[dashboard] Transfer DNS/mDNS cache from dashboard to CLI to avoid blocking (#10685)

esphome/__main__.py

@@ -114,6 +114,14 @@ class Purpose(StrEnum):
     LOGGING = "logging"
 
 
+def _resolve_with_cache(address: str, purpose: Purpose) -> list[str]:
+    """Resolve an address using cache if available, otherwise return the address itself."""
+    if CORE.address_cache and (cached := CORE.address_cache.get_addresses(address)):
+        _LOGGER.debug("Using cached addresses for %s: %s", purpose.value, cached)
+        return cached
+    return [address]
+
+
 def choose_upload_log_host(
     default: list[str] | str | None,
     check_default: str | None,
@@ -142,7 +150,7 @@ def choose_upload_log_host(
                     (purpose == Purpose.LOGGING and has_api())
                     or (purpose == Purpose.UPLOADING and has_ota())
                 ):
-                    resolved.append(CORE.address)
+                    resolved.extend(_resolve_with_cache(CORE.address, purpose))
 
                 if purpose == Purpose.LOGGING:
                     if has_api() and has_mqtt_ip_lookup():
@@ -152,15 +160,14 @@ def choose_upload_log_host(
                         resolved.append("MQTT")
 
                     if has_api() and has_non_ip_address():
-                        resolved.append(CORE.address)
+                        resolved.extend(_resolve_with_cache(CORE.address, purpose))
 
                 elif purpose == Purpose.UPLOADING:
                     if has_ota() and has_mqtt_ip_lookup():
                         resolved.append("MQTTIP")
 
                     if has_ota() and has_non_ip_address():
-                        resolved.append(CORE.address)
-
+                        resolved.extend(_resolve_with_cache(CORE.address, purpose))
             else:
                 resolved.append(device)
         if not resolved:
@@ -965,6 +972,18 @@ def parse_args(argv):
         help="Add a substitution",
         metavar=("key", "value"),
     )
+    options_parser.add_argument(
+        "--mdns-address-cache",
+        help="mDNS address cache mapping in format 'hostname=ip1,ip2'",
+        action="append",
+        default=[],
+    )
+    options_parser.add_argument(
+        "--dns-address-cache",
+        help="DNS address cache mapping in format 'hostname=ip1,ip2'",
+        action="append",
+        default=[],
+    )
 
     parser = argparse.ArgumentParser(
         description=f"ESPHome {const.__version__}", parents=[options_parser]
@@ -1212,9 +1231,15 @@ def parse_args(argv):
 
 
 def run_esphome(argv):
+    from esphome.address_cache import AddressCache
+
     args = parse_args(argv)
     CORE.dashboard = args.dashboard
 
+    # Create address cache from command-line arguments
+    CORE.address_cache = AddressCache.from_cli_args(
+        args.mdns_address_cache, args.dns_address_cache
+    )
     # Override log level if verbose is set
     if args.verbose:
         args.log_level = "DEBUG"

esphome/address_cache.py

@@ -0,0 +1,142 @@
+"""Address cache for DNS and mDNS lookups."""
+
+from __future__ import annotations
+
+import logging
+from typing import TYPE_CHECKING
+
+if TYPE_CHECKING:
+    from collections.abc import Iterable
+
+_LOGGER = logging.getLogger(__name__)
+
+
+def normalize_hostname(hostname: str) -> str:
+    """Normalize hostname for cache lookups.
+
+    Removes trailing dots and converts to lowercase.
+    """
+    return hostname.rstrip(".").lower()
+
+
+class AddressCache:
+    """Cache for DNS and mDNS address lookups.
+
+    This cache stores pre-resolved addresses from command-line arguments
+    to avoid slow DNS/mDNS lookups during builds.
+    """
+
+    def __init__(
+        self,
+        mdns_cache: dict[str, list[str]] | None = None,
+        dns_cache: dict[str, list[str]] | None = None,
+    ) -> None:
+        """Initialize the address cache.
+
+        Args:
+            mdns_cache: Pre-populated mDNS addresses (hostname -> IPs)
+            dns_cache: Pre-populated DNS addresses (hostname -> IPs)
+        """
+        self.mdns_cache = mdns_cache or {}
+        self.dns_cache = dns_cache or {}
+
+    def _get_cached_addresses(
+        self, hostname: str, cache: dict[str, list[str]], cache_type: str
+    ) -> list[str] | None:
+        """Get cached addresses from a specific cache.
+
+        Args:
+            hostname: The hostname to look up
+            cache: The cache dictionary to check
+            cache_type: Type of cache for logging ("mDNS" or "DNS")
+
+        Returns:
+            List of IP addresses if found in cache, None otherwise
+        """
+        normalized = normalize_hostname(hostname)
+        if addresses := cache.get(normalized):
+            _LOGGER.debug("Using %s cache for %s: %s", cache_type, hostname, addresses)
+            return addresses
+        return None
+
+    def get_mdns_addresses(self, hostname: str) -> list[str] | None:
+        """Get cached mDNS addresses for a hostname.
+
+        Args:
+            hostname: The hostname to look up (should end with .local)
+
+        Returns:
+            List of IP addresses if found in cache, None otherwise
+        """
+        return self._get_cached_addresses(hostname, self.mdns_cache, "mDNS")
+
+    def get_dns_addresses(self, hostname: str) -> list[str] | None:
+        """Get cached DNS addresses for a hostname.
+
+        Args:
+            hostname: The hostname to look up
+
+        Returns:
+            List of IP addresses if found in cache, None otherwise
+        """
+        return self._get_cached_addresses(hostname, self.dns_cache, "DNS")
+
+    def get_addresses(self, hostname: str) -> list[str] | None:
+        """Get cached addresses for a hostname.
+
+        Checks mDNS cache for .local domains, DNS cache otherwise.
+
+        Args:
+            hostname: The hostname to look up
+
+        Returns:
+            List of IP addresses if found in cache, None otherwise
+        """
+        normalized = normalize_hostname(hostname)
+        if normalized.endswith(".local"):
+            return self.get_mdns_addresses(hostname)
+        return self.get_dns_addresses(hostname)
+
+    def has_cache(self) -> bool:
+        """Check if any cache entries exist."""
+        return bool(self.mdns_cache or self.dns_cache)
+
+    @classmethod
+    def from_cli_args(
+        cls, mdns_args: Iterable[str], dns_args: Iterable[str]
+    ) -> AddressCache:
+        """Create cache from command-line arguments.
+
+        Args:
+            mdns_args: List of mDNS cache entries like ['host=ip1,ip2']
+            dns_args: List of DNS cache entries like ['host=ip1,ip2']
+
+        Returns:
+            Configured AddressCache instance
+        """
+        mdns_cache = cls._parse_cache_args(mdns_args)
+        dns_cache = cls._parse_cache_args(dns_args)
+        return cls(mdns_cache=mdns_cache, dns_cache=dns_cache)
+
+    @staticmethod
+    def _parse_cache_args(cache_args: Iterable[str]) -> dict[str, list[str]]:
+        """Parse cache arguments into a dictionary.
+
+        Args:
+            cache_args: List of cache mappings like ['host1=ip1,ip2', 'host2=ip3']
+
+        Returns:
+            Dictionary mapping normalized hostnames to list of IP addresses
+        """
+        cache: dict[str, list[str]] = {}
+        for arg in cache_args:
+            if "=" not in arg:
+                _LOGGER.warning(
+                    "Invalid cache format: %s (expected 'hostname=ip1,ip2')", arg
+                )
+                continue
+            hostname, ips = arg.split("=", 1)
+            # Normalize hostname for consistent lookups
+            normalized = normalize_hostname(hostname)
+            cache[normalized] = [ip.strip() for ip in ips.split(",")]
+        return cache

esphome/core/__init__.py

@@ -39,6 +39,8 @@ from esphome.helpers import ensure_unique_string, get_str_env, is_ha_addon
 from esphome.util import OrderedDict
 
 if TYPE_CHECKING:
+    from esphome.address_cache import AddressCache
+
     from ..cpp_generator import MockObj, MockObjClass, Statement
     from ..types import ConfigType, EntityMetadata
 
@@ -583,6 +585,8 @@ class EsphomeCore:
         self.id_classes = {}
         # The current component being processed during validation
         self.current_component: str | None = None
+        # Address cache for DNS and mDNS lookups from command line arguments
+        self.address_cache: AddressCache | None = None
 
     def reset(self):
         from esphome.pins import PIN_SCHEMA_REGISTRY
@@ -610,6 +614,7 @@ class EsphomeCore:
         self.platform_counts = defaultdict(int)
         self.unique_ids = {}
         self.current_component = None
+        self.address_cache = None
         PIN_SCHEMA_REGISTRY.reset()
 
     @contextmanager

esphome/dashboard/dns.py

@@ -28,6 +28,21 @@ class DNSCache:
         self._cache: dict[str, tuple[float, list[str] | Exception]] = {}
         self._ttl = ttl
 
+    def get_cached_addresses(
+        self, hostname: str, now_monotonic: float
+    ) -> list[str] | None:
+        """Get cached addresses without triggering resolution.
+
+        Returns None if not in cache, list of addresses if found.
+        """
+        # Normalize hostname for consistent lookups
+        normalized = hostname.rstrip(".").lower()
+        if expire_time_addresses := self._cache.get(normalized):
+            expire_time, addresses = expire_time_addresses
+            if expire_time > now_monotonic and not isinstance(addresses, Exception):
+                return addresses
+        return None
+
     async def async_resolve(
         self, hostname: str, now_monotonic: float
     ) -> list[str] | Exception:

esphome/dashboard/status/mdns.py

@@ -4,6 +4,9 @@ import asyncio
 import logging
 import typing
 
+from zeroconf import AddressResolver, IPVersion
+
+from esphome.address_cache import normalize_hostname
 from esphome.zeroconf import (
     ESPHOME_SERVICE_TYPE,
     AsyncEsphomeZeroconf,
@@ -50,6 +53,30 @@ class MDNSStatus:
             return await aiozc.async_resolve_host(host_name)
         return None
 
+    def get_cached_addresses(self, host_name: str) -> list[str] | None:
+        """Get cached addresses for a host without triggering resolution.
+
+        Returns None if not in cache or no zeroconf available.
+        """
+        if not self.aiozc:
+            _LOGGER.debug("No zeroconf instance available for %s", host_name)
+            return None
+
+        # Normalize hostname and get the base name
+        normalized = normalize_hostname(host_name)
+        base_name = normalized.partition(".")[0]
+
+        # Try to load from zeroconf cache without triggering resolution
+        resolver_name = f"{base_name}.local."
+        info = AddressResolver(resolver_name)
+        # Let zeroconf use its own current time for cache checking
+        if info.load_from_cache(self.aiozc.zeroconf):
+            addresses = info.parsed_scoped_addresses(IPVersion.All)
+            _LOGGER.debug("Found %s in zeroconf cache: %s", resolver_name, addresses)
+            return addresses
+        _LOGGER.debug("Not found in zeroconf cache: %s", resolver_name)
+        return None
+
     async def async_refresh_hosts(self) -> None:
         """Refresh the hosts to track."""
         dashboard = self.dashboard

esphome/dashboard/web_server.py

@@ -50,8 +50,8 @@ from esphome.util import get_serial_ports, shlex_quote
 from esphome.yaml_util import FastestAvailableSafeLoader
 
 from .const import DASHBOARD_COMMAND
-from .core import DASHBOARD
-from .entries import UNKNOWN_STATE, entry_state_to_bool
+from .core import DASHBOARD, ESPHomeDashboard
+from .entries import UNKNOWN_STATE, DashboardEntry, entry_state_to_bool
 from .util.file import write_file
 from .util.subprocess import async_run_system_command
 from .util.text import friendly_name_slugify
@@ -314,6 +314,73 @@ class EsphomeCommandWebSocket(tornado.websocket.WebSocketHandler):
         raise NotImplementedError
 
 
+def build_cache_arguments(
+    entry: DashboardEntry | None,
+    dashboard: ESPHomeDashboard,
+    now: float,
+) -> list[str]:
+    """Build cache arguments for passing to CLI.
+
+    Args:
+        entry: Dashboard entry for the configuration
+        dashboard: Dashboard instance with cache access
+        now: Current monotonic time for DNS cache expiry checks
+
+    Returns:
+        List of cache arguments to pass to CLI
+    """
+    cache_args: list[str] = []
+
+    if not entry:
+        return cache_args
+
+    _LOGGER.debug(
+        "Building cache for entry (address=%s, name=%s)",
+        entry.address,
+        entry.name,
+    )
+
+    def add_cache_entry(hostname: str, addresses: list[str], cache_type: str) -> None:
+        """Add a cache entry to the command arguments."""
+        if not addresses:
+            return
+        normalized = hostname.rstrip(".").lower()
+        cache_args.extend(
+            [
+                f"--{cache_type}-address-cache",
+                f"{normalized}={','.join(sort_ip_addresses(addresses))}",
+            ]
+        )
+
+    # Check entry.address for cached addresses
+    if use_address := entry.address:
+        if use_address.endswith(".local"):
+            # mDNS cache for .local addresses
+            if (mdns := dashboard.mdns_status) and (
+                cached := mdns.get_cached_addresses(use_address)
+            ):
+                _LOGGER.debug("mDNS cache hit for %s: %s", use_address, cached)
+                add_cache_entry(use_address, cached, "mdns")
+        # DNS cache for non-.local addresses
+        elif cached := dashboard.dns_cache.get_cached_addresses(use_address, now):
+            _LOGGER.debug("DNS cache hit for %s: %s", use_address, cached)
+            add_cache_entry(use_address, cached, "dns")
+
+    # Check entry.name if we haven't already cached via address
+    # For mDNS devices, entry.name typically doesn't have .local suffix
+    if entry.name and not use_address:
+        mdns_name = (
+            f"{entry.name}.local" if not entry.name.endswith(".local") else entry.name
+        )
+        if (mdns := dashboard.mdns_status) and (
+            cached := mdns.get_cached_addresses(mdns_name)
+        ):
+            _LOGGER.debug("mDNS cache hit for %s: %s", mdns_name, cached)
+            add_cache_entry(mdns_name, cached, "mdns")
+
+    return cache_args
+
+
 class EsphomePortCommandWebSocket(EsphomeCommandWebSocket):
     """Base class for commands that require a port."""
 
@@ -326,52 +393,22 @@ class EsphomePortCommandWebSocket(EsphomeCommandWebSocket):
         configuration = json_message["configuration"]
         config_file = settings.rel_path(configuration)
         port = json_message["port"]
-        addresses: list[str] = []
+
+        # Build cache arguments to pass to CLI
+        cache_args: list[str] = []
+
         if (
             port == "OTA"  # pylint: disable=too-many-boolean-expressions
             and (entry := entries.get(config_file))
             and entry.loaded_integrations
             and "api" in entry.loaded_integrations
         ):
-            # First priority: entry.address AKA use_address
-            if (
-                (use_address := entry.address)
-                and (
-                    address_list := await dashboard.dns_cache.async_resolve(
-                        use_address, time.monotonic()
-                    )
-                )
-                and not isinstance(address_list, Exception)
-            ):
-                addresses.extend(sort_ip_addresses(address_list))
+            cache_args = build_cache_arguments(entry, dashboard, time.monotonic())
 
-            # Second priority: mDNS
-            if (
-                (mdns := dashboard.mdns_status)
-                and (address_list := await mdns.async_resolve_host(entry.name))
-                and (
-                    new_addresses := [
-                        addr for addr in address_list if addr not in addresses
-                    ]
-                )
-            ):
-                # Use the IP address if available but only
-                # if the API is loaded and the device is online
-                # since MQTT logging will not work otherwise
-                addresses.extend(sort_ip_addresses(new_addresses))
-
-        if not addresses:
-            # If no address was found, use the port directly
-            # as otherwise they will get the chooser which
-            # does not work with the dashboard as there is no
-            # interactive way to get keyboard input
-            addresses = [port]
-
-        device_args: list[str] = [
-            arg for address in addresses for arg in ("--device", address)
-        ]
-
-        return [*DASHBOARD_COMMAND, *args, config_file, *device_args]
+        # Cache arguments must come before the subcommand
+        cmd = [*DASHBOARD_COMMAND, *cache_args, *args, config_file, "--device", port]
+        _LOGGER.debug("Built command: %s", cmd)
+        return cmd
 
 
 class EsphomeLogsHandler(EsphomePortCommandWebSocket):

esphome/espota2.py

@@ -311,10 +311,14 @@ def perform_ota(
 def run_ota_impl_(
     remote_host: str | list[str], remote_port: int, password: str, filename: str
 ) -> tuple[int, str | None]:
+    from esphome.core import CORE
+
     # Handle both single host and list of hosts
     try:
         # Resolve all hosts at once for parallel DNS resolution
-        res = resolve_ip_address(remote_host, remote_port)
+        res = resolve_ip_address(
+            remote_host, remote_port, address_cache=CORE.address_cache
+        )
     except EsphomeError as err:
         _LOGGER.error(
             "Error resolving IP address of %s. Is it connected to WiFi?",

esphome/helpers.py

@@ -9,10 +9,14 @@ from pathlib import Path
 import platform
 import re
 import tempfile
+from typing import TYPE_CHECKING
 from urllib.parse import urlparse
 
 from esphome.const import __version__ as ESPHOME_VERSION
 
+if TYPE_CHECKING:
+    from esphome.address_cache import AddressCache
+
 # Type aliases for socket address information
 AddrInfo = tuple[
     int,  # family (AF_INET, AF_INET6, etc.)
@@ -173,7 +177,24 @@ def addr_preference_(res: AddrInfo) -> int:
     return 1
 
 
-def resolve_ip_address(host: str | list[str], port: int) -> list[AddrInfo]:
+def _add_ip_addresses_to_addrinfo(
+    addresses: list[str], port: int, res: list[AddrInfo]
+) -> None:
+    """Helper to add IP addresses to addrinfo results with error handling."""
+    import socket
+
+    for addr in addresses:
+        try:
+            res += socket.getaddrinfo(
+                addr, port, proto=socket.IPPROTO_TCP, flags=socket.AI_NUMERICHOST
+            )
+        except OSError:
+            _LOGGER.debug("Failed to parse IP address '%s'", addr)
+
+
+def resolve_ip_address(
+    host: str | list[str], port: int, address_cache: AddressCache | None = None
+) -> list[AddrInfo]:
     import socket
 
     # There are five cases here. The host argument could be one of:
@@ -194,22 +215,44 @@ def resolve_ip_address(host: str | list[str], port: int) -> list[AddrInfo]:
         hosts = [host]
 
     res: list[AddrInfo] = []
+
+    # Fast path: if all hosts are already IP addresses
     if all(is_ip_address(h) for h in hosts):
-        # Fast path: all are IP addresses, use socket.getaddrinfo with AI_NUMERICHOST
-        for addr in hosts:
-            try:
-                res += socket.getaddrinfo(
-                    addr, port, proto=socket.IPPROTO_TCP, flags=socket.AI_NUMERICHOST
-                )
-            except OSError:
-                _LOGGER.debug("Failed to parse IP address '%s'", addr)
+        _add_ip_addresses_to_addrinfo(hosts, port, res)
         # Sort by preference
         res.sort(key=addr_preference_)
         return res
 
+    # Process hosts
+    cached_addresses: list[str] = []
+    uncached_hosts: list[str] = []
+    has_cache = address_cache is not None
+
+    for h in hosts:
+        if is_ip_address(h):
+            if has_cache:
+                # If we have a cache, treat IPs as cached
+                cached_addresses.append(h)
+            else:
+                # If no cache, pass IPs through to resolver with hostnames
+                uncached_hosts.append(h)
+        elif address_cache and (cached := address_cache.get_addresses(h)):
+            # Found in cache
+            cached_addresses.extend(cached)
+        else:
+            # Not cached, need to resolve
+            if address_cache and address_cache.has_cache():
+                _LOGGER.info("Host %s not in cache, will need to resolve", h)
+            uncached_hosts.append(h)
+
+    # Process cached addresses (includes direct IPs and cached lookups)
+    _add_ip_addresses_to_addrinfo(cached_addresses, port, res)
+
+    # If we have uncached hosts (only non-IP hostnames), resolve them
+    if uncached_hosts:
         from esphome.resolver import AsyncResolver
 
-    resolver = AsyncResolver(hosts, port)
+        resolver = AsyncResolver(uncached_hosts, port)
         addr_infos = resolver.resolve()
         # Convert aioesphomeapi AddrInfo to our format
         for addr_info in addr_infos:
@@ -256,14 +299,7 @@ def sort_ip_addresses(address_list: list[str]) -> list[str]:
     # First "resolve" all the IP addresses to getaddrinfo() tuples of the form
     # (family, type, proto, canonname, sockaddr)
     res: list[AddrInfo] = []
-    for addr in address_list:
-        # This should always work as these are supposed to be IP addresses
-        try:
-            res += socket.getaddrinfo(
-                addr, 0, proto=socket.IPPROTO_TCP, flags=socket.AI_NUMERICHOST
-            )
-        except OSError:
-            _LOGGER.info("Failed to parse IP address '%s'", addr)
+    _add_ip_addresses_to_addrinfo(address_list, 0, res)
 
     # Now use that information to sort them.
     res.sort(key=addr_preference_)

tests/dashboard/conftest.py

@@ -0,0 +1,21 @@
+"""Common fixtures for dashboard tests."""
+
+from __future__ import annotations
+
+from unittest.mock import Mock
+
+import pytest
+
+from esphome.dashboard.core import ESPHomeDashboard
+
+
+@pytest.fixture
+def mock_dashboard() -> Mock:
+    """Create a mock dashboard."""
+    dashboard = Mock(spec=ESPHomeDashboard)
+    dashboard.entries = Mock()
+    dashboard.entries.async_all.return_value = []
+    dashboard.stop_event = Mock()
+    dashboard.stop_event.is_set.return_value = True
+    dashboard.ping_request = Mock()
+    return dashboard

tests/dashboard/status/test_dns.py

@@ -0,0 +1,121 @@
+"""Unit tests for esphome.dashboard.dns module."""
+
+from __future__ import annotations
+
+import time
+from unittest.mock import patch
+
+import pytest
+
+from esphome.dashboard.dns import DNSCache
+
+
+@pytest.fixture
+def dns_cache_fixture() -> DNSCache:
+    """Create a DNSCache instance."""
+    return DNSCache()
+
+
+def test_get_cached_addresses_not_in_cache(dns_cache_fixture: DNSCache) -> None:
+    """Test get_cached_addresses when hostname is not in cache."""
+    now = time.monotonic()
+    result = dns_cache_fixture.get_cached_addresses("unknown.example.com", now)
+    assert result is None
+
+
+def test_get_cached_addresses_expired(dns_cache_fixture: DNSCache) -> None:
+    """Test get_cached_addresses when cache entry is expired."""
+    now = time.monotonic()
+    # Add entry that's already expired
+    dns_cache_fixture._cache["example.com"] = (now - 1, ["192.168.1.10"])
+
+    result = dns_cache_fixture.get_cached_addresses("example.com", now)
+    assert result is None
+    # Expired entry should still be in cache (not removed by get_cached_addresses)
+    assert "example.com" in dns_cache_fixture._cache
+
+
+def test_get_cached_addresses_valid(dns_cache_fixture: DNSCache) -> None:
+    """Test get_cached_addresses with valid cache entry."""
+    now = time.monotonic()
+    # Add entry that expires in 60 seconds
+    dns_cache_fixture._cache["example.com"] = (
+        now + 60,
+        ["192.168.1.10", "192.168.1.11"],
+    )
+
+    result = dns_cache_fixture.get_cached_addresses("example.com", now)
+    assert result == ["192.168.1.10", "192.168.1.11"]
+    # Entry should still be in cache
+    assert "example.com" in dns_cache_fixture._cache
+
+
+def test_get_cached_addresses_hostname_normalization(
+    dns_cache_fixture: DNSCache,
+) -> None:
+    """Test get_cached_addresses normalizes hostname."""
+    now = time.monotonic()
+    # Add entry with lowercase hostname
+    dns_cache_fixture._cache["example.com"] = (now + 60, ["192.168.1.10"])
+
+    # Test with various forms
+    assert dns_cache_fixture.get_cached_addresses("EXAMPLE.COM", now) == [
+        "192.168.1.10"
+    ]
+    assert dns_cache_fixture.get_cached_addresses("example.com.", now) == [
+        "192.168.1.10"
+    ]
+    assert dns_cache_fixture.get_cached_addresses("EXAMPLE.COM.", now) == [
+        "192.168.1.10"
+    ]
+
+
+def test_get_cached_addresses_ipv6(dns_cache_fixture: DNSCache) -> None:
+    """Test get_cached_addresses with IPv6 addresses."""
+    now = time.monotonic()
+    dns_cache_fixture._cache["example.com"] = (now + 60, ["2001:db8::1", "fe80::1"])
+
+    result = dns_cache_fixture.get_cached_addresses("example.com", now)
+    assert result == ["2001:db8::1", "fe80::1"]
+
+
+def test_get_cached_addresses_empty_list(dns_cache_fixture: DNSCache) -> None:
+    """Test get_cached_addresses with empty address list."""
+    now = time.monotonic()
+    dns_cache_fixture._cache["example.com"] = (now + 60, [])
+
+    result = dns_cache_fixture.get_cached_addresses("example.com", now)
+    assert result == []
+
+
+def test_get_cached_addresses_exception_in_cache(dns_cache_fixture: DNSCache) -> None:
+    """Test get_cached_addresses when cache contains an exception."""
+    now = time.monotonic()
+    # Store an exception (from failed resolution)
+    dns_cache_fixture._cache["example.com"] = (now + 60, OSError("Resolution failed"))
+
+    result = dns_cache_fixture.get_cached_addresses("example.com", now)
+    assert result is None  # Should return None for exceptions
+
+
+def test_async_resolve_not_called(dns_cache_fixture: DNSCache) -> None:
+    """Test that get_cached_addresses never calls async_resolve."""
+    now = time.monotonic()
+
+    with patch.object(dns_cache_fixture, "async_resolve") as mock_resolve:
+        # Test non-cached
+        result = dns_cache_fixture.get_cached_addresses("uncached.com", now)
+        assert result is None
+        mock_resolve.assert_not_called()
+
+        # Test expired
+        dns_cache_fixture._cache["expired.com"] = (now - 1, ["192.168.1.10"])
+        result = dns_cache_fixture.get_cached_addresses("expired.com", now)
+        assert result is None
+        mock_resolve.assert_not_called()
+
+        # Test valid
+        dns_cache_fixture._cache["valid.com"] = (now + 60, ["192.168.1.10"])
+        result = dns_cache_fixture.get_cached_addresses("valid.com", now)
+        assert result == ["192.168.1.10"]
+        mock_resolve.assert_not_called()

tests/dashboard/status/test_mdns.py

@@ -0,0 +1,168 @@
+"""Unit tests for esphome.dashboard.status.mdns module."""
+
+from __future__ import annotations
+
+from unittest.mock import Mock, patch
+
+import pytest
+import pytest_asyncio
+from zeroconf import AddressResolver, IPVersion
+
+from esphome.dashboard.status.mdns import MDNSStatus
+
+
+@pytest_asyncio.fixture
+async def mdns_status(mock_dashboard: Mock) -> MDNSStatus:
+    """Create an MDNSStatus instance in async context."""
+    # We're in an async context so get_running_loop will work
+    return MDNSStatus(mock_dashboard)
+
+
+@pytest.mark.asyncio
+async def test_get_cached_addresses_no_zeroconf(mdns_status: MDNSStatus) -> None:
+    """Test get_cached_addresses when no zeroconf instance is available."""
+    mdns_status.aiozc = None
+    result = mdns_status.get_cached_addresses("device.local")
+    assert result is None
+
+
+@pytest.mark.asyncio
+async def test_get_cached_addresses_not_in_cache(mdns_status: MDNSStatus) -> None:
+    """Test get_cached_addresses when address is not in cache."""
+    mdns_status.aiozc = Mock()
+    mdns_status.aiozc.zeroconf = Mock()
+
+    with patch("esphome.dashboard.status.mdns.AddressResolver") as mock_resolver:
+        mock_info = Mock(spec=AddressResolver)
+        mock_info.load_from_cache.return_value = False
+        mock_resolver.return_value = mock_info
+
+        result = mdns_status.get_cached_addresses("device.local")
+        assert result is None
+        mock_info.load_from_cache.assert_called_once_with(mdns_status.aiozc.zeroconf)
+
+
+@pytest.mark.asyncio
+async def test_get_cached_addresses_found_in_cache(mdns_status: MDNSStatus) -> None:
+    """Test get_cached_addresses when address is found in cache."""
+    mdns_status.aiozc = Mock()
+    mdns_status.aiozc.zeroconf = Mock()
+
+    with patch("esphome.dashboard.status.mdns.AddressResolver") as mock_resolver:
+        mock_info = Mock(spec=AddressResolver)
+        mock_info.load_from_cache.return_value = True
+        mock_info.parsed_scoped_addresses.return_value = ["192.168.1.10", "fe80::1"]
+        mock_resolver.return_value = mock_info
+
+        result = mdns_status.get_cached_addresses("device.local")
+        assert result == ["192.168.1.10", "fe80::1"]
+        mock_info.load_from_cache.assert_called_once_with(mdns_status.aiozc.zeroconf)
+        mock_info.parsed_scoped_addresses.assert_called_once_with(IPVersion.All)
+
+
+@pytest.mark.asyncio
+async def test_get_cached_addresses_with_trailing_dot(mdns_status: MDNSStatus) -> None:
+    """Test get_cached_addresses with hostname having trailing dot."""
+    mdns_status.aiozc = Mock()
+    mdns_status.aiozc.zeroconf = Mock()
+
+    with patch("esphome.dashboard.status.mdns.AddressResolver") as mock_resolver:
+        mock_info = Mock(spec=AddressResolver)
+        mock_info.load_from_cache.return_value = True
+        mock_info.parsed_scoped_addresses.return_value = ["192.168.1.10"]
+        mock_resolver.return_value = mock_info
+
+        result = mdns_status.get_cached_addresses("device.local.")
+        assert result == ["192.168.1.10"]
+        # Should normalize to device.local. for zeroconf
+        mock_resolver.assert_called_once_with("device.local.")
+
+
+@pytest.mark.asyncio
+async def test_get_cached_addresses_uppercase_hostname(mdns_status: MDNSStatus) -> None:
+    """Test get_cached_addresses with uppercase hostname."""
+    mdns_status.aiozc = Mock()
+    mdns_status.aiozc.zeroconf = Mock()
+
+    with patch("esphome.dashboard.status.mdns.AddressResolver") as mock_resolver:
+        mock_info = Mock(spec=AddressResolver)
+        mock_info.load_from_cache.return_value = True
+        mock_info.parsed_scoped_addresses.return_value = ["192.168.1.10"]
+        mock_resolver.return_value = mock_info
+
+        result = mdns_status.get_cached_addresses("DEVICE.LOCAL")
+        assert result == ["192.168.1.10"]
+        # Should normalize to device.local. for zeroconf
+        mock_resolver.assert_called_once_with("device.local.")
+
+
+@pytest.mark.asyncio
+async def test_get_cached_addresses_simple_hostname(mdns_status: MDNSStatus) -> None:
+    """Test get_cached_addresses with simple hostname (no domain)."""
+    mdns_status.aiozc = Mock()
+    mdns_status.aiozc.zeroconf = Mock()
+
+    with patch("esphome.dashboard.status.mdns.AddressResolver") as mock_resolver:
+        mock_info = Mock(spec=AddressResolver)
+        mock_info.load_from_cache.return_value = True
+        mock_info.parsed_scoped_addresses.return_value = ["192.168.1.10"]
+        mock_resolver.return_value = mock_info
+
+        result = mdns_status.get_cached_addresses("device")
+        assert result == ["192.168.1.10"]
+        # Should append .local. for zeroconf
+        mock_resolver.assert_called_once_with("device.local.")
+
+
+@pytest.mark.asyncio
+async def test_get_cached_addresses_ipv6_only(mdns_status: MDNSStatus) -> None:
+    """Test get_cached_addresses returning only IPv6 addresses."""
+    mdns_status.aiozc = Mock()
+    mdns_status.aiozc.zeroconf = Mock()
+
+    with patch("esphome.dashboard.status.mdns.AddressResolver") as mock_resolver:
+        mock_info = Mock(spec=AddressResolver)
+        mock_info.load_from_cache.return_value = True
+        mock_info.parsed_scoped_addresses.return_value = ["fe80::1", "2001:db8::1"]
+        mock_resolver.return_value = mock_info
+
+        result = mdns_status.get_cached_addresses("device.local")
+        assert result == ["fe80::1", "2001:db8::1"]
+
+
+@pytest.mark.asyncio
+async def test_get_cached_addresses_empty_list(mdns_status: MDNSStatus) -> None:
+    """Test get_cached_addresses returning empty list from cache."""
+    mdns_status.aiozc = Mock()
+    mdns_status.aiozc.zeroconf = Mock()
+
+    with patch("esphome.dashboard.status.mdns.AddressResolver") as mock_resolver:
+        mock_info = Mock(spec=AddressResolver)
+        mock_info.load_from_cache.return_value = True
+        mock_info.parsed_scoped_addresses.return_value = []
+        mock_resolver.return_value = mock_info
+
+        result = mdns_status.get_cached_addresses("device.local")
+        assert result == []
+
+
+@pytest.mark.asyncio
+async def test_async_setup_success(mock_dashboard: Mock) -> None:
+    """Test successful async_setup."""
+    mdns_status = MDNSStatus(mock_dashboard)
+    with patch("esphome.dashboard.status.mdns.AsyncEsphomeZeroconf") as mock_zc:
+        mock_zc.return_value = Mock()
+        result = mdns_status.async_setup()
+        assert result is True
+        assert mdns_status.aiozc is not None
+
+
+@pytest.mark.asyncio
+async def test_async_setup_failure(mock_dashboard: Mock) -> None:
+    """Test async_setup with OSError."""
+    mdns_status = MDNSStatus(mock_dashboard)
+    with patch("esphome.dashboard.status.mdns.AsyncEsphomeZeroconf") as mock_zc:
+        mock_zc.side_effect = OSError("Network error")
+        result = mdns_status.async_setup()
+        assert result is False
+        assert mdns_status.aiozc is None

tests/dashboard/test_web_server.py

@@ -730,3 +730,83 @@ def test_start_web_server_with_unix_socket(tmp_path: Path) -> None:
         mock_server_class.assert_called_once_with(app)
         mock_bind.assert_called_once_with(str(socket_path), mode=0o666)
         server.add_socket.assert_called_once()
+
+
+def test_build_cache_arguments_no_entry(mock_dashboard: Mock) -> None:
+    """Test with no entry returns empty list."""
+    result = web_server.build_cache_arguments(None, mock_dashboard, 0.0)
+    assert result == []
+
+
+def test_build_cache_arguments_no_address_no_name(mock_dashboard: Mock) -> None:
+    """Test with entry but no address or name."""
+    entry = Mock(spec=web_server.DashboardEntry)
+    entry.address = None
+    entry.name = None
+    result = web_server.build_cache_arguments(entry, mock_dashboard, 0.0)
+    assert result == []
+
+
+def test_build_cache_arguments_mdns_address_cached(mock_dashboard: Mock) -> None:
+    """Test with .local address that has cached mDNS results."""
+    entry = Mock(spec=web_server.DashboardEntry)
+    entry.address = "device.local"
+    entry.name = None
+    mock_dashboard.mdns_status = Mock()
+    mock_dashboard.mdns_status.get_cached_addresses.return_value = [
+        "192.168.1.10",
+        "fe80::1",
+    ]
+
+    result = web_server.build_cache_arguments(entry, mock_dashboard, 0.0)
+
+    assert result == [
+        "--mdns-address-cache",
+        "device.local=192.168.1.10,fe80::1",
+    ]
+    mock_dashboard.mdns_status.get_cached_addresses.assert_called_once_with(
+        "device.local"
+    )
+
+
+def test_build_cache_arguments_dns_address_cached(mock_dashboard: Mock) -> None:
+    """Test with non-.local address that has cached DNS results."""
+    entry = Mock(spec=web_server.DashboardEntry)
+    entry.address = "example.com"
+    entry.name = None
+    mock_dashboard.dns_cache = Mock()
+    mock_dashboard.dns_cache.get_cached_addresses.return_value = [
+        "93.184.216.34",
+        "2606:2800:220:1:248:1893:25c8:1946",
+    ]
+
+    now = 100.0
+    result = web_server.build_cache_arguments(entry, mock_dashboard, now)
+
+    # IPv6 addresses are sorted before IPv4
+    assert result == [
+        "--dns-address-cache",
+        "example.com=2606:2800:220:1:248:1893:25c8:1946,93.184.216.34",
+    ]
+    mock_dashboard.dns_cache.get_cached_addresses.assert_called_once_with(
+        "example.com", now
+    )
+
+
+def test_build_cache_arguments_name_without_address(mock_dashboard: Mock) -> None:
+    """Test with name but no address - should check mDNS with .local suffix."""
+    entry = Mock(spec=web_server.DashboardEntry)
+    entry.name = "my-device"
+    entry.address = None
+    mock_dashboard.mdns_status = Mock()
+    mock_dashboard.mdns_status.get_cached_addresses.return_value = ["192.168.1.20"]
+
+    result = web_server.build_cache_arguments(entry, mock_dashboard, 0.0)
+
+    assert result == [
+        "--mdns-address-cache",
+        "my-device.local=192.168.1.20",
+    ]
+    mock_dashboard.mdns_status.get_cached_addresses.assert_called_once_with(
+        "my-device.local"
+    )

tests/unit_tests/test_address_cache.py

@@ -0,0 +1,305 @@
+"""Tests for the address_cache module."""
+
+from __future__ import annotations
+
+import logging
+
+import pytest
+from pytest import LogCaptureFixture
+
+from esphome.address_cache import AddressCache, normalize_hostname
+
+
+def test_normalize_simple_hostname() -> None:
+    """Test normalizing a simple hostname."""
+    assert normalize_hostname("device") == "device"
+    assert normalize_hostname("device.local") == "device.local"
+    assert normalize_hostname("server.example.com") == "server.example.com"
+
+
+def test_normalize_removes_trailing_dots() -> None:
+    """Test that trailing dots are removed."""
+    assert normalize_hostname("device.") == "device"
+    assert normalize_hostname("device.local.") == "device.local"
+    assert normalize_hostname("server.example.com.") == "server.example.com"
+    assert normalize_hostname("device...") == "device"
+
+
+def test_normalize_converts_to_lowercase() -> None:
+    """Test that hostnames are converted to lowercase."""
+    assert normalize_hostname("DEVICE") == "device"
+    assert normalize_hostname("Device.Local") == "device.local"
+    assert normalize_hostname("Server.Example.COM") == "server.example.com"
+
+
+def test_normalize_combined() -> None:
+    """Test combination of trailing dots and case conversion."""
+    assert normalize_hostname("DEVICE.LOCAL.") == "device.local"
+    assert normalize_hostname("Server.Example.COM...") == "server.example.com"
+
+
+def test_init_empty() -> None:
+    """Test initialization with empty caches."""
+    cache = AddressCache()
+    assert cache.mdns_cache == {}
+    assert cache.dns_cache == {}
+    assert not cache.has_cache()
+
+
+def test_init_with_caches() -> None:
+    """Test initialization with provided caches."""
+    mdns_cache: dict[str, list[str]] = {"device.local": ["192.168.1.10"]}
+    dns_cache: dict[str, list[str]] = {"server.com": ["10.0.0.1"]}
+    cache = AddressCache(mdns_cache=mdns_cache, dns_cache=dns_cache)
+    assert cache.mdns_cache == mdns_cache
+    assert cache.dns_cache == dns_cache
+    assert cache.has_cache()
+
+
+def test_get_mdns_addresses() -> None:
+    """Test getting mDNS addresses."""
+    cache = AddressCache(mdns_cache={"device.local": ["192.168.1.10", "192.168.1.11"]})
+
+    # Direct lookup
+    assert cache.get_mdns_addresses("device.local") == [
+        "192.168.1.10",
+        "192.168.1.11",
+    ]
+
+    # Case insensitive lookup
+    assert cache.get_mdns_addresses("Device.Local") == [
+        "192.168.1.10",
+        "192.168.1.11",
+    ]
+
+    # With trailing dot
+    assert cache.get_mdns_addresses("device.local.") == [
+        "192.168.1.10",
+        "192.168.1.11",
+    ]
+
+    # Not found
+    assert cache.get_mdns_addresses("unknown.local") is None
+
+
+def test_get_dns_addresses() -> None:
+    """Test getting DNS addresses."""
+    cache = AddressCache(dns_cache={"server.com": ["10.0.0.1", "10.0.0.2"]})
+
+    # Direct lookup
+    assert cache.get_dns_addresses("server.com") == ["10.0.0.1", "10.0.0.2"]
+
+    # Case insensitive lookup
+    assert cache.get_dns_addresses("Server.COM") == ["10.0.0.1", "10.0.0.2"]
+
+    # With trailing dot
+    assert cache.get_dns_addresses("server.com.") == ["10.0.0.1", "10.0.0.2"]
+
+    # Not found
+    assert cache.get_dns_addresses("unknown.com") is None
+
+
+def test_get_addresses_auto_detection() -> None:
+    """Test automatic cache selection based on hostname."""
+    cache = AddressCache(
+        mdns_cache={"device.local": ["192.168.1.10"]},
+        dns_cache={"server.com": ["10.0.0.1"]},
+    )
+
+    # Should use mDNS cache for .local domains
+    assert cache.get_addresses("device.local") == ["192.168.1.10"]
+    assert cache.get_addresses("device.local.") == ["192.168.1.10"]
+    assert cache.get_addresses("Device.Local") == ["192.168.1.10"]
+
+    # Should use DNS cache for non-.local domains
+    assert cache.get_addresses("server.com") == ["10.0.0.1"]
+    assert cache.get_addresses("server.com.") == ["10.0.0.1"]
+    assert cache.get_addresses("Server.COM") == ["10.0.0.1"]
+
+    # Not found
+    assert cache.get_addresses("unknown.local") is None
+    assert cache.get_addresses("unknown.com") is None
+
+
+def test_has_cache() -> None:
+    """Test checking if cache has entries."""
+    # Empty cache
+    cache = AddressCache()
+    assert not cache.has_cache()
+
+    # Only mDNS cache
+    cache = AddressCache(mdns_cache={"device.local": ["192.168.1.10"]})
+    assert cache.has_cache()
+
+    # Only DNS cache
+    cache = AddressCache(dns_cache={"server.com": ["10.0.0.1"]})
+    assert cache.has_cache()
+
+    # Both caches
+    cache = AddressCache(
+        mdns_cache={"device.local": ["192.168.1.10"]},
+        dns_cache={"server.com": ["10.0.0.1"]},
+    )
+    assert cache.has_cache()
+
+
+def test_from_cli_args_empty() -> None:
+    """Test creating cache from empty CLI arguments."""
+    cache = AddressCache.from_cli_args([], [])
+    assert cache.mdns_cache == {}
+    assert cache.dns_cache == {}
+
+
+def test_from_cli_args_single_entry() -> None:
+    """Test creating cache from single CLI argument."""
+    mdns_args: list[str] = ["device.local=192.168.1.10"]
+    dns_args: list[str] = ["server.com=10.0.0.1"]
+
+    cache = AddressCache.from_cli_args(mdns_args, dns_args)
+
+    assert cache.mdns_cache == {"device.local": ["192.168.1.10"]}
+    assert cache.dns_cache == {"server.com": ["10.0.0.1"]}
+
+
+def test_from_cli_args_multiple_ips() -> None:
+    """Test creating cache with multiple IPs per host."""
+    mdns_args: list[str] = ["device.local=192.168.1.10,192.168.1.11"]
+    dns_args: list[str] = ["server.com=10.0.0.1,10.0.0.2,10.0.0.3"]
+
+    cache = AddressCache.from_cli_args(mdns_args, dns_args)
+
+    assert cache.mdns_cache == {"device.local": ["192.168.1.10", "192.168.1.11"]}
+    assert cache.dns_cache == {"server.com": ["10.0.0.1", "10.0.0.2", "10.0.0.3"]}
+
+
+def test_from_cli_args_multiple_entries() -> None:
+    """Test creating cache with multiple host entries."""
+    mdns_args: list[str] = [
+        "device1.local=192.168.1.10",
+        "device2.local=192.168.1.20,192.168.1.21",
+    ]
+    dns_args: list[str] = ["server1.com=10.0.0.1", "server2.com=10.0.0.2"]
+
+    cache = AddressCache.from_cli_args(mdns_args, dns_args)
+
+    assert cache.mdns_cache == {
+        "device1.local": ["192.168.1.10"],
+        "device2.local": ["192.168.1.20", "192.168.1.21"],
+    }
+    assert cache.dns_cache == {
+        "server1.com": ["10.0.0.1"],
+        "server2.com": ["10.0.0.2"],
+    }
+
+
+def test_from_cli_args_normalization() -> None:
+    """Test that CLI arguments are normalized."""
+    mdns_args: list[str] = ["Device1.Local.=192.168.1.10", "DEVICE2.LOCAL=192.168.1.20"]
+    dns_args: list[str] = ["Server1.COM.=10.0.0.1", "SERVER2.com=10.0.0.2"]
+
+    cache = AddressCache.from_cli_args(mdns_args, dns_args)
+
+    # Hostnames should be normalized (lowercase, no trailing dots)
+    assert cache.mdns_cache == {
+        "device1.local": ["192.168.1.10"],
+        "device2.local": ["192.168.1.20"],
+    }
+    assert cache.dns_cache == {
+        "server1.com": ["10.0.0.1"],
+        "server2.com": ["10.0.0.2"],
+    }
+
+
+def test_from_cli_args_whitespace_handling() -> None:
+    """Test that whitespace in IPs is handled."""
+    mdns_args: list[str] = ["device.local= 192.168.1.10 , 192.168.1.11 "]
+    dns_args: list[str] = ["server.com= 10.0.0.1 , 10.0.0.2 "]
+
+    cache = AddressCache.from_cli_args(mdns_args, dns_args)
+
+    assert cache.mdns_cache == {"device.local": ["192.168.1.10", "192.168.1.11"]}
+    assert cache.dns_cache == {"server.com": ["10.0.0.1", "10.0.0.2"]}
+
+
+def test_from_cli_args_invalid_format(caplog: LogCaptureFixture) -> None:
+    """Test handling of invalid argument format."""
+    mdns_args: list[str] = ["invalid_format", "device.local=192.168.1.10"]
+    dns_args: list[str] = ["server.com=10.0.0.1", "also_invalid"]
+
+    cache = AddressCache.from_cli_args(mdns_args, dns_args)
+
+    # Valid entries should still be processed
+    assert cache.mdns_cache == {"device.local": ["192.168.1.10"]}
+    assert cache.dns_cache == {"server.com": ["10.0.0.1"]}
+
+    # Check that warnings were logged for invalid entries
+    assert "Invalid cache format: invalid_format" in caplog.text
+    assert "Invalid cache format: also_invalid" in caplog.text
+
+
+def test_from_cli_args_ipv6() -> None:
+    """Test handling of IPv6 addresses."""
+    mdns_args: list[str] = ["device.local=fe80::1,2001:db8::1"]
+    dns_args: list[str] = ["server.com=2001:db8::2,::1"]
+
+    cache = AddressCache.from_cli_args(mdns_args, dns_args)
+
+    assert cache.mdns_cache == {"device.local": ["fe80::1", "2001:db8::1"]}
+    assert cache.dns_cache == {"server.com": ["2001:db8::2", "::1"]}
+
+
+def test_logging_output(caplog: LogCaptureFixture) -> None:
+    """Test that appropriate debug logging occurs."""
+    caplog.set_level(logging.DEBUG)
+
+    cache = AddressCache(
+        mdns_cache={"device.local": ["192.168.1.10"]},
+        dns_cache={"server.com": ["10.0.0.1"]},
+    )
+
+    # Test successful lookups log at debug level
+    result: list[str] | None = cache.get_mdns_addresses("device.local")
+    assert result == ["192.168.1.10"]
+    assert "Using mDNS cache for device.local" in caplog.text
+
+    caplog.clear()
+    result = cache.get_dns_addresses("server.com")
+    assert result == ["10.0.0.1"]
+    assert "Using DNS cache for server.com" in caplog.text
+
+    # Test that failed lookups don't log
+    caplog.clear()
+    result = cache.get_mdns_addresses("unknown.local")
+    assert result is None
+    assert "Using mDNS cache" not in caplog.text
+
+
+@pytest.mark.parametrize(
+    "hostname,expected",
+    [
+        ("test.local", "test.local"),
+        ("Test.Local.", "test.local"),
+        ("TEST.LOCAL...", "test.local"),
+        ("example.com", "example.com"),
+        ("EXAMPLE.COM.", "example.com"),
+    ],
+)
+def test_normalize_hostname_parametrized(hostname: str, expected: str) -> None:
+    """Test hostname normalization with various inputs."""
+    assert normalize_hostname(hostname) == expected
+
+
+@pytest.mark.parametrize(
+    "mdns_arg,expected",
+    [
+        ("host=1.2.3.4", {"host": ["1.2.3.4"]}),
+        ("Host.Local=1.2.3.4,5.6.7.8", {"host.local": ["1.2.3.4", "5.6.7.8"]}),
+        ("HOST.LOCAL.=::1", {"host.local": ["::1"]}),
+    ],
+)
+def test_parse_cache_args_parametrized(
+    mdns_arg: str, expected: dict[str, list[str]]
+) -> None:
+    """Test parsing of cache arguments with various formats."""
+    cache = AddressCache.from_cli_args([mdns_arg], [])
+    assert cache.mdns_cache == expected

tests/unit_tests/test_helpers.py

@@ -11,6 +11,7 @@ from hypothesis.strategies import ip_addresses
 import pytest
 
 from esphome import helpers
+from esphome.address_cache import AddressCache
 from esphome.core import EsphomeError
 
 
@@ -830,3 +831,84 @@ def test_resolve_ip_address_sorting() -> None:
         assert result[0][4][0] == "2001:db8::1"  # IPv6 (preference 1)
         assert result[1][4][0] == "192.168.1.100"  # IPv4 (preference 2)
         assert result[2][4][0] == "fe80::1"  # Link-local no scope (preference 3)
+
+
+def test_resolve_ip_address_with_cache() -> None:
+    """Test that the cache is used when provided."""
+    cache = AddressCache(
+        mdns_cache={"test.local": ["192.168.1.100", "192.168.1.101"]},
+        dns_cache={
+            "example.com": ["93.184.216.34", "2606:2800:220:1:248:1893:25c8:1946"]
+        },
+    )
+
+    # Test mDNS cache hit
+    result = helpers.resolve_ip_address("test.local", 6053, address_cache=cache)
+
+    # Should return cached addresses without calling resolver
+    assert len(result) == 2
+    assert result[0][4][0] == "192.168.1.100"
+    assert result[1][4][0] == "192.168.1.101"
+
+    # Test DNS cache hit
+    result = helpers.resolve_ip_address("example.com", 6053, address_cache=cache)
+
+    # Should return cached addresses with IPv6 first due to preference
+    assert len(result) == 2
+    assert result[0][4][0] == "2606:2800:220:1:248:1893:25c8:1946"  # IPv6 first
+    assert result[1][4][0] == "93.184.216.34"  # IPv4 second
+
+
+def test_resolve_ip_address_cache_miss() -> None:
+    """Test that resolver is called when not in cache."""
+    cache = AddressCache(mdns_cache={"other.local": ["192.168.1.200"]})
+
+    mock_addr_info = AddrInfo(
+        family=socket.AF_INET,
+        type=socket.SOCK_STREAM,
+        proto=socket.IPPROTO_TCP,
+        sockaddr=IPv4Sockaddr(address="192.168.1.100", port=6053),
+    )
+
+    with patch("esphome.resolver.AsyncResolver") as MockResolver:
+        mock_resolver = MockResolver.return_value
+        mock_resolver.resolve.return_value = [mock_addr_info]
+
+        result = helpers.resolve_ip_address("test.local", 6053, address_cache=cache)
+
+        # Should call resolver since test.local is not in cache
+        MockResolver.assert_called_once_with(["test.local"], 6053)
+        assert len(result) == 1
+        assert result[0][4][0] == "192.168.1.100"
+
+
+def test_resolve_ip_address_mixed_cached_uncached() -> None:
+    """Test resolution with mix of cached and uncached hosts."""
+    cache = AddressCache(mdns_cache={"cached.local": ["192.168.1.50"]})
+
+    mock_addr_info = AddrInfo(
+        family=socket.AF_INET,
+        type=socket.SOCK_STREAM,
+        proto=socket.IPPROTO_TCP,
+        sockaddr=IPv4Sockaddr(address="192.168.1.100", port=6053),
+    )
+
+    with patch("esphome.resolver.AsyncResolver") as MockResolver:
+        mock_resolver = MockResolver.return_value
+        mock_resolver.resolve.return_value = [mock_addr_info]
+
+        # Pass a list with cached IP, cached hostname, and uncached hostname
+        result = helpers.resolve_ip_address(
+            ["192.168.1.10", "cached.local", "uncached.local"],
+            6053,
+            address_cache=cache,
+        )
+
+        # Should only resolve uncached.local
+        MockResolver.assert_called_once_with(["uncached.local"], 6053)
+
+        # Results should include all addresses
+        addresses = [r[4][0] for r in result]
+        assert "192.168.1.10" in addresses  # Direct IP
+        assert "192.168.1.50" in addresses  # From cache
+        assert "192.168.1.100" in addresses  # From resolver