Change default: gatherers by default do not leave default values - th…

…is is to make them compatible with the SlotMakerMeta by default.

src/ducktools/classbuilder/__init__.py

@@ -743,7 +743,7 @@ def field_slot_gatherer(cls_or_ns):
 
 def make_annotation_gatherer(
     field_type=Field,
-    leave_default_values=True,
+    leave_default_values=False,
 ):
     """
     Create a new annotation gatherer that will work with `Field` instances
@@ -809,7 +809,7 @@ def field_annotation_gatherer(cls_or_ns):
 
 def make_field_gatherer(
     field_type=Field,
-    leave_default_values=True,
+    leave_default_values=False,
 ):
     def field_attribute_gatherer(cls_or_ns):
         if isinstance(cls_or_ns, (_MappingProxyType, dict)):
@@ -842,7 +842,7 @@ def field_attribute_gatherer(cls_or_ns):
 
 def make_unified_gatherer(
     field_type=Field,
-    leave_default_values=True,
+    leave_default_values=False,
 ):
     """
     Create a gatherer that will work via first slots, then
@@ -892,7 +892,7 @@ def field_unified_gatherer(cls_or_ns):
 
 # The unified gatherer used for slot classes must remove default
 # values for slots to work correctly.
-unified_gatherer = make_unified_gatherer(leave_default_values=False)
+unified_gatherer = make_unified_gatherer()
 
 
 # Now the gatherers have been defined, add __repr__ and __eq__ to Field.

tests/annotations/test_annotated.py

@@ -60,9 +60,10 @@ class ExampleAnnotated:
     for key in "defgh":
         assert key not in annos
 
-    # Instance variables not removed from class
-    # Field replaced with default value on class
-    assert modifications["c"] == "c"
+    # Instance variables to be removed from class
+    assert modifications["a"] is NOTHING
+    assert modifications["b"] is NOTHING
+    assert modifications["c"] is NOTHING
 
 
 def test_make_annotation_gatherer():
@@ -71,7 +72,7 @@ class NewField(Field):
 
     gatherer = make_annotation_gatherer(
         field_type=NewField,
-        leave_default_values=False,
+        leave_default_values=True,
     )
 
     class ExampleAnnotated:
@@ -91,10 +92,11 @@ class ExampleAnnotated:
 
     assert annos["blank_field"] == NewField(type=str)
 
-    # ABC should be present in annos but removed from the class
+    # ABC should be present in annos and in the class
     for key in "abc":
         assert annos[key] == NewField(default=key, type=annotations[key])
-        assert modifications[key] is NOTHING
+
+    assert modifications["c"] == "c"
 
     # Opposite for classvar
     for key in "defgh":