Merge branch 'integration' into memory_api

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:
@@ -972,6 +979,18 @@ 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]
@@ -1230,9 +1249,15 @@ 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/components/api/api.proto

@@ -7,7 +7,7 @@ service APIConnection {
     option (needs_setup_connection) = false;
     option (needs_authentication) = false;
   }
-  rpc connect (ConnectRequest) returns (ConnectResponse) {
+  rpc authenticate (AuthenticationRequest) returns (AuthenticationResponse) {
     option (needs_setup_connection) = false;
     option (needs_authentication) = false;
   }
@@ -129,7 +129,7 @@ message HelloResponse {
 
 // Message sent at the beginning of each connection to authenticate the client
 // Can only be sent by the client and only at the beginning of the connection
-message ConnectRequest {
+message AuthenticationRequest {
   option (id) = 3;
   option (source) = SOURCE_CLIENT;
   option (no_delay) = true;
@@ -141,7 +141,7 @@ message ConnectRequest {
 
 // Confirmation of successful connection. After this the connection is available for all traffic.
 // Can only be sent by the server and only at the beginning of the connection
-message ConnectResponse {
+message AuthenticationResponse {
   option (id) = 4;
   option (source) = SOURCE_SERVER;
   option (no_delay) = true;

esphome/components/api/api_connection.cpp

@@ -1387,14 +1387,14 @@ bool APIConnection::send_hello_response(const HelloRequest &msg) {
   return this->send_message(resp, HelloResponse::MESSAGE_TYPE);
 }
 #ifdef USE_API_PASSWORD
-bool APIConnection::send_connect_response(const ConnectRequest &msg) {
-  ConnectResponse resp;
+bool APIConnection::send_authenticate_response(const AuthenticationRequest &msg) {
+  AuthenticationResponse resp;
   // bool invalid_password = 1;
   resp.invalid_password = !this->parent_->check_password(msg.password);
   if (!resp.invalid_password) {
     this->complete_authentication_();
   }
-  return this->send_message(resp, ConnectResponse::MESSAGE_TYPE);
+  return this->send_message(resp, AuthenticationResponse::MESSAGE_TYPE);
 }
 #endif  // USE_API_PASSWORD
 

esphome/components/api/api_connection.h

@@ -198,7 +198,7 @@ class APIConnection final : public APIServerConnection {
 #endif
   bool send_hello_response(const HelloRequest &msg) override;
 #ifdef USE_API_PASSWORD
-  bool send_connect_response(const ConnectRequest &msg) override;
+  bool send_authenticate_response(const AuthenticationRequest &msg) override;
 #endif
   bool send_disconnect_response(const DisconnectRequest &msg) override;
   bool send_ping_response(const PingRequest &msg) override;

esphome/components/api/api_pb2.cpp

@@ -43,7 +43,7 @@ void HelloResponse::calculate_size(ProtoSize &size) const {
   size.add_length(1, this->name_ref_.size());
 }
 #ifdef USE_API_PASSWORD
-bool ConnectRequest::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
+bool AuthenticationRequest::decode_length(uint32_t field_id, ProtoLengthDelimited value) {
   switch (field_id) {
     case 1:
       this->password = value.as_string();
@@ -53,8 +53,8 @@ bool ConnectRequest::decode_length(uint32_t field_id, ProtoLengthDelimited value
   }
   return true;
 }
-void ConnectResponse::encode(ProtoWriteBuffer buffer) const { buffer.encode_bool(1, this->invalid_password); }
-void ConnectResponse::calculate_size(ProtoSize &size) const { size.add_bool(1, this->invalid_password); }
+void AuthenticationResponse::encode(ProtoWriteBuffer buffer) const { buffer.encode_bool(1, this->invalid_password); }
+void AuthenticationResponse::calculate_size(ProtoSize &size) const { size.add_bool(1, this->invalid_password); }
 #endif
 #ifdef USE_AREAS
 void AreaInfo::encode(ProtoWriteBuffer buffer) const {

esphome/components/api/api_pb2.h

@@ -361,12 +361,12 @@ class HelloResponse final : public ProtoMessage {
  protected:
 };
 #ifdef USE_API_PASSWORD
-class ConnectRequest final : public ProtoDecodableMessage {
+class AuthenticationRequest final : public ProtoDecodableMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 3;
   static constexpr uint8_t ESTIMATED_SIZE = 9;
 #ifdef HAS_PROTO_MESSAGE_DUMP
-  const char *message_name() const override { return "connect_request"; }
+  const char *message_name() const override { return "authentication_request"; }
 #endif
   std::string password{};
 #ifdef HAS_PROTO_MESSAGE_DUMP
@@ -376,12 +376,12 @@ class ConnectRequest final : public ProtoDecodableMessage {
  protected:
   bool decode_length(uint32_t field_id, ProtoLengthDelimited value) override;
 };
-class ConnectResponse final : public ProtoMessage {
+class AuthenticationResponse final : public ProtoMessage {
  public:
   static constexpr uint8_t MESSAGE_TYPE = 4;
   static constexpr uint8_t ESTIMATED_SIZE = 2;
 #ifdef HAS_PROTO_MESSAGE_DUMP
-  const char *message_name() const override { return "connect_response"; }
+  const char *message_name() const override { return "authentication_response"; }
 #endif
   bool invalid_password{false};
   void encode(ProtoWriteBuffer buffer) const override;

esphome/components/api/api_pb2_dump.cpp

@@ -670,8 +670,11 @@ void HelloResponse::dump_to(std::string &out) const {
   dump_field(out, "name", this->name_ref_);
 }
 #ifdef USE_API_PASSWORD
-void ConnectRequest::dump_to(std::string &out) const { dump_field(out, "password", this->password); }
-void ConnectResponse::dump_to(std::string &out) const { dump_field(out, "invalid_password", this->invalid_password); }
+void AuthenticationRequest::dump_to(std::string &out) const { dump_field(out, "password", this->password); }
+void AuthenticationResponse::dump_to(std::string &out) const {
+  MessageDumpHelper helper(out, "AuthenticationResponse");
+  dump_field(out, "invalid_password", this->invalid_password);
+}
 #endif
 void DisconnectRequest::dump_to(std::string &out) const { out.append("DisconnectRequest {}"); }
 void DisconnectResponse::dump_to(std::string &out) const { out.append("DisconnectResponse {}"); }

esphome/components/api/api_pb2_service.cpp

@@ -25,13 +25,13 @@ void APIServerConnectionBase::read_message(uint32_t msg_size, uint32_t msg_type,
       break;
     }
 #ifdef USE_API_PASSWORD
-    case ConnectRequest::MESSAGE_TYPE: {
-      ConnectRequest msg;
+    case AuthenticationRequest::MESSAGE_TYPE: {
+      AuthenticationRequest msg;
       msg.decode(msg_data, msg_size);
 #ifdef HAS_PROTO_MESSAGE_DUMP
-      ESP_LOGVV(TAG, "on_connect_request: %s", msg.dump().c_str());
+      ESP_LOGVV(TAG, "on_authentication_request: %s", msg.dump().c_str());
 #endif
-      this->on_connect_request(msg);
+      this->on_authentication_request(msg);
       break;
     }
 #endif
@@ -600,8 +600,8 @@ void APIServerConnection::on_hello_request(const HelloRequest &msg) {
   }
 }
 #ifdef USE_API_PASSWORD
-void APIServerConnection::on_connect_request(const ConnectRequest &msg) {
-  if (!this->send_connect_response(msg)) {
+void APIServerConnection::on_authentication_request(const AuthenticationRequest &msg) {
+  if (!this->send_authenticate_response(msg)) {
     this->on_fatal_error();
   }
 }

esphome/components/api/api_pb2_service.h

@@ -27,7 +27,7 @@ class APIServerConnectionBase : public ProtoService {
   virtual void on_hello_request(const HelloRequest &value){};
 
 #ifdef USE_API_PASSWORD
-  virtual void on_connect_request(const ConnectRequest &value){};
+  virtual void on_authentication_request(const AuthenticationRequest &value){};
 #endif
 
   virtual void on_disconnect_request(const DisconnectRequest &value){};
@@ -216,7 +216,7 @@ class APIServerConnection : public APIServerConnectionBase {
  public:
   virtual bool send_hello_response(const HelloRequest &msg) = 0;
 #ifdef USE_API_PASSWORD
-  virtual bool send_connect_response(const ConnectRequest &msg) = 0;
+  virtual bool send_authenticate_response(const AuthenticationRequest &msg) = 0;
 #endif
   virtual bool send_disconnect_response(const DisconnectRequest &msg) = 0;
   virtual bool send_ping_response(const PingRequest &msg) = 0;
@@ -339,7 +339,7 @@ class APIServerConnection : public APIServerConnectionBase {
  protected:
   void on_hello_request(const HelloRequest &msg) override;
 #ifdef USE_API_PASSWORD
-  void on_connect_request(const ConnectRequest &msg) override;
+  void on_authentication_request(const AuthenticationRequest &msg) override;
 #endif
   void on_disconnect_request(const DisconnectRequest &msg) override;
   void on_ping_request(const PingRequest &msg) override;

esphome/components/ina2xx_base/__init__.py

@@ -18,6 +18,7 @@ from esphome.const import (
     DEVICE_CLASS_TEMPERATURE,
     DEVICE_CLASS_VOLTAGE,
     STATE_CLASS_MEASUREMENT,
+    STATE_CLASS_TOTAL_INCREASING,
     UNIT_AMPERE,
     UNIT_CELSIUS,
     UNIT_VOLT,
@@ -162,7 +163,7 @@ INA2XX_SCHEMA = cv.Schema(
                 unit_of_measurement=UNIT_WATT_HOURS,
                 accuracy_decimals=8,
                 device_class=DEVICE_CLASS_ENERGY,
-                state_class=STATE_CLASS_MEASUREMENT,
+                state_class=STATE_CLASS_TOTAL_INCREASING,
             ),
             key=CONF_NAME,
         ),
@@ -170,7 +171,8 @@ INA2XX_SCHEMA = cv.Schema(
             sensor.sensor_schema(
                 unit_of_measurement=UNIT_JOULE,
                 accuracy_decimals=8,
-                state_class=STATE_CLASS_MEASUREMENT,
+                device_class=DEVICE_CLASS_ENERGY,
+                state_class=STATE_CLASS_TOTAL_INCREASING,
             ),
             key=CONF_NAME,
         ),

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:
@@ -194,47 +215,69 @@ 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
 
-    from esphome.resolver import AsyncResolver
+    # Process hosts
+    cached_addresses: list[str] = []
+    uncached_hosts: list[str] = []
+    has_cache = address_cache is not None
 
-    resolver = AsyncResolver(hosts, port)
-    addr_infos = resolver.resolve()
-    # Convert aioesphomeapi AddrInfo to our format
-    for addr_info in addr_infos:
-        sockaddr = addr_info.sockaddr
-        if addr_info.family == socket.AF_INET6:
-            # IPv6
-            sockaddr_tuple = (
-                sockaddr.address,
-                sockaddr.port,
-                sockaddr.flowinfo,
-                sockaddr.scope_id,
-            )
+    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:
-            # IPv4
-            sockaddr_tuple = (sockaddr.address, sockaddr.port)
+            # 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)
 
-        res.append(
-            (
-                addr_info.family,
-                addr_info.type,
-                addr_info.proto,
-                "",  # canonname
-                sockaddr_tuple,
+    # 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(uncached_hosts, port)
+        addr_infos = resolver.resolve()
+        # Convert aioesphomeapi AddrInfo to our format
+        for addr_info in addr_infos:
+            sockaddr = addr_info.sockaddr
+            if addr_info.family == socket.AF_INET6:
+                # IPv6
+                sockaddr_tuple = (
+                    sockaddr.address,
+                    sockaddr.port,
+                    sockaddr.flowinfo,
+                    sockaddr.scope_id,
+                )
+            else:
+                # IPv4
+                sockaddr_tuple = (sockaddr.address, sockaddr.port)
+
+            res.append(
+                (
+                    addr_info.family,
+                    addr_info.type,
+                    addr_info.proto,
+                    "",  # canonname
+                    sockaddr_tuple,
+                )
             )
-        )
 
     # Sort by preference
     res.sort(key=addr_preference_)
@@ -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_)

requirements.txt

@@ -12,7 +12,7 @@ platformio==6.1.18  # When updating platformio, also update /docker/Dockerfile
 esptool==5.0.2
 click==8.1.7
 esphome-dashboard==20250904.0
-aioesphomeapi==40.2.0
+aioesphomeapi==41.0.0
 zeroconf==0.147.2
 puremagic==1.30
 ruamel.yaml==0.18.15 # dashboard_import

tests/components/network/test-ipv6.bk72xx-ard.yaml

@@ -1,8 +1,4 @@
 substitutions:
   network_enable_ipv6: "true"
 
-bk72xx:
-  framework:
-    version: 1.7.0
-
 <<: !include common.yaml

tests/components/network/test.bk72xx-ard.yaml

@@ -0,0 +1 @@
+<<: !include common.yaml

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

@@ -639,3 +639,83 @@ 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/build_gen/test_platformio.py

@@ -0,0 +1,188 @@
+"""Tests for esphome.build_gen.platformio module."""
+
+from __future__ import annotations
+
+from collections.abc import Generator
+from pathlib import Path
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from esphome.build_gen import platformio
+from esphome.core import CORE
+
+
+@pytest.fixture
+def mock_update_storage_json() -> Generator[MagicMock]:
+    """Mock update_storage_json for all tests."""
+    with patch("esphome.build_gen.platformio.update_storage_json") as mock:
+        yield mock
+
+
+@pytest.fixture
+def mock_write_file_if_changed() -> Generator[MagicMock]:
+    """Mock write_file_if_changed for tests."""
+    with patch("esphome.build_gen.platformio.write_file_if_changed") as mock:
+        yield mock
+
+
+def test_write_ini_creates_new_file(
+    tmp_path: Path, mock_update_storage_json: MagicMock
+) -> None:
+    """Test write_ini creates a new platformio.ini file."""
+    CORE.build_path = str(tmp_path)
+
+    content = """
+[env:test]
+platform = espressif32
+board = esp32dev
+framework = arduino
+"""
+
+    platformio.write_ini(content)
+
+    ini_file = tmp_path / "platformio.ini"
+    assert ini_file.exists()
+
+    file_content = ini_file.read_text()
+    assert content in file_content
+    assert platformio.INI_AUTO_GENERATE_BEGIN in file_content
+    assert platformio.INI_AUTO_GENERATE_END in file_content
+
+
+def test_write_ini_updates_existing_file(
+    tmp_path: Path, mock_update_storage_json: MagicMock
+) -> None:
+    """Test write_ini updates existing platformio.ini file."""
+    CORE.build_path = str(tmp_path)
+
+    # Create existing file with custom content
+    ini_file = tmp_path / "platformio.ini"
+    existing_content = f"""
+; Custom header
+[platformio]
+default_envs = test
+
+{platformio.INI_AUTO_GENERATE_BEGIN}
+; Old auto-generated content
+[env:old]
+platform = old
+{platformio.INI_AUTO_GENERATE_END}
+
+; Custom footer
+"""
+    ini_file.write_text(existing_content)
+
+    # New content to write
+    new_content = """
+[env:test]
+platform = espressif32
+board = esp32dev
+framework = arduino
+"""
+
+    platformio.write_ini(new_content)
+
+    file_content = ini_file.read_text()
+
+    # Check that custom parts are preserved
+    assert "; Custom header" in file_content
+    assert "[platformio]" in file_content
+    assert "default_envs = test" in file_content
+    assert "; Custom footer" in file_content
+
+    # Check that new content replaced old auto-generated content
+    assert new_content in file_content
+    assert "[env:old]" not in file_content
+    assert "platform = old" not in file_content
+
+
+def test_write_ini_preserves_custom_sections(
+    tmp_path: Path, mock_update_storage_json: MagicMock
+) -> None:
+    """Test write_ini preserves custom sections outside auto-generate markers."""
+    CORE.build_path = str(tmp_path)
+
+    # Create existing file with multiple custom sections
+    ini_file = tmp_path / "platformio.ini"
+    existing_content = f"""
+[platformio]
+src_dir = .
+include_dir = .
+
+[common]
+lib_deps =
+    Wire
+    SPI
+
+{platformio.INI_AUTO_GENERATE_BEGIN}
+[env:old]
+platform = old
+{platformio.INI_AUTO_GENERATE_END}
+
+[env:custom]
+upload_speed = 921600
+monitor_speed = 115200
+"""
+    ini_file.write_text(existing_content)
+
+    new_content = "[env:auto]\nplatform = new"
+
+    platformio.write_ini(new_content)
+
+    file_content = ini_file.read_text()
+
+    # All custom sections should be preserved
+    assert "[platformio]" in file_content
+    assert "src_dir = ." in file_content
+    assert "[common]" in file_content
+    assert "lib_deps" in file_content
+    assert "[env:custom]" in file_content
+    assert "upload_speed = 921600" in file_content
+
+    # New auto-generated content should replace old
+    assert "[env:auto]" in file_content
+    assert "platform = new" in file_content
+    assert "[env:old]" not in file_content
+
+
+def test_write_ini_no_change_when_content_same(
+    tmp_path: Path,
+    mock_update_storage_json: MagicMock,
+    mock_write_file_if_changed: MagicMock,
+) -> None:
+    """Test write_ini doesn't rewrite file when content is unchanged."""
+    CORE.build_path = str(tmp_path)
+
+    content = "[env:test]\nplatform = esp32"
+    full_content = (
+        f"{platformio.INI_BASE_FORMAT[0]}"
+        f"{platformio.INI_AUTO_GENERATE_BEGIN}\n"
+        f"{content}"
+        f"{platformio.INI_AUTO_GENERATE_END}"
+        f"{platformio.INI_BASE_FORMAT[1]}"
+    )
+
+    ini_file = tmp_path / "platformio.ini"
+    ini_file.write_text(full_content)
+
+    mock_write_file_if_changed.return_value = False  # Indicate no change
+    platformio.write_ini(content)
+
+    # write_file_if_changed should be called with the same content
+    mock_write_file_if_changed.assert_called_once()
+    call_args = mock_write_file_if_changed.call_args[0]
+    assert call_args[0] == str(ini_file)
+    assert content in call_args[1]
+
+
+def test_write_ini_calls_update_storage_json(
+    tmp_path: Path, mock_update_storage_json: MagicMock
+) -> None:
+    """Test write_ini calls update_storage_json."""
+    CORE.build_path = str(tmp_path)
+
+    content = "[env:test]\nplatform = esp32"
+
+    platformio.write_ini(content)
+    mock_update_storage_json.assert_called_once()

tests/unit_tests/conftest.py

@@ -9,8 +9,10 @@ not be part of a unit test suite.
 
 """
 
+from collections.abc import Generator
 from pathlib import Path
 import sys
+from unittest.mock import Mock, patch
 
 import pytest
 
@@ -43,3 +45,45 @@ def setup_core(tmp_path: Path) -> Path:
     """Set up CORE with test paths."""
     CORE.config_path = str(tmp_path / "test.yaml")
     return tmp_path
+
+
+@pytest.fixture
+def mock_write_file_if_changed() -> Generator[Mock, None, None]:
+    """Mock write_file_if_changed for storage_json."""
+    with patch("esphome.storage_json.write_file_if_changed") as mock:
+        yield mock
+
+
+@pytest.fixture
+def mock_copy_file_if_changed() -> Generator[Mock, None, None]:
+    """Mock copy_file_if_changed for core.config."""
+    with patch("esphome.core.config.copy_file_if_changed") as mock:
+        yield mock
+
+
+@pytest.fixture
+def mock_run_platformio_cli() -> Generator[Mock, None, None]:
+    """Mock run_platformio_cli for platformio_api."""
+    with patch("esphome.platformio_api.run_platformio_cli") as mock:
+        yield mock
+
+
+@pytest.fixture
+def mock_run_platformio_cli_run() -> Generator[Mock, None, None]:
+    """Mock run_platformio_cli_run for platformio_api."""
+    with patch("esphome.platformio_api.run_platformio_cli_run") as mock:
+        yield mock
+
+
+@pytest.fixture
+def mock_decode_pc() -> Generator[Mock, None, None]:
+    """Mock _decode_pc for platformio_api."""
+    with patch("esphome.platformio_api._decode_pc") as mock:
+        yield mock
+
+
+@pytest.fixture
+def mock_run_external_command() -> Generator[Mock, None, None]:
+    """Mock run_external_command for platformio_api."""
+    with patch("esphome.platformio_api.run_external_command") as mock:
+        yield mock

tests/unit_tests/core/test_config.py

@@ -1,21 +1,56 @@
 """Unit tests for core config functionality including areas and devices."""
 
 from collections.abc import Callable
+import os
 from pathlib import Path
+import types
 from typing import Any
+from unittest.mock import MagicMock, Mock, patch
 
 import pytest
 
 from esphome import config_validation as cv, core
-from esphome.const import CONF_AREA, CONF_AREAS, CONF_DEVICES
-from esphome.core import config
-from esphome.core.config import Area, validate_area_config
+from esphome.const import (
+    CONF_AREA,
+    CONF_AREAS,
+    CONF_BUILD_PATH,
+    CONF_DEVICES,
+    CONF_ESPHOME,
+    CONF_NAME,
+    CONF_NAME_ADD_MAC_SUFFIX,
+    KEY_CORE,
+)
+from esphome.core import CORE, config
+from esphome.core.config import (
+    Area,
+    preload_core_config,
+    valid_include,
+    valid_project_name,
+    validate_area_config,
+    validate_hostname,
+)
 
 from .common import load_config_from_fixture
 
 FIXTURES_DIR = Path(__file__).parent.parent / "fixtures" / "core" / "config"
 
 
+@pytest.fixture
+def mock_cg_with_include_capture() -> tuple[Mock, list[str]]:
+    """Mock code generation with include capture."""
+    includes_added: list[str] = []
+
+    with patch("esphome.core.config.cg") as mock_cg:
+        mock_raw_statement = MagicMock()
+
+        def capture_include(text: str) -> MagicMock:
+            includes_added.append(text)
+            return mock_raw_statement
+
+        mock_cg.RawStatement.side_effect = capture_include
+        yield mock_cg, includes_added
+
+
 def test_validate_area_config_with_string() -> None:
     """Test that string area config is converted to structured format."""
     result = validate_area_config("Living Room")
@@ -245,3 +280,566 @@ def test_add_platform_defines_priority() -> None:
         f"_add_platform_defines priority ({config._add_platform_defines.priority}) must be lower than "
         f"globals priority ({globals_to_code.priority}) to fix issue #10431 (sensor count bug with lambdas)"
     )
+
+
+def test_valid_include_with_angle_brackets() -> None:
+    """Test valid_include accepts angle bracket includes."""
+    assert valid_include("<ArduinoJson.h>") == "<ArduinoJson.h>"
+
+
+def test_valid_include_with_valid_file(tmp_path: Path) -> None:
+    """Test valid_include accepts valid include files."""
+    CORE.config_path = str(tmp_path / "test.yaml")
+    include_file = tmp_path / "include.h"
+    include_file.touch()
+
+    assert valid_include(str(include_file)) == str(include_file)
+
+
+def test_valid_include_with_valid_directory(tmp_path: Path) -> None:
+    """Test valid_include accepts valid directories."""
+    CORE.config_path = str(tmp_path / "test.yaml")
+    include_dir = tmp_path / "includes"
+    include_dir.mkdir()
+
+    assert valid_include(str(include_dir)) == str(include_dir)
+
+
+def test_valid_include_invalid_extension(tmp_path: Path) -> None:
+    """Test valid_include rejects files with invalid extensions."""
+    CORE.config_path = str(tmp_path / "test.yaml")
+    invalid_file = tmp_path / "file.txt"
+    invalid_file.touch()
+
+    with pytest.raises(cv.Invalid, match="Include has invalid file extension"):
+        valid_include(str(invalid_file))
+
+
+def test_valid_project_name_valid() -> None:
+    """Test valid_project_name accepts valid project names."""
+    assert valid_project_name("esphome.my_project") == "esphome.my_project"
+
+
+def test_valid_project_name_no_namespace() -> None:
+    """Test valid_project_name rejects names without namespace."""
+    with pytest.raises(cv.Invalid, match="project name needs to have a namespace"):
+        valid_project_name("my_project")
+
+
+def test_valid_project_name_multiple_dots() -> None:
+    """Test valid_project_name rejects names with multiple dots."""
+    with pytest.raises(cv.Invalid, match="project name needs to have a namespace"):
+        valid_project_name("esphome.my.project")
+
+
+def test_validate_hostname_valid() -> None:
+    """Test validate_hostname accepts valid hostnames."""
+    config = {CONF_NAME: "my-device", CONF_NAME_ADD_MAC_SUFFIX: False}
+    assert validate_hostname(config) == config
+
+
+def test_validate_hostname_too_long() -> None:
+    """Test validate_hostname rejects hostnames that are too long."""
+    config = {
+        CONF_NAME: "a" * 32,  # 32 chars, max is 31
+        CONF_NAME_ADD_MAC_SUFFIX: False,
+    }
+    with pytest.raises(cv.Invalid, match="Hostnames can only be 31 characters long"):
+        validate_hostname(config)
+
+
+def test_validate_hostname_too_long_with_mac_suffix() -> None:
+    """Test validate_hostname accounts for MAC suffix length."""
+    config = {
+        CONF_NAME: "a" * 25,  # 25 chars, max is 24 with MAC suffix
+        CONF_NAME_ADD_MAC_SUFFIX: True,
+    }
+    with pytest.raises(cv.Invalid, match="Hostnames can only be 24 characters long"):
+        validate_hostname(config)
+
+
+def test_validate_hostname_with_underscore(caplog) -> None:
+    """Test validate_hostname warns about underscores."""
+    config = {CONF_NAME: "my_device", CONF_NAME_ADD_MAC_SUFFIX: False}
+    assert validate_hostname(config) == config
+    assert (
+        "Using the '_' (underscore) character in the hostname is discouraged"
+        in caplog.text
+    )
+
+
+def test_preload_core_config_basic(setup_core: Path) -> None:
+    """Test preload_core_config sets basic CORE attributes."""
+    config = {
+        CONF_ESPHOME: {
+            CONF_NAME: "test_device",
+        },
+        "esp32": {},
+    }
+    result = {}
+
+    platform = preload_core_config(config, result)
+
+    assert CORE.name == "test_device"
+    assert platform == "esp32"
+    assert KEY_CORE in CORE.data
+    assert CONF_BUILD_PATH in config[CONF_ESPHOME]
+
+
+def test_preload_core_config_with_build_path(setup_core: Path) -> None:
+    """Test preload_core_config uses provided build path."""
+    config = {
+        CONF_ESPHOME: {
+            CONF_NAME: "test_device",
+            CONF_BUILD_PATH: "/custom/build/path",
+        },
+        "esp8266": {},
+    }
+    result = {}
+
+    platform = preload_core_config(config, result)
+
+    assert config[CONF_ESPHOME][CONF_BUILD_PATH] == "/custom/build/path"
+    assert platform == "esp8266"
+
+
+def test_preload_core_config_env_build_path(setup_core: Path) -> None:
+    """Test preload_core_config uses ESPHOME_BUILD_PATH env var."""
+    config = {
+        CONF_ESPHOME: {
+            CONF_NAME: "test_device",
+        },
+        "rp2040": {},
+    }
+    result = {}
+
+    with patch.dict(os.environ, {"ESPHOME_BUILD_PATH": "/env/build"}):
+        platform = preload_core_config(config, result)
+
+    assert CONF_BUILD_PATH in config[CONF_ESPHOME]
+    assert "test_device" in config[CONF_ESPHOME][CONF_BUILD_PATH]
+    assert platform == "rp2040"
+
+
+def test_preload_core_config_no_platform(setup_core: Path) -> None:
+    """Test preload_core_config raises when no platform is specified."""
+    config = {
+        CONF_ESPHOME: {
+            CONF_NAME: "test_device",
+        },
+    }
+    result = {}
+
+    # Mock _is_target_platform to avoid expensive component loading
+    with patch("esphome.core.config._is_target_platform") as mock_is_platform:
+        # Return True for known platforms
+        mock_is_platform.side_effect = lambda name: name in [
+            "esp32",
+            "esp8266",
+            "rp2040",
+        ]
+
+        with pytest.raises(cv.Invalid, match="Platform missing"):
+            preload_core_config(config, result)
+
+
+def test_preload_core_config_multiple_platforms(setup_core: Path) -> None:
+    """Test preload_core_config raises when multiple platforms are specified."""
+    config = {
+        CONF_ESPHOME: {
+            CONF_NAME: "test_device",
+        },
+        "esp32": {},
+        "esp8266": {},
+    }
+    result = {}
+
+    # Mock _is_target_platform to avoid expensive component loading
+    with patch("esphome.core.config._is_target_platform") as mock_is_platform:
+        # Return True for known platforms
+        mock_is_platform.side_effect = lambda name: name in [
+            "esp32",
+            "esp8266",
+            "rp2040",
+        ]
+
+        with pytest.raises(cv.Invalid, match="Found multiple target platform blocks"):
+            preload_core_config(config, result)
+
+
+def test_include_file_header(tmp_path: Path, mock_copy_file_if_changed: Mock) -> None:
+    """Test include_file adds include statement for header files."""
+    src_file = tmp_path / "source.h"
+    src_file.write_text("// Header content")
+
+    CORE.build_path = str(tmp_path / "build")
+
+    with patch("esphome.core.config.cg") as mock_cg:
+        # Mock RawStatement to capture the text
+        mock_raw_statement = MagicMock()
+        mock_raw_statement.text = ""
+
+        def raw_statement_side_effect(text):
+            mock_raw_statement.text = text
+            return mock_raw_statement
+
+        mock_cg.RawStatement.side_effect = raw_statement_side_effect
+
+        config.include_file(str(src_file), "test.h")
+
+        mock_copy_file_if_changed.assert_called_once()
+        mock_cg.add_global.assert_called_once()
+        # Check that include statement was added
+        assert '#include "test.h"' in mock_raw_statement.text
+
+
+def test_include_file_cpp(tmp_path: Path, mock_copy_file_if_changed: Mock) -> None:
+    """Test include_file does not add include for cpp files."""
+    src_file = tmp_path / "source.cpp"
+    src_file.write_text("// CPP content")
+
+    CORE.build_path = str(tmp_path / "build")
+
+    with patch("esphome.core.config.cg") as mock_cg:
+        config.include_file(str(src_file), "test.cpp")
+
+        mock_copy_file_if_changed.assert_called_once()
+        # Should not add include statement for .cpp files
+        mock_cg.add_global.assert_not_called()
+
+
+def test_get_usable_cpu_count() -> None:
+    """Test get_usable_cpu_count returns CPU count."""
+    count = config.get_usable_cpu_count()
+    assert isinstance(count, int)
+    assert count > 0
+
+
+def test_get_usable_cpu_count_with_process_cpu_count() -> None:
+    """Test get_usable_cpu_count uses process_cpu_count when available."""
+    # Test with process_cpu_count (Python 3.13+)
+    # Create a mock os module with process_cpu_count
+
+    mock_os = types.SimpleNamespace(process_cpu_count=lambda: 8, cpu_count=lambda: 4)
+
+    with patch("esphome.core.config.os", mock_os):
+        # When process_cpu_count exists, it should be used
+        count = config.get_usable_cpu_count()
+        assert count == 8
+
+    # Test fallback to cpu_count when process_cpu_count not available
+    mock_os_no_process = types.SimpleNamespace(cpu_count=lambda: 4)
+
+    with patch("esphome.core.config.os", mock_os_no_process):
+        count = config.get_usable_cpu_count()
+        assert count == 4
+
+
+def test_list_target_platforms(tmp_path: Path) -> None:
+    """Test _list_target_platforms returns available platforms."""
+    # Create mock components directory structure
+    components_dir = tmp_path / "components"
+    components_dir.mkdir()
+
+    # Create platform and non-platform directories with __init__.py
+    platforms = ["esp32", "esp8266", "rp2040", "libretiny", "host"]
+    non_platforms = ["sensor"]
+
+    for component in platforms + non_platforms:
+        component_dir = components_dir / component
+        component_dir.mkdir()
+        (component_dir / "__init__.py").touch()
+
+    # Create a file (not a directory)
+    (components_dir / "README.md").touch()
+
+    # Create a directory without __init__.py
+    (components_dir / "no_init").mkdir()
+
+    # Mock Path(__file__).parents[1] to return our tmp_path
+    with patch("esphome.core.config.Path") as mock_path:
+        mock_file_path = MagicMock()
+        mock_file_path.parents = [MagicMock(), tmp_path]
+        mock_path.return_value = mock_file_path
+
+        platforms = config._list_target_platforms()
+
+    assert isinstance(platforms, list)
+    # Should include platform components
+    assert "esp32" in platforms
+    assert "esp8266" in platforms
+    assert "rp2040" in platforms
+    assert "libretiny" in platforms
+    assert "host" in platforms
+    # Should not include non-platform components
+    assert "sensor" not in platforms
+    assert "README.md" not in platforms
+    assert "no_init" not in platforms
+
+
+def test_is_target_platform() -> None:
+    """Test _is_target_platform identifies valid platforms."""
+    assert config._is_target_platform("esp32") is True
+    assert config._is_target_platform("esp8266") is True
+    assert config._is_target_platform("rp2040") is True
+    assert config._is_target_platform("invalid_platform") is False
+    assert config._is_target_platform("api") is False  # Component but not platform
+
+
+@pytest.mark.asyncio
+async def test_add_includes_with_single_file(
+    tmp_path: Path,
+    mock_copy_file_if_changed: Mock,
+    mock_cg_with_include_capture: tuple[Mock, list[str]],
+) -> None:
+    """Test add_includes copies a single header file to build directory."""
+    CORE.config_path = str(tmp_path / "config.yaml")
+    CORE.build_path = str(tmp_path / "build")
+    os.makedirs(CORE.build_path, exist_ok=True)
+
+    # Create include file
+    include_file = tmp_path / "my_header.h"
+    include_file.write_text("#define MY_CONSTANT 42")
+
+    mock_cg, includes_added = mock_cg_with_include_capture
+
+    await config.add_includes([str(include_file)])
+
+    # Verify copy_file_if_changed was called to copy the file
+    # Note: add_includes adds files to a src/ subdirectory
+    mock_copy_file_if_changed.assert_called_once_with(
+        str(include_file), str(Path(CORE.build_path) / "src" / "my_header.h")
+    )
+
+    # Verify include statement was added
+    assert any('#include "my_header.h"' in inc for inc in includes_added)
+
+
+@pytest.mark.asyncio
+@pytest.mark.skipif(os.name == "nt", reason="Unix-specific test")
+async def test_add_includes_with_directory_unix(
+    tmp_path: Path,
+    mock_copy_file_if_changed: Mock,
+    mock_cg_with_include_capture: tuple[Mock, list[str]],
+) -> None:
+    """Test add_includes copies all files from a directory on Unix."""
+    CORE.config_path = str(tmp_path / "config.yaml")
+    CORE.build_path = str(tmp_path / "build")
+    os.makedirs(CORE.build_path, exist_ok=True)
+
+    # Create include directory with files
+    include_dir = tmp_path / "includes"
+    include_dir.mkdir()
+    (include_dir / "header1.h").write_text("#define HEADER1")
+    (include_dir / "header2.hpp").write_text("#define HEADER2")
+    (include_dir / "source.cpp").write_text("// Implementation")
+    (include_dir / "README.md").write_text(
+        "# Documentation"
+    )  # Should be copied but not included
+
+    # Create subdirectory with files
+    subdir = include_dir / "subdir"
+    subdir.mkdir()
+    (subdir / "nested.h").write_text("#define NESTED")
+
+    mock_cg, includes_added = mock_cg_with_include_capture
+
+    await config.add_includes([str(include_dir)])
+
+    # Verify copy_file_if_changed was called for all files
+    assert mock_copy_file_if_changed.call_count == 5  # 4 code files + 1 README
+
+    # Verify include statements were added for valid extensions
+    include_strings = " ".join(includes_added)
+    assert "includes/header1.h" in include_strings
+    assert "includes/header2.hpp" in include_strings
+    assert "includes/subdir/nested.h" in include_strings
+    # CPP files are copied but not included
+    assert "source.cpp" not in include_strings or "#include" not in include_strings
+    # README.md should not have an include statement
+    assert "README.md" not in include_strings
+
+
+@pytest.mark.asyncio
+@pytest.mark.skipif(os.name != "nt", reason="Windows-specific test")
+async def test_add_includes_with_directory_windows(
+    tmp_path: Path,
+    mock_copy_file_if_changed: Mock,
+    mock_cg_with_include_capture: tuple[Mock, list[str]],
+) -> None:
+    """Test add_includes copies all files from a directory on Windows."""
+    CORE.config_path = str(tmp_path / "config.yaml")
+    CORE.build_path = str(tmp_path / "build")
+    os.makedirs(CORE.build_path, exist_ok=True)
+
+    # Create include directory with files
+    include_dir = tmp_path / "includes"
+    include_dir.mkdir()
+    (include_dir / "header1.h").write_text("#define HEADER1")
+    (include_dir / "header2.hpp").write_text("#define HEADER2")
+    (include_dir / "source.cpp").write_text("// Implementation")
+    (include_dir / "README.md").write_text(
+        "# Documentation"
+    )  # Should be copied but not included
+
+    # Create subdirectory with files
+    subdir = include_dir / "subdir"
+    subdir.mkdir()
+    (subdir / "nested.h").write_text("#define NESTED")
+
+    mock_cg, includes_added = mock_cg_with_include_capture
+
+    await config.add_includes([str(include_dir)])
+
+    # Verify copy_file_if_changed was called for all files
+    assert mock_copy_file_if_changed.call_count == 5  # 4 code files + 1 README
+
+    # Verify include statements were added for valid extensions
+    include_strings = " ".join(includes_added)
+    assert "includes\\header1.h" in include_strings
+    assert "includes\\header2.hpp" in include_strings
+    assert "includes\\subdir\\nested.h" in include_strings
+    # CPP files are copied but not included
+    assert "source.cpp" not in include_strings or "#include" not in include_strings
+    # README.md should not have an include statement
+    assert "README.md" not in include_strings
+
+
+@pytest.mark.asyncio
+async def test_add_includes_with_multiple_sources(
+    tmp_path: Path, mock_copy_file_if_changed: Mock
+) -> None:
+    """Test add_includes with multiple files and directories."""
+    CORE.config_path = str(tmp_path / "config.yaml")
+    CORE.build_path = str(tmp_path / "build")
+    os.makedirs(CORE.build_path, exist_ok=True)
+
+    # Create various include sources
+    single_file = tmp_path / "single.h"
+    single_file.write_text("#define SINGLE")
+
+    dir1 = tmp_path / "dir1"
+    dir1.mkdir()
+    (dir1 / "file1.h").write_text("#define FILE1")
+
+    dir2 = tmp_path / "dir2"
+    dir2.mkdir()
+    (dir2 / "file2.cpp").write_text("// File2")
+
+    with patch("esphome.core.config.cg"):
+        await config.add_includes([str(single_file), str(dir1), str(dir2)])
+
+    # Verify copy_file_if_changed was called for all files
+    assert mock_copy_file_if_changed.call_count == 3  # 3 files total
+
+
+@pytest.mark.asyncio
+async def test_add_includes_empty_directory(
+    tmp_path: Path, mock_copy_file_if_changed: Mock
+) -> None:
+    """Test add_includes with an empty directory doesn't fail."""
+    CORE.config_path = str(tmp_path / "config.yaml")
+    CORE.build_path = str(tmp_path / "build")
+    os.makedirs(CORE.build_path, exist_ok=True)
+
+    # Create empty directory
+    empty_dir = tmp_path / "empty"
+    empty_dir.mkdir()
+
+    with patch("esphome.core.config.cg"):
+        # Should not raise any errors
+        await config.add_includes([str(empty_dir)])
+
+    # No files to copy from empty directory
+    mock_copy_file_if_changed.assert_not_called()
+
+
+@pytest.mark.asyncio
+@pytest.mark.skipif(os.name == "nt", reason="Unix-specific test")
+async def test_add_includes_preserves_directory_structure_unix(
+    tmp_path: Path, mock_copy_file_if_changed: Mock
+) -> None:
+    """Test that add_includes preserves relative directory structure on Unix."""
+    CORE.config_path = str(tmp_path / "config.yaml")
+    CORE.build_path = str(tmp_path / "build")
+    os.makedirs(CORE.build_path, exist_ok=True)
+
+    # Create nested directory structure
+    lib_dir = tmp_path / "lib"
+    lib_dir.mkdir()
+
+    src_dir = lib_dir / "src"
+    src_dir.mkdir()
+    (src_dir / "core.h").write_text("#define CORE")
+
+    utils_dir = lib_dir / "utils"
+    utils_dir.mkdir()
+    (utils_dir / "helper.h").write_text("#define HELPER")
+
+    with patch("esphome.core.config.cg"):
+        await config.add_includes([str(lib_dir)])
+
+    # Verify copy_file_if_changed was called with correct paths
+    calls = mock_copy_file_if_changed.call_args_list
+    dest_paths = [call[0][1] for call in calls]
+
+    # Check that relative paths are preserved
+    assert any("lib/src/core.h" in path for path in dest_paths)
+    assert any("lib/utils/helper.h" in path for path in dest_paths)
+
+
+@pytest.mark.asyncio
+@pytest.mark.skipif(os.name != "nt", reason="Windows-specific test")
+async def test_add_includes_preserves_directory_structure_windows(
+    tmp_path: Path, mock_copy_file_if_changed: Mock
+) -> None:
+    """Test that add_includes preserves relative directory structure on Windows."""
+    CORE.config_path = str(tmp_path / "config.yaml")
+    CORE.build_path = str(tmp_path / "build")
+    os.makedirs(CORE.build_path, exist_ok=True)
+
+    # Create nested directory structure
+    lib_dir = tmp_path / "lib"
+    lib_dir.mkdir()
+
+    src_dir = lib_dir / "src"
+    src_dir.mkdir()
+    (src_dir / "core.h").write_text("#define CORE")
+
+    utils_dir = lib_dir / "utils"
+    utils_dir.mkdir()
+    (utils_dir / "helper.h").write_text("#define HELPER")
+
+    with patch("esphome.core.config.cg"):
+        await config.add_includes([str(lib_dir)])
+
+    # Verify copy_file_if_changed was called with correct paths
+    calls = mock_copy_file_if_changed.call_args_list
+    dest_paths = [call[0][1] for call in calls]
+
+    # Check that relative paths are preserved
+    assert any("lib\\src\\core.h" in path for path in dest_paths)
+    assert any("lib\\utils\\helper.h" in path for path in dest_paths)
+
+
+@pytest.mark.asyncio
+async def test_add_includes_overwrites_existing_files(
+    tmp_path: Path, mock_copy_file_if_changed: Mock
+) -> None:
+    """Test that add_includes overwrites existing files in build directory."""
+    CORE.config_path = str(tmp_path / "config.yaml")
+    CORE.build_path = str(tmp_path / "build")
+    os.makedirs(CORE.build_path, exist_ok=True)
+
+    # Create include file
+    include_file = tmp_path / "header.h"
+    include_file.write_text("#define NEW_VALUE 42")
+
+    with patch("esphome.core.config.cg"):
+        await config.add_includes([str(include_file)])
+
+    # Verify copy_file_if_changed was called (it handles overwriting)
+    # Note: add_includes adds files to a src/ subdirectory
+    mock_copy_file_if_changed.assert_called_once_with(
+        str(include_file), str(Path(CORE.build_path) / "src" / "header.h")
+    )

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_core.py

@@ -1,3 +1,6 @@
+import os
+from unittest.mock import patch
+
 from hypothesis import given
 import pytest
 from strategies import mac_addr_strings
@@ -577,3 +580,83 @@ class TestEsphomeCore:
 
         assert target.is_esp32 is False
         assert target.is_esp8266 is True
+
+    @pytest.mark.skipif(os.name == "nt", reason="Unix-specific test")
+    def test_data_dir_default_unix(self, target):
+        """Test data_dir returns .esphome in config directory by default on Unix."""
+        target.config_path = "/home/user/config.yaml"
+        assert target.data_dir == "/home/user/.esphome"
+
+    @pytest.mark.skipif(os.name != "nt", reason="Windows-specific test")
+    def test_data_dir_default_windows(self, target):
+        """Test data_dir returns .esphome in config directory by default on Windows."""
+        target.config_path = "D:\\home\\user\\config.yaml"
+        assert target.data_dir == "D:\\home\\user\\.esphome"
+
+    def test_data_dir_ha_addon(self, target):
+        """Test data_dir returns /data when running as Home Assistant addon."""
+        target.config_path = "/config/test.yaml"
+
+        with patch.dict(os.environ, {"ESPHOME_IS_HA_ADDON": "true"}):
+            assert target.data_dir == "/data"
+
+    def test_data_dir_env_override(self, target):
+        """Test data_dir uses ESPHOME_DATA_DIR environment variable when set."""
+        target.config_path = "/home/user/config.yaml"
+
+        with patch.dict(os.environ, {"ESPHOME_DATA_DIR": "/custom/data/path"}):
+            assert target.data_dir == "/custom/data/path"
+
+    @pytest.mark.skipif(os.name == "nt", reason="Unix-specific test")
+    def test_data_dir_priority_unix(self, target):
+        """Test data_dir priority on Unix: HA addon > env var > default."""
+        target.config_path = "/config/test.yaml"
+        expected_default = "/config/.esphome"
+
+        # Test HA addon takes priority over env var
+        with patch.dict(
+            os.environ,
+            {"ESPHOME_IS_HA_ADDON": "true", "ESPHOME_DATA_DIR": "/custom/path"},
+        ):
+            assert target.data_dir == "/data"
+
+        # Test env var is used when not HA addon
+        with patch.dict(
+            os.environ,
+            {"ESPHOME_IS_HA_ADDON": "false", "ESPHOME_DATA_DIR": "/custom/path"},
+        ):
+            assert target.data_dir == "/custom/path"
+
+        # Test default when neither is set
+        with patch.dict(os.environ, {}, clear=True):
+            # Ensure these env vars are not set
+            os.environ.pop("ESPHOME_IS_HA_ADDON", None)
+            os.environ.pop("ESPHOME_DATA_DIR", None)
+            assert target.data_dir == expected_default
+
+    @pytest.mark.skipif(os.name != "nt", reason="Windows-specific test")
+    def test_data_dir_priority_windows(self, target):
+        """Test data_dir priority on Windows: HA addon > env var > default."""
+        target.config_path = "D:\\config\\test.yaml"
+        expected_default = "D:\\config\\.esphome"
+
+        # Test HA addon takes priority over env var
+        with patch.dict(
+            os.environ,
+            {"ESPHOME_IS_HA_ADDON": "true", "ESPHOME_DATA_DIR": "/custom/path"},
+        ):
+            assert target.data_dir == "/data"
+
+        # Test env var is used when not HA addon
+        with patch.dict(
+            os.environ,
+            {"ESPHOME_IS_HA_ADDON": "false", "ESPHOME_DATA_DIR": "/custom/path"},
+        ):
+            assert target.data_dir == "/custom/path"
+
+        # Test default when neither is set
+        with patch.dict(os.environ, {}, clear=True):
+            # Ensure these env vars are not set
+            os.environ.pop("ESPHOME_IS_HA_ADDON", None)
+            os.environ.pop("ESPHOME_DATA_DIR", None)
+            assert target.data_dir == expected_default

tests/unit_tests/test_helpers.py

@@ -1,5 +1,8 @@
 import logging
+import os
+from pathlib import Path
 import socket
+import stat
 from unittest.mock import patch
 
 from aioesphomeapi.host_resolver import AddrInfo, IPv4Sockaddr, IPv6Sockaddr
@@ -8,6 +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
 
 
@@ -554,6 +558,239 @@ def test_addr_preference_ipv6_link_local_with_scope() -> None:
     assert helpers.addr_preference_(addr_info) == 1  # Has scope, so it's usable
 
 
+def test_mkdir_p(tmp_path: Path) -> None:
+    """Test mkdir_p creates directories recursively."""
+    # Test creating nested directories
+    nested_path = tmp_path / "level1" / "level2" / "level3"
+    helpers.mkdir_p(nested_path)
+    assert nested_path.exists()
+    assert nested_path.is_dir()
+
+    # Test that mkdir_p is idempotent (doesn't fail if directory exists)
+    helpers.mkdir_p(nested_path)
+    assert nested_path.exists()
+
+    # Test with empty path (should do nothing)
+    helpers.mkdir_p("")
+
+    # Test with existing directory
+    existing_dir = tmp_path / "existing"
+    existing_dir.mkdir()
+    helpers.mkdir_p(existing_dir)
+    assert existing_dir.exists()
+
+
+def test_mkdir_p_file_exists_error(tmp_path: Path) -> None:
+    """Test mkdir_p raises error when path is a file."""
+    # Create a file
+    file_path = tmp_path / "test_file.txt"
+    file_path.write_text("test content")
+
+    # Try to create directory with same name as existing file
+    with pytest.raises(EsphomeError, match=r"Error creating directories"):
+        helpers.mkdir_p(file_path)
+
+
+def test_mkdir_p_with_existing_file_raises_error(tmp_path: Path) -> None:
+    """Test mkdir_p raises error when trying to create dir over existing file."""
+    # Create a file where we want to create a directory
+    file_path = tmp_path / "existing_file"
+    file_path.write_text("content")
+
+    # Try to create a directory with a path that goes through the file
+    dir_path = file_path / "subdir"
+
+    with pytest.raises(EsphomeError, match=r"Error creating directories"):
+        helpers.mkdir_p(dir_path)
+
+
+@pytest.mark.skipif(os.name == "nt", reason="Unix-specific test")
+def test_read_file_unix(tmp_path: Path) -> None:
+    """Test read_file reads file content correctly on Unix."""
+    # Test reading regular file
+    test_file = tmp_path / "test.txt"
+    expected_content = "Test content\nLine 2\n"
+    test_file.write_text(expected_content)
+
+    content = helpers.read_file(test_file)
+    assert content == expected_content
+
+    # Test reading file with UTF-8 characters
+    utf8_file = tmp_path / "utf8.txt"
+    utf8_content = "Hello 世界 🌍"
+    utf8_file.write_text(utf8_content, encoding="utf-8")
+
+    content = helpers.read_file(utf8_file)
+    assert content == utf8_content
+
+
+@pytest.mark.skipif(os.name != "nt", reason="Windows-specific test")
+def test_read_file_windows(tmp_path: Path) -> None:
+    """Test read_file reads file content correctly on Windows."""
+    # Test reading regular file
+    test_file = tmp_path / "test.txt"
+    expected_content = "Test content\nLine 2\n"
+    test_file.write_text(expected_content)
+
+    content = helpers.read_file(test_file)
+    # On Windows, text mode reading converts \n to \r\n
+    assert content == expected_content.replace("\n", "\r\n")
+
+    # Test reading file with UTF-8 characters
+    utf8_file = tmp_path / "utf8.txt"
+    utf8_content = "Hello 世界 🌍"
+    utf8_file.write_text(utf8_content, encoding="utf-8")
+
+    content = helpers.read_file(utf8_file)
+    assert content == utf8_content
+
+
+def test_read_file_not_found() -> None:
+    """Test read_file raises error for non-existent file."""
+    with pytest.raises(EsphomeError, match=r"Error reading file"):
+        helpers.read_file("/nonexistent/file.txt")
+
+
+def test_read_file_unicode_decode_error(tmp_path: Path) -> None:
+    """Test read_file raises error for invalid UTF-8."""
+    test_file = tmp_path / "invalid.txt"
+    # Write invalid UTF-8 bytes
+    test_file.write_bytes(b"\xff\xfe")
+
+    with pytest.raises(EsphomeError, match=r"Error reading file"):
+        helpers.read_file(test_file)
+
+
+@pytest.mark.skipif(os.name == "nt", reason="Unix-specific test")
+def test_write_file_unix(tmp_path: Path) -> None:
+    """Test write_file writes content correctly on Unix."""
+    # Test writing string content
+    test_file = tmp_path / "test.txt"
+    content = "Test content\nLine 2"
+    helpers.write_file(test_file, content)
+
+    assert test_file.read_text() == content
+    # Check file permissions
+    assert oct(test_file.stat().st_mode)[-3:] == "644"
+
+    # Test overwriting existing file
+    new_content = "New content"
+    helpers.write_file(test_file, new_content)
+    assert test_file.read_text() == new_content
+
+    # Test writing to nested directories (should create them)
+    nested_file = tmp_path / "dir1" / "dir2" / "file.txt"
+    helpers.write_file(nested_file, content)
+    assert nested_file.read_text() == content
+
+
+@pytest.mark.skipif(os.name != "nt", reason="Windows-specific test")
+def test_write_file_windows(tmp_path: Path) -> None:
+    """Test write_file writes content correctly on Windows."""
+    # Test writing string content
+    test_file = tmp_path / "test.txt"
+    content = "Test content\nLine 2"
+    helpers.write_file(test_file, content)
+
+    assert test_file.read_text() == content
+    # Windows doesn't have Unix-style 644 permissions
+
+    # Test overwriting existing file
+    new_content = "New content"
+    helpers.write_file(test_file, new_content)
+    assert test_file.read_text() == new_content
+
+    # Test writing to nested directories (should create them)
+    nested_file = tmp_path / "dir1" / "dir2" / "file.txt"
+    helpers.write_file(nested_file, content)
+    assert nested_file.read_text() == content
+
+
+@pytest.mark.skipif(os.name == "nt", reason="Unix-specific permission test")
+def test_write_file_to_non_writable_directory_unix(tmp_path: Path) -> None:
+    """Test write_file raises error when directory is not writable on Unix."""
+    # Create a directory and make it read-only
+    read_only_dir = tmp_path / "readonly"
+    read_only_dir.mkdir()
+    test_file = read_only_dir / "test.txt"
+
+    # Make directory read-only (no write permission)
+    read_only_dir.chmod(0o555)
+
+    try:
+        with pytest.raises(EsphomeError, match=r"Could not write file"):
+            helpers.write_file(test_file, "content")
+    finally:
+        # Restore write permissions for cleanup
+        read_only_dir.chmod(0o755)
+
+
+@pytest.mark.skipif(os.name != "nt", reason="Windows-specific test")
+def test_write_file_to_non_writable_directory_windows(tmp_path: Path) -> None:
+    """Test write_file error handling on Windows."""
+    # Windows handles permissions differently - test a different error case
+    # Try to write to a file path that contains an existing file as a directory component
+    existing_file = tmp_path / "file.txt"
+    existing_file.write_text("content")
+
+    # Try to write to a path that treats the file as a directory
+    invalid_path = existing_file / "subdir" / "test.txt"
+
+    with pytest.raises(EsphomeError, match=r"Could not write file"):
+        helpers.write_file(invalid_path, "content")
+
+
+@pytest.mark.skipif(os.name == "nt", reason="Unix-specific permission test")
+def test_write_file_with_permission_bits_unix(tmp_path: Path) -> None:
+    """Test that write_file sets correct permissions on Unix."""
+    test_file = tmp_path / "test.txt"
+    helpers.write_file(test_file, "content")
+
+    # Check that file has 644 permissions
+    file_mode = test_file.stat().st_mode
+    assert stat.S_IMODE(file_mode) == 0o644
+
+
+@pytest.mark.skipif(os.name == "nt", reason="Unix-specific permission test")
+def test_copy_file_if_changed_permission_recovery_unix(tmp_path: Path) -> None:
+    """Test copy_file_if_changed handles permission errors correctly on Unix."""
+    # Test with read-only destination file
+    src = tmp_path / "source.txt"
+    dst = tmp_path / "dest.txt"
+    src.write_text("new content")
+    dst.write_text("old content")
+    dst.chmod(0o444)  # Make destination read-only
+
+    try:
+        # Should handle permission error by deleting and retrying
+        helpers.copy_file_if_changed(src, dst)
+        assert dst.read_text() == "new content"
+    finally:
+        # Restore write permissions for cleanup
+        if dst.exists():
+            dst.chmod(0o644)
+
+
+def test_copy_file_if_changed_creates_directories(tmp_path: Path) -> None:
+    """Test copy_file_if_changed creates missing directories."""
+    src = tmp_path / "source.txt"
+    dst = tmp_path / "subdir" / "nested" / "dest.txt"
+    src.write_text("content")
+
+    helpers.copy_file_if_changed(src, dst)
+    assert dst.exists()
+    assert dst.read_text() == "content"
+
+
+def test_copy_file_if_changed_nonexistent_source(tmp_path: Path) -> None:
+    """Test copy_file_if_changed with non-existent source."""
+    src = tmp_path / "nonexistent.txt"
+    dst = tmp_path / "dest.txt"
+
+    with pytest.raises(EsphomeError, match=r"Error copying file"):
+        helpers.copy_file_if_changed(src, dst)
+
+
 def test_resolve_ip_address_sorting() -> None:
     """Test that results are sorted by preference."""
     # Create multiple address infos with different preferences
@@ -594,3 +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

tests/unit_tests/test_platformio_api.py

@@ -1,10 +1,16 @@
 """Tests for platformio_api.py path functions."""
 
+import json
+import os
 from pathlib import Path
-from unittest.mock import patch
+import shutil
+from types import SimpleNamespace
+from unittest.mock import MagicMock, Mock, patch
+
+import pytest
 
 from esphome import platformio_api
-from esphome.core import CORE
+from esphome.core import CORE, EsphomeError
 
 
 def test_idedata_firmware_elf_path(setup_core: Path) -> None:
@@ -104,7 +110,9 @@ def test_flash_image_dataclass() -> None:
     assert image.offset == "0x10000"
 
 
-def test_load_idedata_returns_dict(setup_core: Path) -> None:
+def test_load_idedata_returns_dict(
+    setup_core: Path, mock_run_platformio_cli_run
+) -> None:
     """Test _load_idedata returns parsed idedata dict when successful."""
     CORE.build_path = str(setup_core / "build" / "test")
     CORE.name = "test"
@@ -118,12 +126,511 @@ def test_load_idedata_returns_dict(setup_core: Path) -> None:
     idedata_path.parent.mkdir(parents=True, exist_ok=True)
     idedata_path.write_text('{"prog_path": "/test/firmware.elf"}')
 
-    with patch("esphome.platformio_api.run_platformio_cli_run") as mock_run:
-        mock_run.return_value = '{"prog_path": "/test/firmware.elf"}'
+    mock_run_platformio_cli_run.return_value = '{"prog_path": "/test/firmware.elf"}'
 
-        config = {"name": "test"}
-        result = platformio_api._load_idedata(config)
+    config = {"name": "test"}
+    result = platformio_api._load_idedata(config)
 
     assert result is not None
     assert isinstance(result, dict)
     assert result["prog_path"] == "/test/firmware.elf"
+
+
+def test_load_idedata_uses_cache_when_valid(
+    setup_core: Path, mock_run_platformio_cli_run: Mock
+) -> None:
+    """Test _load_idedata uses cached data when unchanged."""
+    CORE.build_path = str(setup_core / "build" / "test")
+    CORE.name = "test"
+
+    # Create platformio.ini
+    platformio_ini = setup_core / "build" / "test" / "platformio.ini"
+    platformio_ini.parent.mkdir(parents=True, exist_ok=True)
+    platformio_ini.write_text("content")
+
+    # Create idedata cache file that's newer
+    idedata_path = setup_core / ".esphome" / "idedata" / "test.json"
+    idedata_path.parent.mkdir(parents=True, exist_ok=True)
+    idedata_path.write_text('{"prog_path": "/cached/firmware.elf"}')
+
+    # Make idedata newer than platformio.ini
+    platformio_ini_mtime = platformio_ini.stat().st_mtime
+    os.utime(idedata_path, (platformio_ini_mtime + 1, platformio_ini_mtime + 1))
+
+    config = {"name": "test"}
+    result = platformio_api._load_idedata(config)
+
+    # Should not call _run_idedata since cache is valid
+    mock_run_platformio_cli_run.assert_not_called()
+
+    assert result["prog_path"] == "/cached/firmware.elf"
+
+
+def test_load_idedata_regenerates_when_platformio_ini_newer(
+    setup_core: Path, mock_run_platformio_cli_run: Mock
+) -> None:
+    """Test _load_idedata regenerates when platformio.ini is newer."""
+    CORE.build_path = str(setup_core / "build" / "test")
+    CORE.name = "test"
+
+    # Create idedata cache file first
+    idedata_path = setup_core / ".esphome" / "idedata" / "test.json"
+    idedata_path.parent.mkdir(parents=True, exist_ok=True)
+    idedata_path.write_text('{"prog_path": "/old/firmware.elf"}')
+
+    # Create platformio.ini that's newer
+    idedata_mtime = idedata_path.stat().st_mtime
+    platformio_ini = setup_core / "build" / "test" / "platformio.ini"
+    platformio_ini.parent.mkdir(parents=True, exist_ok=True)
+    platformio_ini.write_text("content")
+    # Make platformio.ini newer than idedata
+    os.utime(platformio_ini, (idedata_mtime + 1, idedata_mtime + 1))
+
+    # Mock platformio to return new data
+    new_data = {"prog_path": "/new/firmware.elf"}
+    mock_run_platformio_cli_run.return_value = json.dumps(new_data)
+
+    config = {"name": "test"}
+    result = platformio_api._load_idedata(config)
+
+    # Should call _run_idedata since platformio.ini is newer
+    mock_run_platformio_cli_run.assert_called_once()
+
+    assert result["prog_path"] == "/new/firmware.elf"
+
+
+def test_load_idedata_regenerates_on_corrupted_cache(
+    setup_core: Path, mock_run_platformio_cli_run: Mock
+) -> None:
+    """Test _load_idedata regenerates when cache file is corrupted."""
+    CORE.build_path = str(setup_core / "build" / "test")
+    CORE.name = "test"
+
+    # Create platformio.ini
+    platformio_ini = setup_core / "build" / "test" / "platformio.ini"
+    platformio_ini.parent.mkdir(parents=True, exist_ok=True)
+    platformio_ini.write_text("content")
+
+    # Create corrupted idedata cache file
+    idedata_path = setup_core / ".esphome" / "idedata" / "test.json"
+    idedata_path.parent.mkdir(parents=True, exist_ok=True)
+    idedata_path.write_text('{"prog_path": invalid json')
+
+    # Make idedata newer so it would be used if valid
+    platformio_ini_mtime = platformio_ini.stat().st_mtime
+    os.utime(idedata_path, (platformio_ini_mtime + 1, platformio_ini_mtime + 1))
+
+    # Mock platformio to return new data
+    new_data = {"prog_path": "/new/firmware.elf"}
+    mock_run_platformio_cli_run.return_value = json.dumps(new_data)
+
+    config = {"name": "test"}
+    result = platformio_api._load_idedata(config)
+
+    # Should call _run_idedata since cache is corrupted
+    mock_run_platformio_cli_run.assert_called_once()
+
+    assert result["prog_path"] == "/new/firmware.elf"
+
+
+def test_run_idedata_parses_json_from_output(
+    setup_core: Path, mock_run_platformio_cli_run: Mock
+) -> None:
+    """Test _run_idedata extracts JSON from platformio output."""
+    config = {"name": "test"}
+
+    expected_data = {
+        "prog_path": "/path/to/firmware.elf",
+        "cc_path": "/path/to/gcc",
+        "extra": {"flash_images": []},
+    }
+
+    # Simulate platformio output with JSON embedded
+    mock_run_platformio_cli_run.return_value = (
+        f"Some preamble\n{json.dumps(expected_data)}\nSome postamble"
+    )
+
+    result = platformio_api._run_idedata(config)
+
+    assert result == expected_data
+
+
+def test_run_idedata_raises_on_no_json(
+    setup_core: Path, mock_run_platformio_cli_run: Mock
+) -> None:
+    """Test _run_idedata raises EsphomeError when no JSON found."""
+    config = {"name": "test"}
+
+    mock_run_platformio_cli_run.return_value = "No JSON in this output"
+
+    with pytest.raises(EsphomeError):
+        platformio_api._run_idedata(config)
+
+
+def test_run_idedata_raises_on_invalid_json(
+    setup_core: Path, mock_run_platformio_cli_run: Mock
+) -> None:
+    """Test _run_idedata raises on malformed JSON."""
+    config = {"name": "test"}
+    mock_run_platformio_cli_run.return_value = '{"invalid": json"}'
+
+    # The ValueError from json.loads is re-raised
+    with pytest.raises(ValueError):
+        platformio_api._run_idedata(config)
+
+
+def test_run_platformio_cli_sets_environment_variables(
+    setup_core: Path, mock_run_external_command: Mock
+) -> None:
+    """Test run_platformio_cli sets correct environment variables."""
+    CORE.build_path = str(setup_core / "build" / "test")
+
+    with patch.dict(os.environ, {}, clear=False):
+        mock_run_external_command.return_value = 0
+        platformio_api.run_platformio_cli("test", "arg")
+
+        # Check environment variables were set
+        assert os.environ["PLATFORMIO_FORCE_COLOR"] == "true"
+        assert (
+            setup_core / "build" / "test"
+            in Path(os.environ["PLATFORMIO_BUILD_DIR"]).parents
+            or Path(os.environ["PLATFORMIO_BUILD_DIR"]) == setup_core / "build" / "test"
+        )
+        assert "PLATFORMIO_LIBDEPS_DIR" in os.environ
+        assert "PYTHONWARNINGS" in os.environ
+
+        # Check command was called correctly
+        mock_run_external_command.assert_called_once()
+        args = mock_run_external_command.call_args[0]
+        assert "platformio" in args
+        assert "test" in args
+        assert "arg" in args
+
+
+def test_run_platformio_cli_run_builds_command(
+    setup_core: Path, mock_run_platformio_cli: Mock
+) -> None:
+    """Test run_platformio_cli_run builds correct command."""
+    CORE.build_path = str(setup_core / "build" / "test")
+    mock_run_platformio_cli.return_value = 0
+
+    config = {"name": "test"}
+    platformio_api.run_platformio_cli_run(config, True, "extra", "args")
+
+    mock_run_platformio_cli.assert_called_once_with(
+        "run", "-d", CORE.build_path, "-v", "extra", "args"
+    )
+
+
+def test_run_compile(setup_core: Path, mock_run_platformio_cli_run: Mock) -> None:
+    """Test run_compile with process limit."""
+    from esphome.const import CONF_COMPILE_PROCESS_LIMIT, CONF_ESPHOME
+
+    CORE.build_path = str(setup_core / "build" / "test")
+    config = {CONF_ESPHOME: {CONF_COMPILE_PROCESS_LIMIT: 4}}
+    mock_run_platformio_cli_run.return_value = 0
+
+    platformio_api.run_compile(config, verbose=True)
+
+    mock_run_platformio_cli_run.assert_called_once_with(config, True, "-j4")
+
+
+def test_get_idedata_caches_result(
+    setup_core: Path, mock_run_platformio_cli_run: Mock
+) -> None:
+    """Test get_idedata caches result in CORE.data."""
+    from esphome.const import KEY_CORE
+
+    CORE.build_path = str(setup_core / "build" / "test")
+    CORE.name = "test"
+    CORE.data[KEY_CORE] = {}
+
+    # Create platformio.ini to avoid regeneration
+    platformio_ini = setup_core / "build" / "test" / "platformio.ini"
+    platformio_ini.parent.mkdir(parents=True, exist_ok=True)
+    platformio_ini.write_text("content")
+
+    # Mock platformio to return data
+    idedata = {"prog_path": "/test/firmware.elf"}
+    mock_run_platformio_cli_run.return_value = json.dumps(idedata)
+
+    config = {"name": "test"}
+
+    # First call should load and cache
+    result1 = platformio_api.get_idedata(config)
+    mock_run_platformio_cli_run.assert_called_once()
+
+    # Second call should use cache from CORE.data
+    result2 = platformio_api.get_idedata(config)
+    mock_run_platformio_cli_run.assert_called_once()  # Still only called once
+
+    assert result1 is result2
+    assert isinstance(result1, platformio_api.IDEData)
+    assert result1.firmware_elf_path == "/test/firmware.elf"
+
+
+def test_idedata_addr2line_path_windows(setup_core: Path) -> None:
+    """Test IDEData.addr2line_path on Windows."""
+    raw_data = {"prog_path": "/path/to/firmware.elf", "cc_path": "C:\\tools\\gcc.exe"}
+    idedata = platformio_api.IDEData(raw_data)
+
+    result = idedata.addr2line_path
+    assert result == "C:\\tools\\addr2line.exe"
+
+
+def test_idedata_addr2line_path_unix(setup_core: Path) -> None:
+    """Test IDEData.addr2line_path on Unix."""
+    raw_data = {"prog_path": "/path/to/firmware.elf", "cc_path": "/usr/bin/gcc"}
+    idedata = platformio_api.IDEData(raw_data)
+
+    result = idedata.addr2line_path
+    assert result == "/usr/bin/addr2line"
+
+
+def test_patch_structhash(setup_core: Path) -> None:
+    """Test patch_structhash monkey patches platformio functions."""
+    # Create simple namespace objects to act as modules
+    mock_cli = SimpleNamespace()
+    mock_helpers = SimpleNamespace()
+    mock_run = SimpleNamespace(cli=mock_cli, helpers=mock_helpers)
+
+    # Mock platformio modules
+    with patch.dict(
+        "sys.modules",
+        {
+            "platformio.run.cli": mock_cli,
+            "platformio.run.helpers": mock_helpers,
+            "platformio.run": mock_run,
+            "platformio.project.helpers": MagicMock(),
+            "platformio.fs": MagicMock(),
+            "platformio": MagicMock(),
+        },
+    ):
+        # Call patch_structhash
+        platformio_api.patch_structhash()
+
+        # Verify both modules had clean_build_dir patched
+        # Check that clean_build_dir was set on both modules
+        assert hasattr(mock_cli, "clean_build_dir")
+        assert hasattr(mock_helpers, "clean_build_dir")
+
+        # Verify they got the same function assigned
+        assert mock_cli.clean_build_dir is mock_helpers.clean_build_dir
+
+        # Verify it's a real function (not a Mock)
+        assert callable(mock_cli.clean_build_dir)
+        assert mock_cli.clean_build_dir.__name__ == "patched_clean_build_dir"
+
+
+def test_patched_clean_build_dir_removes_outdated(setup_core: Path) -> None:
+    """Test patched_clean_build_dir removes build dir when platformio.ini is newer."""
+    build_dir = setup_core / "build"
+    build_dir.mkdir()
+    platformio_ini = setup_core / "platformio.ini"
+    platformio_ini.write_text("config")
+
+    # Make platformio.ini newer than build_dir
+    build_mtime = build_dir.stat().st_mtime
+    os.utime(platformio_ini, (build_mtime + 1, build_mtime + 1))
+
+    # Track if directory was removed
+    removed_paths: list[str] = []
+
+    def track_rmtree(path: str) -> None:
+        removed_paths.append(path)
+        shutil.rmtree(path)
+
+    # Create mock modules that patch_structhash expects
+    mock_cli = SimpleNamespace()
+    mock_helpers = SimpleNamespace()
+    mock_project_helpers = MagicMock()
+    mock_project_helpers.get_project_dir.return_value = str(setup_core)
+    mock_fs = SimpleNamespace(rmtree=track_rmtree)
+
+    with patch.dict(
+        "sys.modules",
+        {
+            "platformio": SimpleNamespace(fs=mock_fs),
+            "platformio.fs": mock_fs,
+            "platformio.project.helpers": mock_project_helpers,
+            "platformio.run": SimpleNamespace(cli=mock_cli, helpers=mock_helpers),
+            "platformio.run.cli": mock_cli,
+            "platformio.run.helpers": mock_helpers,
+        },
+    ):
+        # Call patch_structhash to install the patched function
+        platformio_api.patch_structhash()
+
+        # Call the patched function
+        mock_helpers.clean_build_dir(str(build_dir), [])
+
+        # Verify directory was removed and recreated
+        assert len(removed_paths) == 1
+        assert removed_paths[0] == str(build_dir)
+        assert build_dir.exists()  # makedirs recreated it
+
+
+def test_patched_clean_build_dir_keeps_updated(setup_core: Path) -> None:
+    """Test patched_clean_build_dir keeps build dir when it's up to date."""
+    build_dir = setup_core / "build"
+    build_dir.mkdir()
+    test_file = build_dir / "test.txt"
+    test_file.write_text("test content")
+
+    platformio_ini = setup_core / "platformio.ini"
+    platformio_ini.write_text("config")
+
+    # Make build_dir newer than platformio.ini
+    ini_mtime = platformio_ini.stat().st_mtime
+    os.utime(build_dir, (ini_mtime + 1, ini_mtime + 1))
+
+    # Track if rmtree is called
+    removed_paths: list[str] = []
+
+    def track_rmtree(path: str) -> None:
+        removed_paths.append(path)
+
+    # Create mock modules
+    mock_cli = SimpleNamespace()
+    mock_helpers = SimpleNamespace()
+    mock_project_helpers = MagicMock()
+    mock_project_helpers.get_project_dir.return_value = str(setup_core)
+    mock_fs = SimpleNamespace(rmtree=track_rmtree)
+
+    with patch.dict(
+        "sys.modules",
+        {
+            "platformio": SimpleNamespace(fs=mock_fs),
+            "platformio.fs": mock_fs,
+            "platformio.project.helpers": mock_project_helpers,
+            "platformio.run": SimpleNamespace(cli=mock_cli, helpers=mock_helpers),
+            "platformio.run.cli": mock_cli,
+            "platformio.run.helpers": mock_helpers,
+        },
+    ):
+        # Call patch_structhash to install the patched function
+        platformio_api.patch_structhash()
+
+        # Call the patched function
+        mock_helpers.clean_build_dir(str(build_dir), [])
+
+        # Verify rmtree was NOT called
+        assert len(removed_paths) == 0
+
+        # Verify directory and file still exist
+        assert build_dir.exists()
+        assert test_file.exists()
+        assert test_file.read_text() == "test content"
+
+
+def test_patched_clean_build_dir_creates_missing(setup_core: Path) -> None:
+    """Test patched_clean_build_dir creates build dir when it doesn't exist."""
+    build_dir = setup_core / "build"
+    platformio_ini = setup_core / "platformio.ini"
+    platformio_ini.write_text("config")
+
+    # Ensure build_dir doesn't exist
+    assert not build_dir.exists()
+
+    # Track if rmtree is called
+    removed_paths: list[str] = []
+
+    def track_rmtree(path: str) -> None:
+        removed_paths.append(path)
+
+    # Create mock modules
+    mock_cli = SimpleNamespace()
+    mock_helpers = SimpleNamespace()
+    mock_project_helpers = MagicMock()
+    mock_project_helpers.get_project_dir.return_value = str(setup_core)
+    mock_fs = SimpleNamespace(rmtree=track_rmtree)
+
+    with patch.dict(
+        "sys.modules",
+        {
+            "platformio": SimpleNamespace(fs=mock_fs),
+            "platformio.fs": mock_fs,
+            "platformio.project.helpers": mock_project_helpers,
+            "platformio.run": SimpleNamespace(cli=mock_cli, helpers=mock_helpers),
+            "platformio.run.cli": mock_cli,
+            "platformio.run.helpers": mock_helpers,
+        },
+    ):
+        # Call patch_structhash to install the patched function
+        platformio_api.patch_structhash()
+
+        # Call the patched function
+        mock_helpers.clean_build_dir(str(build_dir), [])
+
+        # Verify rmtree was NOT called
+        assert len(removed_paths) == 0
+
+        # Verify directory was created
+        assert build_dir.exists()
+
+
+def test_process_stacktrace_esp8266_exception(setup_core: Path, caplog) -> None:
+    """Test process_stacktrace handles ESP8266 exceptions."""
+    config = {"name": "test"}
+
+    # Test exception type parsing
+    line = "Exception (28):"
+    backtrace_state = False
+
+    result = platformio_api.process_stacktrace(config, line, backtrace_state)
+
+    assert "Access to invalid address: LOAD (wild pointer?)" in caplog.text
+    assert result is False
+
+
+def test_process_stacktrace_esp8266_backtrace(
+    setup_core: Path, mock_decode_pc: Mock
+) -> None:
+    """Test process_stacktrace handles ESP8266 multi-line backtrace."""
+    config = {"name": "test"}
+
+    # Start of backtrace
+    line1 = ">>>stack>>>"
+    state = platformio_api.process_stacktrace(config, line1, False)
+    assert state is True
+
+    # Backtrace content with addresses
+    line2 = "40201234 40205678"
+    state = platformio_api.process_stacktrace(config, line2, state)
+    assert state is True
+    assert mock_decode_pc.call_count == 2
+
+    # End of backtrace
+    line3 = "<<<stack<<<"
+    state = platformio_api.process_stacktrace(config, line3, state)
+    assert state is False
+
+
+def test_process_stacktrace_esp32_backtrace(
+    setup_core: Path, mock_decode_pc: Mock
+) -> None:
+    """Test process_stacktrace handles ESP32 single-line backtrace."""
+    config = {"name": "test"}
+
+    line = "Backtrace: 0x40081234:0x3ffb1234 0x40085678:0x3ffb5678"
+    state = platformio_api.process_stacktrace(config, line, False)
+
+    # Should decode both addresses
+    assert mock_decode_pc.call_count == 2
+    mock_decode_pc.assert_any_call(config, "40081234")
+    mock_decode_pc.assert_any_call(config, "40085678")
+    assert state is False
+
+
+def test_process_stacktrace_bad_alloc(
+    setup_core: Path, mock_decode_pc: Mock, caplog
+) -> None:
+    """Test process_stacktrace handles bad alloc messages."""
+    config = {"name": "test"}
+
+    line = "last failed alloc call: 40201234(512)"
+    state = platformio_api.process_stacktrace(config, line, False)
+
+    assert "Memory allocation of 512 bytes failed at 40201234" in caplog.text
+    mock_decode_pc.assert_called_once_with(config, "40201234")
+    assert state is False

tests/unit_tests/test_storage_json.py

@@ -1,12 +1,15 @@
 """Tests for storage_json.py path functions."""
 
+from datetime import datetime
+import json
 from pathlib import Path
 import sys
-from unittest.mock import patch
+from unittest.mock import MagicMock, Mock, patch
 
 import pytest
 
 from esphome import storage_json
+from esphome.const import CONF_DISABLED, CONF_MDNS
 from esphome.core import CORE
 
 
@@ -115,7 +118,9 @@ def test_storage_json_firmware_bin_path_property(setup_core: Path) -> None:
     assert storage.firmware_bin_path == "/path/to/firmware.bin"
 
 
-def test_storage_json_save_creates_directory(setup_core: Path, tmp_path: Path) -> None:
+def test_storage_json_save_creates_directory(
+    setup_core: Path, tmp_path: Path, mock_write_file_if_changed: Mock
+) -> None:
     """Test StorageJSON.save creates storage directory if it doesn't exist."""
     storage_dir = tmp_path / "new_data" / "storage"
     storage_file = storage_dir / "test.json"
@@ -139,11 +144,10 @@ def test_storage_json_save_creates_directory(setup_core: Path, tmp_path: Path) -
         no_mdns=False,
     )
 
-    with patch("esphome.storage_json.write_file_if_changed") as mock_write:
-        storage.save(str(storage_file))
-        mock_write.assert_called_once()
-        call_args = mock_write.call_args[0]
-        assert call_args[0] == str(storage_file)
+    storage.save(str(storage_file))
+    mock_write_file_if_changed.assert_called_once()
+    call_args = mock_write_file_if_changed.call_args[0]
+    assert call_args[0] == str(storage_file)
 
 
 def test_storage_json_from_wizard(setup_core: Path) -> None:
@@ -180,3 +184,477 @@ def test_storage_paths_with_ha_addon(mock_is_ha_addon: bool, tmp_path: Path) ->
     result = storage_json.esphome_storage_path()
     expected = str(Path("/data") / "esphome.json")
     assert result == expected
+
+
+def test_storage_json_as_dict() -> None:
+    """Test StorageJSON.as_dict returns correct dictionary."""
+    storage = storage_json.StorageJSON(
+        storage_version=1,
+        name="test_device",
+        friendly_name="Test Device",
+        comment="Test comment",
+        esphome_version="2024.1.0",
+        src_version=1,
+        address="192.168.1.100",
+        web_port=80,
+        target_platform="ESP32",
+        build_path="/path/to/build",
+        firmware_bin_path="/path/to/firmware.bin",
+        loaded_integrations={"wifi", "api", "ota"},
+        loaded_platforms={"sensor", "binary_sensor"},
+        no_mdns=True,
+        framework="arduino",
+        core_platform="esp32",
+    )
+
+    result = storage.as_dict()
+
+    assert result["storage_version"] == 1
+    assert result["name"] == "test_device"
+    assert result["friendly_name"] == "Test Device"
+    assert result["comment"] == "Test comment"
+    assert result["esphome_version"] == "2024.1.0"
+    assert result["src_version"] == 1
+    assert result["address"] == "192.168.1.100"
+    assert result["web_port"] == 80
+    assert result["esp_platform"] == "ESP32"
+    assert result["build_path"] == "/path/to/build"
+    assert result["firmware_bin_path"] == "/path/to/firmware.bin"
+    assert "api" in result["loaded_integrations"]
+    assert "wifi" in result["loaded_integrations"]
+    assert "ota" in result["loaded_integrations"]
+    assert result["loaded_integrations"] == sorted(
+        ["wifi", "api", "ota"]
+    )  # Should be sorted
+    assert "sensor" in result["loaded_platforms"]
+    assert result["loaded_platforms"] == sorted(
+        ["sensor", "binary_sensor"]
+    )  # Should be sorted
+    assert result["no_mdns"] is True
+    assert result["framework"] == "arduino"
+    assert result["core_platform"] == "esp32"
+
+
+def test_storage_json_to_json() -> None:
+    """Test StorageJSON.to_json returns valid JSON string."""
+    storage = storage_json.StorageJSON(
+        storage_version=1,
+        name="test",
+        friendly_name="Test",
+        comment=None,
+        esphome_version="2024.1.0",
+        src_version=None,
+        address="test.local",
+        web_port=None,
+        target_platform="ESP8266",
+        build_path=None,
+        firmware_bin_path=None,
+        loaded_integrations=set(),
+        loaded_platforms=set(),
+        no_mdns=False,
+    )
+
+    json_str = storage.to_json()
+
+    # Should be valid JSON
+    parsed = json.loads(json_str)
+    assert parsed["name"] == "test"
+    assert parsed["storage_version"] == 1
+
+    # Should end with newline
+    assert json_str.endswith("\n")
+
+
+def test_storage_json_save(tmp_path: Path) -> None:
+    """Test StorageJSON.save writes file correctly."""
+    storage = storage_json.StorageJSON(
+        storage_version=1,
+        name="test",
+        friendly_name="Test",
+        comment=None,
+        esphome_version="2024.1.0",
+        src_version=None,
+        address="test.local",
+        web_port=None,
+        target_platform="ESP32",
+        build_path=None,
+        firmware_bin_path=None,
+        loaded_integrations=set(),
+        loaded_platforms=set(),
+        no_mdns=False,
+    )
+
+    save_path = tmp_path / "test.json"
+
+    with patch("esphome.storage_json.write_file_if_changed") as mock_write:
+        storage.save(str(save_path))
+        mock_write.assert_called_once_with(str(save_path), storage.to_json())
+
+
+def test_storage_json_from_esphome_core(setup_core: Path) -> None:
+    """Test StorageJSON.from_esphome_core creates correct storage object."""
+    # Mock CORE object
+    mock_core = MagicMock()
+    mock_core.name = "my_device"
+    mock_core.friendly_name = "My Device"
+    mock_core.comment = "A test device"
+    mock_core.address = "192.168.1.50"
+    mock_core.web_port = 8080
+    mock_core.target_platform = "esp32"
+    mock_core.is_esp32 = True
+    mock_core.build_path = "/build/my_device"
+    mock_core.firmware_bin = "/build/my_device/firmware.bin"
+    mock_core.loaded_integrations = {"wifi", "api"}
+    mock_core.loaded_platforms = {"sensor"}
+    mock_core.config = {CONF_MDNS: {CONF_DISABLED: True}}
+    mock_core.target_framework = "esp-idf"
+
+    with patch("esphome.components.esp32.get_esp32_variant") as mock_variant:
+        mock_variant.return_value = "ESP32-C3"
+
+        result = storage_json.StorageJSON.from_esphome_core(mock_core, old=None)
+
+    assert result.name == "my_device"
+    assert result.friendly_name == "My Device"
+    assert result.comment == "A test device"
+    assert result.address == "192.168.1.50"
+    assert result.web_port == 8080
+    assert result.target_platform == "ESP32-C3"
+    assert result.build_path == "/build/my_device"
+    assert result.firmware_bin_path == "/build/my_device/firmware.bin"
+    assert result.loaded_integrations == {"wifi", "api"}
+    assert result.loaded_platforms == {"sensor"}
+    assert result.no_mdns is True
+    assert result.framework == "esp-idf"
+    assert result.core_platform == "esp32"
+
+
+def test_storage_json_from_esphome_core_mdns_enabled(setup_core: Path) -> None:
+    """Test from_esphome_core with mDNS enabled."""
+    mock_core = MagicMock()
+    mock_core.name = "test"
+    mock_core.friendly_name = "Test"
+    mock_core.comment = None
+    mock_core.address = "test.local"
+    mock_core.web_port = None
+    mock_core.target_platform = "esp8266"
+    mock_core.is_esp32 = False
+    mock_core.build_path = "/build"
+    mock_core.firmware_bin = "/build/firmware.bin"
+    mock_core.loaded_integrations = set()
+    mock_core.loaded_platforms = set()
+    mock_core.config = {}  # No MDNS config means enabled
+    mock_core.target_framework = "arduino"
+
+    result = storage_json.StorageJSON.from_esphome_core(mock_core, old=None)
+
+    assert result.no_mdns is False
+
+
+def test_storage_json_load_valid_file(tmp_path: Path) -> None:
+    """Test StorageJSON.load with valid JSON file."""
+    storage_data = {
+        "storage_version": 1,
+        "name": "loaded_device",
+        "friendly_name": "Loaded Device",
+        "comment": "Loaded from file",
+        "esphome_version": "2024.1.0",
+        "src_version": 2,
+        "address": "10.0.0.1",
+        "web_port": 8080,
+        "esp_platform": "ESP32",
+        "build_path": "/loaded/build",
+        "firmware_bin_path": "/loaded/firmware.bin",
+        "loaded_integrations": ["wifi", "api"],
+        "loaded_platforms": ["sensor"],
+        "no_mdns": True,
+        "framework": "arduino",
+        "core_platform": "esp32",
+    }
+
+    file_path = tmp_path / "storage.json"
+    file_path.write_text(json.dumps(storage_data))
+
+    result = storage_json.StorageJSON.load(str(file_path))
+
+    assert result is not None
+    assert result.name == "loaded_device"
+    assert result.friendly_name == "Loaded Device"
+    assert result.comment == "Loaded from file"
+    assert result.esphome_version == "2024.1.0"
+    assert result.src_version == 2
+    assert result.address == "10.0.0.1"
+    assert result.web_port == 8080
+    assert result.target_platform == "ESP32"
+    assert result.build_path == "/loaded/build"
+    assert result.firmware_bin_path == "/loaded/firmware.bin"
+    assert result.loaded_integrations == {"wifi", "api"}
+    assert result.loaded_platforms == {"sensor"}
+    assert result.no_mdns is True
+    assert result.framework == "arduino"
+    assert result.core_platform == "esp32"
+
+
+def test_storage_json_load_invalid_file(tmp_path: Path) -> None:
+    """Test StorageJSON.load with invalid JSON file."""
+    file_path = tmp_path / "invalid.json"
+    file_path.write_text("not valid json{")
+
+    result = storage_json.StorageJSON.load(str(file_path))
+
+    assert result is None
+
+
+def test_storage_json_load_nonexistent_file() -> None:
+    """Test StorageJSON.load with non-existent file."""
+    result = storage_json.StorageJSON.load("/nonexistent/file.json")
+
+    assert result is None
+
+
+def test_storage_json_equality() -> None:
+    """Test StorageJSON equality comparison."""
+    storage1 = storage_json.StorageJSON(
+        storage_version=1,
+        name="test",
+        friendly_name="Test",
+        comment=None,
+        esphome_version="2024.1.0",
+        src_version=1,
+        address="test.local",
+        web_port=80,
+        target_platform="ESP32",
+        build_path="/build",
+        firmware_bin_path="/firmware.bin",
+        loaded_integrations={"wifi"},
+        loaded_platforms=set(),
+        no_mdns=False,
+    )
+
+    storage2 = storage_json.StorageJSON(
+        storage_version=1,
+        name="test",
+        friendly_name="Test",
+        comment=None,
+        esphome_version="2024.1.0",
+        src_version=1,
+        address="test.local",
+        web_port=80,
+        target_platform="ESP32",
+        build_path="/build",
+        firmware_bin_path="/firmware.bin",
+        loaded_integrations={"wifi"},
+        loaded_platforms=set(),
+        no_mdns=False,
+    )
+
+    storage3 = storage_json.StorageJSON(
+        storage_version=1,
+        name="different",  # Different name
+        friendly_name="Test",
+        comment=None,
+        esphome_version="2024.1.0",
+        src_version=1,
+        address="test.local",
+        web_port=80,
+        target_platform="ESP32",
+        build_path="/build",
+        firmware_bin_path="/firmware.bin",
+        loaded_integrations={"wifi"},
+        loaded_platforms=set(),
+        no_mdns=False,
+    )
+
+    assert storage1 == storage2
+    assert storage1 != storage3
+    assert storage1 != "not a storage object"
+
+
+def test_esphome_storage_json_as_dict() -> None:
+    """Test EsphomeStorageJSON.as_dict returns correct dictionary."""
+    storage = storage_json.EsphomeStorageJSON(
+        storage_version=1,
+        cookie_secret="secret123",
+        last_update_check="2024-01-15T10:30:00",
+        remote_version="2024.1.1",
+    )
+
+    result = storage.as_dict()
+
+    assert result["storage_version"] == 1
+    assert result["cookie_secret"] == "secret123"
+    assert result["last_update_check"] == "2024-01-15T10:30:00"
+    assert result["remote_version"] == "2024.1.1"
+
+
+def test_esphome_storage_json_last_update_check_property() -> None:
+    """Test EsphomeStorageJSON.last_update_check property."""
+    storage = storage_json.EsphomeStorageJSON(
+        storage_version=1,
+        cookie_secret="secret",
+        last_update_check="2024-01-15T10:30:00",
+        remote_version=None,
+    )
+
+    # Test getter
+    result = storage.last_update_check
+    assert isinstance(result, datetime)
+    assert result.year == 2024
+    assert result.month == 1
+    assert result.day == 15
+    assert result.hour == 10
+    assert result.minute == 30
+
+    # Test setter
+    new_date = datetime(2024, 2, 20, 15, 45, 30)
+    storage.last_update_check = new_date
+    assert storage.last_update_check_str == "2024-02-20T15:45:30"
+
+
+def test_esphome_storage_json_last_update_check_invalid() -> None:
+    """Test EsphomeStorageJSON.last_update_check with invalid date."""
+    storage = storage_json.EsphomeStorageJSON(
+        storage_version=1,
+        cookie_secret="secret",
+        last_update_check="invalid date",
+        remote_version=None,
+    )
+
+    result = storage.last_update_check
+    assert result is None
+
+
+def test_esphome_storage_json_to_json() -> None:
+    """Test EsphomeStorageJSON.to_json returns valid JSON string."""
+    storage = storage_json.EsphomeStorageJSON(
+        storage_version=1,
+        cookie_secret="mysecret",
+        last_update_check="2024-01-15T10:30:00",
+        remote_version="2024.1.1",
+    )
+
+    json_str = storage.to_json()
+
+    # Should be valid JSON
+    parsed = json.loads(json_str)
+    assert parsed["cookie_secret"] == "mysecret"
+    assert parsed["storage_version"] == 1
+
+    # Should end with newline
+    assert json_str.endswith("\n")
+
+
+def test_esphome_storage_json_save(tmp_path: Path) -> None:
+    """Test EsphomeStorageJSON.save writes file correctly."""
+    storage = storage_json.EsphomeStorageJSON(
+        storage_version=1,
+        cookie_secret="secret",
+        last_update_check=None,
+        remote_version=None,
+    )
+
+    save_path = tmp_path / "esphome.json"
+
+    with patch("esphome.storage_json.write_file_if_changed") as mock_write:
+        storage.save(str(save_path))
+        mock_write.assert_called_once_with(str(save_path), storage.to_json())
+
+
+def test_esphome_storage_json_load_valid_file(tmp_path: Path) -> None:
+    """Test EsphomeStorageJSON.load with valid JSON file."""
+    storage_data = {
+        "storage_version": 1,
+        "cookie_secret": "loaded_secret",
+        "last_update_check": "2024-01-20T14:30:00",
+        "remote_version": "2024.1.2",
+    }
+
+    file_path = tmp_path / "esphome.json"
+    file_path.write_text(json.dumps(storage_data))
+
+    result = storage_json.EsphomeStorageJSON.load(str(file_path))
+
+    assert result is not None
+    assert result.storage_version == 1
+    assert result.cookie_secret == "loaded_secret"
+    assert result.last_update_check_str == "2024-01-20T14:30:00"
+    assert result.remote_version == "2024.1.2"
+
+
+def test_esphome_storage_json_load_invalid_file(tmp_path: Path) -> None:
+    """Test EsphomeStorageJSON.load with invalid JSON file."""
+    file_path = tmp_path / "invalid.json"
+    file_path.write_text("not valid json{")
+
+    result = storage_json.EsphomeStorageJSON.load(str(file_path))
+
+    assert result is None
+
+
+def test_esphome_storage_json_load_nonexistent_file() -> None:
+    """Test EsphomeStorageJSON.load with non-existent file."""
+    result = storage_json.EsphomeStorageJSON.load("/nonexistent/file.json")
+
+    assert result is None
+
+
+def test_esphome_storage_json_get_default() -> None:
+    """Test EsphomeStorageJSON.get_default creates default storage."""
+    with patch("esphome.storage_json.os.urandom") as mock_urandom:
+        # Mock urandom to return predictable bytes
+        mock_urandom.return_value = b"test" * 16  # 64 bytes
+
+        result = storage_json.EsphomeStorageJSON.get_default()
+
+    assert result.storage_version == 1
+    assert len(result.cookie_secret) == 128  # 64 bytes hex = 128 chars
+    assert result.last_update_check is None
+    assert result.remote_version is None
+
+
+def test_esphome_storage_json_equality() -> None:
+    """Test EsphomeStorageJSON equality comparison."""
+    storage1 = storage_json.EsphomeStorageJSON(
+        storage_version=1,
+        cookie_secret="secret",
+        last_update_check="2024-01-15T10:30:00",
+        remote_version="2024.1.1",
+    )
+
+    storage2 = storage_json.EsphomeStorageJSON(
+        storage_version=1,
+        cookie_secret="secret",
+        last_update_check="2024-01-15T10:30:00",
+        remote_version="2024.1.1",
+    )
+
+    storage3 = storage_json.EsphomeStorageJSON(
+        storage_version=1,
+        cookie_secret="different",  # Different secret
+        last_update_check="2024-01-15T10:30:00",
+        remote_version="2024.1.1",
+    )
+
+    assert storage1 == storage2
+    assert storage1 != storage3
+    assert storage1 != "not a storage object"
+
+
+def test_storage_json_load_legacy_esphomeyaml_version(tmp_path: Path) -> None:
+    """Test loading storage with legacy esphomeyaml_version field."""
+    storage_data = {
+        "storage_version": 1,
+        "name": "legacy_device",
+        "friendly_name": "Legacy Device",
+        "esphomeyaml_version": "1.14.0",  # Legacy field name
+        "address": "legacy.local",
+        "esp_platform": "ESP8266",
+    }
+
+    file_path = tmp_path / "legacy.json"
+    file_path.write_text(json.dumps(storage_data))
+
+    result = storage_json.StorageJSON.load(str(file_path))
+
+    assert result is not None
+    assert result.esphome_version == "1.14.0"  # Should map to esphome_version

tests/unit_tests/test_util.py

@@ -1,5 +1,7 @@
 """Tests for esphome.util module."""
 
+from __future__ import annotations
+
 from pathlib import Path
 
 import pytest
@@ -308,3 +310,85 @@ def test_filter_yaml_files_case_sensitive() -> None:
     assert "/path/to/config.YAML" not in result
     assert "/path/to/config.YML" not in result
     assert "/path/to/config.Yaml" not in result
+
+
+@pytest.mark.parametrize(
+    ("input_str", "expected"),
+    [
+        # Empty string
+        ("", "''"),
+        # Simple strings that don't need quoting
+        ("hello", "hello"),
+        ("test123", "test123"),
+        ("file.txt", "file.txt"),
+        ("/path/to/file", "/path/to/file"),
+        ("user@host", "user@host"),
+        ("value:123", "value:123"),
+        ("item,list", "item,list"),
+        ("path-with-dash", "path-with-dash"),
+        # Strings that need quoting
+        ("hello world", "'hello world'"),
+        ("test\ttab", "'test\ttab'"),
+        ("line\nbreak", "'line\nbreak'"),
+        ("semicolon;here", "'semicolon;here'"),
+        ("pipe|symbol", "'pipe|symbol'"),
+        ("redirect>file", "'redirect>file'"),
+        ("redirect<file", "'redirect<file'"),
+        ("background&", "'background&'"),
+        ("dollar$sign", "'dollar$sign'"),
+        ("backtick`cmd", "'backtick`cmd'"),
+        ('double"quote', "'double\"quote'"),
+        ("backslash\\path", "'backslash\\path'"),
+        ("question?mark", "'question?mark'"),
+        ("asterisk*wild", "'asterisk*wild'"),
+        ("bracket[test]", "'bracket[test]'"),
+        ("paren(test)", "'paren(test)'"),
+        ("curly{brace}", "'curly{brace}'"),
+        # Single quotes in string (special escaping)
+        ("it's", "'it'\"'\"'s'"),
+        ("don't", "'don'\"'\"'t'"),
+        ("'quoted'", "''\"'\"'quoted'\"'\"''"),
+        # Complex combinations
+        ("test 'with' quotes", "'test '\"'\"'with'\"'\"' quotes'"),
+        ("path/to/file's.txt", "'path/to/file'\"'\"'s.txt'"),
+    ],
+)
+def test_shlex_quote(input_str: str, expected: str) -> None:
+    """Test shlex_quote properly escapes shell arguments."""
+    assert util.shlex_quote(input_str) == expected
+
+
+def test_shlex_quote_safe_characters() -> None:
+    """Test that safe characters are not quoted."""
+    # These characters are considered safe and shouldn't be quoted
+    safe_chars = (
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789@%+=:,./-_"
+    )
+    for char in safe_chars:
+        assert util.shlex_quote(char) == char
+        assert util.shlex_quote(f"test{char}test") == f"test{char}test"
+
+
+def test_shlex_quote_unsafe_characters() -> None:
+    """Test that unsafe characters trigger quoting."""
+    # These characters should trigger quoting
+    unsafe_chars = ' \t\n;|>&<$`"\\?*[](){}!#~^'
+    for char in unsafe_chars:
+        result = util.shlex_quote(f"test{char}test")
+        assert result.startswith("'")
+        assert result.endswith("'")
+
+
+def test_shlex_quote_edge_cases() -> None:
+    """Test edge cases for shlex_quote."""
+    # Multiple single quotes
+    assert util.shlex_quote("'''") == "''\"'\"''\"'\"''\"'\"''"
+
+    # Mixed quotes
+    assert util.shlex_quote('"\'"') == "'\"'\"'\"'\"'"
+
+    # Only whitespace
+    assert util.shlex_quote(" ") == "' '"
+    assert util.shlex_quote("\t") == "'\t'"
+    assert util.shlex_quote("\n") == "'\n'"
+    assert util.shlex_quote("   ") == "'   '"