"""
Unit tests for the part model database migrations
"""

from django_test_migrations.contrib.unittest_case import MigratorTestCase

from InvenTree import helpers


class TestForwardMigrations(MigratorTestCase):
    """
    Test entire schema migration sequence for the part app
    """

    migrate_from = ('part', helpers.getOldestMigrationFile('part'))
    migrate_to = ('part', helpers.getNewestMigrationFile('part'))

    def prepare(self):
        """
        Create initial data
        """

        Part = self.old_state.apps.get_model('part', 'part')

        Part.objects.create(name='A', description='My part A')
        Part.objects.create(name='B', description='My part B')
        Part.objects.create(name='C', description='My part C')
        Part.objects.create(name='D', description='My part D')
        Part.objects.create(name='E', description='My part E')

        # Extract one part object to investigate
        p = Part.objects.all().last()

        # Initially some fields are not present
        with self.assertRaises(AttributeError):
            print(p.has_variants)
        
        with self.assertRaises(AttributeError):
            print(p.is_template)


    def test_models_exist(self):

        Part = self.new_state.apps.get_model('part', 'part')

        self.assertEqual(Part.objects.count(), 5)

        for part in Part.objects.all():
            part.is_template = True
            part.save()
            part.is_template = False
            part.save()

Add initial migration unit test for the 'part' app
Add initial migration unit test for the 'part' app
