Run copy_files to completion in the gate test, pin the build_helpers trigger

tests/script/test_determine_jobs.py

@@ -1003,6 +1003,7 @@ _ESP32_PLATFORMIO_FULL_LIST_FILES = [
     # PlatformIO subsystem (path-prefix trigger) + build generator
     ["esphome/platformio/runner.py"],
     ["esphome/platformio/toolchain.py"],
+    ["esphome/build_helpers/pch.py"],
     ["esphome/build_gen/platformio.py"],
     # Workflow / harness files
     ["script/test_build_components.py"],

tests/unit_tests/components/esp32/test_pch_wiring.py

@@ -1,7 +1,7 @@
 """The pch script must reach PlatformIO builds only; the native ESP-IDF
 toolchain has its own pch flow in build_gen/espidf.py."""
 
-from contextlib import suppress
+from pathlib import Path
 from unittest.mock import patch
 
 import pytest
@@ -16,18 +16,28 @@ from esphome.core import CORE
     [(Toolchain.PLATFORMIO, True), (Toolchain.ESP_IDF, False)],
 )
 def test_copy_files_gates_pch_script_on_toolchain(
-    toolchain: Toolchain, copied: bool
+    toolchain: Toolchain, copied: bool, tmp_path: Path
 ) -> None:
     CORE.toolchain = toolchain
+    CORE.build_path = tmp_path
+    from esphome.components.esp32 import (
+        KEY_ESP32,
+        KEY_EXTRA_BUILD_FILES,
+        KEY_FLASH_SIZE,
+    )
+
     with (
-        patch.object(esp32, "_write_sdkconfig"),
+        patch.object(esp32, "_write_sdkconfig") as write_sdkconfig,
         patch.object(esp32, "_write_idf_component_yml"),
         patch.object(esp32, "copy_pch_script") as copy_script,
         patch.object(esp32, "write_file_if_changed"),
         patch.object(esp32, "get_partition_csv"),
-        patch.dict(CORE.data, {}, clear=False),
-        # Later copy_files steps need a full build dir; the pch gate runs first
-        suppress(Exception),
+        patch.dict(
+            CORE.data,
+            {KEY_ESP32: {KEY_EXTRA_BUILD_FILES: {}, KEY_FLASH_SIZE: "4MB"}},
+        ),
     ):
         esp32.copy_files()
+    # Proves execution reached (and passed) the gate on both rows
+    assert write_sdkconfig.called
     assert copy_script.called is copied