assert_msonable replace obj.to_json() with json.dumps(obj.as_dict(), …

…cls=MontyEncoder)

pymatgen/io/abinit/abiobjects.py

@@ -386,7 +386,7 @@ def as_dict(self):
     @classmethod
     def from_dict(cls, dct: dict) -> Self:
         """Build object from dict."""
-        return cls(**{k: dct[k] for k in dct if k in cls._fields})
+        return cls(**{key: dct[key] for key in dct if key in cls._fields})
 
 
 # An handy Multiton

pymatgen/util/testing/__init__.py

@@ -15,7 +15,7 @@
 from unittest import TestCase
 
 import pytest
-from monty.json import MontyDecoder, MSONable
+from monty.json import MontyDecoder, MontyEncoder, MSONable
 from monty.serialization import loadfn
 
 from pymatgen.core import ROOT, SETTINGS, Structure
@@ -141,7 +141,7 @@ def assert_msonable(self, obj: MSONable, test_is_subclass: bool = True) -> str:
         if test_is_subclass:
             assert isinstance(obj, MSONable)
         assert obj.as_dict() == type(obj).from_dict(obj.as_dict()).as_dict()
-        json_str = obj.to_json()
+        json_str = json.dumps(obj.as_dict(), cls=MontyEncoder)
         round_trip = json.loads(json_str, cls=MontyDecoder)
         assert issubclass(type(round_trip), type(obj)), f"{type(round_trip)} != {type(obj)}"
         return json_str