[output] Let final_validate_unique_channel take the channel key

esphome/components/output/__init__.py

@@ -132,7 +132,7 @@ BINARY_OUTPUT_ACTION_SCHEMA = maybe_simple_id(
 
 
 def final_validate_unique_channel(
-    *, platform: str, hub_key: str
+    *, platform: str, hub_key: str, channel_key: str = CONF_CHANNEL
 ) -> Callable[[ConfigType], ConfigType]:
     """Reject a second output of platform on the same channel of one hub.
 
@@ -141,7 +141,7 @@ def final_validate_unique_channel(
     return fv.unique_platform_key(
         domain=DOMAIN,
         platform=platform,
-        keys=(hub_key, CONF_CHANNEL),
+        keys=(hub_key, channel_key),
         message="Channel '{1}' of '{0}' is already used by another output",
     )
 

tests/component_tests/output/test_output.py

@@ -7,13 +7,14 @@ from types import ModuleType
 import pytest
 
 from esphome import config_validation as cv
+from esphome.components import output
 from esphome.components.lp5562 import output as lp5562_output
 from esphome.components.mcp4461 import output as mcp4461_output
 from esphome.components.mcp4728 import output as mcp4728_output
 from esphome.components.pca9685 import output as pca9685_output
 from esphome.components.sm2135 import output as sm2135_output
 from esphome.config import Config, read_config
-from esphome.const import CONF_CHANNEL, CONF_PLATFORM, PlatformFramework
+from esphome.const import CONF_CHANNEL, CONF_PIN, CONF_PLATFORM, PlatformFramework
 from esphome.core import CORE, ID
 
 from ..types import SetCoreConfigCallable
@@ -92,3 +93,19 @@ def test_hub_channel_must_be_unique(
         module.FINAL_VALIDATE_SCHEMA(entry)
     with pytest.raises(cv.Invalid, match=f"Channel '{channel}' of 'a' is already used"):
         module.FINAL_VALIDATE_SCHEMA(entries[3])
+
+
+def test_hub_channel_key_can_be_renamed(set_core_config: SetCoreConfigCallable) -> None:
+    """A hub that names its channel `pin` passes channel_key and gets the same check."""
+    validate = output.final_validate_unique_channel(
+        platform="fake", hub_key="fake_id", channel_key=CONF_PIN
+    )
+    entries = [
+        {CONF_PLATFORM: "fake", "fake_id": ID("a"), CONF_PIN: pin} for pin in (3, 4, 3)
+    ]
+    full = Config()
+    full["output"] = entries
+    set_core_config(PlatformFramework.ESP32_IDF, full_config=full)
+    validate(entries[1])
+    with pytest.raises(cv.Invalid, match="Channel '3' of 'a' is already used"):
+        validate(entries[2])