fix: recover live refresh from stalled requests (#303)

tests/test_context_polling.py

@@ -114,3 +114,113 @@ const poller = createContextPoller({{
             {"context": "timmy", "event": 2, "age": 2, "changed": []},
         ],
     }
+
+
+def test_context_poller_aborts_a_stalled_request_and_recovers_on_schedule():
+    script = f"""
+const createContextPoller = require({json.dumps(str(POLLER))});
+const timers = [];
+const deadlineTimers = [];
+const errors = [];
+const snapshots = [];
+const signals = [];
+let calls = 0;
+const poller = createContextPoller({{
+  fetchContext: (revisions, options) => {{
+    calls += 1;
+    signals.push(options.signal);
+    if (calls === 1) return new Promise(() => {{}});
+    return Promise.resolve({{ context: {{ user: {{ login: 'timmy' }} }} }});
+  }},
+  onSnapshot: snapshot => snapshots.push(snapshot.context.user.login),
+  onError: error => errors.push({{ name: error.name, message: error.message }}),
+  setTimer: (callback, delay) => {{
+    const timer = {{ callback, delay, cancelled: false }};
+    timers.push(timer);
+    return timer;
+  }},
+  clearTimer: timer => {{ timer.cancelled = true; }},
+  setDeadlineTimer: (callback, delay) => {{
+    const timer = {{ callback, delay, cancelled: false }};
+    deadlineTimers.push(timer);
+    return timer;
+  }},
+  clearDeadlineTimer: timer => {{ timer.cancelled = true; }},
+  intervalMs: 8000,
+  timeoutMs: 25,
+}});
+
+(async () => {{
+  const first = poller.start();
+  const deadline = deadlineTimers.find(timer => timer.delay === 25 && !timer.cancelled);
+  deadline.callback();
+  await first;
+  const retry = timers.find(timer => timer.delay === 8000 && !timer.cancelled);
+  retry.callback();
+  await new Promise(resolve => setImmediate(resolve));
+  process.stdout.write(JSON.stringify({{
+    calls,
+    firstAborted: signals[0].aborted,
+    errors,
+    snapshots,
+  }}));
+}})();
+"""
+
+    assert run_node(script) == {
+        "calls": 2,
+        "firstAborted": True,
+        "errors": [
+            {"name": "TimeoutError", "message": "Live update timed out after 25ms."}
+        ],
+        "snapshots": ["timmy"],
+    }
+
+
+def test_forced_refresh_retires_stale_generation_without_late_overwrite():
+    script = f"""
+const createContextPoller = require({json.dumps(str(POLLER))});
+let resolveFirst;
+let firstSignal;
+const rendered = [];
+const errors = [];
+let calls = 0;
+const poller = createContextPoller({{
+  fetchContext: (revisions, options) => {{
+    calls += 1;
+    if (calls === 1) {{
+      firstSignal = options.signal;
+      return new Promise(resolve => {{ resolveFirst = resolve; }});
+    }}
+    return Promise.resolve({{ context: {{ user: {{ login: 'fresh' }} }} }});
+  }},
+  onSnapshot: snapshot => rendered.push(snapshot.context.user.login),
+  onError: error => errors.push(error.name),
+  setTimer: () => 1,
+  clearTimer: () => {{}},
+  setDeadlineTimer: () => 1,
+  clearDeadlineTimer: () => {{}},
+}});
+
+(async () => {{
+  const stale = poller.start();
+  const fresh = poller.refresh({{ force: true }});
+  await fresh;
+  resolveFirst({{ context: {{ user: {{ login: 'stale' }} }} }});
+  await stale;
+  await new Promise(resolve => setImmediate(resolve));
+  process.stdout.write(JSON.stringify({{
+    calls,
+    firstAborted: firstSignal.aborted,
+    rendered,
+    errors,
+  }}));
+}})();
+"""
+
+    assert run_node(script) == {
+        "calls": 2,
+        "firstAborted": True,
+        "rendered": ["fresh"],
+        "errors": [],
+    }

tests/test_shared_context_snapshot.py

@@ -57,3 +57,21 @@ async def test_dashboard_reports_each_live_section_from_its_own_freshness():
     assert "const notificationsFresh = Array.isArray(snapshot.notifications)" not in html
     assert "Unread updates unavailable · showing last known updates" in html
     assert "Activity refresh failed · showing last activity" in html
+
+
+@pytest.mark.anyio
+async def test_operator_refresh_and_reconnect_supersede_a_stalled_live_request():
+    html = await dashboard()
+
+    assert "async function fetchLiveSnapshot(revisions = {}, { signal } = {})" in html
+    assert "headers: { Accept: 'application/json' },\n      signal," in html
+    assert "function load() { return contextPoller.refresh({ force: true }); }" in html
+    assert "contextPoller.refresh({ force: true });" in html
+
+
+@pytest.mark.anyio
+async def test_stalled_refresh_keeps_the_last_snapshot_with_specific_guidance():
+    html = await dashboard()
+
+    assert "e.name === 'TimeoutError'" in html
+    assert "Update delayed · showing last snapshot" in html

tests/test_work_pages.py

@@ -103,7 +103,7 @@ async def test_dashboard_announces_offline_mode_and_refreshes_after_reconnect():
     bootstrap = (Path(__file__).resolve().parents[1] / "frontend" / "dashboard.js").read_text()
     assert "window.addEventListener('offline'" in bootstrap
     assert "window.addEventListener('online'" in bootstrap
-    assert "contextPoller.refresh()" in bootstrap
+    assert "contextPoller.refresh({ force: true })" in bootstrap
 
 
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