Courier: deposit in parallel when the only route is a send queue (#1368)

* Deposit with couriers in parallel when the only route is a send queue The courier path was nearly unreachable: NostrTransport claims any favorite with a known npub as "reachable" regardless of connectivity, and the mesh favorite exchange shares npubs, so for essentially every courier-eligible recipient the router picked Nostr's reachable branch. With no internet the message just sat in the relay send queue — in the flagship scenario (internet shutdown, mutual friend standing right there) the courier walked away carrying nothing. Add Transport.canDeliverPromptly(to:), defaulting to reachability for radio-backed transports; NostrTransport answers honestly by mirroring the relay manager's connection state (fail-closed behind Tor). When the chosen transport can't hand the message off promptly, the router now also deposits a sealed copy with connected couriers. Double delivery is harmless: receivers dedup by message ID, and delivered/read acks never downgrade the carried status. When relays are up, sends are trusted and no courier quota is spent. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> * Track DM-relay connectivity, not any-relay, for prompt delivery Codex review: NostrRelayManager.isConnected is true when any relay is up, including geohash/custom relays — but private messages target the default (gift-wrap-capable) relay set and queue when none of those are connected. A lone geohash relay would have suppressed the parallel courier deposit while the DM sat in the queue. Publish a DM-scoped connectivity flag and drive canDeliverPromptly from it. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com> --------- Co-authored-by: jack <jackjackbits@users.noreply.github.com> Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
2026-07-24 22:45:19 +00:00 · 2026-07-06 17:45:57 +02:00
parent 75da63c9d7
commit a66c591f8e
6 changed files with 182 additions and 9 deletions
@@ -544,7 +544,16 @@ private final class CourierCaptureTransport: Transport {
    func isPeerConnected(_ peerID: PeerID) -> Bool {
        snapshots.contains { $0.peerID == peerID && $0.isConnected }
    }
-    func isPeerReachable(_ peerID: PeerID) -> Bool { isPeerConnected(peerID) }
+    // Nostr-style reachability: claimed for peers with no live link (known
+    // npub), where prompt delivery additionally needs a relay connection.
+    var reachablePeers: Set<PeerID> = []
+    var promptDelivery = true
+    func isPeerReachable(_ peerID: PeerID) -> Bool {
+        isPeerConnected(peerID) || reachablePeers.contains(peerID)
+    }
+    func canDeliverPromptly(to peerID: PeerID) -> Bool {
+        isPeerReachable(peerID) && promptDelivery
+    }
    func peerNickname(peerID: PeerID) -> String? { nil }
    func getPeerNicknames() -> [PeerID: String] { [:] }

@@ -652,4 +661,70 @@ struct MessageRouterCourierTests {
        #expect(transport.directSends == ["m3"])
        #expect(transport.courierSends.isEmpty)
    }
+
+    /// A peer can be "reachable" through a transport that cannot deliver
+    /// promptly (Nostr claims any favorite with a known npub, even with no
+    /// relay connection). The queued send must not shadow the courier: a
+    /// sealed copy goes to connected couriers in parallel, and receivers
+    /// dedup by message ID if both arrive.
+    @Test @MainActor
+    func queuedReachableSendAlsoDepositsWithCourier() {
+        let bobKey = Data(repeating: 0xB0, count: 32)
+        let bobID = PeerID(publicKey: bobKey)
+        let carolKey = Data(repeating: 0xC0, count: 32)
+        let carolID = PeerID(publicKey: carolKey)
+
+        let transport = CourierCaptureTransport()
+        transport.snapshots = [
+            TransportPeerSnapshot(peerID: carolID, nickname: "carol", isConnected: true, noisePublicKey: carolKey, lastSeen: Date())
+        ]
+        transport.reachablePeers = [bobID]
+        transport.promptDelivery = false
+
+        let directory = CourierDirectory(
+            noiseKey: { peerID in peerID == bobID ? bobKey : nil },
+            isTrustedCourier: { $0 == carolKey }
+        )
+        let router = MessageRouter(transports: [transport], courierDirectory: directory)
+        var carried: [String] = []
+        router.onMessageCarried = { messageID, _ in carried.append(messageID) }
+
+        router.sendPrivate("hi bob", to: bobID, recipientNickname: "bob", messageID: "m4")
+
+        #expect(transport.directSends == ["m4"])
+        #expect(transport.courierSends.count == 1)
+        #expect(transport.courierSends.first?.messageID == "m4")
+        #expect(transport.courierSends.first?.couriers == [carolID])
+        #expect(carried == ["m4"])
+    }
+
+    /// When the reachable transport can deliver promptly (relays up), the
+    /// send is trusted and no courier quota is spent.
+    @Test @MainActor
+    func promptlyDeliverableReachablePeerSkipsCourier() {
+        let bobKey = Data(repeating: 0xB0, count: 32)
+        let bobID = PeerID(publicKey: bobKey)
+        let carolKey = Data(repeating: 0xC0, count: 32)
+        let carolID = PeerID(publicKey: carolKey)
+
+        let transport = CourierCaptureTransport()
+        transport.snapshots = [
+            TransportPeerSnapshot(peerID: carolID, nickname: "carol", isConnected: true, noisePublicKey: carolKey, lastSeen: Date())
+        ]
+        transport.reachablePeers = [bobID]
+
+        let directory = CourierDirectory(
+            noiseKey: { peerID in peerID == bobID ? bobKey : nil },
+            isTrustedCourier: { $0 == carolKey }
+        )
+        let router = MessageRouter(transports: [transport], courierDirectory: directory)
+        var carried: [String] = []
+        router.onMessageCarried = { messageID, _ in carried.append(messageID) }
+
+        router.sendPrivate("hi bob", to: bobID, recipientNickname: "bob", messageID: "m5")
+
+        #expect(transport.directSends == ["m5"])
+        #expect(transport.courierSends.isEmpty)
+        #expect(carried.isEmpty)
+    }
 }
@@ -6,6 +6,7 @@
 // For more information, see <https://unlicense.org>
 //

+import Combine
 import Foundation
 import Testing
 import BitFoundation
@@ -85,6 +86,51 @@ struct NostrTransportTests {
        #expect(didRefresh)
    }

+    @Test("Prompt delivery requires both a known npub and a relay connection")
+    @MainActor
+    func canDeliverPromptlyTracksRelayConnectivity() async throws {
+        let keychain = MockKeychain()
+        let idBridge = NostrIdentityBridge(keychain: keychain)
+        let recipient = try NostrIdentity.generate()
+        let noiseKey = Data((0..<32).map(UInt8.init))
+        let peerID = PeerID(hexData: noiseKey)
+        let relationship = makeRelationship(
+            peerNoisePublicKey: noiseKey,
+            peerNostrPublicKey: recipient.npub,
+            peerNickname: "Alice"
+        )
+        let connectivity = CurrentValueSubject<Bool, Never>(false)
+
+        let transport = NostrTransport(
+            keychain: keychain,
+            idBridge: idBridge,
+            dependencies: makeDependencies(
+                loadFavorites: { [noiseKey: relationship] },
+                relayConnectivity: { connectivity.eraseToAnyPublisher() }
+            )
+        )
+
+        // Reachable (npub known) but relays down: the peer must not be
+        // treated as promptly deliverable, or the router would skip the
+        // courier and let the message rot in the Nostr send queue.
+        #expect(transport.isPeerReachable(peerID))
+        #expect(!transport.canDeliverPromptly(to: peerID))
+
+        connectivity.send(true)
+        let deliverable = await TestHelpers.waitUntil(
+            { transport.canDeliverPromptly(to: peerID) },
+            timeout: 5.0
+        )
+        #expect(deliverable)
+
+        connectivity.send(false)
+        let undeliverable = await TestHelpers.waitUntil(
+            { !transport.canDeliverPromptly(to: peerID) },
+            timeout: 5.0
+        )
+        #expect(undeliverable)
+    }
+
    @Test("Private message resolves short peer ID and emits decryptable packet")
    @MainActor
    func sendPrivateMessageResolvesShortPeerID() async throws {
@@ -375,7 +421,8 @@ struct NostrTransportTests {
        currentIdentity: @escaping @MainActor () throws -> NostrIdentity? = { nil },
        registerPendingGiftWrap: @escaping @MainActor (String) -> Void = { _ in },
        sendEvent: @escaping @MainActor (NostrEvent) -> Void = { _ in },
-        scheduleAfter: @escaping @Sendable (TimeInterval, @escaping @Sendable () -> Void) -> Void = { _, _ in }
+        scheduleAfter: @escaping @Sendable (TimeInterval, @escaping @Sendable () -> Void) -> Void = { _, _ in },
+        relayConnectivity: @escaping @MainActor () -> AnyPublisher<Bool, Never> = { Just(false).eraseToAnyPublisher() }
    ) -> NostrTransport.Dependencies {
        NostrTransport.Dependencies(
            notificationCenter: notificationCenter,
@@ -385,7 +432,8 @@ struct NostrTransportTests {
            currentIdentity: currentIdentity,
            registerPendingGiftWrap: registerPendingGiftWrap,
            sendEvent: sendEvent,
-            scheduleAfter: scheduleAfter
+            scheduleAfter: scheduleAfter,
+            relayConnectivity: relayConnectivity
        )
    }