From 6e2dbbf636dbe98665904618553caddb0eb46315 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 5 Nov 2025 09:15:05 -0600
Subject: [PATCH] [voice_assistant] Eliminate substr() allocations in text
 truncation (#11725)

---
 esphome/components/voice_assistant/voice_assistant.cpp | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/esphome/components/voice_assistant/voice_assistant.cpp b/esphome/components/voice_assistant/voice_assistant.cpp
index 7ece73994f..fd35dc7d09 100644
--- a/esphome/components/voice_assistant/voice_assistant.cpp
+++ b/esphome/components/voice_assistant/voice_assistant.cpp
@@ -657,7 +657,8 @@ void VoiceAssistant::on_event(const api::VoiceAssistantEventResponse &msg) {
         ESP_LOGW(TAG, "No text in STT_END event");
         return;
       } else if (text.length() > 500) {
-        text = text.substr(0, 497) + "...";
+        text.resize(497);
+        text += "...";
       }
       ESP_LOGD(TAG, "Speech recognised as: \"%s\"", text.c_str());
       this->defer([this, text]() { this->stt_end_trigger_->trigger(text); });
@@ -714,7 +715,8 @@ void VoiceAssistant::on_event(const api::VoiceAssistantEventResponse &msg) {
         return;
       }
       if (text.length() > 500) {
-        text = text.substr(0, 497) + "...";
+        text.resize(497);
+        text += "...";
       }
       ESP_LOGD(TAG, "Response: \"%s\"", text.c_str());
       this->defer([this, text]() {