[1.10.x] Fixed #25044 -- Fixed migrations for renaming ManyToManyField's through model.

Backport of f1e408ff40d2c1753f92515c70a44634b4d47467 from master

2 files changed, 65 insertions, 0 deletions

diff --git a/tests/migrations/test_autodetector.py b/tests/migrations/test_autodetector.py
index 42c84c0ced..74dcdae88d 100644
--- a/tests/migrations/test_autodetector.py
+++ b/tests/migrations/test_autodetector.py
@@ -259,6 +259,10 @@ class AutodetectorTests(TestCase):
         ("id", models.AutoField(primary_key=True)),
         ("publishers", models.ManyToManyField("testapp.Publisher", through="testapp.Contract")),
     ])
+    author_with_renamed_m2m_through = ModelState("testapp", "Author", [
+        ("id", models.AutoField(primary_key=True)),
+        ("publishers", models.ManyToManyField("testapp.Publisher", through="testapp.Deal")),
+    ])
     author_with_former_m2m = ModelState("testapp", "Author", [
         ("id", models.AutoField(primary_key=True)),
         ("publishers", models.CharField(max_length=100)),
@@ -286,6 +290,11 @@ class AutodetectorTests(TestCase):
         ("author", models.ForeignKey("testapp.Author", models.CASCADE)),
         ("publisher", models.ForeignKey("testapp.Publisher", models.CASCADE)),
     ])
+    contract_renamed = ModelState("testapp", "Deal", [
+        ("id", models.AutoField(primary_key=True)),
+        ("author", models.ForeignKey("testapp.Author", models.CASCADE)),
+        ("publisher", models.ForeignKey("testapp.Publisher", models.CASCADE)),
+    ])
     publisher = ModelState("testapp", "Publisher", [
         ("id", models.AutoField(primary_key=True)),
         ("name", models.CharField(max_length=100)),
@@ -848,6 +857,21 @@ class AutodetectorTests(TestCase):
         # no AlterField for the related field.
         self.assertNumberMigrations(changes, 'otherapp', 0)
 
+    def test_rename_m2m_through_model(self):
+        """
+        Tests autodetection of renamed models that are used in M2M relations as
+        through models.
+        """
+        # Make state
+        before = self.make_project_state([self.author_with_m2m_through, self.publisher, self.contract])
+        after = self.make_project_state([self.author_with_renamed_m2m_through, self.publisher, self.contract_renamed])
+        autodetector = MigrationAutodetector(before, after, MigrationQuestioner({'ask_rename_model': True}))
+        changes = autodetector._detect_changes()
+        # Right number/type of migrations?
+        self.assertNumberMigrations(changes, 'testapp', 1)
+        self.assertOperationTypes(changes, 'testapp', 0, ['RenameModel'])
+        self.assertOperationAttributes(changes, 'testapp', 0, 0, old_name='Contract', new_name='Deal')
+
     def test_rename_model_with_renamed_rel_field(self):
         """
         Tests autodetection of renamed models while simultaneously renaming one
diff --git a/tests/migrations/test_operations.py b/tests/migrations/test_operations.py
index f86a39f5ee..e208ad5204 100644
--- a/tests/migrations/test_operations.py
+++ b/tests/migrations/test_operations.py
@@ -727,6 +727,47 @@ class OperationTests(OperationTestBase):
         self.assertEqual(Rider.objects.count(), 2)
         self.assertEqual(Pony._meta.get_field('riders').remote_field.through.objects.count(), 2)
 
+    def test_rename_m2m_through_model(self):
+        app_label = "test_rename_through"
+        project_state = self.apply_operations(app_label, ProjectState(), operations=[
+            migrations.CreateModel("Rider", fields=[
+                ("id", models.AutoField(primary_key=True)),
+            ]),
+            migrations.CreateModel("Pony", fields=[
+                ("id", models.AutoField(primary_key=True)),
+            ]),
+            migrations.CreateModel("PonyRider", fields=[
+                ("id", models.AutoField(primary_key=True)),
+                ("rider", models.ForeignKey("test_rename_through.Rider", models.CASCADE)),
+                ("pony", models.ForeignKey("test_rename_through.Pony", models.CASCADE)),
+            ]),
+            migrations.AddField(
+                "Pony",
+                "riders",
+                models.ManyToManyField("test_rename_through.Rider", through="test_rename_through.PonyRider"),
+            ),
+        ])
+        Pony = project_state.apps.get_model(app_label, "Pony")
+        Rider = project_state.apps.get_model(app_label, "Rider")
+        PonyRider = project_state.apps.get_model(app_label, "PonyRider")
+        pony = Pony.objects.create()
+        rider = Rider.objects.create()
+        PonyRider.objects.create(pony=pony, rider=rider)
+
+        project_state = self.apply_operations(app_label, project_state, operations=[
+            migrations.RenameModel("PonyRider", "PonyRider2"),
+        ])
+        Pony = project_state.apps.get_model(app_label, "Pony")
+        Rider = project_state.apps.get_model(app_label, "Rider")
+        PonyRider = project_state.apps.get_model(app_label, "PonyRider2")
+        pony = Pony.objects.first()
+        rider = Rider.objects.create()
+        PonyRider.objects.create(pony=pony, rider=rider)
+        self.assertEqual(Pony.objects.count(), 1)
+        self.assertEqual(Rider.objects.count(), 2)
+        self.assertEqual(PonyRider.objects.count(), 2)
+        self.assertEqual(pony.riders.count(), 2)
+
     def test_add_field(self):
         """
         Tests the AddField operation.