Fix stale deleted sessions in sidebar (#1203)

Co-authored-by: ghreprimand <203024559+ghreprimand@users.noreply.github.com>

static/app.js

@@ -3130,10 +3130,7 @@ function initializeEventListeners() {
         const idx = sessions.findIndex(s => s.id === currentId);
         const nextSession = sessions.filter(s => !s.archived && s.id !== currentId)[Math.max(0, idx)] ||
                             sessions.find(s => !s.archived && s.id !== currentId);
-        const res = await fetch(`${API_BASE}/api/session/${currentId}/archive`, {
-          method: 'POST',
-          headers: { 'Content-Type': 'application/json' },
-        });
+        const res = await fetch(`${API_BASE}/api/session/${currentId}`, { method: 'DELETE' });
         if (res.ok) {
           await sessionModule.loadSessions();
           if (nextSession) {

static/js/sessions.js

@@ -78,6 +78,42 @@ function _deselectCurrentSession(sid) {
   if (window._updateSendBtnIcon) window._updateSendBtnIcon();
 }
 
+function _removeSessionFromLocalState(sid) {
+  if (!sid) return;
+  const id = String(sid);
+  sessions = sessions.filter(s => String(s.id) !== id);
+  _selectedIds.delete(id);
+  try {
+    const savedOrder = Storage.get('session-order');
+    if (savedOrder) {
+      const orderIds = JSON.parse(savedOrder);
+      if (Array.isArray(orderIds) && orderIds.some(x => String(x) === id)) {
+        Storage.set('session-order', JSON.stringify(orderIds.filter(x => String(x) !== id)));
+      }
+    }
+  } catch (e) {
+    console.warn('Failed to prune deleted session order:', e);
+  }
+  document.querySelectorAll('.list-item[data-session-id]').forEach(el => {
+    if (String(el.dataset.sessionId) === id) el.remove();
+  });
+  _deselectCurrentSession(id);
+}
+
+function _normalizeSessionsList(fetched) {
+  if (!Array.isArray(fetched)) return [];
+  const seen = new Set();
+  const unique = [];
+  for (const session of fetched) {
+    if (!session || session.id == null) continue;
+    const id = String(session.id);
+    if (seen.has(id)) continue;
+    seen.add(id);
+    unique.push(session);
+  }
+  return unique;
+}
+
 // Initialize dependencies from app.js (no-op: dependencies now imported directly)
 export function initDependencies() {}
 
@@ -620,15 +656,13 @@ function createSessionItem(s) {
       _forceSidebarOpen();
       return;
     }
-    // Optimistic: remove from UI immediately
-    const sessionEl = document.querySelector(`.list-item[data-session-id="${s.id}"]`);
-    if (sessionEl) sessionEl.remove();
     const wasCurrentSession = currentSessionId === s.id;
     // If streaming, abort it before deleting
     if (wasCurrentSession && window.chatModule && window.chatModule.abortCurrentRequest) {
       window.chatModule.abortCurrentRequest();
     }
     _deselectCurrentSession(s.id);
+    _removeSessionFromLocalState(s.id);
     _skipAutoSelect = true;
     // Clean up persistent chat mapping
     try {
@@ -1321,7 +1355,7 @@ export async function loadSessions() {
       const res = await fetch(`${API_BASE}/api/sessions`);
       fetched = await res.json();
     }
-    sessions = fetched;
+    sessions = _normalizeSessionsList(fetched);
     renderSessionList();
 
     const sessionsSection = uiModule.el('sessions-section');

tests/test_deleted_session_sidebar_regression.py

@@ -0,0 +1,31 @@
+from pathlib import Path
+
+
+APP_JS = Path("static/app.js")
+SESSIONS_JS = Path("static/js/sessions.js")
+
+
+def test_rail_delete_uses_hard_delete_endpoint():
+    source = APP_JS.read_text()
+    rail_block = source[source.index("const railDelete = el('rail-delete-session');"):]
+    rail_block = rail_block[:rail_block.index("// Textarea auto-resize")]
+
+    assert "fetch(`${API_BASE}/api/session/${currentId}`, { method: 'DELETE' })" in rail_block
+    assert "api/session/${currentId}/archive" not in rail_block
+
+
+def test_deleted_sessions_are_pruned_from_local_sidebar_state():
+    source = SESSIONS_JS.read_text()
+
+    assert "function _removeSessionFromLocalState(sid)" in source
+    assert "sessions = sessions.filter(s => String(s.id) !== id);" in source
+    assert "Storage.set('session-order', JSON.stringify(orderIds.filter(x => String(x) !== id)))" in source
+    assert "_removeSessionFromLocalState(s.id);" in source
+
+
+def test_session_fetch_normalizes_duplicate_ids_before_render():
+    source = SESSIONS_JS.read_text()
+
+    assert "function _normalizeSessionsList(fetched)" in source
+    assert "if (seen.has(id)) continue;" in source
+    assert "sessions = _normalizeSessionsList(fetched);" in source