Fixed #21892: RunPython no longer accepts strings

django/db/migrations/operations/special.py

@@ -109,22 +109,15 @@ class RunPython(Operation):
 
     def __init__(self, code, reverse_code=None):
         # Forwards code
-        if isinstance(code, six.string_types):
+        if not callable(code):
-            # Trim any leading whitespace that is at the start of all code lines
+            raise ValueError("RunPython must be supplied with a callable")
-            # so users can nicely indent code in migration files
+        self.code = code
-            code = textwrap.dedent(code)
-            # Run the code through a parser first to make sure it's at least
-            # syntactically correct
-            self.code = compile(code, "<string>", "exec")
-        else:
-            self.code = code
         # Reverse code
         if reverse_code is None:
             self.reverse_code = None
-        elif isinstance(reverse_code, six.string_types):
-            reverse_code = textwrap.dedent(reverse_code)
-            self.reverse_code = compile(reverse_code, "<string>", "exec")
         else:
+            if not callable(reverse_code):
+                raise ValueError("RunPython must be supplied with callable arguments")
             self.reverse_code = reverse_code
 
     def state_forwards(self, app_label, state):

tests/migrations/test_operations.py

@@ -479,13 +479,11 @@ class OperationTests(MigrationTestBase):
 
         project_state = self.set_up_test_model("test_runpython")
         # Create the operation
-        operation = migrations.RunPython(
+        def inner_method(models, schema_editor):
-            """
             Pony = models.get_model("test_runpython", "Pony")
-            Pony.objects.create(pink=2, weight=4.55)
+            Pony.objects.create(pink=1, weight=3.55)
-            Pony.objects.create(weight=1)
+            Pony.objects.create(weight=5)
-            """,
+        operation = migrations.RunPython(inner_method)
-        )
         # Test the state alteration does nothing
         new_state = project_state.clone()
         operation.state_forwards("test_runpython", new_state)
@@ -498,16 +496,9 @@ class OperationTests(MigrationTestBase):
         # And test reversal fails
         with self.assertRaises(NotImplementedError):
             operation.database_backwards("test_runpython", None, new_state, project_state)
-        # Now test we can do it with a callable
+        # Now test we can't use a string
-
+        with self.assertRaises(ValueError):
-        def inner_method(models, schema_editor):
+            operation = migrations.RunPython("print 'ahahaha'")
-            Pony = models.get_model("test_runpython", "Pony")
-            Pony.objects.create(pink=1, weight=3.55)
-            Pony.objects.create(weight=5)
-        operation = migrations.RunPython(inner_method)
-        with connection.schema_editor() as editor:
-            operation.database_forwards("test_runpython", editor, project_state, new_state)
-        self.assertEqual(project_state.render().get_model("test_runpython", "Pony").objects.count(), 4)
 
 
 class MigrateNothingRouter(object):