Refs #33829 -- Added violation_error_message to constraints' __repr__().

django/contrib/postgres/constraints.py

@@ -154,7 +154,7 @@ class ExclusionConstraint(BaseConstraint):
         return super().__eq__(other)
 
     def __repr__(self):
-        return "<%s: index_type=%s expressions=%s name=%s%s%s%s>" % (
+        return "<%s: index_type=%s expressions=%s name=%s%s%s%s%s>" % (
             self.__class__.__qualname__,
             repr(self.index_type),
             repr(self.expressions),
@@ -162,6 +162,12 @@ class ExclusionConstraint(BaseConstraint):
             "" if self.condition is None else " condition=%s" % self.condition,
             "" if self.deferrable is None else " deferrable=%r" % self.deferrable,
             "" if not self.include else " include=%s" % repr(self.include),
+            (
+                ""
+                if self.violation_error_message is None
+                or self.violation_error_message == self.default_violation_error_message
+                else " violation_error_message=%r" % self.violation_error_message
+            ),
         )
 
     def validate(self, model, instance, exclude=None, using=DEFAULT_DB_ALIAS):

django/db/models/constraints.py

@@ -117,10 +117,16 @@ class CheckConstraint(BaseConstraint):
             pass
 
     def __repr__(self):
-        return "<%s: check=%s name=%s>" % (
+        return "<%s: check=%s name=%s%s>" % (
             self.__class__.__qualname__,
             self.check,
             repr(self.name),
+            (
+                ""
+                if self.violation_error_message is None
+                or self.violation_error_message == self.default_violation_error_message
+                else " violation_error_message=%r" % self.violation_error_message
+            ),
         )
 
     def __eq__(self, other):
@@ -287,7 +293,7 @@ class UniqueConstraint(BaseConstraint):
         )
 
     def __repr__(self):
-        return "<%s:%s%s%s%s%s%s%s>" % (
+        return "<%s:%s%s%s%s%s%s%s%s>" % (
             self.__class__.__qualname__,
             "" if not self.fields else " fields=%s" % repr(self.fields),
             "" if not self.expressions else " expressions=%s" % repr(self.expressions),
@@ -296,6 +302,12 @@ class UniqueConstraint(BaseConstraint):
             "" if self.deferrable is None else " deferrable=%r" % self.deferrable,
             "" if not self.include else " include=%s" % repr(self.include),
             "" if not self.opclasses else " opclasses=%s" % repr(self.opclasses),
+            (
+                ""
+                if self.violation_error_message is None
+                or self.violation_error_message == self.default_violation_error_message
+                else " violation_error_message=%r" % self.violation_error_message
+            ),
         )
 
     def __eq__(self, other):

tests/constraints/tests.py

@@ -160,6 +160,18 @@ class CheckConstraintTests(TestCase):
             "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_invalid_check_types(self):
         msg = "CheckConstraint.check must be a Q instance or boolean expression."
         with self.assertRaisesMessage(TypeError, msg):
@@ -486,6 +498,20 @@ class UniqueConstraintTests(TestCase):
             "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_deconstruction(self):
         fields = ["foo", "bar"]
         name = "unique_fields"

tests/postgres_tests/test_constraints.py

@@ -386,6 +386,17 @@ class ExclusionConstraintTests(PostgreSQLTestCase):
             "(OpClass(F(datespan), name=range_ops), '-|-')] "
             "name='exclude_overlapping'>",
         )
+        constraint = ExclusionConstraint(
+            name="exclude_overlapping",
+            expressions=[(F("datespan"), RangeOperators.ADJACENT_TO)],
+            violation_error_message="Overlapping must be excluded",
+        )
+        self.assertEqual(
+            repr(constraint),
+            "<ExclusionConstraint: index_type='GIST' expressions=["
+            "(F(datespan), '-|-')] name='exclude_overlapping' "
+            "violation_error_message='Overlapping must be excluded'>",
+        )
 
     def test_eq(self):
         constraint_1 = ExclusionConstraint(