Migration conflict file

makemigrations.py

# coding: utf-8
"""Cause git to detect a merge conflict when two branches have migrations."""
# myapp/management/commands/makemigrations.py
# you'll need myapp/management/commands/__init__.py and myapp/management/__init__.py in PY2, see Django docs
from __future__ import absolute_import, unicode_literals

import io

import os
import six
from django.conf import settings
from django.db.migrations.loader import MigrationLoader
from django.core.management.commands.makemigrations import Command as MakeMigrationsCommand
# note: if you use django-migrate-sql, you will want to use:
#from migrate_sql.management.commands.makemigrations import Command as MakeMigrationsCommand
# note: for this to work, 'myapp' must be *above* 'migrate-sql' in settings.INSTALLED_APPS


class Command(MakeMigrationsCommand):
    """Cause git to detect a merge conflict when two branches have migrations."""

    def handle(self, *app_labels, **options):
        super(Command, self).handle(*app_labels, **options)
        loader = MigrationLoader(None, ignore_no_migrations=True)

        latest_migration_by_app = {}
        for migration in six.itervalues(loader.disk_migrations):
            name = migration.name
            app_label = migration.app_label
            latest_migration_by_app[app_label] = max(latest_migration_by_app.get(app_label, ''), name)

        result = '# File generated by myapp.management.commands.makemigrations.Command#handle\n'
        result += '\n'.join(
            '{}: {}'.format(app_label, name)
            for app_label, name in sorted(latest_migration_by_app.items())
        )

        with io.open(os.path.join(settings.BASE_DIR, 'latest_migrations.txt'), 'w') as f:
            f.write(result)