777	// also keeps the closure Sendable-clean without touching actor state
	778	// from the connection's queue.
	779	let hasResumed = OSAllocatedUnfairLock(initialState: false)
	780	connection.stateUpdateHandler = { state in
	781	let isFirst: () -> Bool = {
	782	hasResumed.withLock { resumed in
	783	if resumed { return false }
	784	resumed = true
	785	return true
	786	}
	787	}
769	788	switch state {
770	789	case .ready:
771		self?.scheduleReceiveLoop()
772		continuation.resume()
	790	if isFirst() { continuation.resume() }
773	791	case .failed(let error):
774		continuation.resume(throwing: error)
	792	if isFirst() { continuation.resume(throwing: error) }
	793	case .cancelled:
	794	if isFirst() { continuation.resume(throwing: IntegrationError.streamClosed) }
775	795	default:
776	796	break
777	797	}
778	798	}
779	799	connection.start(queue: .global(qos: .utility))
780	800	}
781		}
782
783		private func scheduleReceiveLoop() {
784		DispatchQueue.global(qos: .utility).async { [weak self] in
785		self?.startReceiveLoop()
786		}
	801	// Started from the actor once the connection is ready, replacing the old
	802	// dispatch-queue hop. TCP buffers anything that arrives in the gap.
	803	startReceiveLoop()
787	804	}
788	805
789	806	func cancel() {
		@@ -845,26 +862,33 @@ private final class SMTPChannel {
845	862	}
846	863
847	864	private func startReceiveLoop() {
	865	// The completion runs on the connection's queue; hop back onto the
	866	// actor before touching any state.
848	867	connection.receive(minimumIncompleteLength: 1, maximumLength: 4096) { [weak self] data, _, isComplete, error in
849	868	guard let self else { return }
850
851		if let error {
852		self.failWaiters(with: error)
853		return
	869	Task {
	870	await self.handleReceive(data: data, isComplete: isComplete, error: error)
854	871	}
	872	}
	873	}
855	874
856		if let data, !data.isEmpty {
857		self.receiveBuffer.append(data)
858		self.flushBuffer()
859		}
	875	private func handleReceive(data: Data?, isComplete: Bool, error: Error?) {
	876	if let error {
	877	failWaiters(with: error)
	878	return
	879	}
860	880
861		if isComplete {
862		self.failWaiters(with: IntegrationError.streamClosed)
863		return
864		}
	881	if let data, !data.isEmpty {
	882	receiveBuffer.append(data)
	883	flushBuffer()
	884	}
865	885
866		self.startReceiveLoop()
	886	if isComplete {
	887	failWaiters(with: IntegrationError.streamClosed)
	888	return
867	889	}
	890
	891	startReceiveLoop()
868	892	}
869	893
870	894	private func flushBuffer() {

DomainDig/LookupRuntime.swift +9 −1

		@@ -1,10 +1,18 @@
1	1	import Foundation
2	2
3		struct CachedLookupResult<Value> {
	3	/// Opted out of the project's MainActor default isolation: this is a plain
	4	/// value pair constructed inside `actor LookupRuntime`, and a MainActor-bound
	5	/// memberwise init cannot be called from there under Swift 6.
	6	nonisolated struct CachedLookupResult<Value> {
4	7	let value: Value
5	8	let source: LookupResultSource
6	9	}
7	10
	11	/// Opting out of MainActor isolation also opted out of the implicit
	12	/// Sendable that globally-isolated types get, which is what lets this cross
	13	/// from `actor LookupRuntime` back to its callers.
	14	extension CachedLookupResult: Sendable where Value: Sendable {}
	15
8	16	actor LookupRuntime {
9	17	static let shared = LookupRuntime()
10	18

DomainDig/PortScanService.swift +4 −1

		@@ -106,7 +106,10 @@ struct PortScanService {
106	106	}
107	107	}
108	108
109		private static func printableBanner(from data: Data?, error: Error?) -> String? {
	109	/// Pure data transformation, called from the connection's background queue —
	110	/// `nonisolated` opts it out of the project's MainActor default, which would
	111	/// otherwise make this call a data-race diagnostic under Swift 6.
	112	private nonisolated static func printableBanner(from data: Data?, error: Error?) -> String? {
110	113	guard error == nil,
111	114	let data,
112	115	!data.isEmpty,

DomainDig/SweepActivityController.swift +27 −12

		@@ -2,11 +2,18 @@ import ActivityKit
2	2	import Foundation
3	3
4	4	/// Starts, updates, and ends the sweep Live Activity around a batch run.
	5	///
	6	/// Holds the activity's `id` (a Sendable `String`) rather than the
	7	/// `Activity` object itself. `Activity` is not Sendable, and sending the
	8	/// stored reference into the fire-and-forget update task while `self` still
	9	/// held it was a Swift 6 region-isolation violation (issue #27). Each task
	10	/// re-resolves the activity via `Activity.activities`, ActivityKit's
	11	/// sanctioned lookup, so nothing non-Sendable crosses an isolation boundary.
5	12	@MainActor
6	13	final class SweepActivityController {
7	14	static let shared = SweepActivityController()
8	15
9		private var activity: Activity<SweepActivityAttributes>?
	16	private var activityID: String?
10	17
11	18	private init() { /* Singleton; use the shared instance. */ }
12	19
		@@ -23,14 +30,15 @@ final class SweepActivityController {
23	30	changed: 0,
24	31	warnings: 0
25	32	)
26		activity = try? Activity.request(
	33	let activity = try? Activity.request(
27	34	attributes: SweepActivityAttributes(title: title, startedAt: Date()),
28	35	content: ActivityContent(state: state, staleDate: nil)
29	36	)
	37	activityID = activity?.id
30	38	}
31	39
32	40	func update(completed: Int, total: Int, currentDomain: String?) {
33		guard let activity else { return }
	41	guard let activityID else { return }
34	42	let state = SweepActivityAttributes.ContentState(
35	43	completed: completed,
36	44	total: total,
		@@ -39,25 +47,32 @@ final class SweepActivityController {
39	47	warnings: 0
40	48	)
41	49	Task {
	50	guard let activity = Self.activity(withID: activityID) else { return }
42	51	await activity.update(ActivityContent(state: state, staleDate: nil))
43	52	}
44	53	}
45	54
46	55	func end(changed: Int, warnings: Int, immediately: Bool = false) {
47		guard let activity else { return }
48		self.activity = nil
49		let state = SweepActivityAttributes.ContentState(
50		completed: activity.content.state.total,
51		total: activity.content.state.total,
52		currentDomain: nil,
53		changed: changed,
54		warnings: warnings
55		)
	56	guard let activityID else { return }
	57	self.activityID = nil
56	58	Task {
	59	guard let activity = Self.activity(withID: activityID) else { return }
	60	let total = activity.content.state.total
	61	let state = SweepActivityAttributes.ContentState(
	62	completed: total,
	63	total: total,
	64	currentDomain: nil,
	65	changed: changed,
	66	warnings: warnings
	67	)
57	68	await activity.end(
58	69	ActivityContent(state: state, staleDate: nil),
59	70	dismissalPolicy: immediately ? .immediate : .after(Date().addingTimeInterval(60))
60	71	)
61	72	}
62	73	}
	74
	75	private nonisolated static func activity(withID id: String) -> Activity<SweepActivityAttributes>? {
	76	Activity<SweepActivityAttributes>.activities.first { $0.id == id }
	77	}
63	78	}

DomainDigShareExtension/ShareViewController.swift +15 −11

		@@ -24,14 +24,17 @@ final class ShareViewController: UIViewController {
24	24	label.trailingAnchor.constraint(lessThanOrEqualTo: view.trailingAnchor, constant: -24)
25	25	])
26	26
27		extractSharedDomain { [weak self] domain in
28		DispatchQueue.main.async {
29		self?.finish(domain: domain)
30		}
	27	// Task inherits this view controller's MainActor context, so finish()
	28	// lands back on main without a manual dispatch. The continuation form
	29	// also avoids sending a non-Sendable completion into loadItem's
	30	// @Sendable handler. (#27)
	31	Task { [weak self] in
	32	let domain = await self?.extractSharedDomain()
	33	self?.finish(domain: domain ?? nil)
31	34	}
32	35	}
33	36
34		private func extractSharedDomain(completion: @escaping (String?) -> Void) {
	37	private func extractSharedDomain() async -> String? {
35	38	let providers = (extensionContext?.inputItems ?? [])
36	39	.compactMap { $0 as? NSExtensionItem }
37	40	.flatMap { $0.attachments ?? [] }
		@@ -39,14 +42,15 @@ final class ShareViewController: UIViewController {
39	42	guard let provider = providers.first(where: {
40	43	$0.hasItemConformingToTypeIdentifier(UTType.url.identifier)
41	44	}) else {
42		completion(nil)
43		return
	45	return nil
44	46	}
45	47
46		provider.loadItem(forTypeIdentifier: UTType.url.identifier) { item, _ in
47		let url = item as? URL ?? (item as? Data).flatMap { URL(dataRepresentation: $0, relativeTo: nil) }
48		let host = url?.host?.trimmingCharacters(in: .whitespacesAndNewlines)
49		completion(host?.isEmpty == false ? host : nil)
	48	return await withCheckedContinuation { continuation in
	49	provider.loadItem(forTypeIdentifier: UTType.url.identifier) { item, _ in
	50	let url = item as? URL ?? (item as? Data).flatMap { URL(dataRepresentation: $0, relativeTo: nil) }
	51	let host = url?.host?.trimmingCharacters(in: .whitespacesAndNewlines)
	52	continuation.resume(returning: host?.isEmpty == false ? host : nil)
	53	}
50	54	}
51	55	}
52	56

Commit 872583eca8

Commit `872583eca8`