fix: Correct bug in class keyword argument fast=True, bump version to v0.0.11

Author: autumnjolitz

instruct/about.py

@@ -1 +1 @@
-__version__ = '0.0.10'
+__version__ = '0.0.11'

instruct/templates/macros.jinja

@@ -27,6 +27,9 @@ def make_setter(type_def, fast, derived, type_restriction, coerce_types=(), coer
             if isinstance(val, coerce_types):
                 val = coerce_func(val)
             {%- endif %}
+            {%- if on_sets %}
+            _old_value = self.{{field_name}}
+            {%- endif %}
             {{setter_variable_template|format(key=field_name)|indent(12)}}
             {%- if on_sets %}
             {%- for on_func_name in on_sets %}

tests/test_atomic.py

@@ -157,6 +157,21 @@ def test_reset():
     assert not t.is_dirty
 
 
+def test_fast_setter():
+    class FastData(Base, fast=True):
+        __slots__ = {
+            'a': int,
+            'bar': str
+        }
+
+        @add_event_listener('a')
+        def on_a_set(self, old, new):
+            self.bar = str(new)
+
+    f = FastData(a=1)
+    assert f.bar == '1'
+
+
 def test_getitem():
     class Foo(Base):
         __slots__ = {