Merge pull request #3516 from rommapp/copilot/bug-fix-assign-system-folder

Fix config.yml serialization breaking folder-to-platform mappings

backend/config/config_manager.py

@@ -782,8 +782,8 @@ class ConfigManager:
                 "gamelist": {
                     "export": self.config.GAMELIST_AUTO_EXPORT_ON_SCAN,
                     "media": {
-                        "thumbnail": self.config.GAMELIST_MEDIA_THUMBNAIL,
-                        "image": self.config.GAMELIST_MEDIA_IMAGE,
+                        "thumbnail": str(self.config.GAMELIST_MEDIA_THUMBNAIL),
+                        "image": str(self.config.GAMELIST_MEDIA_IMAGE),
                     },
                 },
                 "pegasus": {

backend/tests/config/conftest.py

@@ -0,0 +1,19 @@
+import pytest
+
+from config.config_manager import ConfigManager
+from config.config_manager import config_manager as cm
+
+
+@pytest.fixture(autouse=True)
+def restore_config_manager_singleton():
+    """``ConfigManager`` is a process-wide singleton (``__new__`` returns the
+    shared instance). Tests in this module point it at temporary config files
+    and mutate it (e.g. ``add_platform_binding``), which would otherwise leak
+    that state into other test modules through the global ``config_manager``.
+
+    Re-initialize the singleton from its original config file after each test
+    so the global instance returns to its default state.
+    """
+    original_config_file = cm.config_file
+    yield
+    ConfigManager(original_config_file)

backend/tests/config/test_config_loader.py

@@ -160,3 +160,24 @@ def test_malformed_yaml_falls_back_to_defaults():
     assert loader.config.ROMS_FOLDER_NAME == "roms"
     assert loader.config.FIRMWARE_FOLDER_NAME == "bios"
     assert loader.config.SCAN_MEDIA == ["box2d", "screenshot", "manual"]
+
+
+def test_config_updates_serialize_gamelist_media_as_plain_strings(tmp_path):
+    config_file = tmp_path / "config.yml"
+    config_file.write_text(
+        "scan:\n"
+        "  gamelist:\n"
+        "    media:\n"
+        "      thumbnail: box2d\n"
+        "      image: screenshot\n"
+    )
+    loader = ConfigManager(str(config_file))
+    loader.add_platform_binding("atarist", "atari-st")
+
+    config_text = config_file.read_text()
+    assert "!!python/object" not in config_text
+    assert "thumbnail: box2d" in config_text
+    assert "image: screenshot" in config_text
+
+    reloaded = ConfigManager(str(config_file))
+    assert reloaded.config.PLATFORMS_BINDING == {"atarist": "atari-st"}