Stage 397: PR #2671 — fix: SSE reconnect jitter + cron run row inline expansion

Closes #2629
Closes #2661

Co-authored-by: AJV20 <AJV20@users.noreply.github.com>

CHANGELOG.md

@@ -3,6 +3,11 @@
 
 ## [Unreleased]
 
+### Changed
+
+- Session-list SSE reconnects now use bounded jitter/backoff instead of a fixed 5-second retry, reducing reconnect bursts after restarts or network drops.
+- Expanded cron run rows now render the full output inline immediately; the truncated preview remains only for collapsed rows, and the full-output fallback no longer drops content when Markdown rendering is unavailable.
+
 
 ## [v0.51.103] — 2026-05-21 — Release CA (stage-396 — 1-PR follow-on — Settings → Plugins distinguishes exclusive/provider activation)
 

static/panels.js

@@ -658,11 +658,14 @@ async function _loadRunContent(jobId, filename, runId){
       body.textContent = data.error;
       return;
     }
+    const expanded = _cronExpansionGet(_cronRunExpandKey(jobId, filename));
+    const output = expanded ? (data.content || data.snippet || '') : (data.snippet || data.content || '');
+    body.classList.toggle('expanded', expanded);
     // Render markdown content using the same renderer as chat messages
     if (typeof renderMd === 'function') {
-      body.innerHTML = renderMd(data.snippet || data.content);
+      body.innerHTML = renderMd(output);
     } else {
-      body.textContent = data.snippet || data.content;
+      body.textContent = output;
     }
     const usageStrip = _formatCronRunUsageStrip(data.usage);
     if (usageStrip) {
@@ -671,13 +674,15 @@ async function _loadRunContent(jobId, filename, runId){
       usage.textContent = usageStrip;
       body.appendChild(usage);
     }
-    // Show "View full output" button if content was truncated
-    if (data.content && data.snippet && data.content.length > data.snippet.length) {
+    // Show "View full output" button only for collapsed previews. Expanded rows render the full body inline.
+    if (!expanded && data.content && data.snippet && data.content.length > data.snippet.length) {
       const btn = document.createElement('button');
       btn.style.cssText = 'margin-top:8px;padding:4px 12px;border-radius:var(--radius-btn);border:1px solid var(--border-subtle);background:var(--surface-subtle);color:var(--text-secondary);cursor:pointer;font-size:12px';
       btn.textContent = t('cron_view_full_output') || 'View full output';
       btn.onclick = () => {
-        body.innerHTML = renderMd ? renderMd(data.content) : '';
+        _cronExpansionSet(_cronRunExpandKey(jobId, filename), true);
+        body.classList.add('expanded');
+        body.innerHTML = renderMd ? renderMd(data.content) : data.content;
         btn.remove();
       };
       body.appendChild(btn);

static/sessions.js

@@ -2112,6 +2112,16 @@ let _sessionEventsSSE = null;
 let _sessionEventsRefreshTimer = 0;
 let _sessionEventsReconnectTimer = 0;
 let _sessionEventsNeedsRefreshOnOpen = false;
+let _sessionEventsReconnectAttempt = 0;
+const _sessionEventsReconnectBaseMs = 5000;
+const _sessionEventsReconnectMaxMs = 30000;
+
+function _sessionEventsReconnectDelayMs(){
+  const attempt = Math.max(0, Number(_sessionEventsReconnectAttempt || 0));
+  const base = Math.min(_sessionEventsReconnectMaxMs, _sessionEventsReconnectBaseMs * Math.pow(2, attempt));
+  const jitter = Math.floor(Math.random() * Math.max(1, Math.floor(base * 0.35)));
+  return Math.min(_sessionEventsReconnectMaxMs, Math.floor(base * 0.75) + jitter);
+}
 let _sessionListRefreshInFlight = false;
 let _sessionListRefreshPendingReason = '';
 
@@ -2233,6 +2243,7 @@ function ensureSessionEventsSSE(){
     // Same-origin relative URL preserves subpath mounts and normal WebUI cookies.
     _sessionEventsSSE = new EventSource('api/sessions/events');
     _sessionEventsSSE.onopen = () => {
+      _sessionEventsReconnectAttempt = 0;
       if(!_sessionEventsNeedsRefreshOnOpen) return;
       _sessionEventsNeedsRefreshOnOpen = false;
       void refreshSessionList('reconnect');
@@ -2244,10 +2255,12 @@ function ensureSessionEventsSSE(){
       _sessionEventsNeedsRefreshOnOpen = true;
       _closeSessionEventsSSE();
       if(_sessionEventsReconnectTimer) return;
+      const delayMs = _sessionEventsReconnectDelayMs();
+      _sessionEventsReconnectAttempt = Math.min(_sessionEventsReconnectAttempt + 1, 6);
       _sessionEventsReconnectTimer = setTimeout(() => {
         _sessionEventsReconnectTimer = 0;
         ensureSessionEventsSSE();
-      }, 5000);
+      }, delayMs);
     };
   }catch(e){
     _closeSessionEventsSSE();

tests/test_issue2661_2629_frontend.py

@@ -0,0 +1,29 @@
+from pathlib import Path
+
+SESSIONS_JS = Path("static/sessions.js").read_text(encoding="utf-8")
+PANELS_JS = Path("static/panels.js").read_text(encoding="utf-8")
+CHANGELOG = Path("CHANGELOG.md").read_text(encoding="utf-8")
+
+
+def test_session_events_reconnect_uses_jittered_backoff_not_fixed_delay():
+    assert "function _sessionEventsReconnectDelayMs()" in SESSIONS_JS
+    assert "Math.random()" in SESSIONS_JS
+    assert "_sessionEventsReconnectMaxMs" in SESSIONS_JS
+    assert "_sessionEventsReconnectAttempt = 0" in SESSIONS_JS
+    ensure_fn = SESSIONS_JS[SESSIONS_JS.find("function ensureSessionEventsSSE()") :]
+    assert "const delayMs = _sessionEventsReconnectDelayMs();" in ensure_fn
+    assert "}, 5000);" not in ensure_fn
+
+
+def test_cron_expanded_run_renders_full_content_inline():
+    assert "const expanded = _cronExpansionGet(_cronRunExpandKey(jobId, filename));" in PANELS_JS
+    assert "const output = expanded ? (data.content || data.snippet || '') : (data.snippet || data.content || '');" in PANELS_JS
+    assert "if (!expanded && data.content && data.snippet && data.content.length > data.snippet.length)" in PANELS_JS
+    assert "_cronExpansionSet(_cronRunExpandKey(jobId, filename), true);" in PANELS_JS
+
+
+def test_changelog_mentions_session_and_cron_polish():
+    unreleased = CHANGELOG.split("## [v0.51.103]", 1)[0]
+    assert "bounded jitter/backoff" in unreleased
+    assert "Expanded cron run rows" in unreleased
+    assert "no longer drops content when Markdown rendering is unavailable" in unreleased