From b7838671ae53b501d829a5fc7d50e04f7dc7790d Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@koston.org>
Date: Wed, 5 Nov 2025 10:57:20 -0600
Subject: [PATCH 1/5] [ld2420] Eliminate substr() allocation in firmware
 version parsing (#11724)

---
 esphome/components/ld2420/ld2420.cpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/esphome/components/ld2420/ld2420.cpp b/esphome/components/ld2420/ld2420.cpp
index b48c336d4e..f544acc112 100644
--- a/esphome/components/ld2420/ld2420.cpp
+++ b/esphome/components/ld2420/ld2420.cpp
@@ -174,7 +174,7 @@ static uint8_t calc_checksum(void *data, size_t size) {
 static int get_firmware_int(const char *version_string) {
   std::string version_str = version_string;
   if (version_str[0] == 'v') {
-    version_str = version_str.substr(1);
+    version_str.erase(0, 1);
   }
   version_str.erase(remove(version_str.begin(), version_str.end(), '.'), version_str.end());
   int version_integer = stoi(version_str);

From 5dc8bfcf13cdadc7cd21f772a8256204fd4eeffb Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Wed, 5 Nov 2025 11:08:10 -0600
Subject: [PATCH 2/5] [template] Mark all component classes as final

---
 .../alarm_control_panel/template_alarm_control_panel.h        | 2 +-
 .../template/binary_sensor/template_binary_sensor.h           | 2 +-
 esphome/components/template/button/template_button.h          | 2 +-
 esphome/components/template/cover/template_cover.h            | 2 +-
 esphome/components/template/datetime/template_date.h          | 2 +-
 esphome/components/template/datetime/template_datetime.h      | 2 +-
 esphome/components/template/datetime/template_time.h          | 2 +-
 esphome/components/template/event/template_event.h            | 2 +-
 esphome/components/template/fan/template_fan.h                | 2 +-
 esphome/components/template/lock/template_lock.h              | 2 +-
 esphome/components/template/number/template_number.h          | 2 +-
 esphome/components/template/output/template_output.h          | 4 ++--
 esphome/components/template/select/template_select.h          | 2 +-
 esphome/components/template/sensor/template_sensor.h          | 2 +-
 esphome/components/template/switch/template_switch.h          | 2 +-
 esphome/components/template/text/template_text.h              | 2 +-
 .../components/template/text_sensor/template_text_sensor.h    | 2 +-
 esphome/components/template/valve/template_valve.h            | 2 +-
 18 files changed, 19 insertions(+), 19 deletions(-)

diff --git a/esphome/components/template/alarm_control_panel/template_alarm_control_panel.h b/esphome/components/template/alarm_control_panel/template_alarm_control_panel.h
index 40a79004da..202dc7c13f 100644
--- a/esphome/components/template/alarm_control_panel/template_alarm_control_panel.h
+++ b/esphome/components/template/alarm_control_panel/template_alarm_control_panel.h
@@ -49,7 +49,7 @@ struct SensorInfo {
   uint8_t store_index;
 };
 
-class TemplateAlarmControlPanel : public alarm_control_panel::AlarmControlPanel, public Component {
+class TemplateAlarmControlPanel final : public alarm_control_panel::AlarmControlPanel, public Component {
  public:
   TemplateAlarmControlPanel();
   void dump_config() override;
diff --git a/esphome/components/template/binary_sensor/template_binary_sensor.h b/esphome/components/template/binary_sensor/template_binary_sensor.h
index bc591391b9..0af709b097 100644
--- a/esphome/components/template/binary_sensor/template_binary_sensor.h
+++ b/esphome/components/template/binary_sensor/template_binary_sensor.h
@@ -7,7 +7,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateBinarySensor : public Component, public binary_sensor::BinarySensor {
+class TemplateBinarySensor final : public Component, public binary_sensor::BinarySensor {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/button/template_button.h b/esphome/components/template/button/template_button.h
index 68e976f64b..5bda82c58f 100644
--- a/esphome/components/template/button/template_button.h
+++ b/esphome/components/template/button/template_button.h
@@ -5,7 +5,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateButton : public button::Button {
+class TemplateButton final : public button::Button {
  public:
   // Implements the abstract `press_action` but the `on_press` trigger already handles the press.
   void press_action() override{};
diff --git a/esphome/components/template/cover/template_cover.h b/esphome/components/template/cover/template_cover.h
index faff69f867..125c67bb86 100644
--- a/esphome/components/template/cover/template_cover.h
+++ b/esphome/components/template/cover/template_cover.h
@@ -14,7 +14,7 @@ enum TemplateCoverRestoreMode {
   COVER_RESTORE_AND_CALL,
 };
 
-class TemplateCover : public cover::Cover, public Component {
+class TemplateCover final : public cover::Cover, public Component {
  public:
   TemplateCover();
 
diff --git a/esphome/components/template/datetime/template_date.h b/esphome/components/template/datetime/template_date.h
index 7fed704d0e..fe64b0ba14 100644
--- a/esphome/components/template/datetime/template_date.h
+++ b/esphome/components/template/datetime/template_date.h
@@ -14,7 +14,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateDate : public datetime::DateEntity, public PollingComponent {
+class TemplateDate final : public datetime::DateEntity, public PollingComponent {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/datetime/template_datetime.h b/esphome/components/template/datetime/template_datetime.h
index ec45bf0326..c44bd85265 100644
--- a/esphome/components/template/datetime/template_datetime.h
+++ b/esphome/components/template/datetime/template_datetime.h
@@ -14,7 +14,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateDateTime : public datetime::DateTimeEntity, public PollingComponent {
+class TemplateDateTime final : public datetime::DateTimeEntity, public PollingComponent {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/datetime/template_time.h b/esphome/components/template/datetime/template_time.h
index ea7474c0ba..0c95330d27 100644
--- a/esphome/components/template/datetime/template_time.h
+++ b/esphome/components/template/datetime/template_time.h
@@ -14,7 +14,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateTime : public datetime::TimeEntity, public PollingComponent {
+class TemplateTime final : public datetime::TimeEntity, public PollingComponent {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/event/template_event.h b/esphome/components/template/event/template_event.h
index 251ae9299b..5467a64141 100644
--- a/esphome/components/template/event/template_event.h
+++ b/esphome/components/template/event/template_event.h
@@ -6,7 +6,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateEvent : public Component, public event::Event {};
+class TemplateEvent final : public Component, public event::Event {};
 
 }  // namespace template_
 }  // namespace esphome
diff --git a/esphome/components/template/fan/template_fan.h b/esphome/components/template/fan/template_fan.h
index b09352f4d4..052b385b93 100644
--- a/esphome/components/template/fan/template_fan.h
+++ b/esphome/components/template/fan/template_fan.h
@@ -6,7 +6,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateFan : public Component, public fan::Fan {
+class TemplateFan final : public Component, public fan::Fan {
  public:
   TemplateFan() {}
   void setup() override;
diff --git a/esphome/components/template/lock/template_lock.h b/esphome/components/template/lock/template_lock.h
index 14fca4635e..ac10794e4d 100644
--- a/esphome/components/template/lock/template_lock.h
+++ b/esphome/components/template/lock/template_lock.h
@@ -8,7 +8,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateLock : public lock::Lock, public Component {
+class TemplateLock final : public lock::Lock, public Component {
  public:
   TemplateLock();
 
diff --git a/esphome/components/template/number/template_number.h b/esphome/components/template/number/template_number.h
index a9307e9246..876ec96b3b 100644
--- a/esphome/components/template/number/template_number.h
+++ b/esphome/components/template/number/template_number.h
@@ -9,7 +9,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateNumber : public number::Number, public PollingComponent {
+class TemplateNumber final : public number::Number, public PollingComponent {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/output/template_output.h b/esphome/components/template/output/template_output.h
index 90de801a5c..9ecfc446b9 100644
--- a/esphome/components/template/output/template_output.h
+++ b/esphome/components/template/output/template_output.h
@@ -7,7 +7,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateBinaryOutput : public output::BinaryOutput {
+class TemplateBinaryOutput final : public output::BinaryOutput {
  public:
   Trigger<bool> *get_trigger() const { return trigger_; }
 
@@ -17,7 +17,7 @@ class TemplateBinaryOutput : public output::BinaryOutput {
   Trigger<bool> *trigger_ = new Trigger<bool>();
 };
 
-class TemplateFloatOutput : public output::FloatOutput {
+class TemplateFloatOutput final : public output::FloatOutput {
  public:
   Trigger<float> *get_trigger() const { return trigger_; }
 
diff --git a/esphome/components/template/select/template_select.h b/esphome/components/template/select/template_select.h
index 2dad059ade..cb5b546976 100644
--- a/esphome/components/template/select/template_select.h
+++ b/esphome/components/template/select/template_select.h
@@ -9,7 +9,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateSelect : public select::Select, public PollingComponent {
+class TemplateSelect final : public select::Select, public PollingComponent {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/sensor/template_sensor.h b/esphome/components/template/sensor/template_sensor.h
index 793d754a0f..3ca965dde3 100644
--- a/esphome/components/template/sensor/template_sensor.h
+++ b/esphome/components/template/sensor/template_sensor.h
@@ -7,7 +7,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateSensor : public sensor::Sensor, public PollingComponent {
+class TemplateSensor final : public sensor::Sensor, public PollingComponent {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/switch/template_switch.h b/esphome/components/template/switch/template_switch.h
index 18a374df35..35c18af448 100644
--- a/esphome/components/template/switch/template_switch.h
+++ b/esphome/components/template/switch/template_switch.h
@@ -8,7 +8,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateSwitch : public switch_::Switch, public Component {
+class TemplateSwitch final : public switch_::Switch, public Component {
  public:
   TemplateSwitch();
 
diff --git a/esphome/components/template/text/template_text.h b/esphome/components/template/text/template_text.h
index c12021f80e..1a0a66ed5b 100644
--- a/esphome/components/template/text/template_text.h
+++ b/esphome/components/template/text/template_text.h
@@ -60,7 +60,7 @@ template<uint8_t SZ> class TextSaver : public TemplateTextSaverBase {
   }
 };
 
-class TemplateText : public text::Text, public PollingComponent {
+class TemplateText final : public text::Text, public PollingComponent {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/text_sensor/template_text_sensor.h b/esphome/components/template/text_sensor/template_text_sensor.h
index 0d01c72023..da5c518c7f 100644
--- a/esphome/components/template/text_sensor/template_text_sensor.h
+++ b/esphome/components/template/text_sensor/template_text_sensor.h
@@ -8,7 +8,7 @@
 namespace esphome {
 namespace template_ {
 
-class TemplateTextSensor : public text_sensor::TextSensor, public PollingComponent {
+class TemplateTextSensor final : public text_sensor::TextSensor, public PollingComponent {
  public:
   template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
diff --git a/esphome/components/template/valve/template_valve.h b/esphome/components/template/valve/template_valve.h
index d6235f8e5c..c452648193 100644
--- a/esphome/components/template/valve/template_valve.h
+++ b/esphome/components/template/valve/template_valve.h
@@ -14,7 +14,7 @@ enum TemplateValveRestoreMode {
   VALVE_RESTORE_AND_CALL,
 };
 
-class TemplateValve : public valve::Valve, public Component {
+class TemplateValve final : public valve::Valve, public Component {
  public:
   TemplateValve();
 

From 4c097616ae862ef5255d45663b91e58ff6161951 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Wed, 5 Nov 2025 11:10:13 -0600
Subject: [PATCH 3/5] move comments

---
 esphome/components/mqtt/mqtt_binary_sensor.cpp | 2 +-
 esphome/components/mqtt/mqtt_component.cpp     | 1 +
 esphome/components/mqtt/mqtt_cover.cpp         | 2 +-
 esphome/components/mqtt/mqtt_event.cpp         | 1 +
 esphome/components/mqtt/mqtt_number.cpp        | 2 ++
 esphome/components/mqtt/mqtt_sensor.cpp        | 3 ++-
 esphome/components/mqtt/mqtt_text_sensor.cpp   | 2 +-
 esphome/components/mqtt/mqtt_valve.cpp         | 2 +-
 8 files changed, 10 insertions(+), 5 deletions(-)

diff --git a/esphome/components/mqtt/mqtt_binary_sensor.cpp b/esphome/components/mqtt/mqtt_binary_sensor.cpp
index 8388e1cd7d..37705477a3 100644
--- a/esphome/components/mqtt/mqtt_binary_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_binary_sensor.cpp
@@ -30,9 +30,9 @@ MQTTBinarySensorComponent::MQTTBinarySensorComponent(binary_sensor::BinarySensor
 }
 
 void MQTTBinarySensorComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   const auto device_class = this->binary_sensor_->get_device_class_ref();
   if (!device_class.empty())
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
   if (this->binary_sensor_->is_status_binary_sensor())
     root[MQTT_PAYLOAD_ON] = mqtt::global_mqtt_client->get_availability().payload_available;
diff --git a/esphome/components/mqtt/mqtt_component.cpp b/esphome/components/mqtt/mqtt_component.cpp
index 8c6d0e6e3e..9e563012ea 100644
--- a/esphome/components/mqtt/mqtt_component.cpp
+++ b/esphome/components/mqtt/mqtt_component.cpp
@@ -91,6 +91,7 @@ bool MQTTComponent::send_discovery_() {
           root[MQTT_ENABLED_BY_DEFAULT] = false;
         const auto icon_ref = this->get_icon_ref_();
         if (!icon_ref.empty())
+          // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
           root[MQTT_ICON] = icon_ref;
 
         const auto entity_category = this->get_entity()->get_entity_category();
diff --git a/esphome/components/mqtt/mqtt_cover.cpp b/esphome/components/mqtt/mqtt_cover.cpp
index 429c45b23b..58fa272a55 100644
--- a/esphome/components/mqtt/mqtt_cover.cpp
+++ b/esphome/components/mqtt/mqtt_cover.cpp
@@ -67,9 +67,9 @@ void MQTTCoverComponent::dump_config() {
   }
 }
 void MQTTCoverComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   const auto device_class = this->cover_->get_device_class_ref();
   if (!device_class.empty())
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
 
   auto traits = this->cover_->get_traits();
diff --git a/esphome/components/mqtt/mqtt_event.cpp b/esphome/components/mqtt/mqtt_event.cpp
index 73b13bba05..46f6b7f479 100644
--- a/esphome/components/mqtt/mqtt_event.cpp
+++ b/esphome/components/mqtt/mqtt_event.cpp
@@ -23,6 +23,7 @@ void MQTTEventComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConf
 
   const auto device_class = this->event_->get_device_class_ref();
   if (!device_class.empty())
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
 
   config.command_topic = false;
diff --git a/esphome/components/mqtt/mqtt_number.cpp b/esphome/components/mqtt/mqtt_number.cpp
index 1dac188478..358e45368a 100644
--- a/esphome/components/mqtt/mqtt_number.cpp
+++ b/esphome/components/mqtt/mqtt_number.cpp
@@ -46,6 +46,7 @@ void MQTTNumberComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCon
   root[MQTT_STEP] = traits.get_step();
   const auto unit_of_measurement = this->number_->traits.get_unit_of_measurement_ref();
   if (!unit_of_measurement.empty())
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_UNIT_OF_MEASUREMENT] = unit_of_measurement;
   switch (this->number_->traits.get_mode()) {
     case NUMBER_MODE_AUTO:
@@ -59,6 +60,7 @@ void MQTTNumberComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCon
   }
   const auto device_class = this->number_->traits.get_device_class_ref();
   if (!device_class.empty())
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
 
   config.command_topic = true;
diff --git a/esphome/components/mqtt/mqtt_sensor.cpp b/esphome/components/mqtt/mqtt_sensor.cpp
index b436e48f20..3d0a656bbb 100644
--- a/esphome/components/mqtt/mqtt_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_sensor.cpp
@@ -44,14 +44,15 @@ void MQTTSensorComponent::set_expire_after(uint32_t expire_after) { this->expire
 void MQTTSensorComponent::disable_expire_after() { this->expire_after_ = 0; }
 
 void MQTTSensorComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   const auto device_class = this->sensor_->get_device_class_ref();
   if (!device_class.empty()) {
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
   }
 
   const auto unit_of_measurement = this->sensor_->get_unit_of_measurement_ref();
   if (!unit_of_measurement.empty())
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_UNIT_OF_MEASUREMENT] = unit_of_measurement;
 
   if (this->get_expire_after() > 0)
diff --git a/esphome/components/mqtt/mqtt_text_sensor.cpp b/esphome/components/mqtt/mqtt_text_sensor.cpp
index f649586845..1e727fed88 100644
--- a/esphome/components/mqtt/mqtt_text_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_text_sensor.cpp
@@ -15,9 +15,9 @@ using namespace esphome::text_sensor;
 
 MQTTTextSensor::MQTTTextSensor(TextSensor *sensor) : sensor_(sensor) {}
 void MQTTTextSensor::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   const auto device_class = this->sensor_->get_device_class_ref();
   if (!device_class.empty()) {
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
   }
   config.command_topic = false;
diff --git a/esphome/components/mqtt/mqtt_valve.cpp b/esphome/components/mqtt/mqtt_valve.cpp
index d594ee381a..32740235c5 100644
--- a/esphome/components/mqtt/mqtt_valve.cpp
+++ b/esphome/components/mqtt/mqtt_valve.cpp
@@ -49,9 +49,9 @@ void MQTTValveComponent::dump_config() {
   }
 }
 void MQTTValveComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
-  // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
   const auto device_class = this->valve_->get_device_class_ref();
   if (!device_class.empty()) {
+    // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
   }
 

From 4c5533b2ead3aead28d231289cede7f5e0a8c7d4 Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Wed, 5 Nov 2025 11:16:43 -0600
Subject: [PATCH 4/5] move comments

---
 esphome/components/mqtt/mqtt_binary_sensor.cpp | 3 ++-
 esphome/components/mqtt/mqtt_component.cpp     | 3 ++-
 esphome/components/mqtt/mqtt_cover.cpp         | 3 ++-
 esphome/components/mqtt/mqtt_event.cpp         | 3 ++-
 esphome/components/mqtt/mqtt_number.cpp        | 6 ++++--
 esphome/components/mqtt/mqtt_sensor.cpp        | 3 ++-
 6 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/esphome/components/mqtt/mqtt_binary_sensor.cpp b/esphome/components/mqtt/mqtt_binary_sensor.cpp
index 37705477a3..3f9089bef8 100644
--- a/esphome/components/mqtt/mqtt_binary_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_binary_sensor.cpp
@@ -31,9 +31,10 @@ MQTTBinarySensorComponent::MQTTBinarySensorComponent(binary_sensor::BinarySensor
 
 void MQTTBinarySensorComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
   const auto device_class = this->binary_sensor_->get_device_class_ref();
-  if (!device_class.empty())
+  if (!device_class.empty()) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
+  }
   if (this->binary_sensor_->is_status_binary_sensor())
     root[MQTT_PAYLOAD_ON] = mqtt::global_mqtt_client->get_availability().payload_available;
   if (this->binary_sensor_->is_status_binary_sensor())
diff --git a/esphome/components/mqtt/mqtt_component.cpp b/esphome/components/mqtt/mqtt_component.cpp
index 9e563012ea..6bcb179f72 100644
--- a/esphome/components/mqtt/mqtt_component.cpp
+++ b/esphome/components/mqtt/mqtt_component.cpp
@@ -90,9 +90,10 @@ bool MQTTComponent::send_discovery_() {
         if (this->is_disabled_by_default_())
           root[MQTT_ENABLED_BY_DEFAULT] = false;
         const auto icon_ref = this->get_icon_ref_();
-        if (!icon_ref.empty())
+        if (!icon_ref.empty()) {
           // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
           root[MQTT_ICON] = icon_ref;
+        }
 
         const auto entity_category = this->get_entity()->get_entity_category();
         switch (entity_category) {
diff --git a/esphome/components/mqtt/mqtt_cover.cpp b/esphome/components/mqtt/mqtt_cover.cpp
index 58fa272a55..4a5a70a1c7 100644
--- a/esphome/components/mqtt/mqtt_cover.cpp
+++ b/esphome/components/mqtt/mqtt_cover.cpp
@@ -68,9 +68,10 @@ void MQTTCoverComponent::dump_config() {
 }
 void MQTTCoverComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConfig &config) {
   const auto device_class = this->cover_->get_device_class_ref();
-  if (!device_class.empty())
+  if (!device_class.empty()) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
+  }
 
   auto traits = this->cover_->get_traits();
   if (traits.get_is_assumed_state()) {
diff --git a/esphome/components/mqtt/mqtt_event.cpp b/esphome/components/mqtt/mqtt_event.cpp
index 46f6b7f479..ab4e095c06 100644
--- a/esphome/components/mqtt/mqtt_event.cpp
+++ b/esphome/components/mqtt/mqtt_event.cpp
@@ -22,9 +22,10 @@ void MQTTEventComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryConf
     event_types.add(event_type);
 
   const auto device_class = this->event_->get_device_class_ref();
-  if (!device_class.empty())
+  if (!device_class.empty()) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
+  }
 
   config.command_topic = false;
 }
diff --git a/esphome/components/mqtt/mqtt_number.cpp b/esphome/components/mqtt/mqtt_number.cpp
index 358e45368a..c50853a66c 100644
--- a/esphome/components/mqtt/mqtt_number.cpp
+++ b/esphome/components/mqtt/mqtt_number.cpp
@@ -45,9 +45,10 @@ void MQTTNumberComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCon
   root[MQTT_MAX] = traits.get_max_value();
   root[MQTT_STEP] = traits.get_step();
   const auto unit_of_measurement = this->number_->traits.get_unit_of_measurement_ref();
-  if (!unit_of_measurement.empty())
+  if (!unit_of_measurement.empty()) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_UNIT_OF_MEASUREMENT] = unit_of_measurement;
+  }
   switch (this->number_->traits.get_mode()) {
     case NUMBER_MODE_AUTO:
       break;
@@ -59,9 +60,10 @@ void MQTTNumberComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCon
       break;
   }
   const auto device_class = this->number_->traits.get_device_class_ref();
-  if (!device_class.empty())
+  if (!device_class.empty()) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_DEVICE_CLASS] = device_class;
+  }
 
   config.command_topic = true;
 }
diff --git a/esphome/components/mqtt/mqtt_sensor.cpp b/esphome/components/mqtt/mqtt_sensor.cpp
index 3d0a656bbb..cc135935bf 100644
--- a/esphome/components/mqtt/mqtt_sensor.cpp
+++ b/esphome/components/mqtt/mqtt_sensor.cpp
@@ -51,9 +51,10 @@ void MQTTSensorComponent::send_discovery(JsonObject root, mqtt::SendDiscoveryCon
   }
 
   const auto unit_of_measurement = this->sensor_->get_unit_of_measurement_ref();
-  if (!unit_of_measurement.empty())
+  if (!unit_of_measurement.empty()) {
     // NOLINTNEXTLINE(clang-analyzer-cplusplus.NewDeleteLeaks) false positive with ArduinoJson
     root[MQTT_UNIT_OF_MEASUREMENT] = unit_of_measurement;
+  }
 
   if (this->get_expire_after() > 0)
     root[MQTT_EXPIRE_AFTER] = this->get_expire_after() / 1000;

From ed0d9e60b85bd0927c1a6e3e74b45ef6583cf1fc Mon Sep 17 00:00:00 2001
From: "J. Nick Koston" <nick@home-assistant.io>
Date: Wed, 5 Nov 2025 11:19:06 -0600
Subject: [PATCH 5/5] [mdns] Eliminate redundant hostname copy to save heap
 memory

---
 esphome/components/mdns/mdns_component.cpp | 4 +---
 esphome/components/mdns/mdns_component.h   | 1 -
 esphome/components/mdns/mdns_esp32.cpp     | 6 ++++--
 esphome/components/mdns/mdns_esp8266.cpp   | 3 ++-
 esphome/components/mdns/mdns_libretiny.cpp | 3 ++-
 esphome/components/mdns/mdns_rp2040.cpp    | 3 ++-
 6 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/esphome/components/mdns/mdns_component.cpp b/esphome/components/mdns/mdns_component.cpp
index d476136554..2c3150ff5d 100644
--- a/esphome/components/mdns/mdns_component.cpp
+++ b/esphome/components/mdns/mdns_component.cpp
@@ -37,8 +37,6 @@ MDNS_STATIC_CONST_CHAR(SERVICE_TCP, "_tcp");
 MDNS_STATIC_CONST_CHAR(VALUE_VERSION, ESPHOME_VERSION);
 
 void MDNSComponent::compile_records_(StaticVector<MDNSService, MDNS_SERVICE_COUNT> &services) {
-  this->hostname_ = App.get_name();
-
   // IMPORTANT: The #ifdef blocks below must match COMPONENTS_WITH_MDNS_SERVICES
   // in mdns/__init__.py. If you add a new service here, update both locations.
 
@@ -179,7 +177,7 @@ void MDNSComponent::dump_config() {
   ESP_LOGCONFIG(TAG,
                 "mDNS:\n"
                 "  Hostname: %s",
-                this->hostname_.c_str());
+                App.get_name().c_str());
 #ifdef USE_MDNS_STORE_SERVICES
   ESP_LOGV(TAG, "  Services:");
   for (const auto &service : this->services_) {
diff --git a/esphome/components/mdns/mdns_component.h b/esphome/components/mdns/mdns_component.h
index 35371fd739..f4237d5a69 100644
--- a/esphome/components/mdns/mdns_component.h
+++ b/esphome/components/mdns/mdns_component.h
@@ -76,7 +76,6 @@ class MDNSComponent : public Component {
 #ifdef USE_MDNS_STORE_SERVICES
   StaticVector<MDNSService, MDNS_SERVICE_COUNT> services_{};
 #endif
-  std::string hostname_;
   void compile_records_(StaticVector<MDNSService, MDNS_SERVICE_COUNT> &services);
 };
 
diff --git a/esphome/components/mdns/mdns_esp32.cpp b/esphome/components/mdns/mdns_esp32.cpp
index c02bfcbadb..ecdc926cc9 100644
--- a/esphome/components/mdns/mdns_esp32.cpp
+++ b/esphome/components/mdns/mdns_esp32.cpp
@@ -2,6 +2,7 @@
 #if defined(USE_ESP32) && defined(USE_MDNS)
 
 #include <mdns.h>
+#include "esphome/core/application.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 #include "mdns_component.h"
@@ -27,8 +28,9 @@ void MDNSComponent::setup() {
     return;
   }
 
-  mdns_hostname_set(this->hostname_.c_str());
-  mdns_instance_name_set(this->hostname_.c_str());
+  const char *hostname = App.get_name().c_str();
+  mdns_hostname_set(hostname);
+  mdns_instance_name_set(hostname);
 
   for (const auto &service : services) {
     auto txt_records = std::make_unique<mdns_txt_item_t[]>(service.txt_records.size());
diff --git a/esphome/components/mdns/mdns_esp8266.cpp b/esphome/components/mdns/mdns_esp8266.cpp
index 25a3defa7b..9bbb406070 100644
--- a/esphome/components/mdns/mdns_esp8266.cpp
+++ b/esphome/components/mdns/mdns_esp8266.cpp
@@ -4,6 +4,7 @@
 #include <ESP8266mDNS.h>
 #include "esphome/components/network/ip_address.h"
 #include "esphome/components/network/util.h"
+#include "esphome/core/application.h"
 #include "esphome/core/hal.h"
 #include "esphome/core/log.h"
 #include "mdns_component.h"
@@ -20,7 +21,7 @@ void MDNSComponent::setup() {
   this->compile_records_(services);
 #endif
 
-  MDNS.begin(this->hostname_.c_str());
+  MDNS.begin(App.get_name().c_str());
 
   for (const auto &service : services) {
     // Strip the leading underscore from the proto and service_type. While it is
diff --git a/esphome/components/mdns/mdns_libretiny.cpp b/esphome/components/mdns/mdns_libretiny.cpp
index a3e317a2bf..fb2088f719 100644
--- a/esphome/components/mdns/mdns_libretiny.cpp
+++ b/esphome/components/mdns/mdns_libretiny.cpp
@@ -3,6 +3,7 @@
 
 #include "esphome/components/network/ip_address.h"
 #include "esphome/components/network/util.h"
+#include "esphome/core/application.h"
 #include "esphome/core/log.h"
 #include "mdns_component.h"
 
@@ -20,7 +21,7 @@ void MDNSComponent::setup() {
   this->compile_records_(services);
 #endif
 
-  MDNS.begin(this->hostname_.c_str());
+  MDNS.begin(App.get_name().c_str());
 
   for (const auto &service : services) {
     // Strip the leading underscore from the proto and service_type. While it is
diff --git a/esphome/components/mdns/mdns_rp2040.cpp b/esphome/components/mdns/mdns_rp2040.cpp
index 791fa3934d..a9f5349f14 100644
--- a/esphome/components/mdns/mdns_rp2040.cpp
+++ b/esphome/components/mdns/mdns_rp2040.cpp
@@ -3,6 +3,7 @@
 
 #include "esphome/components/network/ip_address.h"
 #include "esphome/components/network/util.h"
+#include "esphome/core/application.h"
 #include "esphome/core/log.h"
 #include "mdns_component.h"
 
@@ -20,7 +21,7 @@ void MDNSComponent::setup() {
   this->compile_records_(services);
 #endif
 
-  MDNS.begin(this->hostname_.c_str());
+  MDNS.begin(App.get_name().c_str());
 
   for (const auto &service : services) {
     // Strip the leading underscore from the proto and service_type. While it is