Massive migration optimiser improvements + RenameModel opn

2 files changed, 218 insertions, 1 deletions

diff --git a/tests/migrations/test_operations.py b/tests/migrations/test_operations.py
index 9121755000..fb38605030 100644
--- a/tests/migrations/test_operations.py
+++ b/tests/migrations/test_operations.py
@@ -100,6 +100,30 @@ class OperationTests(MigrationTestBase):
             operation.database_backwards("test_dlmo", editor, new_state, project_state)
         self.assertTableExists("test_dlmo_pony")
 
+    def test_rename_model(self):
+        """
+        Tests the RenameModel operation.
+        """
+        project_state = self.set_up_test_model("test_rnmo")
+        # Test the state alteration
+        operation = migrations.RenameModel("Pony", "Horse")
+        new_state = project_state.clone()
+        operation.state_forwards("test_rnmo", new_state)
+        self.assertNotIn(("test_rnmo", "pony"), new_state.models)
+        self.assertIn(("test_rnmo", "horse"), new_state.models)
+        # Test the database alteration
+        self.assertTableExists("test_rnmo_pony")
+        self.assertTableNotExists("test_rnmo_horse")
+        with connection.schema_editor() as editor:
+            operation.database_forwards("test_rnmo", editor, project_state, new_state)
+        self.assertTableNotExists("test_rnmo_pony")
+        self.assertTableExists("test_rnmo_horse")
+        # And test reversal
+        with connection.schema_editor() as editor:
+            operation.database_backwards("test_rnmo", editor, new_state, project_state)
+        self.assertTableExists("test_dlmo_pony")
+        self.assertTableNotExists("test_rnmo_horse")
+
     def test_add_field(self):
         """
         Tests the AddField operation.
diff --git a/tests/migrations/test_optimizer.py b/tests/migrations/test_optimizer.py
index 7a481c905c..8ba42db467 100644
--- a/tests/migrations/test_optimizer.py
+++ b/tests/migrations/test_optimizer.py
@@ -1,4 +1,5 @@
 # encoding: utf8
+import operator
 from django.test import TestCase
 from django.db.migrations.optimizer import MigrationOptimizer
 from django.db import migrations
@@ -64,7 +65,7 @@ class OptimizerTests(TestCase):
         self.assertOptimizesTo(
             [migrations.DeleteModel("Foo")],
             [migrations.DeleteModel("Foo")],
-            exact=1,
+            exact = 1,
         )
 
     def test_create_delete_model(self):
@@ -79,6 +80,34 @@ class OptimizerTests(TestCase):
             [],
         )
 
+    def test_create_rename_model(self):
+        """
+        CreateModel should absorb RenameModels.
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
+                migrations.RenameModel("Foo", "Bar"),
+            ],
+            [
+                migrations.CreateModel("Bar", [("name", models.CharField(max_length=255))]),
+            ],
+        )
+
+    def test_rename_model_self(self):
+        """
+        RenameModels should absorb themselves.
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.RenameModel("Foo", "Baa"),
+                migrations.RenameModel("Baa", "Bar"),
+            ],
+            [
+                migrations.RenameModel("Foo", "Bar"),
+            ],
+        )
+
     def test_create_alter_delete_model(self):
         """
         CreateModel, AlterModelTable, AlterUniqueTogether, and DeleteModel should collapse into nothing.
@@ -154,3 +183,167 @@ class OptimizerTests(TestCase):
                 migrations.DeleteModel("Foo"),
             ],
         )
+
+    def test_create_model_add_field(self):
+        """
+        AddField should optimize into CreateModel.
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
+                migrations.AddField("Foo", "age", models.IntegerField()),
+            ],
+            [
+                migrations.CreateModel("Foo", [
+                    ("name", models.CharField(max_length=255)),
+                    ("age", models.IntegerField()),
+                ]),
+            ],
+        )
+
+    def test_create_model_alter_field(self):
+        """
+        AlterField should optimize into CreateModel.
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
+                migrations.AlterField("Foo", "name", models.IntegerField()),
+            ],
+            [
+                migrations.CreateModel("Foo", [
+                    ("name", models.IntegerField()),
+                ]),
+            ],
+        )
+
+    def test_create_model_rename_field(self):
+        """
+        RenameField should optimize into CreateModel.
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
+                migrations.RenameField("Foo", "name", "title"),
+            ],
+            [
+                migrations.CreateModel("Foo", [
+                    ("title", models.CharField(max_length=255)),
+                ]),
+            ],
+        )
+
+    def test_add_field_rename_field(self):
+        """
+        RenameField should optimize into AddField
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.AddField("Foo", "name", models.CharField(max_length=255)),
+                migrations.RenameField("Foo", "name", "title"),
+            ],
+            [
+                migrations.AddField("Foo", "title", models.CharField(max_length=255)),
+            ],
+        )
+
+    def test_alter_field_rename_field(self):
+        """
+        RenameField should optimize to the other side of AlterField,
+        and into itself.
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.AlterField("Foo", "name", models.CharField(max_length=255)),
+                migrations.RenameField("Foo", "name", "title"),
+                migrations.RenameField("Foo", "title", "nom"),
+            ],
+            [
+                migrations.RenameField("Foo", "name", "nom"),
+                migrations.AlterField("Foo", "nom", models.CharField(max_length=255)),
+            ],
+        )
+
+    def test_create_model_remove_field(self):
+        """
+        RemoveField should optimize into CreateModel.
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.CreateModel("Foo", [
+                    ("name", models.CharField(max_length=255)),
+                    ("age", models.IntegerField()),
+                ]),
+                migrations.RemoveField("Foo", "age"),
+            ],
+            [
+                migrations.CreateModel("Foo", [
+                    ("name", models.CharField(max_length=255)),
+                ]),
+            ],
+        )
+
+    def test_add_field_alter_field(self):
+        """
+        AlterField should optimize into AddField.
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.AddField("Foo", "age", models.IntegerField()),
+                migrations.AlterField("Foo", "age", models.FloatField(default=2.4)),
+            ],
+            [
+                migrations.AddField("Foo", "age", models.FloatField(default=2.4)),
+            ],
+        )
+
+    def test_add_field_delete_field(self):
+        """
+        RemoveField should cancel AddField
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.AddField("Foo", "age", models.IntegerField()),
+                migrations.RemoveField("Foo", "age"),
+            ],
+            [],
+        )
+
+    def test_alter_field_delete_field(self):
+        """
+        RemoveField should absorb AlterField
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.AlterField("Foo", "age", models.IntegerField()),
+                migrations.RemoveField("Foo", "age"),
+            ],
+            [
+                migrations.RemoveField("Foo", "age"),
+            ],
+        )
+
+    def test_optimize_through_fields(self):
+        """
+        Checks that field-level through checking is working.
+        This should manage to collapse model Foo to nonexistence,
+        and model Bar to a single IntegerField called "width".
+        """
+        self.assertOptimizesTo(
+            [
+                migrations.CreateModel("Foo", [("name", models.CharField(max_length=255))]),
+                migrations.CreateModel("Bar", [("size", models.IntegerField())]),
+                migrations.AddField("Foo", "age", models.IntegerField()),
+                migrations.AddField("Bar", "width", models.IntegerField()),
+                migrations.AlterField("Foo", "age", models.IntegerField()),
+                migrations.RenameField("Bar", "size", "dimensions"),
+                migrations.RemoveField("Foo", "age"),
+                migrations.RenameModel("Foo", "Phou"),
+                migrations.RemoveField("Bar", "dimensions"),
+                migrations.RenameModel("Phou", "Fou"),
+                migrations.DeleteModel("Fou"),
+            ],
+            [
+                migrations.CreateModel("Bar", [("width", models.IntegerField())]),
+            ],
+        )