Prevent calling as_base_types on class objects in openhtf.util.data.

Update openhtf.util.data to check that an object is not a class before calling its as_base_types method. This ensures that class objects themselves are converted to their string representations instead of attempting to call the method on the class. Also add corresponding unit tests.

PiperOrigin-RevId: 963749692

Author: OpenHTF Owners

openhtf/util/data.py

@@ -163,7 +163,7 @@ def convert_to_base_types(obj,
   # Because it's *really* annoying to pass a single string accidentally.
   assert not isinstance(ignore_keys, str), 'Pass a real iterable!'
 
-  if hasattr(obj, 'as_base_types'):
+  if hasattr(obj, 'as_base_types') and not inspect.isclass(obj):
     return obj.as_base_types()
   if hasattr(obj, '_asdict') and not inspect.isclass(obj):
     obj = obj._asdict()

test/util/data_test.py

@@ -46,6 +46,11 @@ def __init__(self):
       def as_base_types(self):
         return self.value
 
+    class ClassWithAsBaseTypes(object):
+
+      def as_base_types(self):
+        return 'called on instance'
+
     @attr.s(slots=True, frozen=True)
     class FrozenAttr(object):
       value = attr.ib(type=int)
@@ -72,7 +77,8 @@ class EnumClass(enum.Enum):
         'special': SpecialBaseTypes('must_not_be_present'),
         'not_copied': not_copied,
         'enum': EnumClass.A,
-
+        'class_with_as_base_types_instance': ClassWithAsBaseTypes(),
+        'class_with_as_base_types_class': ClassWithAsBaseTypes,
         # Some plugs such as UserInputPlug will return None as a response to
         # AsDict().
         'none_dict': AsDict(),
@@ -99,6 +105,12 @@ class StrEnumClass(enum.StrEnum):
     self.assertIsInstance(converted['special'], dict)
     self.assertEqual(converted['special'], {'safe_value': True})
     self.assertIs(converted['not_copied'], not_copied.value)
+    self.assertEqual(
+        converted['class_with_as_base_types_instance'], 'called on instance'
+    )
+    self.assertEqual(
+        converted['class_with_as_base_types_class'], str(ClassWithAsBaseTypes)
+    )
 
     self.assertIsNone(converted['none_dict'])