[esp32] Make Arduino app metadata reproducible (#16053)

esphome/components/esp32/__init__.py

@@ -1724,15 +1724,16 @@ async def to_code(config):
         CORE.relative_internal_path(".espressif")
     )
 
+    # Both ESP-IDF and ESP32 Arduino builds generate IDF app metadata. Keep
+    # volatile build path/time data out of the binary so equivalent projects can
+    # produce reproducible outputs and downstream tooling can reuse artifacts.
+    add_idf_sdkconfig_option("CONFIG_APP_REPRODUCIBLE_BUILD", True)
+
     if conf[CONF_TYPE] == FRAMEWORK_ESP_IDF:
         cg.add_build_flag("-DUSE_ESP_IDF")
         cg.add_build_flag("-DUSE_ESP32_FRAMEWORK_ESP_IDF")
         if use_platformio:
             cg.add_platformio_option("framework", "espidf")
-            # Strip volatile build path/time metadata from PlatformIO-managed
-            # ESP-IDF builds so equivalent projects can produce reproducible
-            # outputs and downstream tooling can safely reuse artifacts.
-            add_idf_sdkconfig_option("CONFIG_APP_REPRODUCIBLE_BUILD", True)
 
         # Wrap std::__throw_* functions to abort immediately, eliminating ~3KB of
         # exception class overhead. See throw_stubs.cpp for implementation.

tests/component_tests/esp32/config/reproducible_build_arduino.yaml

@@ -0,0 +1,8 @@
+esphome:
+  name: test
+
+esp32:
+  board: esp32dev
+  variant: esp32
+  framework:
+    type: arduino

tests/component_tests/esp32/test_esp32.py

@@ -16,6 +16,7 @@ from esphome.const import (
     CONF_ESPHOME,
     CONF_IGNORE_PIN_VALIDATION_ERROR,
     CONF_NUMBER,
+    KEY_NATIVE_IDF,
     PlatformFramework,
 )
 from esphome.core import CORE
@@ -243,3 +244,30 @@ def test_platformio_idf_enables_reproducible_build(
 
     sdkconfig = CORE.data[KEY_ESP32][KEY_SDKCONFIG_OPTIONS]
     assert sdkconfig.get("CONFIG_APP_REPRODUCIBLE_BUILD") is True
+
+
+def test_platformio_arduino_enables_reproducible_build(
+    generate_main: Callable[[str | Path], str],
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Test PlatformIO Arduino builds enable reproducible app metadata."""
+    generate_main(component_config_path("reproducible_build_arduino.yaml"))
+
+    sdkconfig = CORE.data[KEY_ESP32][KEY_SDKCONFIG_OPTIONS]
+    assert sdkconfig.get("CONFIG_APP_REPRODUCIBLE_BUILD") is True
+
+
+def test_native_idf_enables_reproducible_build(
+    component_config_path: Callable[[str], Path],
+) -> None:
+    """Test native ESP-IDF builds enable reproducible app metadata."""
+    from esphome.__main__ import generate_cpp_contents
+    from esphome.config import read_config
+
+    CORE.config_path = component_config_path("reproducible_build.yaml")
+    CORE.config = read_config({})
+    CORE.data[KEY_NATIVE_IDF] = True
+    generate_cpp_contents(CORE.config)
+
+    sdkconfig = CORE.data[KEY_ESP32][KEY_SDKCONFIG_OPTIONS]
+    assert sdkconfig.get("CONFIG_APP_REPRODUCIBLE_BUILD") is True