upstream-zulip/zerver/migrations/0771_alter_realmemoji_author.py

# Generated by Django 5.2.8 on 2025-12-17 17:47

import django.db.models.deletion
from django.conf import settings
from django.db import migrations, models
from django.db.backends.base.schema import BaseDatabaseSchemaEditor
from django.db.migrations.state import StateApps
from django.db.models import OuterRef, Subquery


def set_emoji_author(apps: StateApps, schema_editor: BaseDatabaseSchemaEditor) -> None:
    """
    This function establishes the invariant that all RealmEmoji objects have
    .author set and is a repeat of migration 0376.
    This time, in the same migration, we finally alter the column to make it
    non-nullable - as we no longer expect the existence of any valid sources
    that would produce emojis with author=None.
    """

    RealmEmoji = apps.get_model("zerver", "RealmEmoji")
    UserProfile = apps.get_model("zerver", "UserProfile")
    ROLE_REALM_OWNER = 100

    RealmEmoji.objects.filter(author=None).update(
        author=Subquery(
            UserProfile.objects.filter(
                realm=OuterRef("realm"), is_active=True, role=ROLE_REALM_OWNER
            )
            .order_by("id")[:1]
            .values("pk")
        )
    )
    # If some edge-case realms exist out in the wild on self-hosted deployments,
    # which don't have any active organization owners, we just fall back to
    # choosing a deactivated owner.
    # It will be extremely rare to have a realm with no owners as it's not a valid state,
    # so we're okay with letting this migration crash in those cases when it attempts
    # to make the database field non-nullable. Such situations can be repaired manually.
    RealmEmoji.objects.filter(author=None).update(
        author=Subquery(
            UserProfile.objects.filter(
                realm=OuterRef("realm"), is_active=False, role=ROLE_REALM_OWNER
            )
            .order_by("id")[:1]
            .values("pk")
        )
    )


class Migration(migrations.Migration):
    atomic = False

    dependencies = [
        ("zerver", "0770_recreate_missing_realmemoji"),
    ]

    operations = [
        migrations.RunPython(
            set_emoji_author, reverse_code=migrations.RunPython.noop, elidable=True
        ),
        migrations.AlterField(
            model_name="realmemoji",
            name="author",
            field=models.ForeignKey(
                on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL
            ),
        ),
    ]