[core] Partially revert "Hash entity keys from the raw name to fix collisions" (#18361)

tests/unit_tests/components/mqtt/test_object_id_conflicts.py

@@ -1,239 +0,0 @@
-"""Tests for the MQTT object_id conflict filter.
-
-MQTT still builds default topics and discovery topics from the sanitized
-object_id, so entity names that only differ in characters lost during
-sanitizing conflict there; _topics_conflict() exempts entities that never
-use an object_id-derived topic. See https://github.com/esphome/backlog/issues/85
-"""
-
-from pathlib import Path
-
-import pytest
-
-from esphome.components.mqtt import (
-    _COMMAND_TOPIC_PLATFORMS,
-    _SUB_TOPIC_PLATFORMS,
-    _topics_conflict,
-)
-from esphome.config_validation import Invalid
-from esphome.const import (
-    CONF_COMMAND_TOPIC,
-    CONF_DISCOVERY,
-    CONF_NAME,
-    CONF_STATE_TOPIC,
-    CONF_TOPIC_PREFIX,
-)
-from esphome.core import CORE
-from esphome.core.entity_helpers import (
-    entity_duplicate_validator,
-    validate_no_object_id_conflicts,
-)
-
-COMPONENTS_DIR = Path(__file__).parents[4] / "esphome" / "components"
-
-REASON = "mqtt builds default topics from the entity object_id"
-
-
-# MQTT infrastructure sources, not entity components
-_NON_ENTITY_MQTT_SOURCES = {"mqtt_client", "mqtt_component"}
-# The date, time and datetime MQTT components all belong to the datetime platform
-_DATETIME_STEMS = {"date", "time", "datetime"}
-
-
-def test_command_topic_platforms_in_sync() -> None:
-    """Verify _COMMAND_TOPIC_PLATFORMS matches the MQTT components that subscribe.
-
-    Drift silently reintroduces shared subscribe topics, so this derives the set
-    from the C++ components that actually call subscribe(); that also catches
-    platforms like text that subscribe a command topic without exposing a
-    command_topic key in their schema.
-    """
-    expected: set[str] = set()
-    for path in (COMPONENTS_DIR / "mqtt").glob("mqtt_*.cpp"):
-        if path.stem in _NON_ENTITY_MQTT_SOURCES:
-            continue
-        if "this->subscribe" not in path.read_text(encoding="utf-8"):
-            continue
-        stem = path.stem.removeprefix("mqtt_")
-        expected.add("datetime" if stem in _DATETIME_STEMS else stem)
-    assert expected == _COMMAND_TOPIC_PLATFORMS
-
-
-def test_sub_topic_platforms_in_sync() -> None:
-    """Verify _SUB_TOPIC_PLATFORMS matches the MQTT components with sub-topics.
-
-    Platforms whose MQTT headers use MQTT_COMPONENT_CUSTOM_TOPIC derive extra
-    topics such as position/command from the object_id.
-    """
-    expected = {
-        path.stem.removeprefix("mqtt_")
-        for path in (COMPONENTS_DIR / "mqtt").glob("mqtt_*.h")
-        if path.stem != "mqtt_component"
-        and "MQTT_COMPONENT_CUSTOM_TOPIC" in path.read_text(encoding="utf-8")
-    }
-    assert expected == _SUB_TOPIC_PLATFORMS
-
-
-def test_conflict_filter_exempts_custom_topics() -> None:
-    """Test that custom state topics with discovery off avoid the conflict."""
-    validator = entity_duplicate_validator("sensor")
-    # Both entities have custom state topics and discovery disabled per entity,
-    # so no object_id-derived MQTT topic is used
-    validator(
-        {
-            CONF_NAME: "Датчик открытия",
-            CONF_STATE_TOPIC: "custom/topic/a",
-            CONF_DISCOVERY: False,
-        }
-    )
-    validator(
-        {
-            CONF_NAME: "Датчик закрытия",
-            CONF_STATE_TOPIC: "custom/topic/b",
-            CONF_DISCOVERY: False,
-        }
-    )
-
-    component_validator = validate_no_object_id_conflicts(
-        REASON, conflict_filter=_topics_conflict
-    )
-    config: dict = {CONF_DISCOVERY: True, CONF_TOPIC_PREFIX: "test-device"}
-    assert component_validator(config) is config
-
-    # Without the filter the same conflicts are fatal
-    with pytest.raises(Invalid, match=r"mqtt builds default topics"):
-        validate_no_object_id_conflicts(REASON)({})
-
-
-def test_conflict_on_default_command_topic() -> None:
-    """Test that commandable platforms conflict through their default command topic.
-
-    Custom state topics with discovery off are not enough for platforms that also
-    subscribe to an object_id-derived command topic.
-    """
-    validator = entity_duplicate_validator("switch")
-    validator(
-        {
-            CONF_NAME: "Датчик открытия",
-            CONF_STATE_TOPIC: "custom/topic/a",
-            CONF_DISCOVERY: False,
-        }
-    )
-    validator(
-        {
-            CONF_NAME: "Датчик закрытия",
-            CONF_STATE_TOPIC: "custom/topic/b",
-            CONF_DISCOVERY: False,
-        }
-    )
-
-    component_validator = validate_no_object_id_conflicts(
-        REASON, conflict_filter=_topics_conflict
-    )
-    mqtt_config: dict = {CONF_DISCOVERY: True, CONF_TOPIC_PREFIX: "test-device"}
-    # Both switches share the default command topic: rejected
-    with pytest.raises(Invalid, match=r"mqtt builds default topics"):
-        component_validator(mqtt_config)
-
-    # With custom command topics as well, nothing derives from the object_id
-    CORE.reset()
-    validator = entity_duplicate_validator("switch")
-    validator(
-        {
-            CONF_NAME: "Датчик открытия",
-            CONF_STATE_TOPIC: "custom/topic/a",
-            CONF_COMMAND_TOPIC: "custom/cmd/a",
-            CONF_DISCOVERY: False,
-        }
-    )
-    validator(
-        {
-            CONF_NAME: "Датчик закрытия",
-            CONF_STATE_TOPIC: "custom/topic/b",
-            CONF_COMMAND_TOPIC: "custom/cmd/b",
-            CONF_DISCOVERY: False,
-        }
-    )
-    assert component_validator(mqtt_config) is mqtt_config
-
-
-def test_conflict_on_sub_topic_platforms() -> None:
-    """Test that platforms with extra object_id sub-topics always conflict.
-
-    Covers derive topics like position/command from the object_id through their
-    own config keys, so custom state and command topics cannot exempt them.
-    """
-    validator = entity_duplicate_validator("cover")
-    validator(
-        {
-            CONF_NAME: "Датчик открытия",
-            CONF_STATE_TOPIC: "custom/topic/a",
-            CONF_COMMAND_TOPIC: "custom/cmd/a",
-            CONF_DISCOVERY: False,
-        }
-    )
-    validator(
-        {
-            CONF_NAME: "Датчик закрытия",
-            CONF_STATE_TOPIC: "custom/topic/b",
-            CONF_COMMAND_TOPIC: "custom/cmd/b",
-            CONF_DISCOVERY: False,
-        }
-    )
-
-    component_validator = validate_no_object_id_conflicts(
-        REASON, conflict_filter=_topics_conflict
-    )
-    with pytest.raises(Invalid, match=r"mqtt builds default topics"):
-        component_validator({CONF_DISCOVERY: True, CONF_TOPIC_PREFIX: "test-device"})
-
-
-def test_no_conflict_on_disjoint_default_topics() -> None:
-    """Test that entities whose default topics are disjoint do not conflict.
-
-    One entity uses only the default command topic and the other only the default
-    state topic, so they never share a topic.
-    """
-    validator = entity_duplicate_validator("switch")
-    validator(
-        {
-            CONF_NAME: "Датчик открытия",
-            CONF_STATE_TOPIC: "custom/topic/a",
-            CONF_DISCOVERY: False,
-        }
-    )
-    validator(
-        {
-            CONF_NAME: "Датчик закрытия",
-            CONF_COMMAND_TOPIC: "custom/cmd/b",
-            CONF_DISCOVERY: False,
-        }
-    )
-
-    component_validator = validate_no_object_id_conflicts(
-        REASON, conflict_filter=_topics_conflict
-    )
-    config: dict = {CONF_DISCOVERY: True, CONF_TOPIC_PREFIX: "test-device"}
-    assert component_validator(config) is config
-
-
-def test_no_conflict_on_empty_topic_prefix() -> None:
-    """Test that an empty topic_prefix disables the default topic conflict.
-
-    With topic_prefix set to null no default topics exist at runtime, so entities
-    without custom state topics cannot conflict; only discovery still matters.
-    """
-    validator = entity_duplicate_validator("sensor")
-    validator({CONF_NAME: "Датчик открытия"})
-    validator({CONF_NAME: "Датчик закрытия"})
-
-    component_validator = validate_no_object_id_conflicts(
-        REASON, conflict_filter=_topics_conflict
-    )
-    # No default topics and no discovery: valid
-    config: dict = {CONF_DISCOVERY: False, CONF_TOPIC_PREFIX: ""}
-    assert component_validator(config) is config
-
-    # Discovery still uses object_id-derived config topics: rejected
-    with pytest.raises(Invalid, match=r"mqtt builds default topics"):
-        component_validator({CONF_DISCOVERY: True, CONF_TOPIC_PREFIX: ""})

tests/unit_tests/core/test_entity_helpers.py

@@ -1,4 +1,4 @@
-"""Tests for entity helpers: name selection, entity key hashing, duplicate checks."""
+"""Test get_base_entity_object_id function matches C++ behavior."""
 
 from collections.abc import Callable, Generator
 from pathlib import Path
@@ -25,17 +25,16 @@ from esphome.core.entity_helpers import (
     _setup_entity_impl,
     entity_duplicate_validator,
     finalize_entity_strings,
-    get_base_entity_name,
+    get_base_entity_object_id,
     register_device_class,
     register_icon,
     register_unit_of_measurement,
     setup_device_class,
     setup_entity,
     setup_unit_of_measurement,
-    validate_no_object_id_conflicts,
 )
 from esphome.cpp_generator import MockObj
-from esphome.helpers import fnv1_hash_name, sanitize, snake_case
+from esphome.helpers import fnv1_hash, sanitize, snake_case
 
 from .common import load_config_from_fixture
 
@@ -58,26 +57,206 @@ def restore_core_state() -> Generator[None, None, None]:
     CORE.friendly_name = original_friendly_name
 
 
-def test_get_base_entity_name_priority_order() -> None:
+def test_with_entity_name() -> None:
+    """Test when entity has its own name - should use entity name."""
+    # Simple name
+    assert get_base_entity_object_id("Temperature Sensor", None) == "temperature_sensor"
+    assert (
+        get_base_entity_object_id("Temperature Sensor", "Device Name")
+        == "temperature_sensor"
+    )
+    # Even with device name, entity name takes precedence
+    assert (
+        get_base_entity_object_id("Temperature Sensor", "Device Name", "Sub Device")
+        == "temperature_sensor"
+    )
+
+    # Name with special characters
+    assert (
+        get_base_entity_object_id("Temp!@#$%^&*()Sensor", None)
+        == "temp__________sensor"
+    )
+    assert get_base_entity_object_id("Temp-Sensor_123", None) == "temp-sensor_123"
+
+    # Already snake_case
+    assert get_base_entity_object_id("temperature_sensor", None) == "temperature_sensor"
+
+    # Mixed case
+    assert get_base_entity_object_id("TemperatureSensor", None) == "temperaturesensor"
+    assert get_base_entity_object_id("TEMPERATURE SENSOR", None) == "temperature_sensor"
+
+
+def test_empty_name_with_device_name() -> None:
+    """Test when entity has empty name and is on a sub-device - should use device name."""
+    # C++ behavior: when has_own_name is false and device is set, uses device->get_name()
+    assert (
+        get_base_entity_object_id("", "Friendly Device", "Sub Device 1")
+        == "sub_device_1"
+    )
+    assert (
+        get_base_entity_object_id("", "Kitchen Controller", "controller_1")
+        == "controller_1"
+    )
+    assert get_base_entity_object_id("", None, "Test-Device_123") == "test-device_123"
+
+
+def test_empty_name_with_friendly_name() -> None:
+    """Test when entity has empty name and no device - should use friendly name."""
+    # C++ behavior: when has_own_name is false, uses App.get_friendly_name()
+    assert get_base_entity_object_id("", "Friendly Device") == "friendly_device"
+    assert get_base_entity_object_id("", "Kitchen Controller") == "kitchen_controller"
+    assert get_base_entity_object_id("", "Test-Device_123") == "test-device_123"
+
+    # Special characters in friendly name
+    assert get_base_entity_object_id("", "Device!@#$%") == "device_____"
+
+
+def test_empty_name_no_friendly_name() -> None:
+    """Test when entity has empty name and no friendly name - should use device name."""
+    # Test with CORE.name set
+    CORE.name = "device-name"
+    assert get_base_entity_object_id("", None) == "device-name"
+
+    CORE.name = "Test Device"
+    assert get_base_entity_object_id("", None) == "test_device"
+
+
+def test_edge_cases() -> None:
+    """Test edge cases."""
+    # Only spaces
+    assert get_base_entity_object_id("   ", None) == "___"
+
+    # Unicode characters (should be replaced)
+    assert get_base_entity_object_id("Température", None) == "temp_rature"
+    assert get_base_entity_object_id("测试", None) == "__"
+
+    # Empty string with empty friendly name (empty friendly name is treated as None)
+    # Falls back to CORE.name
+    CORE.name = "device"
+    assert get_base_entity_object_id("", "") == "device"
+
+    # Very long name (should work fine)
+    long_name = "a" * 100 + " " + "b" * 100
+    expected = "a" * 100 + "_" + "b" * 100
+    assert get_base_entity_object_id(long_name, None) == expected
+
+
+@pytest.mark.parametrize(
+    ("name", "expected"),
+    [
+        ("Temperature Sensor", "temperature_sensor"),
+        ("Living Room Light", "living_room_light"),
+        ("Test-Device_123", "test-device_123"),
+        ("Special!@#Chars", "special___chars"),
+        ("UPPERCASE NAME", "uppercase_name"),
+        ("lowercase name", "lowercase_name"),
+        ("Mixed Case Name", "mixed_case_name"),
+        ("   Spaces   ", "___spaces___"),
+    ],
+)
+def test_matches_cpp_helpers(name: str, expected: str) -> None:
+    """Test that the logic matches using snake_case and sanitize directly."""
+    # For non-empty names, verify our function produces same result as direct snake_case + sanitize
+    assert get_base_entity_object_id(name, None) == sanitize(snake_case(name))
+    assert get_base_entity_object_id(name, None) == expected
+
+
+def test_empty_name_fallback() -> None:
+    """Test empty name handling which falls back to friendly_name or CORE.name."""
+    # Empty name is handled specially - it doesn't just use sanitize(snake_case(""))
+    # Instead it falls back to friendly_name or CORE.name
+    assert sanitize(snake_case("")) == ""  # Direct conversion gives empty string
+    # But our function returns a fallback
+    CORE.name = "device"
+    assert get_base_entity_object_id("", None) == "device"  # Uses device name
+
+
+def test_name_add_mac_suffix_behavior() -> None:
+    """Test behavior related to name_add_mac_suffix.
+
+    In C++, an entity's object_id is computed from its name_ via
+    write_object_id_to() (sanitized snake_case). When an entity has no name,
+    configure_entity_() sets name_ from the friendly name, with the MAC suffix
+    appended when name_add_mac_suffix is enabled. Our function always returns
+    the same result since we're calculating the base for duplicate tracking.
+    """
+    # The function should always return the same result regardless of
+    # name_add_mac_suffix setting, as we're calculating the base object_id
+    assert get_base_entity_object_id("", "Test Device") == "test_device"
+    assert get_base_entity_object_id("Entity Name", "Test Device") == "entity_name"
+
+
+def test_priority_order() -> None:
     """Test the priority order: entity name > device name > friendly name > CORE.name."""
     CORE.name = "core-device"
 
-    # 1. Entity name has highest priority and is used as-is, no transformations
+    # 1. Entity name has highest priority
     assert (
-        get_base_entity_name("Entity Name", "Friendly Name", "Device Name")
-        == "Entity Name"
+        get_base_entity_object_id("Entity Name", "Friendly Name", "Device Name")
+        == "entity_name"
     )
-    assert get_base_entity_name("Température", None) == "Température"
 
     # 2. Device name is next priority (when entity name is empty)
-    assert get_base_entity_name("", "Friendly Name", "Device Name") == "Device Name"
+    assert (
+        get_base_entity_object_id("", "Friendly Name", "Device Name") == "device_name"
+    )
 
     # 3. Friendly name is next (when entity and device names are empty)
-    assert get_base_entity_name("", "Friendly Name", None) == "Friendly Name"
+    assert get_base_entity_object_id("", "Friendly Name", None) == "friendly_name"
 
-    # 4. CORE.name is last resort; an empty friendly name falls through to it
-    assert get_base_entity_name("", None, None) == "core-device"
-    assert get_base_entity_name("", "") == "core-device"
+    # 4. CORE.name is last resort
+    assert get_base_entity_object_id("", None, None) == "core-device"
+
+
+@pytest.mark.parametrize(
+    ("name", "friendly_name", "device_name", "expected"),
+    [
+        # name, friendly_name, device_name, expected
+        ("Living Room Light", None, None, "living_room_light"),
+        ("", "Kitchen Controller", None, "kitchen_controller"),
+        (
+            "",
+            "ESP32 Device",
+            "controller_1",
+            "controller_1",
+        ),  # Device name takes precedence
+        ("GPIO2 Button", None, None, "gpio2_button"),
+        ("WiFi Signal", "My Device", None, "wifi_signal"),
+        ("", None, "esp32_node", "esp32_node"),
+        ("Front Door Sensor", "Home Assistant", "door_controller", "front_door_sensor"),
+    ],
+)
+def test_real_world_examples(
+    name: str, friendly_name: str | None, device_name: str | None, expected: str
+) -> None:
+    """Test real-world entity naming scenarios."""
+    result = get_base_entity_object_id(name, friendly_name, device_name)
+    assert result == expected
+
+
+def test_issue_6953_scenarios() -> None:
+    """Test specific scenarios from issue #6953."""
+    # Scenario 1: Multiple empty names on main device with name_add_mac_suffix
+    # The Python code calculates the base, C++ might append MAC suffix dynamically
+    CORE.name = "device-name"
+    CORE.friendly_name = "Friendly Device"
+
+    # All empty names should resolve to same base
+    assert get_base_entity_object_id("", CORE.friendly_name) == "friendly_device"
+    assert get_base_entity_object_id("", CORE.friendly_name) == "friendly_device"
+    assert get_base_entity_object_id("", CORE.friendly_name) == "friendly_device"
+
+    # Scenario 2: Empty names on sub-devices
+    assert (
+        get_base_entity_object_id("", "Main Device", "controller_1") == "controller_1"
+    )
+    assert (
+        get_base_entity_object_id("", "Main Device", "controller_2") == "controller_2"
+    )
+
+    # Scenario 3: xyz duplicates
+    assert get_base_entity_object_id("xyz", None) == "xyz"
+    assert get_base_entity_object_id("xyz", "Device") == "xyz"
 
 
 # Tests for setup_entity function
@@ -336,10 +515,9 @@ def test_entity_duplicate_validator() -> None:
     config1 = {CONF_NAME: "Temperature"}
     validated1 = validator(config1)
     assert validated1 == config1
-    temperature_key = ("", "sensor", fnv1_hash_name("Temperature"))
-    assert temperature_key in CORE.unique_ids
+    assert ("", "sensor", fnv1_hash("temperature")) in CORE.unique_ids
     # Check metadata was stored
-    metadata = CORE.unique_ids[temperature_key]
+    metadata = CORE.unique_ids[("", "sensor", fnv1_hash("temperature"))]
     assert metadata["name"] == "Temperature"
     assert metadata["platform"] == "sensor"
 
@@ -347,9 +525,8 @@ def test_entity_duplicate_validator() -> None:
     config2 = {CONF_NAME: "Humidity"}
     validated2 = validator(config2)
     assert validated2 == config2
-    humidity_key = ("", "sensor", fnv1_hash_name("Humidity"))
-    assert humidity_key in CORE.unique_ids
-    metadata2 = CORE.unique_ids[humidity_key]
+    assert ("", "sensor", fnv1_hash("humidity")) in CORE.unique_ids
+    metadata2 = CORE.unique_ids[("", "sensor", fnv1_hash("humidity"))]
     assert metadata2["name"] == "Humidity"
 
     # Duplicate entity should fail
@@ -360,6 +537,34 @@ def test_entity_duplicate_validator() -> None:
         validator(config3)
 
 
+def test_entity_duplicate_validator_hash_collision() -> None:
+    """Test that two different object_ids with the same FNV-1 hash are rejected."""
+    # Brute-forced FNV-1 32-bit collision pair; both object_ids hash to 0xe95747e4
+    name_a = "Sensor aooxzi"
+    name_b = "Sensor baraia"
+    object_id_a = sanitize(snake_case(name_a))
+    object_id_b = sanitize(snake_case(name_b))
+    assert object_id_a != object_id_b
+    assert fnv1_hash(object_id_a) == fnv1_hash(object_id_b)
+
+    validator = entity_duplicate_validator("sensor")
+
+    config1 = {CONF_NAME: name_a}
+    validated1 = validator(config1)
+    assert validated1 == config1
+
+    config2 = {CONF_NAME: name_b}
+    with pytest.raises(
+        Invalid,
+        match=re.compile(
+            r"Duplicate sensor entity with name 'Sensor baraia' found.*"
+            r"produce the same entity key hash \(0xe95747e4\)",
+            re.DOTALL,
+        ),
+    ):
+        validator(config2)
+
+
 def test_entity_duplicate_validator_with_devices() -> None:
     """Test entity_duplicate_validator with devices."""
     # Create validator for sensor platform
@@ -370,19 +575,18 @@ def test_entity_duplicate_validator_with_devices() -> None:
     device2 = ID("device2", type="Device")
 
     # Same name on different devices should pass
-    name_hash = fnv1_hash_name("Temperature")
     config1 = {CONF_NAME: "Temperature", CONF_DEVICE_ID: device1}
     validated1 = validator(config1)
     assert validated1 == config1
-    assert ("device1", "sensor", name_hash) in CORE.unique_ids
-    metadata1 = CORE.unique_ids[("device1", "sensor", name_hash)]
+    assert ("device1", "sensor", fnv1_hash("temperature")) in CORE.unique_ids
+    metadata1 = CORE.unique_ids[("device1", "sensor", fnv1_hash("temperature"))]
     assert metadata1["device_id"] == "device1"
 
     config2 = {CONF_NAME: "Temperature", CONF_DEVICE_ID: device2}
     validated2 = validator(config2)
     assert validated2 == config2
-    assert ("device2", "sensor", name_hash) in CORE.unique_ids
-    metadata2 = CORE.unique_ids[("device2", "sensor", name_hash)]
+    assert ("device2", "sensor", fnv1_hash("temperature")) in CORE.unique_ids
+    metadata2 = CORE.unique_ids[("device2", "sensor", fnv1_hash("temperature"))]
     assert metadata2["device_id"] == "device2"
 
     # Duplicate on same device should fail
@@ -434,33 +638,6 @@ def test_entity_different_platforms_yaml_validation(
     assert result is not None
 
 
-def test_object_id_conflict_mqtt_yaml_validation(
-    yaml_file: Callable[[str], str], capsys: pytest.CaptureFixture[str]
-) -> None:
-    """Test that names sanitizing to the same object_id fail when mqtt is configured."""
-    result = load_config_from_fixture(
-        yaml_file, "object_id_conflict_mqtt.yaml", FIXTURES_DIR
-    )
-    assert result is None
-
-    captured = capsys.readouterr()
-    assert (
-        "mqtt builds default topics and discovery topics from the entity object_id"
-        in captured.out
-    )
-
-
-def test_object_id_conflict_without_mqtt_yaml_validation(
-    yaml_file: Callable[[str], str],
-) -> None:
-    """Test that names sanitizing to the same object_id pass without mqtt/prometheus."""
-    result = load_config_from_fixture(
-        yaml_file, "object_id_conflict_no_mqtt.yaml", FIXTURES_DIR
-    )
-    # This should succeed
-    assert result is not None
-
-
 def test_entity_duplicate_validator_error_message() -> None:
     """Test that duplicate entity error messages include helpful metadata."""
     # Create validator for sensor platform
@@ -519,8 +696,7 @@ def test_entity_duplicate_validator_internal_entities() -> None:
     validated1 = validator(config1)
     assert validated1 == config1
     # New format includes device_id (empty string for main device)
-    temperature_key = ("", "sensor", fnv1_hash_name("Temperature"))
-    assert temperature_key in CORE.unique_ids
+    assert ("", "sensor", fnv1_hash("temperature")) in CORE.unique_ids
 
     # Internal entity with same name should pass (not added to unique_ids)
     config2 = {CONF_NAME: "Temperature", CONF_INTERNAL: True}
@@ -528,7 +704,9 @@ def test_entity_duplicate_validator_internal_entities() -> None:
     assert validated2 == config2
     # Internal entity should not be added to unique_ids
     # Count how many times the key appears (should still be 1)
-    count = sum(1 for k in CORE.unique_ids if k == temperature_key)
+    count = sum(
+        1 for k in CORE.unique_ids if k == ("", "sensor", fnv1_hash("temperature"))
+    )
     assert count == 1
 
     # Another internal entity with same name should also pass
@@ -536,7 +714,9 @@ def test_entity_duplicate_validator_internal_entities() -> None:
     validated3 = validator(config3)
     assert validated3 == config3
     # Still only one entry in unique_ids (from the non-internal entity)
-    count = sum(1 for k in CORE.unique_ids if k == temperature_key)
+    count = sum(
+        1 for k in CORE.unique_ids if k == ("", "sensor", fnv1_hash("temperature"))
+    )
     assert count == 1
 
     # Non-internal entity with same name should fail
@@ -564,148 +744,30 @@ def test_empty_or_null_device_id_on_entity() -> None:
 
 
 def test_entity_duplicate_validator_non_ascii_names() -> None:
-    """Test that distinct non-ASCII names no longer collide.
-
-    These names used to be rejected because both sanitize to only underscores;
-    the entity key now hashes the raw name so they stay distinct.
-    """
+    """Test that non-ASCII names show helpful error messages."""
     # Create validator for binary_sensor platform
     validator = entity_duplicate_validator("binary_sensor")
 
-    # Both Russian sensors should pass even though they sanitize identically
+    # First Russian sensor should pass
     config1 = {CONF_NAME: "Датчик открытия основного крана"}
     validated1 = validator(config1)
     assert validated1 == config1
 
+    # Second Russian sensor with different text but same ASCII conversion should fail
     config2 = {CONF_NAME: "Датчик закрытия основного крана"}
-    validated2 = validator(config2)
-    assert validated2 == config2
-
-    # An exact duplicate still fails
-    config3 = {CONF_NAME: "Датчик открытия основного крана"}
-    with pytest.raises(
-        Invalid,
-        match=r"Duplicate binary_sensor entity with name 'Датчик открытия основного крана' found",
-    ):
-        validator(config3)
-
-
-def test_entity_duplicate_validator_hash_collision() -> None:
-    """Test that two different names with the same FNV-1 hash are rejected."""
-    # Brute-forced FNV-1 32-bit collision pair; both hash to 0x0ee5ff7b
-    name_a = "Sensor m2CZ"
-    name_b = "Sensor qCaa"
-    assert name_a != name_b
-    assert fnv1_hash_name(name_a) == fnv1_hash_name(name_b)
-
-    validator = entity_duplicate_validator("sensor")
-
-    config1 = {CONF_NAME: name_a}
-    validated1 = validator(config1)
-    assert validated1 == config1
-
-    config2 = {CONF_NAME: name_b}
     with pytest.raises(
         Invalid,
         match=re.compile(
-            rf"Duplicate sensor entity with name '{name_b}' found.*"
-            rf"The names '{name_b}' and '{name_a}' produce the.*"
-            r"same entity key hash \(0x0ee5ff7b\).*"
-            r"To fix: Rename one of the entities",
+            r"Duplicate binary_sensor entity with name 'Датчик закрытия основного крана' found.*"
+            r"Original names: 'Датчик закрытия основного крана' and 'Датчик открытия основного крана'.*"
+            r"Both convert to ASCII ID: '_______________________________'.*"
+            r"To fix: Add unique ASCII characters \(e\.g\., '1', '2', or 'A', 'B'\)",
             re.DOTALL,
         ),
     ):
         validator(config2)
 
 
-def test_object_id_conflicts_rejected_by_component_validator() -> None:
-    """Test that object_id conflicts pass entity validation but fail for mqtt/prometheus."""
-    validator = entity_duplicate_validator("sensor")
-
-    # Both names validate fine in general (distinct raw names, distinct keys)
-    validator({CONF_NAME: "Датчик открытия"})
-    validator({CONF_NAME: "Датчик закрытия"})
-
-    # A component that addresses entities by object_id must reject the config
-    component_validator = validate_no_object_id_conflicts(
-        "mqtt builds default topics from the entity object_id"
-    )
-    with pytest.raises(
-        Invalid,
-        match=re.compile(
-            r"mqtt builds default topics from the entity object_id.*"
-            r"sensor entities 'Датчик открытия', 'Датчик закрытия' "
-            r"share the object_id '_______________'.*"
-            r"To fix: Add unique ASCII characters",
-            re.DOTALL,
-        ),
-    ):
-        component_validator({})
-
-
-def test_object_id_conflicts_skipped_in_testing_mode() -> None:
-    """Test that testing_mode skips the conflict check, as used for grouped testing."""
-    validator = entity_duplicate_validator("sensor")
-    validator({CONF_NAME: "Датчик открытия"})
-    validator({CONF_NAME: "Датчик закрытия"})
-
-    component_validator = validate_no_object_id_conflicts(
-        "mqtt builds default topics from the entity object_id"
-    )
-    CORE.testing_mode = True
-    try:
-        config: dict = {}
-        assert component_validator(config) is config
-    finally:
-        CORE.testing_mode = False
-
-
-def test_object_id_conflicts_none_recorded() -> None:
-    """Test that distinct object_ids produce no conflicts."""
-    validator = entity_duplicate_validator("sensor")
-    validator({CONF_NAME: "Temperature"})
-    validator({CONF_NAME: "Humidity"})
-
-    component_validator = validate_no_object_id_conflicts(
-        "mqtt builds default topics from the entity object_id"
-    )
-    config: dict = {}
-    assert component_validator(config) is config
-
-
-def test_object_id_conflicts_device_scoped() -> None:
-    """Test that the object_id conflict check is scoped per device.
-
-    Same-named entities on different sub-devices were accepted before entity keys
-    moved to raw names, so the check keeps that scope; conflicts within one device
-    are still reported with the device named in the message.
-    """
-    validator = entity_duplicate_validator("sensor")
-    validator({CONF_NAME: "Temperature", CONF_DEVICE_ID: ID("device1", type="Device")})
-    validator({CONF_NAME: "Temperature", CONF_DEVICE_ID: ID("device2", type="Device")})
-
-    component_validator = validate_no_object_id_conflicts(
-        "prometheus builds metric labels from the entity object_id"
-    )
-    config: dict = {}
-    assert component_validator(config) is config
-
-    # Two names sanitizing identically on the same sub-device still conflict
-    validator(
-        {CONF_NAME: "Датчик открытия", CONF_DEVICE_ID: ID("device1", type="Device")}
-    )
-    validator(
-        {CONF_NAME: "Датчик закрытия", CONF_DEVICE_ID: ID("device1", type="Device")}
-    )
-    with pytest.raises(
-        Invalid,
-        match=re.compile(
-            r"prometheus builds metric labels.*on device 'device1'", re.DOTALL
-        ),
-    ):
-        component_validator({})
-
-
 def test_entity_duplicate_validator_same_name_no_enhanced_message() -> None:
     """Test that identical names don't show the enhanced message."""
     # Create validator for sensor platform
@@ -763,7 +825,7 @@ async def test_setup_entity_empty_name_with_device(
 
     # For empty-name entities, Python stores hash 0 - C++ calculates hash at runtime
     assert config.get("_entity_name") == ""
-    assert config.get("_entity_key") == 0
+    assert config.get("_entity_object_id_hash") == 0
 
 
 @pytest.mark.asyncio
@@ -792,7 +854,7 @@ async def test_setup_entity_empty_name_with_mac_suffix(
 
     # For empty-name entities, Python stores hash 0 - C++ calculates hash at runtime
     assert config.get("_entity_name") == ""
-    assert config.get("_entity_key") == 0
+    assert config.get("_entity_object_id_hash") == 0
 
 
 @pytest.mark.asyncio
@@ -822,7 +884,7 @@ async def test_setup_entity_empty_name_with_mac_suffix_no_friendly_name(
 
     # For empty-name entities, Python stores hash 0 - C++ calculates hash at runtime
     assert config.get("_entity_name") == ""
-    assert config.get("_entity_key") == 0
+    assert config.get("_entity_object_id_hash") == 0
 
 
 @pytest.mark.asyncio
@@ -853,7 +915,7 @@ async def test_setup_entity_empty_name_no_mac_suffix_no_friendly_name(
 
     # For empty-name entities, Python stores hash 0 - C++ calculates hash at runtime
     assert config.get("_entity_name") == ""
-    assert config.get("_entity_key") == 0
+    assert config.get("_entity_object_id_hash") == 0
 
 
 def test_register_string_overflow() -> None:

tests/unit_tests/fixtures/core/entity_helpers/object_id_conflict_mqtt.yaml

@@ -1,22 +0,0 @@
-esphome:
-  name: test-object-id-conflict
-
-esp32:
-  board: esp32dev
-
-wifi:
-  ssid: MySSID
-  password: password1
-
-mqtt:
-  broker: test.mosquitto.org
-
-sensor:
-  # Distinct raw names are fine in general, but both sanitize to the same
-  # object_id, which MQTT still uses to build default topics - should fail
-  - platform: template
-    name: "Датчик открытия"
-    lambda: return 21.0;
-  - platform: template
-    name: "Датчик закрытия"
-    lambda: return 22.0;

tests/unit_tests/fixtures/core/entity_helpers/object_id_conflict_no_mqtt.yaml

@@ -1,15 +0,0 @@
-esphome:
-  name: test-object-id-ok
-
-esp32:
-  board: esp32dev
-
-sensor:
-  # Distinct raw names that sanitize to the same object_id are allowed when no
-  # component addresses entities by object_id (no mqtt or prometheus configured)
-  - platform: template
-    name: "Датчик открытия"
-    lambda: return 21.0;
-  - platform: template
-    name: "Датчик закрытия"
-    lambda: return 22.0;

tests/unit_tests/test_preference_hash_stability.py

@@ -5,11 +5,11 @@ users to lose stored preferences (calibration values, restore states, etc.) on
 firmware upgrades, or break entity state routing to API clients.
 
 Two algorithms are locked here (see https://github.com/esphome/backlog/issues/85):
-1. `fnv1_hash_object_id(name)` - the LEGACY hash (snake_case + sanitize, then FNV-1).
-   Existing devices have preferences stored under keys derived from it; slot-based
-   backends (ESP8266, RP2040) keep using it, and key-lookup backends migrate FROM it.
-2. `fnv1_hash_name(name)` - the entity key (FNV-1 over the raw UTF-8 name bytes).
-   Sent to API clients and used as the preference key base on key-lookup backends.
+1. `fnv1_hash_object_id(name)` - the object_id hash (snake_case + sanitize, then FNV-1).
+   The entity key sent to API clients and the base of every stored preference key.
+2. `fnv1_hash_name(name)` - FNV-1 over the raw UTF-8 name bytes. 2026.8 beta
+   firmware stored preferences under keys derived from it; a future key migration
+   must reconstruct those keys to recover that data.
 
 DO NOT CHANGE THE EXPECTED VALUES - if tests fail after modifying a hash algorithm,
 the change breaks backward compatibility and will cause data loss.
@@ -124,8 +124,9 @@ def test_entity_object_id_hash_stability(
     """Verify fnv1_hash_object_id produces stable hashes for entity names.
 
     CRITICAL: These expected values MUST NOT CHANGE. Existing devices have
-    preferences stored under keys derived from this legacy hash; changing it
-    breaks the old-to-new key migration and loses stored preferences.
+    preferences stored under keys derived from this hash, and it is the entity
+    key sent to API clients; changing it loses stored preferences and breaks
+    entity state routing.
     """
     actual = fnv1_hash_object_id(entity_name)
     assert actual == expected_object_id_hash, (
@@ -144,9 +145,8 @@ def compute_legacy_preference_key(
 ) -> int:
     """Compute the legacy preference key: (object_id_hash ^ device_id) ^ version.
 
-    This is the key existing devices have data stored under. Slot-based backends
-    (ESP8266, RP2040) still use it directly; key-lookup backends compute it as the
-    migration source in EntityBase::make_entity_preference_() (entity_base.cpp).
+    This is the key EntityBase::make_entity_preference_() (entity_base.cpp)
+    stores every entity preference under.
     """
     object_id_hash = fnv1_hash_object_id(entity_name)
     preference_hash = object_id_hash ^ device_id
@@ -179,8 +179,8 @@ def test_legacy_preference_key_computation(
 ) -> None:
     """Verify legacy preference key computation matches expected values.
 
-    This test ensures the formula doesn't change, which would break both slot-based
-    preference storage and the migration source keys on key-lookup backends.
+    This test ensures the formula doesn't change, which would lose stored
+    preferences on every platform.
     """
     actual_key = compute_legacy_preference_key(entity_name, version, device_id)
 
@@ -215,12 +215,12 @@ def test_legacy_preference_key_computation(
     ],
 )
 def test_entity_key_hash_stability(entity_name: str, expected_key: int) -> None:
-    """Verify fnv1_hash_name produces stable entity keys.
+    """Verify fnv1_hash_name produces stable raw-name hashes.
 
-    CRITICAL: These expected values MUST NOT CHANGE. The entity key is sent to
-    API clients and is the new preference key base; changing the algorithm
-    would break state routing and lose stored preferences.
-    Must match C++ fnv1_hash_bytes() in esphome/core/helpers.h.
+    CRITICAL: These expected values MUST NOT CHANGE. 2026.8 beta firmware stored
+    preferences under keys derived from this hash; a future key migration must
+    reconstruct those keys, and changing the algorithm would strand that data.
+    Matched C++ fnv1_hash_bytes() (2026.8 beta), which the unrevert restores.
     """
     actual = fnv1_hash_name(entity_name)
     assert actual == expected_key, (