False Positive When Using SeparateDatabaseAndState

[johnnymetz]

Steps to Reproduce

Let's say I have the following Django model:

class Product(models.Model):
    name = models.CharField(max_length=255)
    rating = models.IntegerField(null=True, blank=True)

I want to remove the rating field in a backwards-compatible way, so I create the following two migrations:

Migration 1: Remove rating field from the state

# 0002_remove_product_rating_from_state.py
class Migration(migrations.Migration):
    dependencies = [
        ("appname", "0001_initial"),
    ]

    operations = [
        migrations.SeparateDatabaseAndState(
            state_operations=[
                migrations.RemoveField(
                    model_name="product",
                    name="rating",
                ),
            ],
            database_operations=[],
        ),
    ]

Migration 2: Remove rating field from the database

# 0003_remove_product_rating_from_db.py
class Migration(migrations.Migration):
    dependencies = [
        ("appname", "0002_remove_product_rating_from_state"),
    ]

    operations = [
        migrations.SeparateDatabaseAndState(
            state_operations=[],
            database_operations=[
                migrations.RunSQL(
                    "ALTER TABLE product DROP COLUMN rating;"
                ),
            ],
        ),
    ]

The lintmigrations command reports that 0003_remove_product_rating_from_db is backwards incompatible:

$ python manage.py lintmigrations -q ok
(api, 0004_remove_metabase_field_from_db)... ERR
	DROPPING columns

Expected Result

The lintmigrations should show no errors. The rating field was removed from the state in 0002_remove_product_rating_from_state which makes 0003_remove_product_rating_from_db backwards compatible.

Questions / Comments

Does this seem like the correct solution? One issue is that these two migrations are ONLY backwards compatible if they're deployed separately. Deploying them both at once is obviously backwards incompatible.

If we can't track / enforce when these migrations are deployed, is the recommended solution to continue to report as backwards incompatible and require the user to ignore the false positive?

$ python manage.py lintmigrations -q ok -- ignore_name 0004_remove_metabase_field_from_db
# No errors