Fixed #30396 -- Added system checks for uniqueness of indexes and constraints names.

Co-Authored-By: Mariusz Felisiak <felisiak.mariusz@gmail.com>

4 files changed, 204 insertions, 1 deletions

diff --git a/AUTHORS b/AUTHORS
index 6983965cd1..e9c027167c 100644
--- a/AUTHORS
+++ b/AUTHORS
@@ -152,6 +152,7 @@ answer newbie questions, and generally made Django that much better:
     Cameron Curry
     Cameron Knight (ckknight)
     Can Burak Çilingir <canburak@cs.bilgi.edu.tr>
+    Can Sarıgöl <ertugrulsarigol@gmail.com>
     Carl Meyer <carl@oddbird.net>
     Carles Pina i Estany <carles@pina.cat>
     Carlos Eduardo de Paula <carlosedp@gmail.com>
diff --git a/django/core/checks/model_checks.py b/django/core/checks/model_checks.py
index 6c6ac2c7f4..5c2266ca1d 100644
--- a/django/core/checks/model_checks.py
+++ b/django/core/checks/model_checks.py
@@ -10,6 +10,8 @@ from django.core.checks import Error, Tags, register
 @register(Tags.models)
 def check_all_models(app_configs=None, **kwargs):
     db_table_models = defaultdict(list)
+    indexes = defaultdict(list)
+    constraints = defaultdict(list)
     errors = []
     if app_configs is None:
         models = apps.get_models()
@@ -29,6 +31,10 @@ def check_all_models(app_configs=None, **kwargs):
             )
         else:
             errors.extend(model.check(**kwargs))
+        for model_index in model._meta.indexes:
+            indexes[model_index.name].append(model._meta.label)
+        for model_constraint in model._meta.constraints:
+            constraints[model_constraint.name].append(model._meta.label)
     for db_table, model_labels in db_table_models.items():
         if len(model_labels) != 1:
             errors.append(
@@ -39,6 +45,32 @@ def check_all_models(app_configs=None, **kwargs):
                     id='models.E028',
                 )
             )
+    for index_name, model_labels in indexes.items():
+        if len(model_labels) > 1:
+            model_labels = set(model_labels)
+            errors.append(
+                Error(
+                    "index name '%s' is not unique %s %s." % (
+                        index_name,
+                        'for model' if len(model_labels) == 1 else 'amongst models:',
+                        ', '.join(sorted(model_labels)),
+                    ),
+                    id='models.E029' if len(model_labels) == 1 else 'models.E030',
+                ),
+            )
+    for constraint_name, model_labels in constraints.items():
+        if len(model_labels) > 1:
+            model_labels = set(model_labels)
+            errors.append(
+                Error(
+                    "constraint name '%s' is not unique %s %s." % (
+                        constraint_name,
+                        'for model' if len(model_labels) == 1 else 'amongst models:',
+                        ', '.join(sorted(model_labels)),
+                    ),
+                    id='models.E031' if len(model_labels) == 1 else 'models.E032',
+                ),
+            )
     return errors
 
 
diff --git a/docs/ref/checks.txt b/docs/ref/checks.txt
index 973ccebe90..a15eb558fe 100644
--- a/docs/ref/checks.txt
+++ b/docs/ref/checks.txt
@@ -306,6 +306,13 @@ Models
 * **models.W027**: ``<database>`` does not support check constraints.
 * **models.E028**: ``db_table`` ``<db_table>`` is used by multiple models:
   ``<model list>``.
+* **models.E029**: index name ``<index>`` is not unique for model ``<model>``.
+* **models.E030**: index name ``<index>`` is not unique amongst models:
+  ``<model list>``.
+* **models.E031**: constraint name ``<constraint>`` is not unique for model
+  ``<model>``.
+* **models.E032**: constraint name ``<constraint>`` is not unique amongst
+  models: ``<model list>``.
 
 Security
 --------
diff --git a/tests/check_framework/test_model_checks.py b/tests/check_framework/test_model_checks.py
index 2e55ad637d..0cbc0aff44 100644
--- a/tests/check_framework/test_model_checks.py
+++ b/tests/check_framework/test_model_checks.py
@@ -1,7 +1,7 @@
 from django.core import checks
 from django.core.checks import Error
 from django.db import models
-from django.test import SimpleTestCase
+from django.test import SimpleTestCase, TestCase, skipUnlessDBFeature
 from django.test.utils import (
     isolate_apps, modify_settings, override_system_checks,
 )
@@ -73,3 +73,166 @@ class DuplicateDBTableTests(SimpleTestCase):
 
         self.assertEqual(Model._meta.db_table, ProxyModel._meta.db_table)
         self.assertEqual(checks.run_checks(app_configs=self.apps.get_app_configs()), [])
+
+
+@isolate_apps('check_framework', attr_name='apps')
+@override_system_checks([checks.model_checks.check_all_models])
+class IndexNameTests(SimpleTestCase):
+    def test_collision_in_same_model(self):
+        index = models.Index(fields=['id'], name='foo')
+
+        class Model(models.Model):
+            class Meta:
+                indexes = [index, index]
+
+        self.assertEqual(checks.run_checks(app_configs=self.apps.get_app_configs()), [
+            Error(
+                "index name 'foo' is not unique for model check_framework.Model.",
+                id='models.E029',
+            ),
+        ])
+
+    def test_collision_in_different_models(self):
+        index = models.Index(fields=['id'], name='foo')
+
+        class Model1(models.Model):
+            class Meta:
+                indexes = [index]
+
+        class Model2(models.Model):
+            class Meta:
+                indexes = [index]
+
+        self.assertEqual(checks.run_checks(app_configs=self.apps.get_app_configs()), [
+            Error(
+                "index name 'foo' is not unique amongst models: "
+                "check_framework.Model1, check_framework.Model2.",
+                id='models.E030',
+            ),
+        ])
+
+    def test_collision_abstract_model(self):
+        class AbstractModel(models.Model):
+            class Meta:
+                indexes = [models.Index(fields=['id'], name='foo')]
+                abstract = True
+
+        class Model1(AbstractModel):
+            pass
+
+        class Model2(AbstractModel):
+            pass
+
+        self.assertEqual(checks.run_checks(app_configs=self.apps.get_app_configs()), [
+            Error(
+                "index name 'foo' is not unique amongst models: "
+                "check_framework.Model1, check_framework.Model2.",
+                id='models.E030',
+            ),
+        ])
+
+    @modify_settings(INSTALLED_APPS={'append': 'basic'})
+    @isolate_apps('basic', 'check_framework', kwarg_name='apps')
+    def test_collision_across_apps(self, apps):
+        index = models.Index(fields=['id'], name='foo')
+
+        class Model1(models.Model):
+            class Meta:
+                app_label = 'basic'
+                indexes = [index]
+
+        class Model2(models.Model):
+            class Meta:
+                app_label = 'check_framework'
+                indexes = [index]
+
+        self.assertEqual(checks.run_checks(app_configs=apps.get_app_configs()), [
+            Error(
+                "index name 'foo' is not unique amongst models: basic.Model1, "
+                "check_framework.Model2.",
+                id='models.E030',
+            ),
+        ])
+
+
+@isolate_apps('check_framework', attr_name='apps')
+@override_system_checks([checks.model_checks.check_all_models])
+@skipUnlessDBFeature('supports_table_check_constraints')
+class ConstraintNameTests(TestCase):
+    def test_collision_in_same_model(self):
+        class Model(models.Model):
+            class Meta:
+                constraints = [
+                    models.CheckConstraint(check=models.Q(id__gt=0), name='foo'),
+                    models.CheckConstraint(check=models.Q(id__lt=100), name='foo'),
+                ]
+
+        self.assertEqual(checks.run_checks(app_configs=self.apps.get_app_configs()), [
+            Error(
+                "constraint name 'foo' is not unique for model "
+                "check_framework.Model.",
+                id='models.E031',
+            ),
+        ])
+
+    def test_collision_in_different_models(self):
+        constraint = models.CheckConstraint(check=models.Q(id__gt=0), name='foo')
+
+        class Model1(models.Model):
+            class Meta:
+                constraints = [constraint]
+
+        class Model2(models.Model):
+            class Meta:
+                constraints = [constraint]
+
+        self.assertEqual(checks.run_checks(app_configs=self.apps.get_app_configs()), [
+            Error(
+                "constraint name 'foo' is not unique amongst models: "
+                "check_framework.Model1, check_framework.Model2.",
+                id='models.E032',
+            ),
+        ])
+
+    def test_collision_abstract_model(self):
+        class AbstractModel(models.Model):
+            class Meta:
+                constraints = [models.CheckConstraint(check=models.Q(id__gt=0), name='foo')]
+                abstract = True
+
+        class Model1(AbstractModel):
+            pass
+
+        class Model2(AbstractModel):
+            pass
+
+        self.assertEqual(checks.run_checks(app_configs=self.apps.get_app_configs()), [
+            Error(
+                "constraint name 'foo' is not unique amongst models: "
+                "check_framework.Model1, check_framework.Model2.",
+                id='models.E032',
+            ),
+        ])
+
+    @modify_settings(INSTALLED_APPS={'append': 'basic'})
+    @isolate_apps('basic', 'check_framework', kwarg_name='apps')
+    def test_collision_across_apps(self, apps):
+        constraint = models.CheckConstraint(check=models.Q(id__gt=0), name='foo')
+
+        class Model1(models.Model):
+            class Meta:
+                app_label = 'basic'
+                constraints = [constraint]
+
+        class Model2(models.Model):
+            class Meta:
+                app_label = 'check_framework'
+                constraints = [constraint]
+
+        self.assertEqual(checks.run_checks(app_configs=apps.get_app_configs()), [
+            Error(
+                "constraint name 'foo' is not unique amongst models: "
+                "basic.Model1, check_framework.Model2.",
+                id='models.E032',
+            ),
+        ])