add some more serializer tests for objects

tests/test_state.py

@@ -2,15 +2,43 @@
 
 import pandas as pd
 from hypothesis import Verbosity, given, settings
+from pandas import DataFrame
 
 from autora.state import StandardState
+from autora.variable import Variable, VariableCollection
 
 from .test_serializer import serializer_dump_load_strategy
-from .test_strategies import standard_state_strategy
+from .test_strategies import (
+    dataframe_strategy,
+    standard_state_strategy,
+    variable_strategy,
+    variablecollection_strategy,
+)
 
 logger = logging.getLogger(__name__)
 
 
+@given(variable_strategy(), serializer_dump_load_strategy)
+@settings(verbosity=Verbosity.verbose)
+def test_variable_serialize_deserialize(o: Variable, dump_load):
+    o_loaded = dump_load(o)
+    assert o == o_loaded
+
+
+@given(variablecollection_strategy(), serializer_dump_load_strategy)
+@settings(verbosity=Verbosity.verbose)
+def test_variablecollection_serialize_deserialize(o: VariableCollection, dump_load):
+    o_loaded = dump_load(o)
+    assert o == o_loaded
+
+
+@given(dataframe_strategy(), serializer_dump_load_strategy)
+@settings(verbosity=Verbosity.verbose)
+def test_dataframe_serialize_deserialize(o: DataFrame, dump_load):
+    o_loaded = dump_load(o)
+    o.equals(o_loaded)
+
+
 @given(standard_state_strategy(), serializer_dump_load_strategy)
 @settings(verbosity=Verbosity.verbose)
 def test_state_serialize_deserialize(o: StandardState, dump_load):