clear config store before loading new config (#30)

eppo_client/configuration_store.py

@@ -23,6 +23,7 @@ def get_configuration(self, key: str) -> Optional[T]:
     def set_configurations(self, configs: Dict[str, T]):
         try:
             self.__lock.acquire_write()
+            self.__cache.clear()
             for key, config in configs.items():
                 self.__cache[key] = config
         finally:

test/configuration_store_test.py

@@ -39,3 +39,16 @@ def test_evicts_old_entries_when_max_size_exceeded():
     assert (
         store.get_configuration("test-entry-{}".format(TEST_MAX_SIZE - 1)) == test_exp
     )
+
+
+def test_evicts_old_entries_when_setting_new_flags():
+    store: ConfigurationStore[str] = ConfigurationStore(max_size=TEST_MAX_SIZE)
+
+    store.set_configurations({"flag": mock_flag, "second_flag": mock_flag})
+    assert store.get_configuration("flag") == mock_flag
+    assert store.get_configuration("second_flag") == mock_flag
+
+    # Updating the flags should evict flags that no longer exist
+    store.set_configurations({"flag": mock_flag})
+    assert store.get_configuration("flag") == mock_flag
+    assert store.get_configuration("second_flag") is None