Add entity name template function (#166078)

tests/helpers/template/test_init.py

@@ -807,6 +807,37 @@ def test_if_state_exists(hass: HomeAssistant) -> None:
     assert result == "exists"
 
 
+def test_entity_name(
+    hass: HomeAssistant,
+    entity_registry: er.EntityRegistry,
+) -> None:
+    """Test entity_name method."""
+    assert render(hass, "{{ entity_name('sensor.fake') }}") is None
+
+    entry = entity_registry.async_get_or_create(
+        "sensor", "test", "unique_1", original_name="Registry Sensor"
+    )
+    assert render(hass, f"{{{{ entity_name('{entry.entity_id}') }}}}") == (
+        "Registry Sensor"
+    )
+    assert render(hass, f"{{{{ '{entry.entity_id}' | entity_name }}}}") == (
+        "Registry Sensor"
+    )
+
+    entity_registry.async_update_entity(entry.entity_id, name="My Custom Sensor")
+    assert render(hass, f"{{{{ entity_name('{entry.entity_id}') }}}}") == (
+        "My Custom Sensor"
+    )
+
+    # Falls back to state for entities not in the registry
+    hass.states.async_set(
+        "light.no_unique_id", "on", {"friendly_name": "No Unique ID Light"}
+    )
+    assert render(hass, "{{ entity_name('light.no_unique_id') }}") == (
+        "No Unique ID Light"
+    )
+
+
 def test_is_hidden_entity(
     hass: HomeAssistant,
     entity_registry: er.EntityRegistry,