Do not resolve dependencies from the project "src" folder when the test_build_src option is not enabled

HISTORY.rst

@@ -24,9 +24,13 @@ PlatformIO Core 6
   - Replaced ``monitor_flags`` with independent project configuration options: `monitor_parity <https://docs.platformio.org/en/latest/projectconf/section_env_monitor.html#monitor-parity>`__, `monitor_eol <https://docs.platformio.org/en/latest/projectconf/section_env_monitor.html#monitor-eol>`__, `monitor_raw <https://docs.platformio.org/en/latest/projectconf/section_env_monitor.html#monitor-raw>`__, `monitor_echo <https://docs.platformio.org/en/latest/projectconf/section_env_monitor.html#monitor-echo>`__
   - Fixed an issue when the monitor filters were not applied in their order (`issue #4320 <https://github.com/platformio/platformio-core/issues/4320>`_)
 
+* **Unit Testing**
+
+  - Merged the |UNITTESTING| "building" stage with "uploading" for the embedded target (`issue #4307 <https://github.com/platformio/platformio-core/issues/4307>`_)
+  - Do not resolve dependencies from the project "src" folder when the `test_build_src <https://docs.platformio.org/en/latest//projectconf/section_env_test.html#test-build-src>`__ option is not enabled
+  - Fixed an issue when a custom `pio test --project-config <https://docs.platformio.org/en/latest/core/userguide/cmd_test.html#cmdoption-pio-test-c>`__ was not handled properly (`issue #4299 <https://github.com/platformio/platformio-core/issues/4299>`_)
+
 * Improved a serial port finder for a board with predefined HWIDs
-* Merged the |UNITTESTING| "building" stage with "uploading" for the embedded target (`issue #4307 <https://github.com/platformio/platformio-core/issues/4307>`_)
-* Fixed an issue when a custom `pio test --project-config <https://docs.platformio.org/en/latest/core/userguide/cmd_test.html#cmdoption-pio-test-c>`__ was not handled properly (`issue #4299 <https://github.com/platformio/platformio-core/issues/4299>`_)
 
 6.0.2 (2022-06-01)
 ~~~~~~~~~~~~~~~~~~

platformio/builder/tools/piolib.py

@@ -889,10 +889,13 @@ class ProjectAsLibBuilder(LibBuilderBase):
         return include_dirs
 
     def get_search_files(self):
+        items = []
+        build_type = self.env.GetBuildType()
         # project files
-        items = super().get_search_files()
+        if "test" not in build_type or self.env.GetProjectOption("test_build_src"):
+            items.extend(super().get_search_files())
         # test files
-        if "test" in self.env.GetBuildType():
+        if "test" in build_type:
             items.extend(
                 [
                     os.path.join("$PROJECT_TEST_DIR", item)