From bd69737878834f3918919d5cbad486d841388208 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Wed, 25 Mar 2026 15:21:55 -1000
Subject: [PATCH] Add comment explaining RawExpression usage

---
 esphome/automation.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/esphome/automation.py b/esphome/automation.py
index 0958e862a8..996181f50b 100644
--- a/esphome/automation.py
+++ b/esphome/automation.py
@@ -701,4 +701,7 @@ async def build_callback_automation(
     # data in the struct.
     if forwarder is None:
         forwarder = TriggerForwarder.template(templ)
+    # RawExpression for aggregate init — both forwarder and obj are codegen
+    # MockObjs (not user input), and there's no Expression type for positional
+    # aggregate initialization (StructInitializer uses named fields).
     cg.add(getattr(parent, callback_method)(cg.RawExpression(f"{forwarder}{{{obj}}}")))