mirror of
https://github.com/permissionlesstech/bitchat.git
synced 2026-07-25 03:05:19 +00:00
276cde44e7
On a mesh-only/offline device the app used to bootstrap Tor and spin
Nostr relay reconnects forever ("connecting to Tor…"), wasting battery
even when there was provably no network path at all.
Add an NWPathMonitor-backed reachability signal (NetworkReachabilityMonitor)
and fold it into NetworkActivationService's activation gate:
- Tor bootstrap and relay connect/reconnect are now gated on the network
path being usable. When the path is fully unsatisfied (no interface at
all) we set autoStart off, shut Tor down, and disconnect relays instead
of looping. When a usable path returns we resume.
- Conservative policy: only NWPath.Status.unsatisfied counts as offline.
A flaky-but-present link stays "reachable" (Tor tolerates intermittent
connectivity); we never tear down on the first hiccup.
- Transitions are debounced (ReachabilityDebounce, ~2.5s) so path flapping
cannot thrash Tor/relay startup. The debounce is a pure value type,
unit-tested without the Network framework or real timers.
- Starts optimistic (reachable) so nothing is suppressed before the first
path evaluation arrives.
- BLE mesh never consults this gate and works fully offline.
- NWPathMonitor's background callback hops to the main actor before
touching any state.
Surfaces NetworkActivationService.isNetworkReachable for UI to distinguish
"offline" from "connecting to Tor".
Tests: pure debounce (satisfied → allowed, unsatisfied → suppressed after
interval, flap debounced, recover-after-outage) plus service wiring
(unreachable suppresses Tor+relays, recovery resumes, loss disconnects).
Co-authored-by: jack <jackjackbits@users.noreply.github.com>
Co-authored-by: Claude Fable 5 <noreply@anthropic.com>
Test Harness Guide
This test suite uses an in-memory networking harness to make end-to-end and integration tests deterministic, fast, and race-free without touching production code.
In-Memory Bus
- File:
bitchatTests/Mocks/MockBLEService.swift - Registry/Adjacency: Global
registrymapspeerIDto aMockBLEServiceinstance;adjacencyrecords simulated links between peers. - Setup: Call
MockBLEService.resetTestBus()insetUp()to clear state between tests. - Topology: Use
simulateConnectedPeer(_:)andsimulateDisconnectedPeer(_:)to add/remove links.connectFullMesh()helpers in tests build larger topologies. - Handlers: Tests can observe data via
messageDeliveryHandler(decodedBitchatMessage) andpacketDeliveryHandler(rawBitchatPacket). - De‑duplication: A thread-safe
seenMessageIDsprevents duplicate deliveries during flooding/relays.
Broadcast Flooding
- Flag:
MockBLEService.autoFloodEnabled - Intent: When
true, public broadcasts propagate across the entire connected component (ignores TTL for reach) while still de‑duping to prevent loops. - Usage: Enabled in Integration tests (
setUp) to simulate large-network broadcast; disabled in E2E tests to keep routing explicit and verify TTL behavior (seePublicChatE2ETests.testZeroTTLNotRelayed).
Rehandshake Flow (Noise)
- Why: The legacy NACK recovery path was removed; recovery now relies on Noise session rehandshake after decrypt failure or desync.
- Manager:
NoiseSessionManagermanages per-peer sessions. - Pattern: On decrypt failure, proactively clear the local session and re-initiate a handshake. The peer accepts and replaces their session.
- Test:
IntegrationTests.testRehandshakeAfterDecryptionFailure- Corrupts ciphertext to induce a decrypt error.
- Calls
removeSession(for:)on the initiator’s manager beforeinitiateHandshake(with:)to avoidalreadyEstablished. - Verifies encrypt/decrypt succeeds post-rehandshake.
Tips
- Determinism: Add small async delays only where handler installation/topology changes could race the first send.
- Scoping: Keep
autoFloodEnabledtoggled only within Integration tests; always reset intearDown()to avoid cross-test contamination. - Direct vs Relay: Private messages target a specific peer when adjacent; otherwise they are surfaced to neighbors for relay and, if known, also delivered to the target.
Quick Start
- Create nodes and connect them:
let svc = MockBLEService(); svc.myPeerID = "PEER1"svc.simulateConnectedPeer("PEER2")
- Observe messages:
svc.messageDeliveryHandler = { msg in /* asserts */ }
- Enable broadcast flooding for Integration suites only:
MockBLEService.autoFloodEnabled = true