fix(network): usar a rota default e não cachear IP público None

CHANGELOG.md

@@ -52,6 +52,10 @@ and this project adheres to [Semantic Versioning 2.0.0](https://semver.org/spec/
 - Version badge in README bumped to 0.1.1.
 
 ### Fixed
+- **`mm net` deixa de assumir `en0` e de cachear IP público `None`.**
+  A interface vem da rota default (`route -n get default`); sem rota,
+  cai em `en0`. Falha no ipify não fica 5 minutos no cache — o watch
+  tenta de novo no próximo ciclo.
 - **`mm watch -i` e `mm history -n` rejeitam 0 e negativo.** Antes
   `watch -i -1` crashava no `sleep` e `history -n -5` fatiava o CSV
   ao contrário. Linhas quebradas do CSV são ignoradas em vez de

COMMANDS.md

@@ -111,9 +111,9 @@ mm clean
 **What it does:** network info.
 
 **Shows:**
-- Active interface (`en0`, etc.)
+- Active interface (from the default route; falls back to `en0`)
 - Local IP
-- Public IP (queries `api.ipify.org`)
+- Public IP (queries `api.ipify.org`; a failed lookup is not cached)
 - SSID of connected Wi-Fi
 - Security (WPA2/WPA3)
 - Channel and width (e.g. 52 / 5GHz / 80MHz)

macmanager/cache.py

@@ -19,10 +19,12 @@
 _STORE: dict[tuple, tuple[float, object]] = {}
 
 
-def cached(ttl: float):
+def cached(ttl: float, *, cache_none: bool = True):
     """Decorator that caches a function's return for `ttl` seconds.
 
     Use ttl=0 to disable the cache (useful in tests).
+    `cache_none=False` não guarda None — falha de rede no IP público
+    não pode deixar o watch em "offline" por 5 minutos.
     """
 
     def deco(fn: Callable[..., T]) -> Callable[..., T]:
@@ -46,6 +48,8 @@ def wrapper(*args, **kwargs) -> T:
             if entry and (now - entry[0]) < ttl:
                 return entry[1]  # type: ignore[return-value]
             value = fn(*args, **kwargs)
+            if value is None and not cache_none:
+                return value
             _STORE[cache_key] = (now, value)
             return value
 

macmanager/network.py

@@ -54,9 +54,21 @@ def _local_ip(iface: str = "en0") -> Optional[str]:
     return out or None
 
 
-@cached(ttl=300)
+def parse_route_interface(raw: str) -> Optional[str]:
+    """Extrai a interface da rota default (`route -n get default`)."""
+    m = re.search(r"^\s*interface:\s+(\S+)", raw, flags=re.MULTILINE)
+    return m.group(1) if m else None
+
+
+def _active_interface() -> str:
+    """Interface da rota default. Sem rota, cai em en0."""
+    parsed = parse_route_interface(_run(["route", "-n", "get", "default"], timeout=2))
+    return parsed or "en0"
+
+
+@cached(ttl=300, cache_none=False)
 def _public_ip() -> Optional[str]:
-    """Public IP rarely changes — a 5-min cache avoids hits on every refresh."""
+    """IP público muda pouco — cache de 5 min. None não é cacheado."""
     try:
         with urllib.request.urlopen("https://api.ipify.org", timeout=2) as r:
             return r.read().decode().strip()
@@ -106,7 +118,7 @@ def _wifi_info() -> dict:
 
 @cached(ttl=10)
 def get_network() -> NetworkInfo:
-    iface = "en0"
+    iface = _active_interface()
     local = _local_ip(iface)
     public = _public_ip()
     wifi = _wifi_info()

tests/test_cache.py

@@ -207,6 +207,34 @@ def two() -> int:
         assert is_miss(peek(two))
 
 
+class TestCacheNone:
+    """Falha de rede no IP público não pode ficar 5 min no cache."""
+
+    def test_default_still_caches_none(self) -> None:
+        calls = []
+
+        @cached(ttl=60)
+        def flaky() -> int | None:
+            calls.append(1)
+            return None
+
+        assert flaky() is None
+        assert flaky() is None
+        assert len(calls) == 1
+
+    def test_cache_none_false_retries(self) -> None:
+        calls = []
+
+        @cached(ttl=60, cache_none=False)
+        def flaky() -> int | None:
+            calls.append(1)
+            return None if len(calls) == 1 else 7
+
+        assert flaky() is None
+        assert flaky() == 7
+        assert len(calls) == 2
+
+
 class TestIsMiss:
     def test_sentinel_is_miss(self) -> None:
         assert is_miss(cache_mod._MISS)

tests/test_network.py

@@ -13,10 +13,12 @@
 from macmanager.cache import clear_all
 from macmanager.network import (
     NetworkInfo,
+    _active_interface,
     _local_ip,
     _run,
     _signal_quality,
     _wifi_info,
+    parse_route_interface,
     render_network_panel,
 )
 
@@ -153,3 +155,34 @@ def test_ssid_with_closing_tag_does_not_raise(self) -> None:
         out = buf.getvalue()
         assert "My" in out
         assert "WiFi" in out
+
+
+class TestParseRouteInterface:
+    """USB-C Ethernet / VPN não são en0. A rota default diz qual iface usar."""
+
+    def test_extracts_interface(self) -> None:
+        raw = (
+            "   route to: default\n"
+            "destination: default\n"
+            "    gateway: 192.168.1.1\n"
+            "  interface: en8\n"
+            "      flags: <UP,GATEWAY,DONE>\n"
+        )
+        assert parse_route_interface(raw) == "en8"
+
+    def test_empty_output_returns_none(self) -> None:
+        assert parse_route_interface("") is None
+        assert parse_route_interface("no interface here") is None
+
+
+class TestActiveInterface:
+    def test_falls_back_to_en0(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setattr("macmanager.network._run", lambda *args, **kwargs: "")
+        assert _active_interface() == "en0"
+
+    def test_uses_parsed_interface(self, monkeypatch: pytest.MonkeyPatch) -> None:
+        monkeypatch.setattr(
+            "macmanager.network._run",
+            lambda *args, **kwargs: "  interface: utun4\n",
+        )
+        assert _active_interface() == "utun4"