fix tests

Author: gantoine

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)