Add an Executor for end-to-end running

tests/migrations/test_executor.py

@@ -0,0 +1,35 @@
+from django.test import TransactionTestCase
+from django.db import connection
+from django.db.migrations.executor import MigrationExecutor
+
+
+class ExecutorTests(TransactionTestCase):
+    """
+    Tests the migration executor (full end-to-end running).
+
+    Bear in mind that if these are failing you should fix the other
+    test failures first, as they may be propagating into here.
+    """
+
+    def test_run(self):
+        """
+        Tests running a simple set of migrations.
+        """
+        executor = MigrationExecutor(connection)
+        # Let's look at the plan first and make sure it's up to scratch
+        plan = executor.migration_plan([("migrations", "0002_second")])
+        self.assertEqual(
+            plan,
+            [
+                (executor.loader.graph.nodes["migrations", "0001_initial"], False),
+                (executor.loader.graph.nodes["migrations", "0002_second"], False),
+            ],
+        )
+        # Were the tables there before?
+        self.assertNotIn("migrations_author", connection.introspection.get_table_list(connection.cursor()))
+        self.assertNotIn("migrations_book", connection.introspection.get_table_list(connection.cursor()))
+        # Alright, let's try running it
+        executor.migrate([("migrations", "0002_second")])
+        # Are the tables there now?
+        self.assertIn("migrations_author", connection.introspection.get_table_list(connection.cursor()))
+        self.assertIn("migrations_book", connection.introspection.get_table_list(connection.cursor()))