Fixed #35704 -- Fixed reduction for AddIndex subclasses.

4 files changed, 90 insertions, 39 deletions

diff --git a/django/db/migrations/operations/models.py b/django/db/migrations/operations/models.py
index c8f7a2627a..2469d01efb 100644
--- a/django/db/migrations/operations/models.py
+++ b/django/db/migrations/operations/models.py
@@ -979,7 +979,7 @@ class AddIndex(IndexOperation):
             return []
         if isinstance(operation, RenameIndex) and self.index.name == operation.old_name:
             self.index.name = operation.new_name
-            return [AddIndex(model_name=self.model_name, index=self.index)]
+            return [self.__class__(model_name=self.model_name, index=self.index)]
         return super().reduce(operation, app_label)
 
 
diff --git a/tests/migrations/test_base.py b/tests/migrations/test_base.py
index 0ff1dda1d9..cde4063d04 100644
--- a/tests/migrations/test_base.py
+++ b/tests/migrations/test_base.py
@@ -7,9 +7,11 @@ from importlib import import_module
 from django.apps import apps
 from django.db import connection, connections, migrations, models
 from django.db.migrations.migration import Migration
+from django.db.migrations.optimizer import MigrationOptimizer
 from django.db.migrations.recorder import MigrationRecorder
+from django.db.migrations.serializer import serializer_factory
 from django.db.migrations.state import ProjectState
-from django.test import TransactionTestCase
+from django.test import SimpleTestCase, TransactionTestCase
 from django.test.utils import extend_sys_path
 from django.utils.module_loading import module_dir
 
@@ -400,3 +402,38 @@ class OperationTestBase(MigrationTestBase):
                 )
             )
         return self.apply_operations(app_label, ProjectState(), operations)
+
+
+class OptimizerTestBase(SimpleTestCase):
+    """Common functions to help test the optimizer."""
+
+    def optimize(self, operations, app_label):
+        """
+        Handy shortcut for getting results + number of loops
+        """
+        optimizer = MigrationOptimizer()
+        return optimizer.optimize(operations, app_label), optimizer._iterations
+
+    def serialize(self, value):
+        return serializer_factory(value).serialize()[0]
+
+    def assertOptimizesTo(
+        self, operations, expected, exact=None, less_than=None, app_label=None
+    ):
+        result, iterations = self.optimize(operations, app_label or "migrations")
+        result = [self.serialize(f) for f in result]
+        expected = [self.serialize(f) for f in expected]
+        self.assertEqual(expected, result)
+        if exact is not None and iterations != exact:
+            raise self.failureException(
+                "Optimization did not take exactly %s iterations (it took %s)"
+                % (exact, iterations)
+            )
+        if less_than is not None and iterations >= less_than:
+            raise self.failureException(
+                "Optimization did not take less than %s iterations (it took %s)"
+                % (less_than, iterations)
+            )
+
+    def assertDoesNotOptimize(self, operations, **kwargs):
+        self.assertOptimizesTo(operations, operations, **kwargs)
diff --git a/tests/migrations/test_optimizer.py b/tests/migrations/test_optimizer.py
index 3ed30102bf..0a40b50edc 100644
--- a/tests/migrations/test_optimizer.py
+++ b/tests/migrations/test_optimizer.py
@@ -1,49 +1,17 @@
 from django.db import migrations, models
 from django.db.migrations import operations
 from django.db.migrations.optimizer import MigrationOptimizer
-from django.db.migrations.serializer import serializer_factory
 from django.db.models.functions import Abs
-from django.test import SimpleTestCase
 
 from .models import EmptyManager, UnicodeModel
+from .test_base import OptimizerTestBase
 
 
-class OptimizerTests(SimpleTestCase):
+class OptimizerTests(OptimizerTestBase):
     """
-    Tests the migration autodetector.
+    Tests the migration optimizer.
     """
 
-    def optimize(self, operations, app_label):
-        """
-        Handy shortcut for getting results + number of loops
-        """
-        optimizer = MigrationOptimizer()
-        return optimizer.optimize(operations, app_label), optimizer._iterations
-
-    def serialize(self, value):
-        return serializer_factory(value).serialize()[0]
-
-    def assertOptimizesTo(
-        self, operations, expected, exact=None, less_than=None, app_label=None
-    ):
-        result, iterations = self.optimize(operations, app_label or "migrations")
-        result = [self.serialize(f) for f in result]
-        expected = [self.serialize(f) for f in expected]
-        self.assertEqual(expected, result)
-        if exact is not None and iterations != exact:
-            raise self.failureException(
-                "Optimization did not take exactly %s iterations (it took %s)"
-                % (exact, iterations)
-            )
-        if less_than is not None and iterations >= less_than:
-            raise self.failureException(
-                "Optimization did not take less than %s iterations (it took %s)"
-                % (less_than, iterations)
-            )
-
-    def assertDoesNotOptimize(self, operations, **kwargs):
-        self.assertOptimizesTo(operations, operations, **kwargs)
-
     def test_none_app_label(self):
         optimizer = MigrationOptimizer()
         with self.assertRaisesMessage(TypeError, "app_label must be a str"):
diff --git a/tests/postgres_tests/test_operations.py b/tests/postgres_tests/test_operations.py
index 5780348251..f344d4ae74 100644
--- a/tests/postgres_tests/test_operations.py
+++ b/tests/postgres_tests/test_operations.py
@@ -1,8 +1,9 @@
 import unittest
 
-from migrations.test_base import OperationTestBase
+from migrations.test_base import OperationTestBase, OptimizerTestBase
 
 from django.db import IntegrityError, NotSupportedError, connection, transaction
+from django.db.migrations.operations import RemoveIndex, RenameIndex
 from django.db.migrations.state import ProjectState
 from django.db.migrations.writer import OperationWriter
 from django.db.models import CheckConstraint, Index, Q, UniqueConstraint
@@ -30,7 +31,7 @@ except ImportError:
 
 @unittest.skipUnless(connection.vendor == "postgresql", "PostgreSQL specific tests.")
 @modify_settings(INSTALLED_APPS={"append": "migrations"})
-class AddIndexConcurrentlyTests(OperationTestBase):
+class AddIndexConcurrentlyTests(OptimizerTestBase, OperationTestBase):
     app_label = "test_add_concurrently"
 
     def test_requires_atomic_false(self):
@@ -129,6 +130,51 @@ class AddIndexConcurrentlyTests(OperationTestBase):
             )
         self.assertIndexNotExists(table_name, ["pink"])
 
+    def test_reduce_add_remove_concurrently(self):
+        self.assertOptimizesTo(
+            [
+                AddIndexConcurrently(
+                    "Pony",
+                    Index(fields=["pink"], name="pony_pink_idx"),
+                ),
+                RemoveIndex("Pony", "pony_pink_idx"),
+            ],
+            [],
+        )
+
+    def test_reduce_add_remove(self):
+        self.assertOptimizesTo(
+            [
+                AddIndexConcurrently(
+                    "Pony",
+                    Index(fields=["pink"], name="pony_pink_idx"),
+                ),
+                RemoveIndexConcurrently("Pony", "pony_pink_idx"),
+            ],
+            [],
+        )
+
+    def test_reduce_add_rename(self):
+        self.assertOptimizesTo(
+            [
+                AddIndexConcurrently(
+                    "Pony",
+                    Index(fields=["pink"], name="pony_pink_idx"),
+                ),
+                RenameIndex(
+                    "Pony",
+                    old_name="pony_pink_idx",
+                    new_name="pony_pink_index",
+                ),
+            ],
+            [
+                AddIndexConcurrently(
+                    "Pony",
+                    Index(fields=["pink"], name="pony_pink_index"),
+                ),
+            ],
+        )
+
 
 @unittest.skipUnless(connection.vendor == "postgresql", "PostgreSQL specific tests.")
 @modify_settings(INSTALLED_APPS={"append": "migrations"})