dash: a stalled poll no longer stops its loop

carwatch/webchat.py

@@ -531,7 +531,8 @@ def _switch_later(name: str) -> None:
   d.textContent=s.answer||'';}
  bw.style.display=bar?'block':'none';
 }
-async function pollVoice(){try{const r=await fetch(_q('/api/voice/state'));renderVoice(await r.json());}catch(e){}}
+async function pollVoice(){const c=new AbortController();const t=setTimeout(()=>c.abort(),8000);
+ try{const r=await fetch(_q('/api/voice/state'),{signal:c.signal});renderVoice(await r.json());}catch(e){}finally{clearTimeout(t)}}
 $('speakBtn').onclick=async()=>{try{await fetch(_q('/api/voice/start'),{method:'POST'});pollVoice();}catch(e){}};
 document.querySelector('.vstate').addEventListener('click',e=>e.currentTarget.classList.toggle('open'));
 // Idle back-off (petrus, 15 Sep 2026: the VTA sat at 80 C with its fans up
@@ -547,12 +548,20 @@ def _switch_later(name: str) -> None:
 function cwActive(){cwLastActive=Date.now();}
 function cwIsIdle(){return Date.now()-cwLastActive>60000;}
 ['pointerdown','keydown','touchstart','wheel'].forEach(ev=>document.addEventListener(ev,cwActive,{passive:true}));
-function cwLoop(name,fn){const run=async()=>{if(!document.hidden){try{await fn()}catch(e){}}
+// The next run is scheduled no matter what fn() does: a request that never
+// settles (codexmb, post-merge review of #57) must not stop the loop, which is
+// what setInterval used to guarantee. fn() is raced against CW_DEADLINE ms;
+// the loser is abandoned (its own fetch is bounded by F / pollVoice's abort).
+const CW_DEADLINE=15000;
+function cwLoop(name,fn){const run=async()=>{if(!document.hidden){
+  let t;try{await Promise.race([fn(),new Promise(r=>{t=setTimeout(r,CW_DEADLINE)})])}catch(e){}finally{clearTimeout(t)}}
  setTimeout(run,(cwIsIdle()?CW_IDLE:CW_FAST)[name]);};run();}
 document.addEventListener('visibilitychange',()=>{if(!document.hidden)cwActive();});
 cwLoop('voice',pollVoice);
 const F=(u,o={},ms=4000)=>{const c=new AbortController();const t=setTimeout(()=>c.abort(),ms);
- return fetch(_q(u),Object.assign({signal:c.signal},o)).finally(()=>clearTimeout(t));};
+ // The abort timer covers the body read too, not only the headers: r.json() is
+ // wrapped so the timer clears when the body has arrived (codexmb, #57 review).
+ return fetch(_q(u),Object.assign({signal:c.signal},o)).then(r=>{const j=r.json.bind(r);r.json=()=>j().finally(()=>clearTimeout(t));return r},e=>{clearTimeout(t);throw e});};
 const ACT={brief:['/api/car-brief','composing + speaking your car brief',130000],read:['/api/obd','one live engine read',70000],record:['/api/obd/record-arm','armed: records 120s raw CAN on the next moving read',30000],
  pair:['/api/car-pair','scan + pair car Bluetooth (MBUX in pairing mode)',70000],update:['/api/update','pull latest code + restart',90000]};
 function show(t){const o=$('out');o.style.display='block';o.textContent=t;o.scrollTop=o.scrollHeight;

tests/test_dash_loop.py

@@ -0,0 +1,52 @@
+"""The dash page's poll scheduler (cwLoop) must keep scheduling when a poll
+never settles. Post-merge review of #57 (codexmb): the first version awaited
+fn() with no bound, so one stalled voice request stopped that loop for good,
+which setInterval never did. The scheduler is extracted from webchat.py and
+run under node with fake timers; skipped when node is not installed."""
+import pathlib, re, shutil, subprocess, pytest
+
+SRC = pathlib.Path(__file__).resolve().parents[1] / "carwatch" / "webchat.py"
+
+
+def _scheduler_js():
+    text = SRC.read_text()
+    m = re.search(r"const CW_FAST=.*?function cwLoop.*?run\(\);\}\n", text, re.S)
+    assert m, "cwLoop block not found in webchat.py"
+    return m.group(0)
+
+
+HARNESS = r"""
+const document={hidden:false,addEventListener(){}};
+let now=0; const timers=[];
+const setTimeout=(f,ms)=>{timers.push({at:now+ms,f});return timers.length};
+const clearTimeout=(id)=>{if(id)timers[id-1]=null};
+// Promise continuations (the race settling, finally, the reschedule) are
+// microtasks: drain them after every fired timer or the harness never sees
+// the next setTimeout(run, ...) that the scheduler registers.
+const flush=async()=>{for(let i=0;i<20;i++)await Promise.resolve();};
+async function advance(ms){const target=now+ms;for(;;){const due=timers.filter(t=>t&&t.at<=target).sort((a,b)=>a.at-b.at)[0];if(!due)break;now=due.at;timers[timers.indexOf(due)]=null;due.f();await flush();}now=target;await flush();}
+const Date={now:()=>now};
+%s
+(async()=>{
+let calls=0; const stalled=()=>{calls++;return new Promise(()=>{});};  // never settles
+cwLoop('voice',stalled);
+await advance(0);                    // first call
+const c1=calls;
+await advance(CW_DEADLINE-1);        // before the deadline: no second call (non-overlap)
+const c2=calls;
+await advance(CW_FAST.voice+2);      // deadline passed, next interval elapsed
+const c3=calls;
+console.log(JSON.stringify({c1,c2,c3,deadline:CW_DEADLINE}));
+})();
+"""
+
+@pytest.mark.skipif(shutil.which("node") is None, reason="node not installed")
+def test_stalled_poll_does_not_stop_the_loop(tmp_path):
+    js = tmp_path / "loop.js"
+    js.write_text(HARNESS % _scheduler_js())
+    out = subprocess.run(["node", str(js)], capture_output=True, text=True, timeout=30)
+    assert out.returncode == 0, out.stderr
+    r = __import__("json").loads(out.stdout.strip().splitlines()[-1])
+    assert r["c1"] == 1, r
+    assert r["c2"] == 1, "a second poll started while the first was still pending"
+    assert r["c3"] == 2, "the loop stopped after a poll that never settled"