fix(discovery): a sweep that could not run is not an answer (t62 F1)

The installed-apps sweep stamped an EMPTY answer on every failure path, so a
Shield that was asleep at the entity's startup sweep was cached as "0 apps" for
APP_LIST_TTL (6 h): `homeassistant.update_entity` then issued zero shells and
the sensor kept reporting 0/"pending" until the TTL or the Configure row's
force. A genuinely empty device was indistinguishable from it, so "ok" was
unreachable for an empty list.

Only a sweep that RAN stamps the cache now. Every failure records the outcome
as `unknown` (`_apps_unavailable`), stores no table, and is retried by the next
non-forced refresh; a sweep that reached the device and failed is spaced by
APP_SWEEP_RETRY_SECONDS (30 s, force=True bypasses) so a silent socket is not
hammered once per poll, while an unavailable transport costs nothing and is
retried immediately. `installed_apps_status` exposes ok/unknown/pending, the
sensor surfaces it, and "ok" + an empty table is now the honest empty answer.
Docstrings, the README vocabulary and the docs on what a refresh actually
re-runs are corrected; the "update_entity re-runs only without a fresh table,
the Configure row forces one" wording stays true.

Red proof (pre-fix sources, current tests): the five new/updated tests fail on
HEAD, e.g. `installed_apps_stale` is False after the ADB-down startup sweep, and
the sensor reports 'pending' where it must say 'unknown'.

Same class already fixed for app labels: a fetch that could not run is not an
answer. Also records that the `-3`/resolve-activity/pm-dump output shapes are
documented, not observed.

README.md

@@ -448,6 +448,12 @@ not launchable apps — with the one exception that matters: the active launcher
 is a system app yet is exactly what the user sees. Nothing else is filtered, so an app
 is missing only if Android itself does not report it.
 
+*(Every output shape above is the **documented** Android one, not an observed
+capture: no real Shield was available when this was written, so
+`pm list packages -3`, `resolve-activity --brief` and `pm dump` are exercised from
+fixtures — the same "inferred, not observed" mark the state=6 buffering value
+carries in the source ladder above.)*
+
 Names come from the same cached path the Current App sensor uses: a `pm dump` per
 package, parsed for `application-label`, cached for 24 h. A full sweep runs the dumps
 in a small burst (4 at a time, 50 ms apart), which finishes a typical Shield in
@@ -466,16 +472,22 @@ and `mdi:television` otherwise. The icon never enters your **icon column**: that
 is a picture URL or a `camera.*` entity and feeds `entity_picture`, so writing an
 `mdi:` name there would put a value the media player cannot use into your own map.
 
-Discovery never runs on a state poll: it happens when you press the row, and the result
+Discovery does not run on the watchdog: the Configure row runs it, the dashboard
-is cached for 6 h. With ADB off, or unreachable, the table simply shows the rows you
+sensor refreshes the table when it has no fresh one, and the result is cached for 6 h.
-wrote yourself and the menu says why.
+With ADB off, or unreachable, the table simply shows the rows you wrote yourself and
+the menu says why. A sweep that **could not run** is not cached as an answer: it is
+recorded as `unknown` and retried, so a Shield that was asleep at startup is picked up
+by the next refresh instead of reporting an empty device for six hours.
 
 **For dashboards** the same table is a sensor: `sensor.<name>_installed_apps`, whose
 state is the app **count** and whose `installed_apps` attribute is the list of
-`{package, name, icon}`. Its `discovery` attribute says `ok`, `pending`, `not_connected`
+`{package, name, icon}`. Its `discovery` attribute says `ok`, `pending`, `unknown`,
-or `adb_disabled`. It only exists for ADB-enabled entries, and it is cheap to refresh —
+`not_connected` or `adb_disabled`: `ok` means the table IS the answer — including a
-`homeassistant.update_entity` on it re-runs the sweep only when the cache has expired,
+genuinely empty one — and `unknown` means the last sweep could not run (an empty list
-while the Configure row forces one.
+then says nothing about the device, and the next refresh retries). It only exists for
+ADB-enabled entries, and it is cheap to refresh — `homeassistant.update_entity` on it
+re-runs the sweep only when there is no fresh table (the cache expired, or the last
+sweep could not run), while the Configure row forces one.
 
 ```yaml
 # every installed app, with the name this integration would show

custom_components/nvidia_shield/connection.py

@@ -224,10 +224,22 @@ class ShieldConnectionManager:
         # t55: packages whose label fetch is queued or in flight — a render
         # during the fetch must not enqueue the same package twice.
         self._app_label_inflight: set[str] = set()
-        # t57: the discovered installed-apps table — (rows, stamp), or an empty
+        # t57: the discovered installed-apps table — (rows, stamp), or None when
-        # row list with a stamp when ADB cannot answer. APP_LIST_TTL, refreshed
+        # no sweep has produced a fresh answer. Only a sweep that RAN writes
-        # on demand; never rebuilt on a state poll.
+        # here (t62 F1): a failed or unavailable sweep records itself as UNKNOWN
+        # instead, because stamping an empty answer would serve "0 apps" — and
+        # block every retry — for the whole APP_LIST_TTL. Refreshed on demand;
+        # never rebuilt on a state poll.
         self._installed_apps: tuple[list[dict], float] | None = None
+        # t62 F1: True when the last sweep could not deliver an answer (no
+        # poller, ADB down, a shell that raised or answered nothing) — so an
+        # empty installed_apps() is "unknown", not "this device has no apps".
+        self._apps_unavailable = False
+        # ...and the clock stamp of an ATTEMPTED failure (shells really went
+        # out). A retry then costs two listing shells, so it is spaced by
+        # APP_SWEEP_RETRY_SECONDS instead of firing on every state poll; an
+        # unavailable transport costs nothing and retries immediately.
+        self._apps_failed_at: float | None = None
         #: t57: the in-flight sweep, so concurrent callers share one sweep
         #: instead of stacking a second burst on the same connection.
         self._apps_sweep: asyncio.Task | None = None
@@ -888,12 +900,22 @@ class ShieldConnectionManager:
 
     # ── t57: installed-app discovery ───────────────────────────────────────
 
+    #: t62 F1: how long after an ATTEMPTED sweep failed before another one is
+    #: issued. A retry costs two listing shells, so it waits out one state poll
+    #: (30 s) rather than hammering a silent socket; ``force=True`` bypasses it.
+    #: An unavailable transport (no poller, ADB down) costs nothing and is
+    #: retried on the very next update.
+    APP_SWEEP_RETRY_SECONDS: float = 30.0
+
     def installed_apps(self) -> list[dict]:
         """The discovered apps, ``[{package, name, icon}]``, cached (t57).
 
         Returns the cached table whenever it is fresh, and an EMPTY list when
-        there is nothing usable yet (ADB disabled, not connected, or the first
+        there is no fresh answer: ADB disabled, not connected, the first sweep
-        sweep still running). A caller that wants the table filled calls
+        still running, or a sweep that could not run (t62 F1). Empty is
+        therefore "nothing to show", never by itself "this device has no apps"
+        — ask :meth:`installed_apps_status` which of the two it is. A caller
+        that wants the table filled calls
         :meth:`async_refresh_installed_apps`; this accessor never blocks and
         never issues a shell itself, so a state poll stays free of discovery
         work.
@@ -913,6 +935,23 @@ class ShieldConnectionManager:
         _rows, stamp = self._installed_apps
         return self._clock() - stamp > APP_LIST_TTL
 
+    @property
+    def installed_apps_status(self) -> str:
+        """Why :meth:`installed_apps` may be empty, in one word (t62 F1).
+
+        * ``"ok"`` — a sweep RAN and its answer is fresh. An empty table with
+          this status is a real answer (the device reported no launchable
+          apps), which is the case the old stamped-empty cache could not say.
+        * ``"unknown"`` — the last sweep could not deliver an answer (no
+          poller, ADB down, a shell that raised or answered nothing). Nothing
+          is known about the device, and the next update retries.
+        * ``"pending"`` — no sweep has completed yet, or the last answer
+          expired and a refresh is due.
+        """
+        if not self.installed_apps_stale:
+            return "ok"
+        return "unknown" if self._apps_unavailable else "pending"
+
     async def async_refresh_installed_apps(self, force: bool = False) -> list[dict]:
         """(Re)build the installed-app table over ADB, bounded and shared (t57).
 
@@ -921,13 +960,26 @@ class ShieldConnectionManager:
         ``force``. The sweep is deliberately NOT part of the watchdog: it is a
         handful of shells on demand, not a per-cycle cost.
 
-        Failure is normal and handled without noise — no poller, a disconnected
+        Failure is not an answer (t62 F1). No poller, a disconnected transport,
-        transport, or a shell that answers nothing stores an EMPTY table with a
+        a shell that raises, or a sweep that delivered no output records
-        stamp, so the caller degrades to "no discovered apps" and nothing
+        ``unknown`` and stores NO table, so the next non-forced call — an
-        retries in a loop. The next explicit refresh (or the TTL) tries again.
+        entity poll or the standard ``update_entity`` action — retries instead
+        of serving a stamped empty answer for the whole APP_LIST_TTL. A sweep
+        that reached the device and failed is retried at most once per
+        ``APP_SWEEP_RETRY_SECONDS`` so a silent socket is not hammered; a sweep
+        that RAN stores its answer, including a genuinely empty list.
         """
         if not force and not self.installed_apps_stale:
             return self.installed_apps()
+        if (
+            not force
+            and self._apps_failed_at is not None
+            and self._clock() - self._apps_failed_at < self.APP_SWEEP_RETRY_SECONDS
+        ):
+            # The previous attempt really issued shells and failed: space the
+            # retries by one poll interval instead of re-issuing them every
+            # 30 s on a socket that is not answering (t62 F1).
+            return self.installed_apps()
         if self._apps_sweep is not None and not self._apps_sweep.done():
             await asyncio.shield(self._apps_sweep)
             return self.installed_apps()
@@ -941,14 +993,20 @@ class ShieldConnectionManager:
         return [dict(row) for row in rows]
 
     async def _sweep_installed_apps(self) -> list[dict]:
-        """The sweep itself: list, label, icon — then stamp the cache."""
+        """The sweep itself: list, label, icon — then stamp the cache (t57).
+
+        Only a sweep that RAN stamps the cache (t62 F1): every failure path
+        records ``unknown`` and leaves ``_installed_apps`` alone, so the table
+        the entity serves is the last one that was real — never a fabricated
+        empty answer that also blocks the retry for APP_LIST_TTL.
+        """
         poller = self._poller
         if poller is None or not self.connected:
             _LOGGER.debug(
                 "installed-app discovery skipped (ADB unavailable) — the "
                 "options page and the app list stay on what is already known"
             )
-            self._installed_apps = ([], self._clock())
+            self._note_apps_unavailable(attempted=False)
             return []
         try:
             user_output = await poller.shell("pm list packages -3")
@@ -958,15 +1016,15 @@ class ShieldConnectionManager:
             )
         except Exception as err:  # pragma: no cover - shell swallows its own
             _LOGGER.debug("installed-app discovery failed: %s", err)
-            self._installed_apps = ([], self._clock())
+            self._note_apps_unavailable(attempted=True)
             return []
         if user_output is None and launcher_output is None:
-            # the transport delivered nothing at all: no list is an ANSWER
+            # the transport delivered nothing at all: no list is NOT an answer
             _LOGGER.debug(
-                "installed-app discovery got no output — will try again on the "
+                "installed-app discovery got no output — will retry on the "
-                "next refresh"
+                "next update"
             )
-            self._installed_apps = ([], self._clock())
+            self._note_apps_unavailable(attempted=True)
             return []
 
         packages = [p for p in installed_packages(user_output, launcher_output)
@@ -981,9 +1039,20 @@ class ShieldConnectionManager:
             for package in packages
         ]
         self._installed_apps = (rows, self._clock())
+        self._apps_unavailable = False
+        self._apps_failed_at = None
         _LOGGER.debug("installed-app discovery found %d apps", len(rows))
         return rows
 
+    def _note_apps_unavailable(self, *, attempted: bool) -> None:
+        """Record a sweep that could not deliver an answer (t62 F1).
+
+        ``attempted`` says whether shells were actually issued: only then does
+        the retry window apply, because only then does a retry cost anything.
+        """
+        self._apps_unavailable = True
+        self._apps_failed_at = self._clock() if attempted else None
+
     async def _sweep_labels(self, packages: list[str]) -> dict[str, str]:
         """Labels for a whole sweep, in a bounded burst (t57).
 

custom_components/nvidia_shield/sensor.py

@@ -167,10 +167,14 @@ class NvidiaShieldAppsSensor(NvidiaShieldSensorBase):
     Only ADB-enabled entries get one. Discovery is a handful of shells, so it
     runs once when the entity is added and then only when the table has gone
     stale: ``async_update`` goes through the manager's TTL cache, so a poll on a
-    fresh table issues NO shell. On top of that the user can ask for a refresh
+    fresh table issues NO shell. A sweep that could not run is NOT an answer
-    with the standard ``homeassistant.update_entity`` action, and the Configure
+    (t62 F1): it is recorded as ``unknown`` and retried on the next update
-    page runs the same sweep from its discovery row. With ADB off, or
+    instead of being frozen as a stamped-empty table for APP_LIST_TTL, while a
-    unreachable, the attributes say why and the state is 0 rather than raising.
+    sweep that ran and found nothing IS the answer ``ok`` with a count of 0. On
+    top of that the user can ask for a refresh with the standard
+    ``homeassistant.update_entity`` action, and the Configure page runs the same
+    sweep from its discovery row. With ADB off, or unreachable, the attributes
+    say why and the state is 0 rather than raising.
     """
 
     _attr_translation_key = "installed_apps"
@@ -178,7 +182,9 @@ class NvidiaShieldAppsSensor(NvidiaShieldSensorBase):
     # Polling is what makes the standard `homeassistant.update_entity` action
     # work for it — the user-facing "refresh the app list" trigger. The poll is
     # free while the table is fresh: the manager returns the cache and issues no
-    # shell until APP_LIST_TTL expires.
+    # shell until APP_LIST_TTL expires. A sweep that COULD NOT run leaves no
+    # fresh table (t62 F1), so a later poll retries it — that retry is the
+    # recovery the old stamped-empty answer blocked for up to six hours.
     _attr_should_poll = True
 
     def __init__(self, hass: HomeAssistant, entry: ConfigEntry) -> None:
@@ -203,7 +209,13 @@ class NvidiaShieldAppsSensor(NvidiaShieldSensorBase):
             self.async_write_ha_state()
 
     async def async_update(self) -> None:
-        """Refresh the table on demand (explicitly requested only)."""
+        """Refresh the table when there is no fresh answer (t57, t62 F1).
+
+        HA's own poll (``_attr_should_poll``) and an explicit
+        ``homeassistant.update_entity`` both land here; the manager's TTL makes
+        it a no-op while the table is fresh, and a retry while it is not —
+        including after a sweep that could not run.
+        """
         manager = self._manager()
         if manager is None:
             return
@@ -216,21 +228,28 @@ class NvidiaShieldAppsSensor(NvidiaShieldSensorBase):
 
     @property
     def extra_state_attributes(self) -> dict:
-        """The table itself, plus why it may be empty (never a crash)."""
+        """The table itself, plus why it may be empty (never a crash).
+
+        ``discovery`` is the honest reason (t62 F1): ``ok`` means the table IS
+        the answer, including a genuinely empty one, while ``unknown`` means
+        the last sweep could not run — so an empty list says nothing about the
+        device and the next update retries.
+        """
         manager = self._manager()
         if manager is None:
             return {"installed_apps": [], "discovery": "unavailable"}
         apps = manager.installed_apps()
         attrs = {"installed_apps": apps}
-        if not apps:
+        if apps:
-            if not self._entry.options.get(CONF_ADB_ENABLED, True):
-                attrs["discovery"] = "adb_disabled"
-            elif not manager.connected:
-                attrs["discovery"] = "not_connected"
-            else:
-                attrs["discovery"] = "pending"
-        else:
             attrs["discovery"] = "ok"
+        elif not self._entry.options.get(CONF_ADB_ENABLED, True):
+            attrs["discovery"] = "adb_disabled"
+        elif not manager.connected:
+            attrs["discovery"] = "not_connected"
+        else:
+            # "ok" here is a real empty answer, "unknown" a sweep that could
+            # not run, "pending" one that has not completed yet.
+            attrs["discovery"] = manager.installed_apps_status
         return attrs
 
 

tests/test_installed_apps.py

@@ -393,7 +393,11 @@ class TestDiscoverySweep:
 
 
 class TestDiscoveryDegradesGracefully:
-    """ADB off, down or mute: an empty list and a note, never a crash or a loop."""
+    """ADB off, down or mute: an empty list and a note, never a crash or a loop.
+
+    t62 F1: "could not ask" and "asked, nothing there" are different answers.
+    Only the second one is cached; the first is retried.
+    """
 
     async def test_no_poller_is_an_empty_list(self):
         manager = ShieldConnectionManager(hass=None, entry=None, poller=None)
@@ -416,19 +420,64 @@ class TestDiscoveryDegradesGracefully:
         assert rows == []
         assert poller.shell_calls == []  # nothing was even attempted
 
-    async def test_a_mute_transport_reports_empty_without_raising(self):
+    async def test_a_mute_transport_is_spaced_but_not_stamped(self):
+        """t62 F1: a failed sweep is retried — but not once per state poll."""
+        now = [1000.0]
         poller = _DiscoveryPoller(failure=True)
-        manager = _manager(poller)
+        manager = ShieldConnectionManager(
+            hass=None, entry=None, poller=poller, clock=lambda: now[0]
+        )
 
         rows = await manager.async_refresh_installed_apps()
 
         assert rows == []
         assert poller.shell_calls  # it tried
-        # and a second call does NOT re-shell in a loop: the empty answer is
+        assert manager.installed_apps_status == "unknown"  # NOT an empty answer
-        # stamped, and only an explicit force/TTL asks again
+        # the next poll inside the window does NOT re-shell (no hammering)..
         calls = len(poller.shell_calls)
         assert await manager.async_refresh_installed_apps() == []
         assert len(poller.shell_calls) == calls
+        # ..but nothing was stamped as an answer, so once the window passes the
+        # sweep runs again. Pre-fix it waited out APP_LIST_TTL (6 h) instead.
+        now[0] += manager.APP_SWEEP_RETRY_SECONDS + 1
+        assert await manager.async_refresh_installed_apps() == []
+        assert len(poller.shell_calls) > calls
+
+    async def test_a_sweep_that_could_not_run_is_not_a_fresh_answer(self):
+        """t62 F1 (red proof): startup with ADB down must not BE the answer.
+
+        The entity's one startup sweep runs with the poller down. Once ADB comes
+        back, ``homeassistant.update_entity`` (``sensor.async_update``) must
+        recover the table. Pre-fix the startup sweep stamped an empty answer, so
+        this call issued ZERO shells and kept reporting 0/"pending" for
+        APP_LIST_TTL = 6 h.
+        """
+        poller = _DiscoveryPoller(dumps={"ar.tvplayer.tv": DUMP_TIVIMATE})
+        poller.connected = False
+        manager = _manager(poller)
+
+        assert await manager.async_refresh_installed_apps() == []  # the startup
+        assert poller.shell_calls == []  # it was not even attempted
+        assert manager.installed_apps_stale is True  # ...so it is not an answer
+        assert manager.installed_apps_status == "unknown"
+
+        poller.connected = True  # ADB is back
+        rows = await manager.async_refresh_installed_apps()
+
+        assert rows, "update_entity must recover the table once ADB returns"
+        assert "pm list packages -3" in poller.shell_calls
+        assert manager.installed_apps_status == "ok"
+
+    async def test_a_genuinely_empty_answer_is_ok(self):
+        """t62 F1: 'ok' must be reachable for a really empty device."""
+        poller = _DiscoveryPoller(packages="", launcher="")
+        manager = _manager(poller)
+
+        assert await manager.async_refresh_installed_apps() == []
+
+        assert poller.shell_calls  # the commands RAN and answered
+        assert manager.installed_apps_stale is False  # stamped: a real answer
+        assert manager.installed_apps_status == "ok"
 
     async def test_the_accessor_never_shells(self):
         poller = _DiscoveryPoller()
@@ -534,6 +583,31 @@ class TestInstalledAppsSensor:
         assert attrs["installed_apps"] == []
         assert attrs["discovery"] in ("pending", "not_connected", "adb_disabled")
 
+    async def test_an_empty_discovery_is_ok_not_pending(self):
+        """t62 F1: a sweep that RAN and found nothing is the answer 'ok'."""
+        poller = _DiscoveryPoller(packages="", launcher="")
+        manager = _manager(poller)
+        await manager.async_refresh_installed_apps()
+        sensor = self._sensor(manager, {"adb_enabled": True})
+
+        assert sensor.native_value == 0
+        assert sensor.extra_state_attributes == {
+            "installed_apps": [],
+            "discovery": "ok",
+        }
+
+    async def test_a_sweep_that_could_not_run_is_unknown_not_pending(self):
+        """t62 F1: 'pending' used to cover both "running" and "could not run"."""
+        poller = _DiscoveryPoller(failure=True)
+        manager = _manager(poller)
+        await manager.async_refresh_installed_apps()
+        sensor = self._sensor(manager, {"adb_enabled": True})
+
+        assert sensor.extra_state_attributes == {
+            "installed_apps": [],
+            "discovery": "unknown",
+        }
+
     def test_adb_disabled_is_reported_as_such(self):
         poller = _DiscoveryPoller()
         manager = _manager(poller)