Fixed #13640: Avoid generating an exception when a model has an attribute...

from django.utils.tree import Node

from django.db import connections, DEFAULT_DB_ALIAS

from django.db.models import signals

from django.db.models.expressions import ExpressionNode

from django.db.models.fields import FieldDoesNotExist

from django.db.models.query_utils import InvalidQuery

from django.db.models.sql import aggregates as base_aggregates_module

            value = True

        elif callable(value):

            value = value()

        elif hasattr(value, 'evaluate'):

        elif isinstance(value, ExpressionNode):

            # If value is a query expression, evaluate it

            value = SQLEvaluator(value, self)

            having_clause = value.contains_aggregate

            1

        )

class ModelValidationTest(TestCase):

    def test_pk_validation(self):

        one = NonAutoPK.objects.create(name="one")

        again = NonAutoPK(name="one")

        self.assertRaises(ValidationError, again.validate_unique)

class EvaluateMethodTest(TestCase):

    """

    Regression test for #13640: cannot filter by objects with 'evaluate' attr

    """

    def test_model_with_evaluate_method(self):

        """

        Ensures that you can filter by objects that have an 'evaluate' attr

        """

        dept = Department.objects.create(pk=1, name='abc')

        dept.evaluate = 'abc'

        Worker.objects.filter(department=dept)