[scheduler] Refactor call() for improved code organization

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>
Co-authored-by: J. Nick Koston <nick@home-assistant.io>

.github/workflows/ci.yml

@@ -180,6 +180,7 @@ jobs:
       memory_impact: ${{ steps.determine.outputs.memory-impact }}
       cpp-unit-tests-run-all: ${{ steps.determine.outputs.cpp-unit-tests-run-all }}
       cpp-unit-tests-components: ${{ steps.determine.outputs.cpp-unit-tests-components }}
+      component-test-batches: ${{ steps.determine.outputs.component-test-batches }}
     steps:
       - name: Check out code from GitHub
         uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
@@ -214,6 +215,7 @@ jobs:
           echo "memory-impact=$(echo "$output" | jq -c '.memory_impact')" >> $GITHUB_OUTPUT
           echo "cpp-unit-tests-run-all=$(echo "$output" | jq -r '.cpp_unit_tests_run_all')" >> $GITHUB_OUTPUT
           echo "cpp-unit-tests-components=$(echo "$output" | jq -c '.cpp_unit_tests_components')" >> $GITHUB_OUTPUT
+          echo "component-test-batches=$(echo "$output" | jq -c '.component_test_batches')" >> $GITHUB_OUTPUT
 
   integration-tests:
     name: Run integration tests
@@ -458,7 +460,7 @@ jobs:
       GH_TOKEN: ${{ github.token }}
     strategy:
       fail-fast: false
-      max-parallel: 1
+      max-parallel: 2
       matrix:
         include:
           - id: clang-tidy
@@ -536,59 +538,18 @@ jobs:
         run: script/ci-suggest-changes
         if: always()
 
-  test-build-components-splitter:
-    name: Split components for intelligent grouping (40 weighted per batch)
-    runs-on: ubuntu-24.04
-    needs:
-      - common
-      - determine-jobs
-    if: github.event_name == 'pull_request' && fromJSON(needs.determine-jobs.outputs.component-test-count) > 0
-    outputs:
-      matrix: ${{ steps.split.outputs.components }}
-    steps:
-      - name: Check out code from GitHub
-        uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0
-      - name: Restore Python
-        uses: ./.github/actions/restore-python
-        with:
-          python-version: ${{ env.DEFAULT_PYTHON }}
-          cache-key: ${{ needs.common.outputs.cache-key }}
-      - name: Split components intelligently based on bus configurations
-        id: split
-        run: |
-          . venv/bin/activate
-
-          # Use intelligent splitter that groups components with same bus configs
-          components='${{ needs.determine-jobs.outputs.changed-components-with-tests }}'
-
-          # Only isolate directly changed components when targeting dev branch
-          # For beta/release branches, group everything for faster CI
-          if [[ "${{ github.base_ref }}" == beta* ]] || [[ "${{ github.base_ref }}" == release* ]]; then
-            directly_changed='[]'
-            echo "Target branch: ${{ github.base_ref }} - grouping all components"
-          else
-            directly_changed='${{ needs.determine-jobs.outputs.directly-changed-components-with-tests }}'
-            echo "Target branch: ${{ github.base_ref }} - isolating directly changed components"
-          fi
-
-          echo "Splitting components intelligently..."
-          output=$(python3 script/split_components_for_ci.py --components "$components" --directly-changed "$directly_changed" --batch-size 40 --output github)
-
-          echo "$output" >> $GITHUB_OUTPUT
-
   test-build-components-split:
     name: Test components batch (${{ matrix.components }})
     runs-on: ubuntu-24.04
     needs:
       - common
       - determine-jobs
-      - test-build-components-splitter
     if: github.event_name == 'pull_request' && fromJSON(needs.determine-jobs.outputs.component-test-count) > 0
     strategy:
       fail-fast: false
       max-parallel: ${{ (startsWith(github.base_ref, 'beta') || startsWith(github.base_ref, 'release')) && 8 || 4 }}
       matrix:
-        components: ${{ fromJson(needs.test-build-components-splitter.outputs.matrix) }}
+        components: ${{ fromJson(needs.determine-jobs.outputs.component-test-batches) }}
     steps:
       - name: Show disk space
         run: |
@@ -980,7 +941,6 @@ jobs:
       - clang-tidy-nosplit
       - clang-tidy-split
       - determine-jobs
-      - test-build-components-splitter
       - test-build-components-split
       - pre-commit-ci-lite
       - memory-impact-target-branch

.github/workflows/codeql.yml

@@ -58,7 +58,7 @@ jobs:
 
       # Initializes the CodeQL tools for scanning.
       - name: Initialize CodeQL
-        uses: github/codeql-action/init@4e94bd11f71e507f7f87df81788dff88d1dacbfb # v4.31.0
+        uses: github/codeql-action/init@0499de31b99561a6d14a36a5f662c2a54f91beee # v4.31.2
         with:
           languages: ${{ matrix.language }}
           build-mode: ${{ matrix.build-mode }}
@@ -86,6 +86,6 @@ jobs:
           exit 1
 
       - name: Perform CodeQL Analysis
-        uses: github/codeql-action/analyze@4e94bd11f71e507f7f87df81788dff88d1dacbfb # v4.31.0
+        uses: github/codeql-action/analyze@0499de31b99561a6d14a36a5f662c2a54f91beee # v4.31.2
         with:
           category: "/language:${{matrix.language}}"

.pre-commit-config.yaml

@@ -11,7 +11,7 @@ ci:
 repos:
   - repo: https://github.com/astral-sh/ruff-pre-commit
     # Ruff version.
-    rev: v0.14.2
+    rev: v0.14.3
     hooks:
       # Run the linter.
       - id: ruff

esphome/__main__.py

@@ -207,14 +207,14 @@ def choose_upload_log_host(
                     if has_mqtt_logging():
                         resolved.append("MQTT")
 
-                    if has_api() and has_non_ip_address():
+                    if has_api() and has_non_ip_address() and has_resolvable_address():
                         resolved.extend(_resolve_with_cache(CORE.address, purpose))
 
                 elif purpose == Purpose.UPLOADING:
                     if has_ota() and has_mqtt_ip_lookup():
                         resolved.append("MQTTIP")
 
-                    if has_ota() and has_non_ip_address():
+                    if has_ota() and has_non_ip_address() and has_resolvable_address():
                         resolved.extend(_resolve_with_cache(CORE.address, purpose))
             else:
                 resolved.append(device)
@@ -318,7 +318,17 @@ def has_resolvable_address() -> bool:
     """Check if CORE.address is resolvable (via mDNS, DNS, or is an IP address)."""
     # Any address (IP, mDNS hostname, or regular DNS hostname) is resolvable
     # The resolve_ip_address() function in helpers.py handles all types via AsyncResolver
-    return CORE.address is not None
+    if CORE.address is None:
+        return False
+
+    if has_ip_address():
+        return True
+
+    if has_mdns():
+        return True
+
+    # .local mDNS hostnames are only resolvable if mDNS is enabled
+    return not CORE.address.endswith(".local")
 
 
 def mqtt_get_ip(config: ConfigType, username: str, password: str, client_id: str):

esphome/automation.py

@@ -182,7 +182,7 @@ def validate_automation(extra_schema=None, extra_validators=None, single=False):
             value = cv.Schema([extra_validators])(value)
         if single:
             if len(value) != 1:
-                raise cv.Invalid("Cannot have more than 1 automation for templates")
+                raise cv.Invalid("This trigger allows only a single automation")
             return value[0]
         return value
 

esphome/components/e131/e131.cpp

@@ -3,6 +3,8 @@
 #include "e131_addressable_light_effect.h"
 #include "esphome/core/log.h"
 
+#include <algorithm>
+
 namespace esphome {
 namespace e131 {
 
@@ -76,14 +78,14 @@ void E131Component::loop() {
 }
 
 void E131Component::add_effect(E131AddressableLightEffect *light_effect) {
-  if (light_effects_.count(light_effect)) {
+  if (std::find(light_effects_.begin(), light_effects_.end(), light_effect) != light_effects_.end()) {
     return;
   }
 
   ESP_LOGD(TAG, "Registering '%s' for universes %d-%d.", light_effect->get_name(), light_effect->get_first_universe(),
            light_effect->get_last_universe());
 
-  light_effects_.insert(light_effect);
+  light_effects_.push_back(light_effect);
 
   for (auto universe = light_effect->get_first_universe(); universe <= light_effect->get_last_universe(); ++universe) {
     join_(universe);
@@ -91,14 +93,17 @@ void E131Component::add_effect(E131AddressableLightEffect *light_effect) {
 }
 
 void E131Component::remove_effect(E131AddressableLightEffect *light_effect) {
-  if (!light_effects_.count(light_effect)) {
+  auto it = std::find(light_effects_.begin(), light_effects_.end(), light_effect);
+  if (it == light_effects_.end()) {
     return;
   }
 
   ESP_LOGD(TAG, "Unregistering '%s' for universes %d-%d.", light_effect->get_name(), light_effect->get_first_universe(),
            light_effect->get_last_universe());
 
-  light_effects_.erase(light_effect);
+  // Swap with last element and pop for O(1) removal (order doesn't matter)
+  *it = light_effects_.back();
+  light_effects_.pop_back();
 
   for (auto universe = light_effect->get_first_universe(); universe <= light_effect->get_last_universe(); ++universe) {
     leave_(universe);

esphome/components/e131/e131.h

@@ -7,7 +7,6 @@
 #include <cinttypes>
 #include <map>
 #include <memory>
-#include <set>
 #include <vector>
 
 namespace esphome {
@@ -47,9 +46,8 @@ class E131Component : public esphome::Component {
 
   E131ListenMethod listen_method_{E131_MULTICAST};
   std::unique_ptr<socket::Socket> socket_;
-  std::set<E131AddressableLightEffect *> light_effects_;
+  std::vector<E131AddressableLightEffect *> light_effects_;
   std::map<int, int> universe_consumers_;
-  std::map<int, E131Packet> universe_packets_;
 };
 
 }  // namespace e131

esphome/components/gpio/binary_sensor/__init__.py

@@ -94,6 +94,8 @@ async def to_code(config):
         )
         use_interrupt = False
 
-    cg.add(var.set_use_interrupt(use_interrupt))
     if use_interrupt:
         cg.add(var.set_interrupt_type(config[CONF_INTERRUPT_TYPE]))
+    else:
+        # Only generate call when disabling interrupts (default is true)
+        cg.add(var.set_use_interrupt(use_interrupt))

esphome/components/image/__init__.py

@@ -671,18 +671,33 @@ async def write_image(config, all_frames=False):
     resize = config.get(CONF_RESIZE)
     if is_svg_file(path):
         # Local import so use of non-SVG files needn't require cairosvg installed
+        from pyexpat import ExpatError
+        from xml.etree.ElementTree import ParseError
+
         from cairosvg import svg2png
+        from cairosvg.helpers import PointError
 
         if not resize:
             resize = (None, None)
-        with open(path, "rb") as file:
-            image = svg2png(
-                file_obj=file,
-                output_width=resize[0],
-                output_height=resize[1],
-            )
-        image = Image.open(io.BytesIO(image))
-        width, height = image.size
+        try:
+            with open(path, "rb") as file:
+                image = svg2png(
+                    file_obj=file,
+                    output_width=resize[0],
+                    output_height=resize[1],
+                )
+            image = Image.open(io.BytesIO(image))
+            width, height = image.size
+        except (
+            ValueError,
+            ParseError,
+            IndexError,
+            ExpatError,
+            AttributeError,
+            TypeError,
+            PointError,
+        ) as e:
+            raise core.EsphomeError(f"Could not load SVG image {path}: {e}") from e
     else:
         image = Image.open(path)
         width, height = image.size

esphome/components/image/image.cpp

@@ -125,7 +125,7 @@ lv_img_dsc_t *Image::get_lv_img_dsc() {
 
       case IMAGE_TYPE_RGB:
 #if LV_COLOR_DEPTH == 32
-        switch (this->transparent_) {
+        switch (this->transparency_) {
           case TRANSPARENCY_ALPHA_CHANNEL:
             this->dsc_.header.cf = LV_IMG_CF_TRUE_COLOR_ALPHA;
             break;
@@ -156,7 +156,8 @@ lv_img_dsc_t *Image::get_lv_img_dsc() {
             break;
         }
 #else
-        this->dsc_.header.cf = this->transparent_ == TRANSPARENCY_ALPHA_CHANNEL ? LV_IMG_CF_RGB565A8 : LV_IMG_CF_RGB565;
+        this->dsc_.header.cf =
+            this->transparency_ == TRANSPARENCY_ALPHA_CHANNEL ? LV_IMG_CF_RGB565A8 : LV_IMG_CF_RGB565;
 #endif
         break;
     }

esphome/components/lvgl/widgets/canvas.py

@@ -33,7 +33,7 @@ from ..lv_validation import (
     pixels,
     size,
 )
-from ..lvcode import LocalVariable, lv, lv_assign
+from ..lvcode import LocalVariable, lv, lv_assign, lv_expr
 from ..schemas import STYLE_PROPS, STYLE_REMAP, TEXT_SCHEMA, point_schema
 from ..types import LvType, ObjUpdateAction, WidgetType
 from . import Widget, get_widgets
@@ -70,15 +70,18 @@ class CanvasType(WidgetType):
         width = config[CONF_WIDTH]
         height = config[CONF_HEIGHT]
         use_alpha = "_ALPHA" if config[CONF_TRANSPARENT] else ""
-        lv.canvas_set_buffer(
-            w.obj,
-            lv.custom_mem_alloc(
-                literal(f"LV_CANVAS_BUF_SIZE_TRUE_COLOR{use_alpha}({width}, {height})")
-            ),
-            width,
-            height,
-            literal(f"LV_IMG_CF_TRUE_COLOR{use_alpha}"),
+        buf_size = literal(
+            f"LV_CANVAS_BUF_SIZE_TRUE_COLOR{use_alpha}({width}, {height})"
         )
+        with LocalVariable("buf", cg.void, lv_expr.custom_mem_alloc(buf_size)) as buf:
+            cg.add(cg.RawExpression(f"memset({buf}, 0, {buf_size});"))
+            lv.canvas_set_buffer(
+                w.obj,
+                buf,
+                width,
+                height,
+                literal(f"LV_IMG_CF_TRUE_COLOR{use_alpha}"),
+            )
 
 
 canvas_spec = CanvasType()

esphome/components/substitutions/jinja.py

@@ -138,6 +138,7 @@ def _concat_nodes_override(values: Iterator[Any]) -> Any:
             values = chain(head, values)
         raw = "".join([str(v) for v in values])
 
+    result = None
     try:
         # Attempt to parse the concatenated string into a Python literal.
         # This allows expressions like "1 + 2" to be evaluated to the integer 3.
@@ -145,11 +146,16 @@ def _concat_nodes_override(values: Iterator[Any]) -> Any:
         # fall back to returning the raw string. This is consistent with
         #  Home Assistant's behavior when evaluating templates
         result = literal_eval(raw)
+    except (ValueError, SyntaxError, MemoryError, TypeError):
+        pass
+    else:
+        if isinstance(result, set):
+            # Sets are not supported, return raw string
+            return raw
+
         if not isinstance(result, str):
             return result
 
-    except (ValueError, SyntaxError, MemoryError, TypeError):
-        pass
     return raw
 
 

esphome/components/template/binary_sensor/template_binary_sensor.cpp

@@ -6,17 +6,21 @@ namespace template_ {
 
 static const char *const TAG = "template.binary_sensor";
 
-void TemplateBinarySensor::setup() { this->loop(); }
+void TemplateBinarySensor::setup() {
+  if (!this->f_.has_value()) {
+    this->disable_loop();
+  } else {
+    this->loop();
+  }
+}
 
 void TemplateBinarySensor::loop() {
-  if (!this->f_.has_value())
-    return;
-
-  auto s = (*this->f_)();
+  auto s = this->f_();
   if (s.has_value()) {
     this->publish_state(*s);
   }
 }
+
 void TemplateBinarySensor::dump_config() { LOG_BINARY_SENSOR("", "Template Binary Sensor", this); }
 
 }  // namespace template_

esphome/components/template/binary_sensor/template_binary_sensor.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "esphome/core/component.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/binary_sensor/binary_sensor.h"
 
 namespace esphome {
@@ -8,7 +9,7 @@ namespace template_ {
 
 class TemplateBinarySensor : public Component, public binary_sensor::BinarySensor {
  public:
-  void set_template(optional<bool> (*f)()) { this->f_ = f; }
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void setup() override;
   void loop() override;
@@ -17,7 +18,7 @@ class TemplateBinarySensor : public Component, public binary_sensor::BinarySenso
   float get_setup_priority() const override { return setup_priority::HARDWARE; }
 
  protected:
-  optional<optional<bool> (*)()> f_;
+  TemplateLambda<bool> f_;
 };
 
 }  // namespace template_

esphome/components/template/cover/template_cover.cpp

@@ -33,28 +33,27 @@ void TemplateCover::setup() {
       break;
     }
   }
+  if (!this->state_f_.has_value() && !this->tilt_f_.has_value())
+    this->disable_loop();
 }
 void TemplateCover::loop() {
   bool changed = false;
 
-  if (this->state_f_.has_value()) {
-    auto s = (*this->state_f_)();
-    if (s.has_value()) {
-      auto pos = clamp(*s, 0.0f, 1.0f);
-      if (pos != this->position) {
-        this->position = pos;
-        changed = true;
-      }
+  auto s = this->state_f_();
+  if (s.has_value()) {
+    auto pos = clamp(*s, 0.0f, 1.0f);
+    if (pos != this->position) {
+      this->position = pos;
+      changed = true;
     }
   }
-  if (this->tilt_f_.has_value()) {
-    auto s = (*this->tilt_f_)();
-    if (s.has_value()) {
-      auto tilt = clamp(*s, 0.0f, 1.0f);
-      if (tilt != this->tilt) {
-        this->tilt = tilt;
-        changed = true;
-      }
+
+  auto tilt = this->tilt_f_();
+  if (tilt.has_value()) {
+    auto tilt_val = clamp(*tilt, 0.0f, 1.0f);
+    if (tilt_val != this->tilt) {
+      this->tilt = tilt_val;
+      changed = true;
     }
   }
 
@@ -63,7 +62,6 @@ void TemplateCover::loop() {
 }
 void TemplateCover::set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
 void TemplateCover::set_assumed_state(bool assumed_state) { this->assumed_state_ = assumed_state; }
-void TemplateCover::set_state_lambda(optional<float> (*f)()) { this->state_f_ = f; }
 float TemplateCover::get_setup_priority() const { return setup_priority::HARDWARE; }
 Trigger<> *TemplateCover::get_open_trigger() const { return this->open_trigger_; }
 Trigger<> *TemplateCover::get_close_trigger() const { return this->close_trigger_; }
@@ -124,7 +122,6 @@ CoverTraits TemplateCover::get_traits() {
 }
 Trigger<float> *TemplateCover::get_position_trigger() const { return this->position_trigger_; }
 Trigger<float> *TemplateCover::get_tilt_trigger() const { return this->tilt_trigger_; }
-void TemplateCover::set_tilt_lambda(optional<float> (*tilt_f)()) { this->tilt_f_ = tilt_f; }
 void TemplateCover::set_has_stop(bool has_stop) { this->has_stop_ = has_stop; }
 void TemplateCover::set_has_toggle(bool has_toggle) { this->has_toggle_ = has_toggle; }
 void TemplateCover::set_has_position(bool has_position) { this->has_position_ = has_position; }

esphome/components/template/cover/template_cover.h

@@ -2,6 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/cover/cover.h"
 
 namespace esphome {
@@ -17,7 +18,8 @@ class TemplateCover : public cover::Cover, public Component {
  public:
   TemplateCover();
 
-  void set_state_lambda(optional<float> (*f)());
+  template<typename F> void set_state_lambda(F &&f) { this->state_f_.set(std::forward<F>(f)); }
+  template<typename F> void set_tilt_lambda(F &&f) { this->tilt_f_.set(std::forward<F>(f)); }
   Trigger<> *get_open_trigger() const;
   Trigger<> *get_close_trigger() const;
   Trigger<> *get_stop_trigger() const;
@@ -26,7 +28,6 @@ class TemplateCover : public cover::Cover, public Component {
   Trigger<float> *get_tilt_trigger() const;
   void set_optimistic(bool optimistic);
   void set_assumed_state(bool assumed_state);
-  void set_tilt_lambda(optional<float> (*tilt_f)());
   void set_has_stop(bool has_stop);
   void set_has_position(bool has_position);
   void set_has_tilt(bool has_tilt);
@@ -45,8 +46,8 @@ class TemplateCover : public cover::Cover, public Component {
   void stop_prev_trigger_();
 
   TemplateCoverRestoreMode restore_mode_{COVER_RESTORE};
-  optional<optional<float> (*)()> state_f_;
-  optional<optional<float> (*)()> tilt_f_;
+  TemplateLambda<float> state_f_;
+  TemplateLambda<float> tilt_f_;
   bool assumed_state_{false};
   bool optimistic_{false};
   Trigger<> *open_trigger_;

esphome/components/template/datetime/template_date.cpp

@@ -40,14 +40,13 @@ void TemplateDate::update() {
   if (!this->f_.has_value())
     return;
 
-  auto val = (*this->f_)();
-  if (!val.has_value())
-    return;
-
-  this->year_ = val->year;
-  this->month_ = val->month;
-  this->day_ = val->day_of_month;
-  this->publish_state();
+  auto val = this->f_();
+  if (val.has_value()) {
+    this->year_ = val->year;
+    this->month_ = val->month;
+    this->day_ = val->day_of_month;
+    this->publish_state();
+  }
 }
 
 void TemplateDate::control(const datetime::DateCall &call) {

esphome/components/template/datetime/template_date.h

@@ -9,13 +9,14 @@
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
 #include "esphome/core/time.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
 
 class TemplateDate : public datetime::DateEntity, public PollingComponent {
  public:
-  void set_template(optional<ESPTime> (*f)()) { this->f_ = f; }
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void setup() override;
   void update() override;
@@ -35,7 +36,7 @@ class TemplateDate : public datetime::DateEntity, public PollingComponent {
   ESPTime initial_value_{};
   bool restore_value_{false};
   Trigger<ESPTime> *set_trigger_ = new Trigger<ESPTime>();
-  optional<optional<ESPTime> (*)()> f_;
+  TemplateLambda<ESPTime> f_;
 
   ESPPreferenceObject pref_;
 };

esphome/components/template/datetime/template_datetime.cpp

@@ -43,17 +43,16 @@ void TemplateDateTime::update() {
   if (!this->f_.has_value())
     return;
 
-  auto val = (*this->f_)();
-  if (!val.has_value())
-    return;
-
-  this->year_ = val->year;
-  this->month_ = val->month;
-  this->day_ = val->day_of_month;
-  this->hour_ = val->hour;
-  this->minute_ = val->minute;
-  this->second_ = val->second;
-  this->publish_state();
+  auto val = this->f_();
+  if (val.has_value()) {
+    this->year_ = val->year;
+    this->month_ = val->month;
+    this->day_ = val->day_of_month;
+    this->hour_ = val->hour;
+    this->minute_ = val->minute;
+    this->second_ = val->second;
+    this->publish_state();
+  }
 }
 
 void TemplateDateTime::control(const datetime::DateTimeCall &call) {

esphome/components/template/datetime/template_datetime.h

@@ -9,13 +9,14 @@
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
 #include "esphome/core/time.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
 
 class TemplateDateTime : public datetime::DateTimeEntity, public PollingComponent {
  public:
-  void set_template(optional<ESPTime> (*f)()) { this->f_ = f; }
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void setup() override;
   void update() override;
@@ -35,7 +36,7 @@ class TemplateDateTime : public datetime::DateTimeEntity, public PollingComponen
   ESPTime initial_value_{};
   bool restore_value_{false};
   Trigger<ESPTime> *set_trigger_ = new Trigger<ESPTime>();
-  optional<optional<ESPTime> (*)()> f_;
+  TemplateLambda<ESPTime> f_;
 
   ESPPreferenceObject pref_;
 };

esphome/components/template/datetime/template_time.cpp

@@ -40,14 +40,13 @@ void TemplateTime::update() {
   if (!this->f_.has_value())
     return;
 
-  auto val = (*this->f_)();
-  if (!val.has_value())
-    return;
-
-  this->hour_ = val->hour;
-  this->minute_ = val->minute;
-  this->second_ = val->second;
-  this->publish_state();
+  auto val = this->f_();
+  if (val.has_value()) {
+    this->hour_ = val->hour;
+    this->minute_ = val->minute;
+    this->second_ = val->second;
+    this->publish_state();
+  }
 }
 
 void TemplateTime::control(const datetime::TimeCall &call) {

esphome/components/template/datetime/template_time.h

@@ -9,13 +9,14 @@
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
 #include "esphome/core/time.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
 
 class TemplateTime : public datetime::TimeEntity, public PollingComponent {
  public:
-  void set_template(optional<ESPTime> (*f)()) { this->f_ = f; }
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void setup() override;
   void update() override;
@@ -35,7 +36,7 @@ class TemplateTime : public datetime::TimeEntity, public PollingComponent {
   ESPTime initial_value_{};
   bool restore_value_{false};
   Trigger<ESPTime> *set_trigger_ = new Trigger<ESPTime>();
-  optional<optional<ESPTime> (*)()> f_;
+  TemplateLambda<ESPTime> f_;
 
   ESPPreferenceObject pref_;
 };

esphome/components/template/lock/template_lock.cpp

@@ -11,14 +11,16 @@ static const char *const TAG = "template.lock";
 TemplateLock::TemplateLock()
     : lock_trigger_(new Trigger<>()), unlock_trigger_(new Trigger<>()), open_trigger_(new Trigger<>()) {}
 
-void TemplateLock::loop() {
+void TemplateLock::setup() {
   if (!this->f_.has_value())
-    return;
-  auto val = (*this->f_)();
-  if (!val.has_value())
-    return;
+    this->disable_loop();
+}
 
-  this->publish_state(*val);
+void TemplateLock::loop() {
+  auto val = this->f_();
+  if (val.has_value()) {
+    this->publish_state(*val);
+  }
 }
 void TemplateLock::control(const lock::LockCall &call) {
   if (this->prev_trigger_ != nullptr) {
@@ -45,7 +47,6 @@ void TemplateLock::open_latch() {
   this->open_trigger_->trigger();
 }
 void TemplateLock::set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
-void TemplateLock::set_state_lambda(optional<lock::LockState> (*f)()) { this->f_ = f; }
 float TemplateLock::get_setup_priority() const { return setup_priority::HARDWARE; }
 Trigger<> *TemplateLock::get_lock_trigger() const { return this->lock_trigger_; }
 Trigger<> *TemplateLock::get_unlock_trigger() const { return this->unlock_trigger_; }

esphome/components/template/lock/template_lock.h

@@ -2,6 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/lock/lock.h"
 
 namespace esphome {
@@ -11,9 +12,10 @@ class TemplateLock : public lock::Lock, public Component {
  public:
   TemplateLock();
 
+  void setup() override;
   void dump_config() override;
 
-  void set_state_lambda(optional<lock::LockState> (*f)());
+  template<typename F> void set_state_lambda(F &&f) { this->f_.set(std::forward<F>(f)); }
   Trigger<> *get_lock_trigger() const;
   Trigger<> *get_unlock_trigger() const;
   Trigger<> *get_open_trigger() const;
@@ -26,7 +28,7 @@ class TemplateLock : public lock::Lock, public Component {
   void control(const lock::LockCall &call) override;
   void open_latch() override;
 
-  optional<optional<lock::LockState> (*)()> f_;
+  TemplateLambda<lock::LockState> f_;
   bool optimistic_{false};
   Trigger<> *lock_trigger_;
   Trigger<> *unlock_trigger_;

esphome/components/template/number/template_number.cpp

@@ -30,11 +30,10 @@ void TemplateNumber::update() {
   if (!this->f_.has_value())
     return;
 
-  auto val = (*this->f_)();
-  if (!val.has_value())
-    return;
-
-  this->publish_state(*val);
+  auto val = this->f_();
+  if (val.has_value()) {
+    this->publish_state(*val);
+  }
 }
 
 void TemplateNumber::control(float value) {

esphome/components/template/number/template_number.h

@@ -4,13 +4,14 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
 
 class TemplateNumber : public number::Number, public PollingComponent {
  public:
-  void set_template(optional<float> (*f)()) { this->f_ = f; }
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void setup() override;
   void update() override;
@@ -28,7 +29,7 @@ class TemplateNumber : public number::Number, public PollingComponent {
   float initial_value_{NAN};
   bool restore_value_{false};
   Trigger<float> *set_trigger_ = new Trigger<float>();
-  optional<optional<float> (*)()> f_;
+  TemplateLambda<float> f_;
 
   ESPPreferenceObject pref_;
 };

esphome/components/template/select/template_select.cpp

@@ -31,16 +31,14 @@ void TemplateSelect::update() {
   if (!this->f_.has_value())
     return;
 
-  auto val = (*this->f_)();
-  if (!val.has_value())
-    return;
-
-  if (!this->has_option(*val)) {
-    ESP_LOGE(TAG, "Lambda returned an invalid option: %s", (*val).c_str());
-    return;
+  auto val = this->f_();
+  if (val.has_value()) {
+    if (!this->has_option(*val)) {
+      ESP_LOGE(TAG, "Lambda returned an invalid option: %s", (*val).c_str());
+      return;
+    }
+    this->publish_state(*val);
   }
-
-  this->publish_state(*val);
 }
 
 void TemplateSelect::control(const std::string &value) {

esphome/components/template/select/template_select.h

@@ -4,13 +4,14 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
 
 class TemplateSelect : public select::Select, public PollingComponent {
  public:
-  void set_template(optional<std::string> (*f)()) { this->f_ = f; }
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void setup() override;
   void update() override;
@@ -28,7 +29,7 @@ class TemplateSelect : public select::Select, public PollingComponent {
   size_t initial_option_index_{0};
   bool restore_value_ = false;
   Trigger<std::string> *set_trigger_ = new Trigger<std::string>();
-  optional<optional<std::string> (*)()> f_;
+  TemplateLambda<std::string> f_;
 
   ESPPreferenceObject pref_;
 };

esphome/components/template/sensor/template_sensor.cpp

@@ -11,13 +11,14 @@ void TemplateSensor::update() {
   if (!this->f_.has_value())
     return;
 
-  auto val = (*this->f_)();
+  auto val = this->f_();
   if (val.has_value()) {
     this->publish_state(*val);
   }
 }
+
 float TemplateSensor::get_setup_priority() const { return setup_priority::HARDWARE; }
-void TemplateSensor::set_template(optional<float> (*f)()) { this->f_ = f; }
+
 void TemplateSensor::dump_config() {
   LOG_SENSOR("", "Template Sensor", this);
   LOG_UPDATE_INTERVAL(this);

esphome/components/template/sensor/template_sensor.h

@@ -1,6 +1,7 @@
 #pragma once
 
 #include "esphome/core/component.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/sensor/sensor.h"
 
 namespace esphome {
@@ -8,7 +9,7 @@ namespace template_ {
 
 class TemplateSensor : public sensor::Sensor, public PollingComponent {
  public:
-  void set_template(optional<float> (*f)());
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void update() override;
 
@@ -17,7 +18,7 @@ class TemplateSensor : public sensor::Sensor, public PollingComponent {
   float get_setup_priority() const override;
 
  protected:
-  optional<optional<float> (*)()> f_;
+  TemplateLambda<float> f_;
 };
 
 }  // namespace template_

esphome/components/template/switch/template_switch.cpp

@@ -9,13 +9,10 @@ static const char *const TAG = "template.switch";
 TemplateSwitch::TemplateSwitch() : turn_on_trigger_(new Trigger<>()), turn_off_trigger_(new Trigger<>()) {}
 
 void TemplateSwitch::loop() {
-  if (!this->f_.has_value())
-    return;
-  auto s = (*this->f_)();
-  if (!s.has_value())
-    return;
-
-  this->publish_state(*s);
+  auto s = this->f_();
+  if (s.has_value()) {
+    this->publish_state(*s);
+  }
 }
 void TemplateSwitch::write_state(bool state) {
   if (this->prev_trigger_ != nullptr) {
@@ -35,11 +32,13 @@ void TemplateSwitch::write_state(bool state) {
 }
 void TemplateSwitch::set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
 bool TemplateSwitch::assumed_state() { return this->assumed_state_; }
-void TemplateSwitch::set_state_lambda(optional<bool> (*f)()) { this->f_ = f; }
 float TemplateSwitch::get_setup_priority() const { return setup_priority::HARDWARE - 2.0f; }
 Trigger<> *TemplateSwitch::get_turn_on_trigger() const { return this->turn_on_trigger_; }
 Trigger<> *TemplateSwitch::get_turn_off_trigger() const { return this->turn_off_trigger_; }
 void TemplateSwitch::setup() {
+  if (!this->f_.has_value())
+    this->disable_loop();
+
   optional<bool> initial_state = this->get_initial_state_with_restore_mode();
 
   if (initial_state.has_value()) {

esphome/components/template/switch/template_switch.h

@@ -2,6 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/switch/switch.h"
 
 namespace esphome {
@@ -14,7 +15,7 @@ class TemplateSwitch : public switch_::Switch, public Component {
   void setup() override;
   void dump_config() override;
 
-  void set_state_lambda(optional<bool> (*f)());
+  template<typename F> void set_state_lambda(F &&f) { this->f_.set(std::forward<F>(f)); }
   Trigger<> *get_turn_on_trigger() const;
   Trigger<> *get_turn_off_trigger() const;
   void set_optimistic(bool optimistic);
@@ -28,7 +29,7 @@ class TemplateSwitch : public switch_::Switch, public Component {
 
   void write_state(bool state) override;
 
-  optional<optional<bool> (*)()> f_;
+  TemplateLambda<bool> f_;
   bool optimistic_{false};
   bool assumed_state_{false};
   Trigger<> *turn_on_trigger_;

esphome/components/template/text/template_text.cpp

@@ -7,10 +7,8 @@ namespace template_ {
 static const char *const TAG = "template.text";
 
 void TemplateText::setup() {
-  if (!(this->f_ == nullptr)) {
-    if (this->f_.has_value())
-      return;
-  }
+  if (this->f_.has_value())
+    return;
   std::string value = this->initial_value_;
   if (!this->pref_) {
     ESP_LOGD(TAG, "State from initial: %s", value.c_str());
@@ -26,17 +24,13 @@ void TemplateText::setup() {
 }
 
 void TemplateText::update() {
-  if (this->f_ == nullptr)
-    return;
-
   if (!this->f_.has_value())
     return;
 
-  auto val = (*this->f_)();
-  if (!val.has_value())
-    return;
-
-  this->publish_state(*val);
+  auto val = this->f_();
+  if (val.has_value()) {
+    this->publish_state(*val);
+  }
 }
 
 void TemplateText::control(const std::string &value) {

esphome/components/template/text/template_text.h

@@ -4,6 +4,7 @@
 #include "esphome/core/automation.h"
 #include "esphome/core/component.h"
 #include "esphome/core/preferences.h"
+#include "esphome/core/template_lambda.h"
 
 namespace esphome {
 namespace template_ {
@@ -61,7 +62,7 @@ template<uint8_t SZ> class TextSaver : public TemplateTextSaverBase {
 
 class TemplateText : public text::Text, public PollingComponent {
  public:
-  void set_template(optional<std::string> (*f)()) { this->f_ = f; }
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void setup() override;
   void update() override;
@@ -78,7 +79,7 @@ class TemplateText : public text::Text, public PollingComponent {
   bool optimistic_ = false;
   std::string initial_value_;
   Trigger<std::string> *set_trigger_ = new Trigger<std::string>();
-  optional<optional<std::string> (*)()> f_{nullptr};
+  TemplateLambda<std::string> f_{};
 
   TemplateTextSaverBase *pref_ = nullptr;
 };

esphome/components/template/text_sensor/template_text_sensor.cpp

@@ -10,13 +10,14 @@ void TemplateTextSensor::update() {
   if (!this->f_.has_value())
     return;
 
-  auto val = (*this->f_)();
+  auto val = this->f_();
   if (val.has_value()) {
     this->publish_state(*val);
   }
 }
+
 float TemplateTextSensor::get_setup_priority() const { return setup_priority::HARDWARE; }
-void TemplateTextSensor::set_template(optional<std::string> (*f)()) { this->f_ = f; }
+
 void TemplateTextSensor::dump_config() { LOG_TEXT_SENSOR("", "Template Sensor", this); }
 
 }  // namespace template_

esphome/components/template/text_sensor/template_text_sensor.h

@@ -2,6 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/text_sensor/text_sensor.h"
 
 namespace esphome {
@@ -9,7 +10,7 @@ namespace template_ {
 
 class TemplateTextSensor : public text_sensor::TextSensor, public PollingComponent {
  public:
-  void set_template(optional<std::string> (*f)());
+  template<typename F> void set_template(F &&f) { this->f_.set(std::forward<F>(f)); }
 
   void update() override;
 
@@ -18,7 +19,7 @@ class TemplateTextSensor : public text_sensor::TextSensor, public PollingCompone
   void dump_config() override;
 
  protected:
-  optional<optional<std::string> (*)()> f_{};
+  TemplateLambda<std::string> f_{};
 };
 
 }  // namespace template_

esphome/components/template/valve/template_valve.cpp

@@ -33,19 +33,19 @@ void TemplateValve::setup() {
       break;
     }
   }
+  if (!this->state_f_.has_value())
+    this->disable_loop();
 }
 
 void TemplateValve::loop() {
   bool changed = false;
 
-  if (this->state_f_.has_value()) {
-    auto s = (*this->state_f_)();
-    if (s.has_value()) {
-      auto pos = clamp(*s, 0.0f, 1.0f);
-      if (pos != this->position) {
-        this->position = pos;
-        changed = true;
-      }
+  auto s = this->state_f_();
+  if (s.has_value()) {
+    auto pos = clamp(*s, 0.0f, 1.0f);
+    if (pos != this->position) {
+      this->position = pos;
+      changed = true;
     }
   }
 
@@ -55,7 +55,6 @@ void TemplateValve::loop() {
 
 void TemplateValve::set_optimistic(bool optimistic) { this->optimistic_ = optimistic; }
 void TemplateValve::set_assumed_state(bool assumed_state) { this->assumed_state_ = assumed_state; }
-void TemplateValve::set_state_lambda(optional<float> (*f)()) { this->state_f_ = f; }
 float TemplateValve::get_setup_priority() const { return setup_priority::HARDWARE; }
 
 Trigger<> *TemplateValve::get_open_trigger() const { return this->open_trigger_; }

esphome/components/template/valve/template_valve.h

@@ -2,6 +2,7 @@
 
 #include "esphome/core/component.h"
 #include "esphome/core/automation.h"
+#include "esphome/core/template_lambda.h"
 #include "esphome/components/valve/valve.h"
 
 namespace esphome {
@@ -17,7 +18,7 @@ class TemplateValve : public valve::Valve, public Component {
  public:
   TemplateValve();
 
-  void set_state_lambda(optional<float> (*f)());
+  template<typename F> void set_state_lambda(F &&f) { this->state_f_.set(std::forward<F>(f)); }
   Trigger<> *get_open_trigger() const;
   Trigger<> *get_close_trigger() const;
   Trigger<> *get_stop_trigger() const;
@@ -42,7 +43,7 @@ class TemplateValve : public valve::Valve, public Component {
   void stop_prev_trigger_();
 
   TemplateValveRestoreMode restore_mode_{VALVE_NO_RESTORE};
-  optional<optional<float> (*)()> state_f_;
+  TemplateLambda<float> state_f_;
   bool assumed_state_{false};
   bool optimistic_{false};
   Trigger<> *open_trigger_;

esphome/core/scheduler.cpp

@@ -316,59 +316,37 @@ optional<uint32_t> HOT Scheduler::next_schedule_in(uint32_t now) {
     return 0;
   return next_exec - now_64;
 }
+
+void Scheduler::full_cleanup_removed_items_() {
+  // We hold the lock for the entire cleanup operation because:
+  // 1. We're rebuilding the entire items_ list, so we need exclusive access throughout
+  // 2. Other threads must see either the old state or the new state, not intermediate states
+  // 3. The operation is already expensive (O(n)), so lock overhead is negligible
+  // 4. No operations inside can block or take other locks, so no deadlock risk
+  LockGuard guard{this->lock_};
+
+  std::vector<std::unique_ptr<SchedulerItem>> valid_items;
+
+  // Move all non-removed items to valid_items, recycle removed ones
+  for (auto &item : this->items_) {
+    if (!is_item_removed_(item.get())) {
+      valid_items.push_back(std::move(item));
+    } else {
+      // Recycle removed items
+      this->recycle_item_(std::move(item));
+    }
+  }
+
+  // Replace items_ with the filtered list
+  this->items_ = std::move(valid_items);
+  // Rebuild the heap structure since items are no longer in heap order
+  std::make_heap(this->items_.begin(), this->items_.end(), SchedulerItem::cmp);
+  this->to_remove_ = 0;
+}
+
 void HOT Scheduler::call(uint32_t now) {
 #ifndef ESPHOME_THREAD_SINGLE
-  // Process defer queue first to guarantee FIFO execution order for deferred items.
-  // Previously, defer() used the heap which gave undefined order for equal timestamps,
-  // causing race conditions on multi-core systems (ESP32, BK7200).
-  // With the defer queue:
-  // - Deferred items (delay=0) go directly to defer_queue_ in set_timer_common_
-  // - Items execute in exact order they were deferred (FIFO guarantee)
-  // - No deferred items exist in to_add_, so processing order doesn't affect correctness
-  // Single-core platforms don't use this queue and fall back to the heap-based approach.
-  //
-  // Note: Items cancelled via cancel_item_locked_() are marked with remove=true but still
-  // processed here. They are skipped during execution by should_skip_item_().
-  // This is intentional - no memory leak occurs.
-  //
-  // We use an index (defer_queue_front_) to track the read position instead of calling
-  // erase() on every pop, which would be O(n). The queue is processed once per loop -
-  // any items added during processing are left for the next loop iteration.
-
-  // Snapshot the queue end point - only process items that existed at loop start
-  // Items added during processing (by callbacks or other threads) run next loop
-  // No lock needed: single consumer (main loop), stale read just means we process less this iteration
-  size_t defer_queue_end = this->defer_queue_.size();
-
-  while (this->defer_queue_front_ < defer_queue_end) {
-    std::unique_ptr<SchedulerItem> item;
-    {
-      LockGuard lock(this->lock_);
-      // SAFETY: Moving out the unique_ptr leaves a nullptr in the vector at defer_queue_front_.
-      // This is intentional and safe because:
-      // 1. The vector is only cleaned up by cleanup_defer_queue_locked_() at the end of this function
-      // 2. Any code iterating defer_queue_ MUST check for nullptr items (see mark_matching_items_removed_
-      //    and has_cancelled_timeout_in_container_ in scheduler.h)
-      // 3. The lock protects concurrent access, but the nullptr remains until cleanup
-      item = std::move(this->defer_queue_[this->defer_queue_front_]);
-      this->defer_queue_front_++;
-    }
-
-    // Execute callback without holding lock to prevent deadlocks
-    // if the callback tries to call defer() again
-    if (!this->should_skip_item_(item.get())) {
-      now = this->execute_item_(item.get(), now);
-    }
-    // Recycle the defer item after execution
-    this->recycle_item_(std::move(item));
-  }
-
-  // If we've consumed all items up to the snapshot point, clean up the dead space
-  // Single consumer (main loop), so no lock needed for this check
-  if (this->defer_queue_front_ >= defer_queue_end) {
-    LockGuard lock(this->lock_);
-    this->cleanup_defer_queue_locked_();
-  }
+  this->process_defer_queue_(now);
 #endif /* not ESPHOME_THREAD_SINGLE */
 
   // Convert the fresh timestamp from main loop to 64-bit for scheduler operations
@@ -429,30 +407,7 @@ void HOT Scheduler::call(uint32_t now) {
   // If we still have too many cancelled items, do a full cleanup
   // This only happens if cancelled items are stuck in the middle/bottom of the heap
   if (this->to_remove_ >= MAX_LOGICALLY_DELETED_ITEMS) {
-    // We hold the lock for the entire cleanup operation because:
-    // 1. We're rebuilding the entire items_ list, so we need exclusive access throughout
-    // 2. Other threads must see either the old state or the new state, not intermediate states
-    // 3. The operation is already expensive (O(n)), so lock overhead is negligible
-    // 4. No operations inside can block or take other locks, so no deadlock risk
-    LockGuard guard{this->lock_};
-
-    std::vector<std::unique_ptr<SchedulerItem>> valid_items;
-
-    // Move all non-removed items to valid_items, recycle removed ones
-    for (auto &item : this->items_) {
-      if (!is_item_removed_(item.get())) {
-        valid_items.push_back(std::move(item));
-      } else {
-        // Recycle removed items
-        this->recycle_item_(std::move(item));
-      }
-    }
-
-    // Replace items_ with the filtered list
-    this->items_ = std::move(valid_items);
-    // Rebuild the heap structure since items are no longer in heap order
-    std::make_heap(this->items_.begin(), this->items_.end(), SchedulerItem::cmp);
-    this->to_remove_ = 0;
+    this->full_cleanup_removed_items_();
   }
   while (!this->items_.empty()) {
     // Don't copy-by value yet

esphome/core/scheduler.h

@@ -263,7 +263,65 @@ class Scheduler {
   // Helper to recycle a SchedulerItem
   void recycle_item_(std::unique_ptr<SchedulerItem> item);
 
+  // Helper to perform full cleanup when too many items are cancelled
+  void full_cleanup_removed_items_();
+
 #ifndef ESPHOME_THREAD_SINGLE
+  // Helper to process defer queue - inline for performance in hot path
+  inline void process_defer_queue_(uint32_t &now) {
+    // Process defer queue first to guarantee FIFO execution order for deferred items.
+    // Previously, defer() used the heap which gave undefined order for equal timestamps,
+    // causing race conditions on multi-core systems (ESP32, BK7200).
+    // With the defer queue:
+    // - Deferred items (delay=0) go directly to defer_queue_ in set_timer_common_
+    // - Items execute in exact order they were deferred (FIFO guarantee)
+    // - No deferred items exist in to_add_, so processing order doesn't affect correctness
+    // Single-core platforms don't use this queue and fall back to the heap-based approach.
+    //
+    // Note: Items cancelled via cancel_item_locked_() are marked with remove=true but still
+    // processed here. They are skipped during execution by should_skip_item_().
+    // This is intentional - no memory leak occurs.
+    //
+    // We use an index (defer_queue_front_) to track the read position instead of calling
+    // erase() on every pop, which would be O(n). The queue is processed once per loop -
+    // any items added during processing are left for the next loop iteration.
+
+    // Snapshot the queue end point - only process items that existed at loop start
+    // Items added during processing (by callbacks or other threads) run next loop
+    // No lock needed: single consumer (main loop), stale read just means we process less this iteration
+    size_t defer_queue_end = this->defer_queue_.size();
+
+    while (this->defer_queue_front_ < defer_queue_end) {
+      std::unique_ptr<SchedulerItem> item;
+      {
+        LockGuard lock(this->lock_);
+        // SAFETY: Moving out the unique_ptr leaves a nullptr in the vector at defer_queue_front_.
+        // This is intentional and safe because:
+        // 1. The vector is only cleaned up by cleanup_defer_queue_locked_() at the end of this function
+        // 2. Any code iterating defer_queue_ MUST check for nullptr items (see mark_matching_items_removed_
+        //    and has_cancelled_timeout_in_container_ in scheduler.h)
+        // 3. The lock protects concurrent access, but the nullptr remains until cleanup
+        item = std::move(this->defer_queue_[this->defer_queue_front_]);
+        this->defer_queue_front_++;
+      }
+
+      // Execute callback without holding lock to prevent deadlocks
+      // if the callback tries to call defer() again
+      if (!this->should_skip_item_(item.get())) {
+        now = this->execute_item_(item.get(), now);
+      }
+      // Recycle the defer item after execution
+      this->recycle_item_(std::move(item));
+    }
+
+    // If we've consumed all items up to the snapshot point, clean up the dead space
+    // Single consumer (main loop), so no lock needed for this check
+    if (this->defer_queue_front_ >= defer_queue_end) {
+      LockGuard lock(this->lock_);
+      this->cleanup_defer_queue_locked_();
+    }
+  }
+
   // Helper to cleanup defer_queue_ after processing
   // IMPORTANT: Caller must hold the scheduler lock before calling this function.
   inline void cleanup_defer_queue_locked_() {

esphome/core/template_lambda.h

@@ -0,0 +1,51 @@
+#pragma once
+
+#include "esphome/core/optional.h"
+
+namespace esphome {
+
+/** Lightweight wrapper for template platform lambdas (stateless function pointers only).
+ *
+ * This optimizes template platforms by storing only a function pointer (4 bytes on ESP32)
+ * instead of std::function (16-32 bytes).
+ *
+ * IMPORTANT: This only supports stateless lambdas (no captures). The set_template() method
+ * is an internal API used by YAML codegen, not intended for external use.
+ *
+ * Lambdas must return optional<T> to support the pattern:
+ *   return {};    // Don't publish a value
+ *   return 42.0;  // Publish this value
+ *
+ * operator() returns optional<T>, returning nullopt when no lambda is set (nullptr check).
+ *
+ * @tparam T The return type (e.g., float for sensor values)
+ * @tparam Args Optional arguments for the lambda
+ */
+template<typename T, typename... Args> class TemplateLambda {
+ public:
+  TemplateLambda() : f_(nullptr) {}
+
+  /** Set the lambda function pointer.
+   * INTERNAL API: Only for use by YAML codegen.
+   * Only stateless lambdas (no captures) are supported.
+   */
+  void set(optional<T> (*f)(Args...)) { this->f_ = f; }
+
+  /** Check if a lambda is set */
+  bool has_value() const { return this->f_ != nullptr; }
+
+  /** Call the lambda, returning nullopt if no lambda is set */
+  optional<T> operator()(Args &&...args) {
+    if (this->f_ == nullptr)
+      return nullopt;
+    return this->f_(std::forward<Args>(args)...);
+  }
+
+  /** Alias for operator() for compatibility */
+  optional<T> call(Args &&...args) { return (*this)(std::forward<Args>(args)...); }
+
+ protected:
+  optional<T> (*f_)(Args...);  // Function pointer (4 bytes on ESP32)
+};
+
+}  // namespace esphome

requirements_test.txt

@@ -1,6 +1,6 @@
 pylint==4.0.2
 flake8==7.3.0  # also change in .pre-commit-config.yaml when updating
-ruff==0.14.2  # also change in .pre-commit-config.yaml when updating
+ruff==0.14.3  # also change in .pre-commit-config.yaml when updating
 pyupgrade==3.21.0  # also change in .pre-commit-config.yaml when updating
 pre-commit
 

script/determine-jobs.py

@@ -43,12 +43,14 @@ from enum import StrEnum
 from functools import cache
 import json
 import os
+from pathlib import Path
 import subprocess
 import sys
 from typing import Any
 
 from helpers import (
     CPP_FILE_EXTENSIONS,
+    ESPHOME_TESTS_COMPONENTS_PATH,
     PYTHON_FILE_EXTENSIONS,
     changed_files,
     core_changed,
@@ -65,12 +67,17 @@ from helpers import (
     parse_test_filename,
     root_path,
 )
+from split_components_for_ci import create_intelligent_batches
 
 # Threshold for splitting clang-tidy jobs
 # For small PRs (< 65 files), use nosplit for faster CI
 # For large PRs (>= 65 files), use split for better parallelization
 CLANG_TIDY_SPLIT_THRESHOLD = 65
 
+# Component test batch size (weighted)
+# Isolated components count as 10x, groupable components count as 1x
+COMPONENT_TEST_BATCH_SIZE = 40
+
 
 class Platform(StrEnum):
     """Platform identifiers for memory impact analysis."""
@@ -686,6 +693,22 @@ def main() -> None:
     # Determine which C++ unit tests to run
     cpp_run_all, cpp_components = determine_cpp_unit_tests(args.branch)
 
+    # Split components into batches for CI testing
+    # This intelligently groups components with similar bus configurations
+    component_test_batches: list[str]
+    if changed_components_with_tests:
+        tests_dir = Path(root_path) / ESPHOME_TESTS_COMPONENTS_PATH
+        batches, _ = create_intelligent_batches(
+            components=changed_components_with_tests,
+            tests_dir=tests_dir,
+            batch_size=COMPONENT_TEST_BATCH_SIZE,
+            directly_changed=directly_changed_with_tests,
+        )
+        # Convert batches to space-separated strings for CI matrix
+        component_test_batches = [" ".join(batch) for batch in batches]
+    else:
+        component_test_batches = []
+
     output: dict[str, Any] = {
         "integration_tests": run_integration,
         "clang_tidy": run_clang_tidy,
@@ -703,6 +726,7 @@ def main() -> None:
         "memory_impact": memory_impact,
         "cpp_unit_tests_run_all": cpp_run_all,
         "cpp_unit_tests_components": cpp_components,
+        "component_test_batches": component_test_batches,
     }
 
     # Output as JSON

script/split_components_for_ci.py

@@ -62,6 +62,10 @@ def create_intelligent_batches(
 ) -> tuple[list[list[str]], dict[tuple[str, str], list[str]]]:
     """Create batches optimized for component grouping.
 
+    IMPORTANT: This function is called from both split_components_for_ci.py (standalone script)
+    and determine-jobs.py (integrated into job determination). Be careful when refactoring
+    to ensure changes work in both contexts.
+
     Args:
         components: List of component names to batch
         tests_dir: Path to tests/components directory

tests/component_tests/gpio/test_gpio_binary_sensor.py

@@ -18,7 +18,8 @@ def test_gpio_binary_sensor_basic_setup(
 
     assert "new gpio::GPIOBinarySensor();" in main_cpp
     assert "App.register_binary_sensor" in main_cpp
-    assert "bs_gpio->set_use_interrupt(true);" in main_cpp
+    # set_use_interrupt(true) should NOT be generated (uses C++ default)
+    assert "bs_gpio->set_use_interrupt(true);" not in main_cpp
     assert "bs_gpio->set_interrupt_type(gpio::INTERRUPT_ANY_EDGE);" in main_cpp
 
 
@@ -51,8 +52,8 @@ def test_gpio_binary_sensor_esp8266_other_pins_use_interrupt(
         "tests/component_tests/gpio/test_gpio_binary_sensor_esp8266.yaml"
     )
 
-    # GPIO5 should still use interrupts
-    assert "bs_gpio5->set_use_interrupt(true);" in main_cpp
+    # GPIO5 should still use interrupts (default, so no setter call)
+    assert "bs_gpio5->set_use_interrupt(true);" not in main_cpp
     assert "bs_gpio5->set_interrupt_type(gpio::INTERRUPT_ANY_EDGE);" in main_cpp
 
 

tests/components/template/common-base.yaml

@@ -9,6 +9,13 @@ esphome:
         id: template_sens
         state: !lambda "return 42.0;"
 
+    # Test C++ API: set_template() with stateless lambda (no captures)
+    # NOTE: set_template() is not intended to be a public API, but we test it to ensure it doesn't break.
+    - lambda: |-
+        id(template_sens).set_template([]() -> esphome::optional<float> {
+          return 123.0f;
+        });
+
     - datetime.date.set:
         id: test_date
         date:
@@ -215,6 +222,7 @@ cover:
 
 number:
   - platform: template
+    id: template_number
     name: "Template number"
     optimistic: true
     min_value: 0

tests/integration/fixtures/runtime_stats.yaml

@@ -32,6 +32,7 @@ switch:
     name: "Test Switch"
     id: test_switch
     optimistic: true
+    lambda: return false;
 
 interval:
   - interval: 0.5s

tests/script/test_determine_jobs.py

@@ -152,6 +152,14 @@ def test_main_all_tests_should_run(
     assert output["memory_impact"]["should_run"] == "false"
     assert output["cpp_unit_tests_run_all"] is False
     assert output["cpp_unit_tests_components"] == ["wifi", "api", "sensor"]
+    # component_test_batches should be present and be a list of space-separated strings
+    assert "component_test_batches" in output
+    assert isinstance(output["component_test_batches"], list)
+    # Each batch should be a space-separated string of component names
+    for batch in output["component_test_batches"]:
+        assert isinstance(batch, str)
+        # Should contain at least one component (no empty batches)
+        assert len(batch) > 0
 
 
 def test_main_no_tests_should_run(
@@ -209,6 +217,9 @@ def test_main_no_tests_should_run(
     assert output["memory_impact"]["should_run"] == "false"
     assert output["cpp_unit_tests_run_all"] is False
     assert output["cpp_unit_tests_components"] == []
+    # component_test_batches should be empty list
+    assert "component_test_batches" in output
+    assert output["component_test_batches"] == []
 
 
 def test_main_with_branch_argument(

tests/unit_tests/fixtures/substitutions/00-simple_var.approved.yaml

@@ -33,3 +33,4 @@ test_list:
     {{{ "x", "79"}, { "y", "82"}}}
   - '{{{"AA"}}}'
   - '"HELLO"'
+  - '{ 79, 82 }'

tests/unit_tests/fixtures/substitutions/00-simple_var.input.yaml

@@ -34,3 +34,4 @@ test_list:
     {{{ "x", "${ position.x }"}, { "y", "${ position.y }"}}}
   - ${ '{{{"AA"}}}' }
   - ${ '"HELLO"' }
+  - '{ ${position.x}, ${position.y} }'

tests/unit_tests/test_main.py

@@ -744,7 +744,7 @@ def test_choose_upload_log_host_ota_local_all_options() -> None:
         check_default=None,
         purpose=Purpose.UPLOADING,
     )
-    assert result == ["MQTTIP", "test.local"]
+    assert result == ["MQTTIP"]
 
 
 @pytest.mark.usefixtures("mock_serial_ports")
@@ -794,7 +794,7 @@ def test_choose_upload_log_host_ota_local_all_options_logging() -> None:
         check_default=None,
         purpose=Purpose.LOGGING,
     )
-    assert result == ["MQTTIP", "MQTT", "test.local"]
+    assert result == ["MQTTIP", "MQTT"]
 
 
 @pytest.mark.usefixtures("mock_no_mqtt_logging")
@@ -1564,7 +1564,7 @@ def test_has_resolvable_address() -> None:
     setup_core(
         config={CONF_MDNS: {CONF_DISABLED: True}}, address="esphome-device.local"
     )
-    assert has_resolvable_address() is True
+    assert has_resolvable_address() is False
 
     # Test with mDNS disabled and regular DNS hostname (resolvable)
     setup_core(config={CONF_MDNS: {CONF_DISABLED: True}}, address="device.example.com")