feat: cache is_unspecified for zeroconf ip address objects (#1331)

src/zeroconf/_utils/ipaddress.py

@@ -34,13 +34,14 @@
 
 class ZeroconfIPv4Address(IPv4Address):
 
-    __slots__ = ("_str", "_is_link_local")
+    __slots__ = ("_str", "_is_link_local", "_is_unspecified")
 
     def __init__(self, *args: Any, **kwargs: Any) -> None:
         """Initialize a new IPv4 address."""
         super().__init__(*args, **kwargs)
         self._str = super().__str__()
         self._is_link_local = super().is_link_local
+        self._is_unspecified = super().is_unspecified
 
     def __str__(self) -> str:
         """Return the string representation of the IPv4 address."""
@@ -51,16 +52,22 @@ def is_link_local(self) -> bool:
         """Return True if this is a link-local address."""
         return self._is_link_local
 
+    @property
+    def is_unspecified(self) -> bool:
+        """Return True if this is an unspecified address."""
+        return self._is_unspecified
+
 
 class ZeroconfIPv6Address(IPv6Address):
 
-    __slots__ = ("_str", "_is_link_local")
+    __slots__ = ("_str", "_is_link_local", "_is_unspecified")
 
     def __init__(self, *args: Any, **kwargs: Any) -> None:
         """Initialize a new IPv6 address."""
         super().__init__(*args, **kwargs)
         self._str = super().__str__()
         self._is_link_local = super().is_link_local
+        self._is_unspecified = super().is_unspecified
 
     def __str__(self) -> str:
         """Return the string representation of the IPv6 address."""
@@ -71,6 +78,11 @@ def is_link_local(self) -> bool:
         """Return True if this is a link-local address."""
         return self._is_link_local
 
+    @property
+    def is_unspecified(self) -> bool:
+        """Return True if this is an unspecified address."""
+        return self._is_unspecified
+
 
 @lru_cache(maxsize=512)
 def _cached_ip_addresses(address: Union[str, bytes, int]) -> Optional[Union[IPv4Address, IPv6Address]]:

tests/utils/test_ipaddress.py

@@ -18,7 +18,19 @@ def test_cached_ip_addresses_wrapper():
     ipv4 = ipaddress.cached_ip_addresses('169.254.0.0')
     assert ipv4 is not None
     assert ipv4.is_link_local is True
+    assert ipv4.is_unspecified is False
+
+    ipv4 = ipaddress.cached_ip_addresses('0.0.0.0')
+    assert ipv4 is not None
+    assert ipv4.is_link_local is False
+    assert ipv4.is_unspecified is True
 
     ipv6 = ipaddress.cached_ip_addresses('fe80::1')
     assert ipv6 is not None
     assert ipv6.is_link_local is True
+    assert ipv6.is_unspecified is False
+
+    ipv6 = ipaddress.cached_ip_addresses('0:0:0:0:0:0:0:0')
+    assert ipv6 is not None
+    assert ipv6.is_link_local is False
+    assert ipv6.is_unspecified is True