[select][fan] Use StringRef for on_value/on_preset_set triggers to avoid heap allocation

tests/integration/test_select_stringref_trigger.py

@@ -0,0 +1,84 @@
+"""Integration test for select on_value trigger with StringRef parameter."""
+
+from __future__ import annotations
+
+import asyncio
+import re
+
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+@pytest.mark.asyncio
+async def test_select_stringref_trigger(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test select on_value trigger passes StringRef that works with string operations."""
+    loop = asyncio.get_running_loop()
+
+    # Track log messages to verify StringRef operations work
+    value_logged_future = loop.create_future()
+    concatenated_future = loop.create_future()
+    comparison_future = loop.create_future()
+    index_logged_future = loop.create_future()
+
+    # Patterns to match in logs
+    value_pattern = re.compile(r"Select value: Option B")
+    concatenated_pattern = re.compile(r"Concatenated: Option B selected")
+    comparison_pattern = re.compile(r"Option B was selected")
+    index_pattern = re.compile(r"Select index: 1")
+
+    def check_output(line: str) -> None:
+        """Check log output for expected messages."""
+        if not value_logged_future.done() and value_pattern.search(line):
+            value_logged_future.set_result(True)
+        if not concatenated_future.done() and concatenated_pattern.search(line):
+            concatenated_future.set_result(True)
+        if not comparison_future.done() and comparison_pattern.search(line):
+            comparison_future.set_result(True)
+        if not index_logged_future.done() and index_pattern.search(line):
+            index_logged_future.set_result(True)
+
+    async with (
+        run_compiled(yaml_config, line_callback=check_output),
+        api_client_connected() as client,
+    ):
+        # Verify device info
+        device_info = await client.device_info()
+        assert device_info is not None
+        assert device_info.name == "select-stringref-test"
+
+        # List entities to find our select
+        entities, _ = await client.list_entities_services()
+
+        select_entity = next(
+            (e for e in entities if hasattr(e, "options") and e.name == "Test Select"),
+            None,
+        )
+        assert select_entity is not None, "Test Select entity not found"
+
+        # Change select to Option B - this should trigger on_value with StringRef
+        client.select_command(select_entity.key, "Option B")
+
+        # Wait for all log messages confirming StringRef operations work
+        try:
+            await asyncio.wait_for(
+                asyncio.gather(
+                    value_logged_future,
+                    concatenated_future,
+                    comparison_future,
+                    index_logged_future,
+                ),
+                timeout=5.0,
+            )
+        except TimeoutError:
+            results = {
+                "value_logged": value_logged_future.done(),
+                "concatenated": concatenated_future.done(),
+                "comparison": comparison_future.done(),
+                "index_logged": index_logged_future.done(),
+            }
+            pytest.fail(f"StringRef operations failed - received: {results}")