Debug testutils._build_comparison_str (#4724)

Summary:
Pull Request resolved: #4724

Previously we could get absent (and thus confusing) output in some edge cases (unequal type in top-level objects; unequal type for two instances of Ax `Base); this covers.

{F1984377139}

Reviewed By: mgarrard

Differential Revision: D89909334

fbshipit-source-id: c24b054f35fe0d9b649c02fc14653177146fd572

Author: Lena Kashtelyan

ax/utils/common/equality.py

@@ -149,7 +149,6 @@ def object_attribute_dicts_equal(
     return not bool(unequal_type or unequal_value)
 
 
-# pyre-fixme[3]: Return annotation cannot contain `Any`.
 def object_attribute_dicts_find_unequal_fields(
     one_dict: dict[str, Any],
     other_dict: dict[str, Any],

ax/utils/common/tests/test_testutils.py

@@ -46,8 +46,8 @@ def test_equal(self) -> None:
             self.assertEqual(MyBase("red"), MyBase("panda"))
         except AssertionError as err:
             expected_suffix = (
-                "\n\nFields with different values:\n\n1) field: red "
-                "(type <class 'str'>) != panda (type <class 'str'>)"
+                "Fields with different values:\n\n1) field: \nred "
+                "(type <class 'str'>) \n!=\npanda (type <class 'str'>)"
             )
             self.assertIn(expected_suffix, str(err))
 

ax/utils/common/testutils.py

@@ -174,7 +174,7 @@ def _build_comparison_str(
     """
 
     def _unequal_str(first: Any, second: Any) -> str:
-        return f"{first} (type {type(first)}) != {second} (type {type(second)})."
+        return f"\n{first} (type {type(first)}) \n!=\n{second} (type {type(second)})."
 
     if first == second:
         return ""
@@ -189,12 +189,20 @@ def _unequal_str(first: Any, second: Any) -> str:
 
     msg = ""
     indent = " " * level * 4
-    unequal_types, unequal_val = object_attribute_dicts_find_unequal_fields(
-        one_dict=first.__dict__ if isinstance(first, Base) else first,
-        other_dict=second.__dict__ if isinstance(second, Base) else second,
-        fast_return=False,
-        skip_db_id_check=skip_db_id_check,
-    )
+    unequal_types, unequal_val = {}, {}
+    if type(first) is not type(second):
+        unequal_types["__type__"] = (first, second)
+    else:
+        unequal_types_recursive, unequal_val_recursive = (
+            object_attribute_dicts_find_unequal_fields(
+                one_dict=first.__dict__ if isinstance(first, Base) else first,
+                other_dict=second.__dict__ if isinstance(second, Base) else second,
+                fast_return=False,
+                skip_db_id_check=skip_db_id_check,
+            )
+        )
+        unequal_types.update(unequal_types_recursive)
+        unequal_val.update(unequal_val_recursive)
     unequal_types_suffixed = {
         f"{k} (field had values of unequal type)": v for k, v in unequal_types.items()
     }
@@ -223,7 +231,11 @@ def _unequal_str(first: Any, second: Any) -> str:
                 "unreachable."
             )
         msg += f"\n{indent}{bul} {field}: {_unequal_str(first=first, second=second)}\n"
-        if isinstance(first, (dict, Base)) and isinstance(second, (dict, Base)):
+        if "(field had values of unequal type)" in field:
+            return msg
+        if type(first) is not type(second) or (
+            isinstance(first, (dict, Base)) and isinstance(second, (dict, Base))
+        ):
             msg += _build_comparison_str(
                 first=first,
                 second=second,