Commit 7d4a51e2 authored by Moayad Mardini's avatar Moayad Mardini Committed by Baptiste Mispelon
Browse files

[1.7.x] Fixed #22679 -- Fixed empty tuple serialization in MigrationWriter. 

Thanks rockallite.wulf for the report.

Backport of ad994a3c from master.
parent fb45e666

django/db/migrations/writer.py

+6 −2
Original line number Diff line number Diff line
@@ -206,7 +206,9 @@ class MigrationWriter(object): 
            if isinstance(value, set):

                format = "set([%s])"

            elif isinstance(value, tuple):

                format = "(%s)" if len(value) > 1 else "(%s,)"

                # When len(value)==0, the empty tuple should be serialized as

                # "()", not "(,)" because (,) is invalid Python syntax.

                format = "(%s)" if len(value) != 1 else "(%s,)"

            else:

                format = "[%s]"

            return format % (", ".join(strings)), imports
@@ -296,7 +298,9 @@ class MigrationWriter(object): 
                item_string, item_imports = cls.serialize(item)

                imports.update(item_imports)

                strings.append(item_string)

            format = "(%s)" if len(strings) > 1 else "(%s,)"

            # When len(strings)==0, the empty iterable should be serialized as

            # "()", not "(,)" because (,) is invalid Python syntax.

            format = "(%s)" if len(strings) != 1 else "(%s,)"

            return format % (", ".join(strings)), imports

        # Uh oh.

        else:

tests/migrations/test_writer.py

+12 −0
Original line number Diff line number Diff line
@@ -125,6 +125,18 @@ class WriterTests(TestCase): 
            )

        )



    def test_serialize_empty_nonempty_tuple(self):

        """

        Ticket #22679: makemigrations generates invalid code for (an empty

        tuple) default_permissions = ()

        """

        empty_tuple = ()

        one_item_tuple = ('a')

        many_items_tuple = ('a', 'b', 'c')

        self.assertSerializedEqual(empty_tuple)

        self.assertSerializedEqual(one_item_tuple)

        self.assertSerializedEqual(many_items_tuple)



    def test_simple_migration(self):

        """

        Tests serializing a simple migration.