fix(connection): ignore spurious navigator.onLine offline hint in Tauri (#1234)

src/lib/network/activeServerReachability.ts

@@ -1,4 +1,5 @@
 import { isDevOfflineBrowseForced } from '@/store/devOfflineBrowseStore';
+import { isNavigatorOfflineHint } from '@/lib/network/navigatorOnlineHint';
 
 export type ConnectionStatus = 'connected' | 'disconnected' | 'checking';
 
@@ -53,9 +54,9 @@ export function resetActiveServerConnectionSnapshot(): void {
   connectionStatus = 'checking';
 }
 
-/** True only when the browser is online and the last active-server probe succeeded. */
+/** True only when no navigator offline hint applies and the last active-server probe succeeded. */
 export function isActiveServerReachable(): boolean {
   if (isDevOfflineBrowseForced()) return false;
-  if (typeof navigator !== 'undefined' && !navigator.onLine) return false;
+  if (isNavigatorOfflineHint()) return false;
   return activeServerReachable === true;
 }

src/lib/network/navigatorOnlineHint.test.ts

@@ -0,0 +1,35 @@
+import { describe, expect, it, vi, beforeEach, afterEach } from 'vitest';
+
+const isTauri = vi.fn(() => false);
+
+vi.mock('@tauri-apps/api/core', () => ({
+  isTauri: () => isTauri(),
+}));
+
+import { isNavigatorOfflineHint } from './navigatorOnlineHint';
+
+describe('isNavigatorOfflineHint', () => {
+  beforeEach(() => {
+    isTauri.mockReturnValue(false);
+  });
+
+  afterEach(() => {
+    vi.unstubAllGlobals();
+  });
+
+  it('returns false in Tauri even when navigator.onLine is false', () => {
+    isTauri.mockReturnValue(true);
+    vi.stubGlobal('navigator', { onLine: false });
+    expect(isNavigatorOfflineHint()).toBe(false);
+  });
+
+  it('returns true in non-Tauri when navigator.onLine is false (offline hint applies)', () => {
+    vi.stubGlobal('navigator', { onLine: false });
+    expect(isNavigatorOfflineHint()).toBe(true);
+  });
+
+  it('returns false when navigator.onLine is true', () => {
+    vi.stubGlobal('navigator', { onLine: true });
+    expect(isNavigatorOfflineHint()).toBe(false);
+  });
+});

src/lib/network/navigatorOnlineHint.ts

@@ -0,0 +1,21 @@
+import { isTauri } from '@tauri-apps/api/core';
+
+/**
+ * Whether callers should treat `navigator.onLine === false` as an offline signal.
+ *
+ * Returns `true` only in non-Tauri hosts when `navigator.onLine` is false.
+ * WebKitGTK inside Tauri often leaves `navigator.onLine === false` even when
+ * HTTP to the user's Subsonic/Navidrome server works (ping, search, playback).
+ * Desktop builds must not trust that hint — use Subsonic probes instead.
+ *
+ * @see https://github.com/orgs/tauri-apps/discussions/9269
+ */
+export function isNavigatorOfflineHint(): boolean {
+  if (typeof navigator === 'undefined') return false;
+  try {
+    if (isTauri()) return false;
+  } catch {
+    /* isTauri unavailable in some test harnesses — fall through */
+  }
+  return !navigator.onLine;
+}

src/lib/network/subsonicNetworkGuard.ts

@@ -3,6 +3,7 @@ import { hasLocalPlaybackUrl } from '@/store/localPlaybackResolve';
 import { isDevOfflineBrowseForced } from '@/store/devOfflineBrowseStore';
 import { resolveServerIdForIndexKey } from '@/lib/server/serverLookup';
 import { isActiveServerReachable } from '@/lib/network/activeServerReachability';
+import { isNavigatorOfflineHint } from '@/lib/network/navigatorOnlineHint';
 
 function isSameServerProfile(a: string, b: string): boolean {
   if (!a || !b) return false;
@@ -18,7 +19,7 @@ function isSameServerProfile(a: string, b: string): boolean {
 export function isSubsonicServerReachable(serverId: string): boolean {
   if (!serverId) return false;
   if (isDevOfflineBrowseForced()) return false;
-  if (typeof navigator !== 'undefined' && !navigator.onLine) return false;
+  if (isNavigatorOfflineHint()) return false;
   const activeId = useAuthStore.getState().activeServerId;
   if (!activeId || isSameServerProfile(serverId, activeId)) {
     return isActiveServerReachable();
@@ -34,7 +35,7 @@ export function isSubsonicServerReachable(serverId: string): boolean {
 export function shouldAttemptSubsonicForServer(serverId: string, trackId?: string): boolean {
   if (!serverId) return false;
   if (isDevOfflineBrowseForced()) return false;
-  if (typeof navigator !== 'undefined' && !navigator.onLine) return false;
+  if (isNavigatorOfflineHint()) return false;
   if (trackId && hasLocalPlaybackUrl(trackId, serverId)) return false;
   return isSubsonicServerReachable(serverId);
 }