fix: Fix repr() for ComputedProperty (#291)

Fixes #256

Author: Chris Rossi

packages/google-cloud-ndb/google/cloud/ndb/model.py

@@ -4267,6 +4267,7 @@ class ComputedProperty(GenericProperty):
     """
 
     _kwargs = None
+    _func = None
 
     def __init__(
         self, func, name=None, indexed=None, repeated=None, verbose_name=None

packages/google-cloud-ndb/tests/unit/test_model.py

@@ -3723,6 +3723,19 @@ def lower_name(self):
         prop = model.ComputedProperty(lower_name)
         assert prop._func == lower_name
 
+    @staticmethod
+    def test_repr():
+        """Regression test for #256
+
+        https://github.com/googleapis/python-ndb/issues/256
+        """
+
+        def lower_name(self):
+            return self.lower()  # pragma: NO COVER
+
+        prop = model.ComputedProperty(lower_name)
+        assert "lower_name" in repr(prop)
+
     @staticmethod
     def test__set_value():
         prop = model.ComputedProperty(lambda self: self)  # pragma: NO COVER