invalid product fields used by the check constraint are excluded valid product invalid product rawsql can not be checked and is always considered valid nullable fields should be considered valid on none values partial unique constraints are not ignored by model validateconstraints null values are ignored existing instances have their existing row excluded unique fields are excluded validation on a child instance values not matching condition are ignored existing instances have their existing row excluded unique field is excluded existing instances have their existing row excluded unique field is excluded existing instances have their existing row excluded unique field is excluded values not matching condition are ignored existing instances have their existing row excluded unique field is excluded field from a condition is excluded behavior can be changed with set constraints behavior can be changed with set constraints invalid product fields used by the check constraint are excluded valid product invalid product rawsql can not be checked and is always considered valid nullable fields should be considered valid on none values partial unique constraints are not ignored by model validate_constraints null values are ignored existing instances have their existing row excluded unique fields are excluded validation on a child instance values not matching condition are ignored existing instances have their existing row excluded unique field is excluded existing instances have their existing row excluded unique field is excluded existing instances have their existing row excluded unique field is excluded values not matching condition are ignored existing instances have their existing row excluded unique field is excluded field from a condition is excluded behavior can be changed with set constraints behavior can be changed with set constraints
from unittest import mock

from django.core.exceptions import ValidationError
from django.db import IntegrityError, connection, models
from django.db.models import F
from django.db.models.constraints import BaseConstraint, UniqueConstraint
from django.db.models.functions import Lower
from django.db.transaction import atomic
from django.test import SimpleTestCase, TestCase, skipIfDBFeature, skipUnlessDBFeature
from django.test.utils import ignore_warnings
from django.utils.deprecation import RemovedInDjango60Warning

from .models import (
    ChildModel,
    ChildUniqueConstraintProduct,
    JSONFieldModel,
    Product,
    UniqueConstraintConditionProduct,
    UniqueConstraintDeferrable,
    UniqueConstraintInclude,
    UniqueConstraintProduct,
)


def get_constraints(table):
    with connection.cursor() as cursor:
        return connection.introspection.get_constraints(cursor, table)


class BaseConstraintTests(SimpleTestCase):
    def test_constraint_sql(self):
        c = BaseConstraint(name="name")
        msg = "This method must be implemented by a subclass."
        with self.assertRaisesMessage(NotImplementedError, msg):
            c.constraint_sql(None, None)

    def test_contains_expressions(self):
        c = BaseConstraint(name="name")
        self.assertIs(c.contains_expressions, False)

    def test_create_sql(self):
        c = BaseConstraint(name="name")
        msg = "This method must be implemented by a subclass."
        with self.assertRaisesMessage(NotImplementedError, msg):
            c.create_sql(None, None)

    def test_remove_sql(self):
        c = BaseConstraint(name="name")
        msg = "This method must be implemented by a subclass."
        with self.assertRaisesMessage(NotImplementedError, msg):
            c.remove_sql(None, None)

    def test_validate(self):
        c = BaseConstraint(name="name")
        msg = "This method must be implemented by a subclass."
        with self.assertRaisesMessage(NotImplementedError, msg):
            c.validate(None, None)

    def test_default_violation_error_message(self):
        c = BaseConstraint(name="name")
        self.assertEqual(
            c.get_violation_error_message(), "Constraint “name” is violated."
        )

    def test_custom_violation_error_message(self):
        c = BaseConstraint(
            name="base_name", violation_error_message="custom %(name)s message"
        )
        self.assertEqual(c.get_violation_error_message(), "custom base_name message")

    def test_custom_violation_error_message_clone(self):
        constraint = BaseConstraint(
            name="base_name",
            violation_error_message="custom %(name)s message",
        ).clone()
        self.assertEqual(
            constraint.get_violation_error_message(),
            "custom base_name message",
        )

    def test_custom_violation_code_message(self):
        c = BaseConstraint(name="base_name", violation_error_code="custom_code")
        self.assertEqual(c.violation_error_code, "custom_code")

    def test_deconstruction(self):
        constraint = BaseConstraint(
            name="base_name",
            violation_error_message="custom %(name)s message",
            violation_error_code="custom_code",
        )
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.BaseConstraint")
        self.assertEqual(args, ())
        self.assertEqual(
            kwargs,
            {
                "name": "base_name",
                "violation_error_message": "custom %(name)s message",
                "violation_error_code": "custom_code",
            },
        )

    def test_deprecation(self):
        msg = "Passing positional arguments to BaseConstraint is deprecated."
        with self.assertRaisesMessage(RemovedInDjango60Warning, msg):
            BaseConstraint("name", "violation error message")

    def test_name_required(self):
        msg = (
            "BaseConstraint.__init__() missing 1 required keyword-only argument: 'name'"
        )
        with self.assertRaisesMessage(TypeError, msg):
            BaseConstraint()

    @ignore_warnings(category=RemovedInDjango60Warning)
    def test_positional_arguments(self):
        c = BaseConstraint("name", "custom %(name)s message")
        self.assertEqual(c.get_violation_error_message(), "custom name message")


class CheckConstraintTests(TestCase):
    def test_eq(self):
        check1 = models.Q(price__gt=models.F("discounted_price"))
        check2 = models.Q(price__lt=models.F("discounted_price"))
        self.assertEqual(
            models.CheckConstraint(check=check1, name="price"),
            models.CheckConstraint(check=check1, name="price"),
        )
        self.assertEqual(models.CheckConstraint(check=check1, name="price"), mock.ANY)
        self.assertNotEqual(
            models.CheckConstraint(check=check1, name="price"),
            models.CheckConstraint(check=check1, name="price2"),
        )
        self.assertNotEqual(
            models.CheckConstraint(check=check1, name="price"),
            models.CheckConstraint(check=check2, name="price"),
        )
        self.assertNotEqual(models.CheckConstraint(check=check1, name="price"), 1)
        self.assertNotEqual(
            models.CheckConstraint(check=check1, name="price"),
            models.CheckConstraint(
                check=check1, name="price", violation_error_message="custom error"
            ),
        )
        self.assertNotEqual(
            models.CheckConstraint(
                check=check1, name="price", violation_error_message="custom error"
            ),
            models.CheckConstraint(
                check=check1, name="price", violation_error_message="other custom error"
            ),
        )
        self.assertEqual(
            models.CheckConstraint(
                check=check1, name="price", violation_error_message="custom error"
            ),
            models.CheckConstraint(
                check=check1, name="price", violation_error_message="custom error"
            ),
        )
        self.assertNotEqual(
            models.CheckConstraint(check=check1, name="price"),
            models.CheckConstraint(
                check=check1, name="price", violation_error_code="custom_code"
            ),
        )
        self.assertEqual(
            models.CheckConstraint(
                check=check1, name="price", violation_error_code="custom_code"
            ),
            models.CheckConstraint(
                check=check1, name="price", violation_error_code="custom_code"
            ),
        )

    def test_repr(self):
        constraint = models.CheckConstraint(
            check=models.Q(price__gt=models.F("discounted_price")),
            name="price_gt_discounted_price",
        )
        self.assertEqual(
            repr(constraint),
            "<CheckConstraint: check=(AND: ('price__gt', F(discounted_price))) "
            "name='price_gt_discounted_price'>",
        )

    def test_repr_with_violation_error_message(self):
        constraint = models.CheckConstraint(
            check=models.Q(price__lt=1),
            name="price_lt_one",
            violation_error_message="More than 1",
        )
        self.assertEqual(
            repr(constraint),
            "<CheckConstraint: check=(AND: ('price__lt', 1)) name='price_lt_one' "
            "violation_error_message='More than 1'>",
        )

    def test_repr_with_violation_error_code(self):
        constraint = models.CheckConstraint(
            check=models.Q(price__lt=1),
            name="price_lt_one",
            violation_error_code="more_than_one",
        )
        self.assertEqual(
            repr(constraint),
            "<CheckConstraint: check=(AND: ('price__lt', 1)) name='price_lt_one' "
            "violation_error_code='more_than_one'>",
        )

    def test_invalid_check_types(self):
        msg = "CheckConstraint.check must be a Q instance or boolean expression."
        with self.assertRaisesMessage(TypeError, msg):
            models.CheckConstraint(check=models.F("discounted_price"), name="check")

    def test_deconstruction(self):
        check = models.Q(price__gt=models.F("discounted_price"))
        name = "price_gt_discounted_price"
        constraint = models.CheckConstraint(check=check, name=name)
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.CheckConstraint")
        self.assertEqual(args, ())
        self.assertEqual(kwargs, {"check": check, "name": name})

    @skipUnlessDBFeature("supports_table_check_constraints")
    def test_database_constraint(self):
        Product.objects.create(price=10, discounted_price=5)
        with self.assertRaises(IntegrityError):
            Product.objects.create(price=10, discounted_price=20)

    @skipUnlessDBFeature("supports_table_check_constraints")
    def test_database_constraint_unicode(self):
        Product.objects.create(price=10, discounted_price=5, unit="μg/mL")
        with self.assertRaises(IntegrityError):
            Product.objects.create(price=10, discounted_price=7, unit="l")

    @skipUnlessDBFeature(
        "supports_table_check_constraints", "can_introspect_check_constraints"
    )
    def test_name(self):
        constraints = get_constraints(Product._meta.db_table)
        for expected_name in (
            "price_gt_discounted_price",
            "constraints_product_price_gt_0",
        ):
            with self.subTest(expected_name):
                self.assertIn(expected_name, constraints)

    @skipUnlessDBFeature(
        "supports_table_check_constraints", "can_introspect_check_constraints"
    )
    def test_abstract_name(self):
        constraints = get_constraints(ChildModel._meta.db_table)
        self.assertIn("constraints_childmodel_adult", constraints)

    def test_validate(self):
        check = models.Q(price__gt=models.F("discounted_price"))
        constraint = models.CheckConstraint(check=check, name="price")
        
        invalid_product = Product(price=10, discounted_price=42)
        with self.assertRaises(ValidationError):
            constraint.validate(Product, invalid_product)
        with self.assertRaises(ValidationError):
            constraint.validate(Product, invalid_product, exclude={"unit"})
        
        constraint.validate(Product, invalid_product, exclude={"price"})
        constraint.validate(Product, invalid_product, exclude={"discounted_price"})
        constraint.validate(
            Product,
            invalid_product,
            exclude={"discounted_price", "price"},
        )
        
        constraint.validate(Product, Product(price=10, discounted_price=5))

    def test_validate_custom_error(self):
        check = models.Q(price__gt=models.F("discounted_price"))
        constraint = models.CheckConstraint(
            check=check,
            name="price",
            violation_error_message="discount is fake",
            violation_error_code="fake_discount",
        )
        
        invalid_product = Product(price=10, discounted_price=42)
        msg = "discount is fake"
        with self.assertRaisesMessage(ValidationError, msg) as cm:
            constraint.validate(Product, invalid_product)
        self.assertEqual(cm.exception.code, "fake_discount")

    def test_validate_boolean_expressions(self):
        constraint = models.CheckConstraint(
            check=models.expressions.ExpressionWrapper(
                models.Q(price__gt=500) | models.Q(price__lt=500),
                output_field=models.BooleanField(),
            ),
            name="price_neq_500_wrap",
        )
        msg = f"Constraint “{constraint.name}” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            constraint.validate(Product, Product(price=500, discounted_price=5))
        constraint.validate(Product, Product(price=501, discounted_price=5))
        constraint.validate(Product, Product(price=499, discounted_price=5))

    def test_validate_rawsql_expressions_noop(self):
        constraint = models.CheckConstraint(
            check=models.expressions.RawSQL(
                "price < %s OR price > %s",
                (500, 500),
                output_field=models.BooleanField(),
            ),
            name="price_neq_500_raw",
        )
        
        constraint.validate(Product, Product(price=500, discounted_price=5))
        constraint.validate(Product, Product(price=501, discounted_price=5))
        constraint.validate(Product, Product(price=499, discounted_price=5))

    @skipUnlessDBFeature("supports_comparing_boolean_expr")
    def test_validate_nullable_field_with_none(self):
        
        constraint = models.CheckConstraint(
            check=models.Q(price__gte=0),
            name="positive_price",
        )
        constraint.validate(Product, Product())

    @skipIfDBFeature("supports_comparing_boolean_expr")
    def test_validate_nullable_field_with_isnull(self):
        constraint = models.CheckConstraint(
            check=models.Q(price__gte=0) | models.Q(price__isnull=True),
            name="positive_price",
        )
        constraint.validate(Product, Product())

    @skipUnlessDBFeature("supports_json_field")
    def test_validate_nullable_jsonfield(self):
        is_null_constraint = models.CheckConstraint(
            check=models.Q(data__isnull=True),
            name="nullable_data",
        )
        is_not_null_constraint = models.CheckConstraint(
            check=models.Q(data__isnull=False),
            name="nullable_data",
        )
        is_null_constraint.validate(JSONFieldModel, JSONFieldModel(data=None))
        msg = f"Constraint “{is_null_constraint.name}” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            is_null_constraint.validate(JSONFieldModel, JSONFieldModel(data={}))
        msg = f"Constraint “{is_not_null_constraint.name}” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            is_not_null_constraint.validate(JSONFieldModel, JSONFieldModel(data=None))
        is_not_null_constraint.validate(JSONFieldModel, JSONFieldModel(data={}))

    def test_validate_pk_field(self):
        constraint_with_pk = models.CheckConstraint(
            check=~models.Q(pk=models.F("age")),
            name="pk_not_age_check",
        )
        constraint_with_pk.validate(ChildModel, ChildModel(pk=1, age=2))
        msg = f"Constraint “{constraint_with_pk.name}” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            constraint_with_pk.validate(ChildModel, ChildModel(pk=1, age=1))
        with self.assertRaisesMessage(ValidationError, msg):
            constraint_with_pk.validate(ChildModel, ChildModel(id=1, age=1))
        constraint_with_pk.validate(ChildModel, ChildModel(pk=1, age=1), exclude={"pk"})


class UniqueConstraintTests(TestCase):
    @classmethod
    def setUpTestData(cls):
        cls.p1 = UniqueConstraintProduct.objects.create(name="p1", color="red")
        cls.p2 = UniqueConstraintProduct.objects.create(name="p2")

    def test_eq(self):
        self.assertEqual(
            models.UniqueConstraint(fields=["foo", "bar"], name="unique"),
            models.UniqueConstraint(fields=["foo", "bar"], name="unique"),
        )
        self.assertEqual(
            models.UniqueConstraint(fields=["foo", "bar"], name="unique"),
            mock.ANY,
        )
        self.assertNotEqual(
            models.UniqueConstraint(fields=["foo", "bar"], name="unique"),
            models.UniqueConstraint(fields=["foo", "bar"], name="unique2"),
        )
        self.assertNotEqual(
            models.UniqueConstraint(fields=["foo", "bar"], name="unique"),
            models.UniqueConstraint(fields=["foo", "baz"], name="unique"),
        )
        self.assertNotEqual(
            models.UniqueConstraint(fields=["foo", "bar"], name="unique"), 1
        )
        self.assertNotEqual(
            models.UniqueConstraint(fields=["foo", "bar"], name="unique"),
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_message="custom error",
            ),
        )
        self.assertNotEqual(
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_message="custom error",
            ),
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_message="other custom error",
            ),
        )
        self.assertEqual(
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_message="custom error",
            ),
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_message="custom error",
            ),
        )
        self.assertNotEqual(
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_code="custom_error",
            ),
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_code="other_custom_error",
            ),
        )
        self.assertEqual(
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_code="custom_error",
            ),
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                violation_error_code="custom_error",
            ),
        )

    def test_eq_with_condition(self):
        self.assertEqual(
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                condition=models.Q(foo=models.F("bar")),
            ),
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                condition=models.Q(foo=models.F("bar")),
            ),
        )
        self.assertNotEqual(
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                condition=models.Q(foo=models.F("bar")),
            ),
            models.UniqueConstraint(
                fields=["foo", "bar"],
                name="unique",
                condition=models.Q(foo=models.F("baz")),
            ),
        )

    def test_eq_with_deferrable(self):
        constraint_1 = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="unique",
            deferrable=models.Deferrable.DEFERRED,
        )
        constraint_2 = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="unique",
            deferrable=models.Deferrable.IMMEDIATE,
        )
        self.assertEqual(constraint_1, constraint_1)
        self.assertNotEqual(constraint_1, constraint_2)

    def test_eq_with_include(self):
        constraint_1 = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="include",
            include=["baz_1"],
        )
        constraint_2 = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="include",
            include=["baz_2"],
        )
        self.assertEqual(constraint_1, constraint_1)
        self.assertNotEqual(constraint_1, constraint_2)

    def test_eq_with_opclasses(self):
        constraint_1 = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="opclasses",
            opclasses=["text_pattern_ops", "varchar_pattern_ops"],
        )
        constraint_2 = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="opclasses",
            opclasses=["varchar_pattern_ops", "text_pattern_ops"],
        )
        self.assertEqual(constraint_1, constraint_1)
        self.assertNotEqual(constraint_1, constraint_2)

    def test_eq_with_expressions(self):
        constraint = models.UniqueConstraint(
            Lower("title"),
            F("author"),
            name="book_func_uq",
        )
        same_constraint = models.UniqueConstraint(
            Lower("title"),
            "author",
            name="book_func_uq",
        )
        another_constraint = models.UniqueConstraint(
            Lower("title"),
            name="book_func_uq",
        )
        self.assertEqual(constraint, same_constraint)
        self.assertEqual(constraint, mock.ANY)
        self.assertNotEqual(constraint, another_constraint)

    def test_eq_with_nulls_distinct(self):
        constraint_1 = models.UniqueConstraint(
            Lower("title"),
            nulls_distinct=False,
            name="book_func_nulls_distinct_uq",
        )
        constraint_2 = models.UniqueConstraint(
            Lower("title"),
            nulls_distinct=True,
            name="book_func_nulls_distinct_uq",
        )
        constraint_3 = models.UniqueConstraint(
            Lower("title"),
            name="book_func_nulls_distinct_uq",
        )
        self.assertEqual(constraint_1, constraint_1)
        self.assertEqual(constraint_1, mock.ANY)
        self.assertNotEqual(constraint_1, constraint_2)
        self.assertNotEqual(constraint_1, constraint_3)
        self.assertNotEqual(constraint_2, constraint_3)

    def test_repr(self):
        fields = ["foo", "bar"]
        name = "unique_fields"
        constraint = models.UniqueConstraint(fields=fields, name=name)
        self.assertEqual(
            repr(constraint),
            "<UniqueConstraint: fields=('foo', 'bar') name='unique_fields'>",
        )

    def test_repr_with_condition(self):
        constraint = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="unique_fields",
            condition=models.Q(foo=models.F("bar")),
        )
        self.assertEqual(
            repr(constraint),
            "<UniqueConstraint: fields=('foo', 'bar') name='unique_fields' "
            "condition=(AND: ('foo', F(bar)))>",
        )

    def test_repr_with_deferrable(self):
        constraint = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="unique_fields",
            deferrable=models.Deferrable.IMMEDIATE,
        )
        self.assertEqual(
            repr(constraint),
            "<UniqueConstraint: fields=('foo', 'bar') name='unique_fields' "
            "deferrable=Deferrable.IMMEDIATE>",
        )

    def test_repr_with_include(self):
        constraint = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="include_fields",
            include=["baz_1", "baz_2"],
        )
        self.assertEqual(
            repr(constraint),
            "<UniqueConstraint: fields=('foo', 'bar') name='include_fields' "
            "include=('baz_1', 'baz_2')>",
        )

    def test_repr_with_opclasses(self):
        constraint = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="opclasses_fields",
            opclasses=["text_pattern_ops", "varchar_pattern_ops"],
        )
        self.assertEqual(
            repr(constraint),
            "<UniqueConstraint: fields=('foo', 'bar') name='opclasses_fields' "
            "opclasses=['text_pattern_ops', 'varchar_pattern_ops']>",
        )

    def test_repr_with_nulls_distinct(self):
        constraint = models.UniqueConstraint(
            fields=["foo", "bar"],
            name="nulls_distinct_fields",
            nulls_distinct=False,
        )
        self.assertEqual(
            repr(constraint),
            "<UniqueConstraint: fields=('foo', 'bar') name='nulls_distinct_fields' "
            "nulls_distinct=False>",
        )

    def test_repr_with_expressions(self):
        constraint = models.UniqueConstraint(
            Lower("title"),
            F("author"),
            name="book_func_uq",
        )
        self.assertEqual(
            repr(constraint),
            "<UniqueConstraint: expressions=(Lower(F(title)), F(author)) "
            "name='book_func_uq'>",
        )

    def test_repr_with_violation_error_message(self):
        constraint = models.UniqueConstraint(
            models.F("baz__lower"),
            name="unique_lower_baz",
            violation_error_message="BAZ",
        )
        self.assertEqual(
            repr(constraint),
            (
                "<UniqueConstraint: expressions=(F(baz__lower),) "
                "name='unique_lower_baz' violation_error_message='BAZ'>"
            ),
        )

    def test_repr_with_violation_error_code(self):
        constraint = models.UniqueConstraint(
            models.F("baz__lower"),
            name="unique_lower_baz",
            violation_error_code="baz",
        )
        self.assertEqual(
            repr(constraint),
            (
                "<UniqueConstraint: expressions=(F(baz__lower),) "
                "name='unique_lower_baz' violation_error_code='baz'>"
            ),
        )

    def test_deconstruction(self):
        fields = ["foo", "bar"]
        name = "unique_fields"
        constraint = models.UniqueConstraint(fields=fields, name=name)
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.UniqueConstraint")
        self.assertEqual(args, ())
        self.assertEqual(kwargs, {"fields": tuple(fields), "name": name})

    def test_deconstruction_with_condition(self):
        fields = ["foo", "bar"]
        name = "unique_fields"
        condition = models.Q(foo=models.F("bar"))
        constraint = models.UniqueConstraint(
            fields=fields, name=name, condition=condition
        )
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.UniqueConstraint")
        self.assertEqual(args, ())
        self.assertEqual(
            kwargs, {"fields": tuple(fields), "name": name, "condition": condition}
        )

    def test_deconstruction_with_deferrable(self):
        fields = ["foo"]
        name = "unique_fields"
        constraint = models.UniqueConstraint(
            fields=fields,
            name=name,
            deferrable=models.Deferrable.DEFERRED,
        )
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.UniqueConstraint")
        self.assertEqual(args, ())
        self.assertEqual(
            kwargs,
            {
                "fields": tuple(fields),
                "name": name,
                "deferrable": models.Deferrable.DEFERRED,
            },
        )

    def test_deconstruction_with_include(self):
        fields = ["foo", "bar"]
        name = "unique_fields"
        include = ["baz_1", "baz_2"]
        constraint = models.UniqueConstraint(fields=fields, name=name, include=include)
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.UniqueConstraint")
        self.assertEqual(args, ())
        self.assertEqual(
            kwargs,
            {
                "fields": tuple(fields),
                "name": name,
                "include": tuple(include),
            },
        )

    def test_deconstruction_with_opclasses(self):
        fields = ["foo", "bar"]
        name = "unique_fields"
        opclasses = ["varchar_pattern_ops", "text_pattern_ops"]
        constraint = models.UniqueConstraint(
            fields=fields, name=name, opclasses=opclasses
        )
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.UniqueConstraint")
        self.assertEqual(args, ())
        self.assertEqual(
            kwargs,
            {
                "fields": tuple(fields),
                "name": name,
                "opclasses": opclasses,
            },
        )

    def test_deconstruction_with_nulls_distinct(self):
        fields = ["foo", "bar"]
        name = "unique_fields"
        constraint = models.UniqueConstraint(
            fields=fields, name=name, nulls_distinct=True
        )
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.UniqueConstraint")
        self.assertEqual(args, ())
        self.assertEqual(
            kwargs,
            {
                "fields": tuple(fields),
                "name": name,
                "nulls_distinct": True,
            },
        )

    def test_deconstruction_with_expressions(self):
        name = "unique_fields"
        constraint = models.UniqueConstraint(Lower("title"), name=name)
        path, args, kwargs = constraint.deconstruct()
        self.assertEqual(path, "django.db.models.UniqueConstraint")
        self.assertEqual(args, (Lower("title"),))
        self.assertEqual(kwargs, {"name": name})

    def test_database_constraint(self):
        with self.assertRaises(IntegrityError):
            UniqueConstraintProduct.objects.create(
                name=self.p1.name, color=self.p1.color
            )

    @skipUnlessDBFeature("supports_partial_indexes")
    def test_database_constraint_with_condition(self):
        UniqueConstraintConditionProduct.objects.create(name="p1")
        UniqueConstraintConditionProduct.objects.create(name="p2")
        with self.assertRaises(IntegrityError):
            UniqueConstraintConditionProduct.objects.create(name="p1")

    def test_model_validation(self):
        msg = "Unique constraint product with this Name and Color already exists."
        with self.assertRaisesMessage(ValidationError, msg):
            UniqueConstraintProduct(
                name=self.p1.name, color=self.p1.color
            ).validate_constraints()

    @skipUnlessDBFeature("supports_partial_indexes")
    def test_model_validation_with_condition(self):
        
        obj1 = UniqueConstraintConditionProduct.objects.create(name="p1", color="red")
        obj2 = UniqueConstraintConditionProduct.objects.create(name="p2")
        UniqueConstraintConditionProduct(
            name=obj1.name, color="blue"
        ).validate_constraints()
        msg = "Constraint “name_without_color_uniq” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            UniqueConstraintConditionProduct(name=obj2.name).validate_constraints()

    def test_model_validation_constraint_no_code_error(self):
        class ValidateNoCodeErrorConstraint(UniqueConstraint):
            def validate(self, model, instance, **kwargs):
                raise ValidationError({"name": ValidationError("Already exists.")})

        class NoCodeErrorConstraintModel(models.Model):
            name = models.CharField(max_length=255)

            class Meta:
                constraints = [
                    ValidateNoCodeErrorConstraint(
                        Lower("name"),
                        name="custom_validate_no_code_error",
                    )
                ]

        msg = "{'name': ['Already exists.']}"
        with self.assertRaisesMessage(ValidationError, msg):
            NoCodeErrorConstraintModel(name="test").validate_constraints()

    def test_validate(self):
        constraint = UniqueConstraintProduct._meta.constraints[0]
        msg = "Unique constraint product with this Name and Color already exists."
        non_unique_product = UniqueConstraintProduct(
            name=self.p1.name, color=self.p1.color
        )
        with self.assertRaisesMessage(ValidationError, msg) as cm:
            constraint.validate(UniqueConstraintProduct, non_unique_product)
        self.assertEqual(cm.exception.code, "unique_together")
        
        constraint.validate(
            UniqueConstraintProduct,
            UniqueConstraintProduct(name=self.p2.name, color=None),
        )
        
        constraint.validate(UniqueConstraintProduct, self.p1)
        
        constraint.validate(
            UniqueConstraintProduct,
            non_unique_product,
            exclude={"name"},
        )
        constraint.validate(
            UniqueConstraintProduct,
            non_unique_product,
            exclude={"color"},
        )
        constraint.validate(
            UniqueConstraintProduct,
            non_unique_product,
            exclude={"name", "color"},
        )
        
        with self.assertRaisesMessage(ValidationError, msg):
            constraint.validate(
                UniqueConstraintProduct,
                ChildUniqueConstraintProduct(name=self.p1.name, color=self.p1.color),
            )

    @skipUnlessDBFeature("supports_partial_indexes")
    def test_validate_condition(self):
        p1 = UniqueConstraintConditionProduct.objects.create(name="p1")
        constraint = UniqueConstraintConditionProduct._meta.constraints[0]
        msg = "Constraint “name_without_color_uniq” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            constraint.validate(
                UniqueConstraintConditionProduct,
                UniqueConstraintConditionProduct(name=p1.name, color=None),
            )
        
        constraint.validate(
            UniqueConstraintConditionProduct,
            UniqueConstraintConditionProduct(name=p1.name, color="anything-but-none"),
        )
        
        constraint.validate(UniqueConstraintConditionProduct, p1)
        
        constraint.validate(
            UniqueConstraintConditionProduct,
            UniqueConstraintConditionProduct(name=p1.name, color=None),
            exclude={"name"},
        )

    @skipUnlessDBFeature("supports_partial_indexes")
    def test_validate_conditon_custom_error(self):
        p1 = UniqueConstraintConditionProduct.objects.create(name="p1")
        constraint = models.UniqueConstraint(
            fields=["name"],
            name="name_without_color_uniq",
            condition=models.Q(color__isnull=True),
            violation_error_code="custom_code",
            violation_error_message="Custom message",
        )
        msg = "Custom message"
        with self.assertRaisesMessage(ValidationError, msg) as cm:
            constraint.validate(
                UniqueConstraintConditionProduct,
                UniqueConstraintConditionProduct(name=p1.name, color=None),
            )
        self.assertEqual(cm.exception.code, "custom_code")

    def test_validate_expression(self):
        constraint = models.UniqueConstraint(Lower("name"), name="name_lower_uniq")
        msg = "Constraint “name_lower_uniq” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            constraint.validate(
                UniqueConstraintProduct,
                UniqueConstraintProduct(name=self.p1.name.upper()),
            )
        constraint.validate(
            UniqueConstraintProduct,
            UniqueConstraintProduct(name="another-name"),
        )
        
        constraint.validate(UniqueConstraintProduct, self.p1)
        
        constraint.validate(
            UniqueConstraintProduct,
            UniqueConstraintProduct(name=self.p1.name.upper()),
            exclude={"name"},
        )

    def test_validate_ordered_expression(self):
        constraint = models.UniqueConstraint(
            Lower("name").desc(), name="name_lower_uniq_desc"
        )
        msg = "Constraint “name_lower_uniq_desc” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            constraint.validate(
                UniqueConstraintProduct,
                UniqueConstraintProduct(name=self.p1.name.upper()),
            )
        constraint.validate(
            UniqueConstraintProduct,
            UniqueConstraintProduct(name="another-name"),
        )
        
        constraint.validate(UniqueConstraintProduct, self.p1)
        
        constraint.validate(
            UniqueConstraintProduct,
            UniqueConstraintProduct(name=self.p1.name.upper()),
            exclude={"name"},
        )

    def test_validate_expression_condition(self):
        constraint = models.UniqueConstraint(
            Lower("name"),
            name="name_lower_without_color_uniq",
            condition=models.Q(color__isnull=True),
        )
        non_unique_product = UniqueConstraintProduct(name=self.p2.name.upper())
        msg = "Constraint “name_lower_without_color_uniq” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            constraint.validate(UniqueConstraintProduct, non_unique_product)
        
        constraint.validate(
            UniqueConstraintProduct,
            UniqueConstraintProduct(name=self.p1.name, color=self.p1.color),
        )
        
        constraint.validate(UniqueConstraintProduct, self.p2)
        
        constraint.validate(
            UniqueConstraintProduct,
            non_unique_product,
            exclude={"name"},
        )
        
        constraint.validate(
            UniqueConstraintProduct,
            non_unique_product,
            exclude={"color"},
        )

    def test_validate_expression_str(self):
        constraint = models.UniqueConstraint("name", name="name_uniq")
        msg = "Constraint “name_uniq” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            constraint.validate(
                UniqueConstraintProduct,
                UniqueConstraintProduct(name=self.p1.name),
            )
        constraint.validate(
            UniqueConstraintProduct,
            UniqueConstraintProduct(name=self.p1.name),
            exclude={"name"},
        )

    @skipUnlessDBFeature("supports_table_check_constraints")
    def test_validate_nullable_textfield_with_isnull_true(self):
        is_null_constraint = models.UniqueConstraint(
            "price",
            "discounted_price",
            condition=models.Q(unit__isnull=True),
            name="uniq_prices_no_unit",
        )
        is_not_null_constraint = models.UniqueConstraint(
            "price",
            "discounted_price",
            condition=models.Q(unit__isnull=False),
            name="uniq_prices_unit",
        )

        Product.objects.create(price=2, discounted_price=1)
        Product.objects.create(price=4, discounted_price=3, unit="ng/mL")

        msg = "Constraint “uniq_prices_no_unit” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            is_null_constraint.validate(
                Product, Product(price=2, discounted_price=1, unit=None)
            )
        is_null_constraint.validate(
            Product, Product(price=2, discounted_price=1, unit="ng/mL")
        )
        is_null_constraint.validate(Product, Product(price=4, discounted_price=3))

        msg = "Constraint “uniq_prices_unit” is violated."
        with self.assertRaisesMessage(ValidationError, msg):
            is_not_null_constraint.validate(
                Product,
                Product(price=4, discounted_price=3, unit="μg/mL"),
            )
        is_not_null_constraint.validate(Product, Product(price=4, discounted_price=3))
        is_not_null_constraint.validate(Product, Product(price=2, discounted_price=1))

    def test_name(self):
        constraints = get_constraints(UniqueConstraintProduct._meta.db_table)
        expected_name = "name_color_uniq"
        self.assertIn(expected_name, constraints)

    def test_condition_must_be_q(self):
        with self.assertRaisesMessage(
            ValueError, "UniqueConstraint.condition must be a Q instance."
        ):
            models.UniqueConstraint(name="uniq", fields=["name"], condition="invalid")

    @skipUnlessDBFeature("supports_deferrable_unique_constraints")
    def test_initially_deferred_database_constraint(self):
        obj_1 = UniqueConstraintDeferrable.objects.create(name="p1", shelf="front")
        obj_2 = UniqueConstraintDeferrable.objects.create(name="p2", shelf="back")

        def swap():
            obj_1.name, obj_2.name = obj_2.name, obj_1.name
            obj_1.save()
            obj_2.save()

        swap()
        
        with self.assertRaises(IntegrityError):
            with atomic(), connection.cursor() as cursor:
                constraint_name = connection.ops.quote_name("name_init_deferred_uniq")
                cursor.execute("SET CONSTRAINTS %s IMMEDIATE" % constraint_name)
                swap()

    @skipUnlessDBFeature("supports_deferrable_unique_constraints")
    def test_initially_immediate_database_constraint(self):
        obj_1 = UniqueConstraintDeferrable.objects.create(name="p1", shelf="front")
        obj_2 = UniqueConstraintDeferrable.objects.create(name="p2", shelf="back")
        obj_1.shelf, obj_2.shelf = obj_2.shelf, obj_1.shelf
        with self.assertRaises(IntegrityError), atomic():
            obj_1.save()
        
        with connection.cursor() as cursor:
            constraint_name = connection.ops.quote_name("sheld_init_immediate_uniq")
            cursor.execute("SET CONSTRAINTS %s DEFERRED" % constraint_name)
            obj_1.save()
            obj_2.save()

    def test_deferrable_with_condition(self):
        message = "UniqueConstraint with conditions cannot be deferred."
        with self.assertRaisesMessage(ValueError, message):
            models.UniqueConstraint(
                fields=["name"],
                name="name_without_color_unique",
                condition=models.Q(color__isnull=True),
                deferrable=models.Deferrable.DEFERRED,
            )

    def test_deferrable_with_include(self):
        message = "UniqueConstraint with include fields cannot be deferred."
        with self.assertRaisesMessage(ValueError, message):
            models.UniqueConstraint(
                fields=["name"],
                name="name_inc_color_color_unique",
                include=["color"],
                deferrable=models.Deferrable.DEFERRED,
            )

    def test_deferrable_with_opclasses(self):
        message = "UniqueConstraint with opclasses cannot be deferred."
        with self.assertRaisesMessage(ValueError, message):
            models.UniqueConstraint(
                fields=["name"],
                name="name_text_pattern_ops_unique",
                opclasses=["text_pattern_ops"],
                deferrable=models.Deferrable.DEFERRED,
            )

    def test_deferrable_with_expressions(self):
        message = "UniqueConstraint with expressions cannot be deferred."
        with self.assertRaisesMessage(ValueError, message):
            models.UniqueConstraint(
                Lower("name"),
                name="deferred_expression_unique",
                deferrable=models.Deferrable.DEFERRED,
            )

    def test_invalid_defer_argument(self):
        message = "UniqueConstraint.deferrable must be a Deferrable instance."
        with self.assertRaisesMessage(TypeError, message):
            models.UniqueConstraint(
                fields=["name"],
                name="name_invalid",
                deferrable="invalid",
            )

    @skipUnlessDBFeature(
        "supports_table_check_constraints",
        "supports_covering_indexes",
    )
    def test_include_database_constraint(self):
        UniqueConstraintInclude.objects.create(name="p1", color="red")
        with self.assertRaises(IntegrityError):
            UniqueConstraintInclude.objects.create(name="p1", color="blue")

    def test_invalid_include_argument(self):
        msg = "UniqueConstraint.include must be a list or tuple."
        with self.assertRaisesMessage(TypeError, msg):
            models.UniqueConstraint(
                name="uniq_include",
                fields=["field"],
                include="other",
            )

    def test_invalid_opclasses_argument(self):
        msg = "UniqueConstraint.opclasses must be a list or tuple."
        with self.assertRaisesMessage(TypeError, msg):
            models.UniqueConstraint(
                name="uniq_opclasses",
                fields=["field"],
                opclasses="jsonb_path_ops",
            )

    def test_invalid_nulls_distinct_argument(self):
        msg = "UniqueConstraint.nulls_distinct must be a bool."
        with self.assertRaisesMessage(TypeError, msg):
            models.UniqueConstraint(
                name="uniq_opclasses", fields=["field"], nulls_distinct="NULLS DISTINCT"
            )

    def test_opclasses_and_fields_same_length(self):
        msg = (
            "UniqueConstraint.fields and UniqueConstraint.opclasses must have "
            "the same number of elements."
        )
        with self.assertRaisesMessage(ValueError, msg):
            models.UniqueConstraint(
                name="uniq_opclasses",
                fields=["field"],
                opclasses=["foo", "bar"],
            )

    def test_requires_field_or_expression(self):
        msg = (
            "At least one field or expression is required to define a unique "
            "constraint."
        )
        with self.assertRaisesMessage(ValueError, msg):
            models.UniqueConstraint(name="name")

    def test_expressions_and_fields_mutually_exclusive(self):
        msg = "UniqueConstraint.fields and expressions are mutually exclusive."
        with self.assertRaisesMessage(ValueError, msg):
            models.UniqueConstraint(Lower("field_1"), fields=["field_2"], name="name")

    def test_expressions_with_opclasses(self):
        msg = (
            "UniqueConstraint.opclasses cannot be used with expressions. Use "
            "django.contrib.postgres.indexes.OpClass() instead."
        )
        with self.assertRaisesMessage(ValueError, msg):
            models.UniqueConstraint(
                Lower("field"),
                name="test_func_opclass",
                opclasses=["jsonb_path_ops"],
            )

    def test_requires_name(self):
        msg = "A unique constraint must be named."
        with self.assertRaisesMessage(ValueError, msg):
            models.UniqueConstraint(fields=["field"])