morro

sqlalchemy/test/entities.py

@@ -0,0 +1,83 @@
+import sqlalchemy as sa
+from sqlalchemy import exc as sa_exc
+
+_repr_stack = set()
+class BasicEntity(object):
+    def __init__(self, **kw):
+        for key, value in kw.iteritems():
+            setattr(self, key, value)
+
+    def __repr__(self):
+        if id(self) in _repr_stack:
+            return object.__repr__(self)
+        _repr_stack.add(id(self))
+        try:
+            return "%s(%s)" % (
+                (self.__class__.__name__),
+                ', '.join(["%s=%r" % (key, getattr(self, key))
+                           for key in sorted(self.__dict__.keys())
+                           if not key.startswith('_')]))
+        finally:
+            _repr_stack.remove(id(self))
+
+_recursion_stack = set()
+class ComparableEntity(BasicEntity):
+    def __hash__(self):
+        return hash(self.__class__)
+
+    def __ne__(self, other):
+        return not self.__eq__(other)
+
+    def __eq__(self, other):
+        """'Deep, sparse compare.
+
+        Deeply compare two entities, following the non-None attributes of the
+        non-persisted object, if possible.
+
+        """
+        if other is self:
+            return True
+        elif not self.__class__ == other.__class__:
+            return False
+
+        if id(self) in _recursion_stack:
+            return True
+        _recursion_stack.add(id(self))
+
+        try:
+            # pick the entity thats not SA persisted as the source
+            try:
+                self_key = sa.orm.attributes.instance_state(self).key
+            except sa.orm.exc.NO_STATE:
+                self_key = None
+                
+            if other is None:
+                a = self
+                b = other
+            elif self_key is not None:
+                a = other
+                b = self
+            else:
+                a = self
+                b = other
+
+            for attr in a.__dict__.keys():
+                if attr.startswith('_'):
+                    continue
+                value = getattr(a, attr)
+
+                try:
+                    # handle lazy loader errors
+                    battr = getattr(b, attr)
+                except (AttributeError, sa_exc.UnboundExecutionError):
+                    return False
+
+                if hasattr(value, '__iter__'):
+                    if list(value) != list(battr):
+                        return False
+                else:
+                    if value is not None and value != battr:
+                        return False
+            return True
+        finally:
+            _recursion_stack.remove(id(self))