[host] Fix memory allocation in preferences load() method

esphome/components/host/preferences.h

@@ -42,9 +42,10 @@ class HostPreferences : public ESPPreferences {
     if (len > 255)
       return false;
     this->setup_();
-    if (this->data.count(key) == 0)
+    auto it = this->data.find(key);
+    if (it == this->data.end())
       return false;
-    auto vec = this->data[key];
+    const auto &vec = it->second;
     if (vec.size() != len)
       return false;
     memcpy(data, vec.data(), len);

tests/integration/fixtures/host_preferences_save_load.yaml

@@ -0,0 +1,104 @@
+esphome:
+  name: test_device
+  on_boot:
+    - lambda: |-
+        ESP_LOGD("test", "Host preferences test starting");
+
+host:
+
+logger:
+  level: DEBUG
+
+api:
+
+preferences:
+  flash_write_interval: 0s  # Disable automatic saving for test control
+
+switch:
+  - platform: template
+    name: "Test Switch"
+    id: test_switch
+    optimistic: true
+    restore_mode: DISABLED  # Don't auto-restore for test control
+
+number:
+  - platform: template
+    name: "Test Number"
+    id: test_number
+    min_value: 0
+    max_value: 100
+    step: 0.1
+    optimistic: true
+    restore_value: false  # Don't auto-restore for test control
+
+button:
+  - platform: template
+    name: "Save Preferences"
+    on_press:
+      - lambda: |-
+          // Save current values to preferences
+          ESPPreferenceObject switch_pref = global_preferences->make_preference<bool>(0x1234);
+          ESPPreferenceObject number_pref = global_preferences->make_preference<float>(0x5678);
+
+          bool switch_value = id(test_switch).state;
+          float number_value = id(test_number).state;
+
+          if (switch_pref.save(&switch_value)) {
+            ESP_LOGI("test", "Preference saved: key=switch, value=%.1f", switch_value ? 1.0 : 0.0);
+          }
+          if (number_pref.save(&number_value)) {
+            ESP_LOGI("test", "Preference saved: key=number, value=%.1f", number_value);
+          }
+
+          // Force sync to disk
+          global_preferences->sync();
+
+  - platform: template
+    name: "Load Preferences"
+    on_press:
+      - lambda: |-
+          // Load values from preferences
+          ESPPreferenceObject switch_pref = global_preferences->make_preference<bool>(0x1234);
+          ESPPreferenceObject number_pref = global_preferences->make_preference<float>(0x5678);
+
+          // Also try to load non-existent preferences (tests our fix)
+          ESPPreferenceObject fake_pref1 = global_preferences->make_preference<uint32_t>(0x9999);
+          ESPPreferenceObject fake_pref2 = global_preferences->make_preference<uint32_t>(0xAAAA);
+
+          bool switch_value = false;
+          float number_value = 0.0;
+          uint32_t fake_value = 0;
+
+          // These should not exist and shouldn't create map entries
+          fake_pref1.load(&fake_value);
+          fake_pref2.load(&fake_value);
+
+          if (switch_pref.load(&switch_value)) {
+            id(test_switch).publish_state(switch_value);
+            ESP_LOGI("test", "Preference loaded: key=switch, value=%.1f", switch_value ? 1.0 : 0.0);
+          } else {
+            ESP_LOGW("test", "Failed to load switch preference");
+          }
+
+          if (number_pref.load(&number_value)) {
+            id(test_number).publish_state(number_value);
+            ESP_LOGI("test", "Preference loaded: key=number, value=%.1f", number_value);
+          } else {
+            ESP_LOGW("test", "Failed to load number preference");
+          }
+
+  - platform: template
+    name: "Verify Preferences"
+    on_press:
+      - lambda: |-
+          // Verify current values match what we expect
+          bool switch_value = id(test_switch).state;
+          float number_value = id(test_number).state;
+
+          // After loading, switch should be true (1.0) and number should be 42.5
+          if (switch_value == true && number_value == 42.5) {
+            ESP_LOGI("test", "Preferences verified: values match!");
+          } else {
+            ESP_LOGE("test", "Preferences mismatch: switch=%d, number=%.1f",
+                     switch_value, number_value);
+          }

tests/integration/test_host_preferences.py

@@ -0,0 +1,153 @@
+"""Test host preferences save and load functionality."""
+
+from __future__ import annotations
+
+import asyncio
+import re
+from typing import Any
+
+from aioesphomeapi import ButtonInfo, EntityInfo, NumberInfo, SwitchInfo
+import pytest
+
+from .types import APIClientConnectedFactory, RunCompiledFunction
+
+
+def find_entity_by_name(
+    entities: list[EntityInfo], entity_type: type, name: str
+) -> Any:
+    """Helper to find an entity by type and name."""
+    return next(
+        (e for e in entities if isinstance(e, entity_type) and e.name == name), None
+    )
+
+
+@pytest.mark.asyncio
+async def test_host_preferences_save_load(
+    yaml_config: str,
+    run_compiled: RunCompiledFunction,
+    api_client_connected: APIClientConnectedFactory,
+) -> None:
+    """Test that preferences are correctly saved and loaded after our optimization fix."""
+    loop = asyncio.get_running_loop()
+    log_lines: list[str] = []
+    preferences_saved = loop.create_future()
+    preferences_loaded = loop.create_future()
+    values_match = loop.create_future()
+
+    # Patterns to match preference logs
+    save_pattern = re.compile(r"Preference saved: key=(\w+), value=([0-9.]+)")
+    load_pattern = re.compile(r"Preference loaded: key=(\w+), value=([0-9.]+)")
+    verify_pattern = re.compile(r"Preferences verified: values match!")
+
+    saved_values: dict[str, float] = {}
+    loaded_values: dict[str, float] = {}
+
+    def check_output(line: str) -> None:
+        """Check log output for preference operations."""
+        log_lines.append(line)
+
+        # Look for save operations
+        match = save_pattern.search(line)
+        if match:
+            key = match.group(1)
+            value = float(match.group(2))
+            saved_values[key] = value
+            if len(saved_values) >= 2 and not preferences_saved.done():
+                preferences_saved.set_result(True)
+
+        # Look for load operations
+        match = load_pattern.search(line)
+        if match:
+            key = match.group(1)
+            value = float(match.group(2))
+            loaded_values[key] = value
+            if len(loaded_values) >= 2 and not preferences_loaded.done():
+                preferences_loaded.set_result(True)
+
+        # Look for verification
+        if verify_pattern.search(line) and not values_match.done():
+            values_match.set_result(True)
+
+    async with (
+        run_compiled(yaml_config, line_callback=check_output),
+        api_client_connected() as client,
+    ):
+        # Get entity list
+        entities, _ = await client.list_entities_services()
+
+        # Find our test entities using helper
+        test_switch = find_entity_by_name(entities, SwitchInfo, "Test Switch")
+        test_number = find_entity_by_name(entities, NumberInfo, "Test Number")
+        save_button = find_entity_by_name(entities, ButtonInfo, "Save Preferences")
+        load_button = find_entity_by_name(entities, ButtonInfo, "Load Preferences")
+        verify_button = find_entity_by_name(entities, ButtonInfo, "Verify Preferences")
+
+        assert test_switch is not None, "Test Switch not found"
+        assert test_number is not None, "Test Number not found"
+        assert save_button is not None, "Save Preferences button not found"
+        assert load_button is not None, "Load Preferences button not found"
+        assert verify_button is not None, "Verify Preferences button not found"
+
+        # Set initial values
+        client.switch_command(test_switch.key, True)
+        client.number_command(test_number.key, 42.5)
+
+        # Save preferences
+        client.button_command(save_button.key)
+
+        # Wait for save to complete
+        try:
+            await asyncio.wait_for(preferences_saved, timeout=5.0)
+        except TimeoutError:
+            pytest.fail("Preferences not saved within timeout")
+
+        # Verify we saved the expected values
+        assert "switch" in saved_values, f"Switch preference not saved: {saved_values}"
+        assert "number" in saved_values, f"Number preference not saved: {saved_values}"
+        assert saved_values["switch"] == 1.0, (
+            f"Switch value incorrect: {saved_values['switch']}"
+        )
+        assert saved_values["number"] == 42.5, (
+            f"Number value incorrect: {saved_values['number']}"
+        )
+
+        # Change the values to something else
+        client.switch_command(test_switch.key, False)
+        client.number_command(test_number.key, 13.7)
+
+        # Load preferences (should restore the saved values)
+        client.button_command(load_button.key)
+
+        # Wait for load to complete
+        try:
+            await asyncio.wait_for(preferences_loaded, timeout=5.0)
+        except TimeoutError:
+            pytest.fail("Preferences not loaded within timeout")
+
+        # Verify loaded values match saved values
+        assert "switch" in loaded_values, (
+            f"Switch preference not loaded: {loaded_values}"
+        )
+        assert "number" in loaded_values, (
+            f"Number preference not loaded: {loaded_values}"
+        )
+        assert loaded_values["switch"] == saved_values["switch"], (
+            f"Loaded switch value {loaded_values['switch']} doesn't match saved {saved_values['switch']}"
+        )
+        assert loaded_values["number"] == saved_values["number"], (
+            f"Loaded number value {loaded_values['number']} doesn't match saved {saved_values['number']}"
+        )
+
+        # Verify the values were actually restored
+        client.button_command(verify_button.key)
+
+        # Wait for verification
+        try:
+            await asyncio.wait_for(values_match, timeout=5.0)
+        except TimeoutError:
+            pytest.fail("Preference verification failed within timeout")
+
+        # Test that non-existent preferences don't crash (tests our fix)
+        # This will trigger load attempts for keys that don't exist
+        # Our fix should prevent map entries from being created
+        client.button_command(load_button.key)