test_migrations.py

from django.core.management import call_command
from django.core.management.commands.makemigrations import Command
from django.db.migrations.writer import MigrationWriter
import mock
import pytest


def test_migrations_up_to_date():
    # --exit exits if there are _no_ changes, which is what we are looking for
    with pytest.raises(SystemExit):
        with mock.patch.object(Command, 'write_migration_files') as write:
            call_command('makemigrations', dry_run=True, exit=True)

        # output the actual migration contents for easier fixing
        (changes,), _ = write.call_args
        for app_label, app_migrations in changes.items():
            print "Migrations for '%s':\n" % app_label
            for migration in app_migrations:
                writer = MigrationWriter(migration)
                print writer.as_string()