Ticket #31492: test.py

@skipUnlessDBFeature('supports_foreign_keys')
def test_alter_field_reloads_state_on_fk_with_to_field_target_type_change(self):
    app_label = 'test_alflrsfkwtflttc'
    project_state = self.apply_operations(app_label, ProjectState(), operations=[
        migrations.CreateModel('Rider', fields=[
            ('id', models.AutoField(primary_key=True)),
            ('code', models.PositiveIntegerField(unique=True)),
        ]),
        migrations.CreateModel('Pony', fields=[
            ('id', models.AutoField(primary_key=True)),
            ('rider', models.ForeignKey('%s.Rider' % app_label, models.CASCADE, to_field='code')),
        ]),
    ])
    operation = migrations.AlterField(
        'Rider',
        'code',
        models.CharField(max_length=100, unique=True),
    )
    self.apply_operations(app_label, project_state, operations=[operation])
    id_type, id_null = [
        (c.type_code, c.null_ok)
        for c in self.get_table_description('test_alflrsfkwtflttc_rider')
        if c.name == 'code'
    ][0]
    fk_type, fk_null = [
        (c.type_code, c.null_ok)
        for c in self.get_table_description('test_alflrsfkwtflttc_pony')
        if c.name == 'rider_id'
    ][0]
    self.assertEqual(id_type, fk_type)
    self.assertEqual(id_null, fk_null)