wrote basic (not yet working) test of functionality

Author: patrickhyw

env/integtest_tuning_agent.py

@@ -5,17 +5,26 @@
     ENV_INTEGTESTS_DBGYM_CONFIG_FPATH,
     get_integtest_workspace_path,
 )
-from env.tuning_agent import TuningAgent
+from env.tuning_agent import DBMSConfig, TuningAgent
 from util.workspace import DBGymConfig
 
 
 class MockTuningAgent(TuningAgent):
-    pass
+    def __init__(self, *args, **kwargs) -> None:
+        super().__init__(*args, **kwargs)
+        self.config_to_return = None
+
+    def _step(self) -> DBMSConfig:
+        ret = self.config_to_return
+        assert ret is not None
+        # This ensures you must set self.config_to_return every time
+        ret = None
+        return ret
 
 
 class PostgresConnTests(unittest.TestCase):
     dbgym_cfg: DBGymConfig
-    
+
     @staticmethod
     def setUpClass() -> None:
         # If you're running the test locally, this check makes runs past the first one much faster.
@@ -26,7 +35,10 @@ def setUpClass() -> None:
 
     def test_test(self) -> None:
         agent = MockTuningAgent(PostgresConnTests.dbgym_cfg)
+        config_a = DBMSConfig(["a"], {"a": "a"}, {"a": ["a"]})
+        agent.config_to_return = config_a
         agent.step()
+        self.assertEqual(agent.get_past_config(0), config_a)
 
 
 if __name__ == "__main__":

env/tuning_agent.py

@@ -26,3 +26,6 @@ def step(self) -> None:
     # Subclasses should override this function.
     def _step(self) -> DBMSConfig:
         raise NotImplementedError
+    
+    def get_past_config(self, step_num: int) -> DBMSConfig:
+        assert step_num >= 0 and step_num < self.next_step_num