perf(#4759): parallelize fresh sidebar boot fetches

static/sessions.js

@@ -4148,16 +4148,7 @@ async function _runRenderSessionListRefresh(opts, _gen){
       retryTimeouts:true,
       retryStatuses:[502,503,504],
     };
-    const sessData = _sessionListHasLoadedOnce
-      ? await api('/api/sessions' + sessionListQS,{timeoutToast:false})
-      : await api('/api/sessions' + sessionListQS,sessionRequestOpts);
-    let projData={projects:_allProjects||[]};
-    try{
-      const projectQS = _showAllProfiles ? '?all_profiles=1' : '';
-      projData = await api('/api/projects' + projectQS,{timeoutToast:false});
-    }catch(projectError){
-      console.warn('renderProjectsList',projectError);
-    }
+    const {sessData, projData}=await _loadSidebarSessionListPayload(sessionListQS, sessionRequestOpts);
     // Discard stale response — a newer renderSessionList() call superseded us.
     if (_gen !== _renderSessionListGen) return;
     // #4671: while a profile switch is mid-flight, drop ANY payload — even one whose
@@ -4211,6 +4202,25 @@ async function _runRenderSessionListRefresh(opts, _gen){
   }
 }
 
+async function _loadSidebarSessionListPayload(sessionListQS, sessionRequestOpts){
+  const projectPromise = (async() => {
+    try{
+      const projectQS = _showAllProfiles ? '?all_profiles=1' : '';
+      return await api('/api/projects' + projectQS,{timeoutToast:false});
+    }catch(projectError){
+      console.warn('renderProjectsList',projectError);
+      return {projects:_allProjects||[]};
+    }
+  })();
+
+  const sessData = _sessionListHasLoadedOnce
+    ? await api('/api/sessions' + sessionListQS,{timeoutToast:false})
+    : await api('/api/sessions' + sessionListQS,sessionRequestOpts);
+  const projData = await projectPromise;
+
+  return {sessData,projData};
+}
+
 async function _drainRenderSessionListQueue(initialRequest){
   let request=initialRequest;
   try{

tests/test_issue4759_parallel_sidebar_boot_fetch.py

@@ -0,0 +1,330 @@
+"""Regression tests for #4759: parallelize first-load sidebar boot fetches."""
+
+from __future__ import annotations
+
+import json
+import shutil
+import subprocess
+from pathlib import Path
+
+import pytest
+
+
+ROOT = Path(__file__).resolve().parents[1]
+SESSIONS_JS = (ROOT / "static" / "sessions.js").read_text(encoding="utf-8")
+NODE = shutil.which("node")
+
+
+def _extract_function(source_text: str, function_name: str) -> str:
+    marker = f"async function {function_name}("
+    start = source_text.find(marker)
+    if start < 0:
+        marker = f"function {function_name}("
+        start = source_text.find(marker)
+    assert start >= 0, f"{function_name}() not found"
+    brace_start = source_text.find("{", start)
+    assert brace_start >= 0, f"{function_name} body not found"
+
+    depth = 0
+    in_string = None
+    escaped = False
+    in_line_comment = False
+    in_block_comment = False
+
+    for index in range(brace_start, len(source_text)):
+        char = source_text[index]
+        nxt = source_text[index + 1] if index + 1 < len(source_text) else ""
+
+        if in_line_comment:
+            if char == "\n":
+                in_line_comment = False
+            continue
+        if in_block_comment:
+            if char == "*" and nxt == "/":
+                in_block_comment = False
+            continue
+        if in_string:
+            if escaped:
+                escaped = False
+            elif char == "\\":
+                escaped = True
+            elif char == in_string:
+                in_string = None
+            continue
+        if char == "/" and nxt == "/":
+            in_line_comment = True
+            continue
+        if char == "/" and nxt == "*":
+            in_block_comment = True
+            continue
+        if char in ("'", '"', "`"):
+            in_string = char
+            continue
+
+        if char == "{":
+            depth += 1
+        elif char == "}":
+            depth -= 1
+            if depth == 0:
+                return source_text[start : index + 1]
+
+    raise AssertionError(f"could not extract {function_name}()")
+
+
+def _run_node(script: str):
+    completed = subprocess.run(
+        [NODE, "-e", script],
+        cwd=ROOT,
+        text=True,
+        capture_output=True,
+        check=False,
+    )
+    assert completed.returncode == 0, completed.stderr or completed.stdout
+    return json.loads(completed.stdout.strip())
+
+
+@pytest.mark.skipif(NODE is None, reason="node not on PATH")
+def test_cold_boot_starts_projects_fetch_before_sessions_resolve():
+    """The project request must start before the session request settles."""
+    fetch_helper = _extract_function(SESSIONS_JS, "_loadSidebarSessionListPayload")
+    script = f"""
+    const calls = [];
+    let resolveSessions;
+    let resolveProjects;
+
+    global._showAllProfiles = false;
+    global._allProjects = [];
+    global._sessionListHasLoadedOnce = false;
+    global.api = (url) => {{
+  if (url.startsWith('/api/projects')) {{
+    calls.push('projects');
+    return new Promise(resolve => {{
+      resolveProjects = resolve;
+    }});
+  }}
+  if (url.startsWith('/api/sessions')) {{
+    calls.push('sessions');
+    return new Promise(resolve => {{
+      resolveSessions = resolve;
+    }});
+  }}
+  return Promise.reject(new Error('unexpected endpoint ' + url));
+}};
+{fetch_helper}
+
+(async () => {{
+  const run = _loadSidebarSessionListPayload('?v=1', {{
+    timeoutToast:false,
+    timeoutMs:90000,
+    retries:1,
+    retryTimeouts:true,
+    retryStatuses:[502,503,504],
+  }});
+
+  await Promise.resolve();
+  const orderAtSettleBoundary = calls.slice();
+
+  resolveSessions({{
+    sessions:[{{session_id:'s1'}}],
+    other_profile_count:0,
+    archived_count:0,
+    archived_webui_count:0,
+    archived_cli_count:0,
+  }});
+  resolveProjects({{projects:[]}});
+  const payload = await run;
+  console.log(JSON.stringify({{orderAtSettleBoundary,payload,calls:calls}}));
+}})().catch(error => {{
+  console.error(error);
+  process.exit(1);
+}});
+"""
+
+    body = _run_node(script)
+    assert body["orderAtSettleBoundary"] == ["projects", "sessions"]
+    assert body["payload"]["sessData"]["sessions"] == [{"session_id": "s1"}]
+    assert body["payload"]["projData"]["projects"] == []
+
+
+@pytest.mark.skipif(NODE is None, reason="node not on PATH")
+def test_project_failure_falls_back_without_blocking_session_payload():
+    """Project endpoint failure should still return session payload and fallback projects."""
+    fetch_helper = _extract_function(SESSIONS_JS, "_loadSidebarSessionListPayload")
+    script = f"""
+    const calls = [];
+    global._showAllProfiles = true;
+    global._allProjects = [];
+    global._sessionListHasLoadedOnce = false;
+    global.api = (url) => {{
+  if (url.startsWith('/api/projects')) {{
+    calls.push('projects');
+    return Promise.reject(new Error('project endpoint down'));
+  }}
+  if (url.startsWith('/api/sessions')) {{
+    calls.push('sessions');
+    return Promise.resolve({{
+      sessions:[{{session_id:'s1'}}],
+      other_profile_count:0,
+      archived_count:0,
+      archived_webui_count:0,
+      archived_cli_count:0,
+    }});
+  }}
+  return Promise.reject(new Error('unexpected endpoint ' + url));
+}};
+{fetch_helper}
+
+(async () => {{
+  const payload = await _loadSidebarSessionListPayload('?v=1', {{
+    timeoutToast:false,
+    timeoutMs:90000,
+    retries:1,
+    retryTimeouts:true,
+    retryStatuses:[502,503,504],
+  }});
+  console.log(JSON.stringify({{calls, payload}}));
+}})().catch(error => {{
+  console.error(error);
+  process.exit(1);
+}});
+"""
+
+    body = _run_node(script)
+    assert body["calls"] == ["projects", "sessions"]
+    assert body["payload"]["sessData"]["sessions"][0]["session_id"] == "s1"
+    assert body["payload"]["projData"]["projects"] == []
+
+
+@pytest.mark.skipif(NODE is None, reason="node not on PATH")
+def test_existing_session_request_options_are_preserved():
+    """The cold-load /api/sessions request keeps the existing timeout/retry policy."""
+    fetch_helper = _extract_function(SESSIONS_JS, "_loadSidebarSessionListPayload")
+    refresh_fn = _extract_function(SESSIONS_JS, "_runRenderSessionListRefresh")
+    script = f"""
+global._SESSION_LIST_BOOT_TIMEOUT_MS = 90000;
+global._sessionListHasLoadedOnce = false;
+global._renderSessionListGen = 1;
+global._profileSwitchListEmbargo = false;
+global._pendingSessionListPayload = null;
+global._showAllProfiles = false;
+global._allProjects = [];
+global._contentSearchResults = [];
+global.$ = () => ({{ value: '' }});
+global._isSessionListUserInteracting = () => false;
+global._schedulePendingSessionListApply = () => {{}};
+global._showSessionListLoadError = error => {{ throw new Error(error && error.message ? error.message : String(error)); }};
+global._applySessionListPayload = () => {{}};
+global._sessionListQueryString = () => '?v=1';
+const calls = [];
+global.api = (url, opts) => {{
+  calls.push({{endpoint:url.replace('/api/',''), opts}});
+  if(url.startsWith('/api/sessions')){{
+    return Promise.resolve({{
+      sessions:[{{session_id:'s1'}}],
+      other_profile_count:0,
+      archived_count:0,
+      archived_webui_count:0,
+      archived_cli_count:0,
+    }});
+  }}
+  return Promise.resolve({{projects:[]}});
+}};
+{fetch_helper}
+{refresh_fn}
+
+(async () => {{
+  await _runRenderSessionListRefresh({{}}, 1);
+  const sessionCall = calls.find(entry => entry.endpoint === 'sessions?') || calls.find(entry => entry.endpoint.startsWith('sessions'));
+  const projectCall = calls.find(entry => entry.endpoint === 'projects?') || calls.find(entry => entry.endpoint.startsWith('projects'));
+  console.log(JSON.stringify({{
+    sessionOpts: sessionCall ? sessionCall.opts : null,
+    projectOpts: projectCall ? projectCall.opts : null,
+    calls,
+  }}));
+}})().catch(error => {{
+  console.error(error);
+  process.exit(1);
+}});
+"""
+
+    body = _run_node(script)
+    session_opts = body["sessionOpts"] or {}
+    project_opts = body["projectOpts"] or {}
+
+    assert session_opts["timeoutToast"] is False
+    assert session_opts["timeoutMs"] == 90000
+    assert session_opts["retries"] == 1
+    assert session_opts["retryTimeouts"] is True
+    assert session_opts["retryStatuses"] == [502, 503, 504]
+    assert project_opts == {"timeoutToast": False}
+
+
+@pytest.mark.skipif(NODE is None, reason="node not on PATH")
+def test_warm_refresh_parallelizes_projects_fetch_and_keeps_minimal_session_opts():
+    """Warm refresh uses minimal session opts, but still starts projects immediately."""
+    fetch_helper = _extract_function(SESSIONS_JS, "_loadSidebarSessionListPayload")
+    script = f"""
+const calls = [];
+let resolveSessions;
+let resolveProjects;
+global._showAllProfiles = false;
+global._allProjects = [];
+global._sessionListHasLoadedOnce = true;
+global.api = (url, opts) => {{
+  if (url.startsWith('/api/projects')) {{
+    calls.push({{ endpoint:'projects', opts: opts || null }});
+    return new Promise(resolve => {{
+      resolveProjects = resolve;
+    }});
+  }}
+  if (url.startsWith('/api/sessions')) {{
+    calls.push({{ endpoint:'sessions', opts: opts || null }});
+    return new Promise(resolve => {{
+      resolveSessions = resolve;
+    }});
+  }}
+  return Promise.reject(new Error('unexpected endpoint ' + url));
+}};
+{fetch_helper}
+
+(async () => {{
+  const run = _loadSidebarSessionListPayload('?v=1', {{
+    timeoutToast:false,
+    timeoutMs:90000,
+    retries:1,
+    retryTimeouts:true,
+    retryStatuses:[502,503,504],
+  }});
+
+  await Promise.resolve();
+  const orderAtSettleBoundary = calls.map(call => call.endpoint);
+  const sessionOpts = calls.find(call => call.endpoint === 'sessions').opts;
+  const projectOpts = calls.find(call => call.endpoint === 'projects').opts;
+
+  resolveSessions({{
+    sessions:[{{session_id:'warm-1'}}],
+    other_profile_count:0,
+    archived_count:0,
+    archived_webui_count:0,
+    archived_cli_count:0,
+  }});
+  resolveProjects({{projects:[{{name:'demo'}}]}});
+  const payload = await run;
+  console.log(JSON.stringify({{
+    orderAtSettleBoundary,
+    sessionOpts,
+    projectOpts,
+    payload,
+  }}));
+}})().catch(error => {{
+  console.error(error);
+  process.exit(1);
+}});
+"""
+
+    body = _run_node(script)
+    assert body["orderAtSettleBoundary"] == ["projects", "sessions"]
+    assert body["sessionOpts"] == {"timeoutToast": False}
+    assert body["projectOpts"] == {"timeoutToast": False}
+    assert body["payload"]["sessData"]["sessions"] == [{"session_id": "warm-1"}]
+    assert body["payload"]["projData"]["projects"] == [{"name": "demo"}]