Add SoftDeleteModel, ActiveUndeleteManager; tests for same

src/mitol/common/changelog.d/20240108_173730_jkachel_move_soft_undelete_models_to_common.md

@@ -0,0 +1,42 @@
+<!--
+A new scriv changelog fragment.
+
+Uncomment the section that is right (remove the HTML comment wrapper).
+-->
+
+<!--
+### Removed
+
+- A bullet item for the Removed category.
+
+-->
+
+### Added
+
+- Adds the SoftDeleteModel
+- Adds ActiveUndeleteManager to support models that use SoftDeleteModel
+
+<!--
+### Changed
+
+- A bullet item for the Changed category.
+
+-->
+<!--
+### Deprecated
+
+- A bullet item for the Deprecated category.
+
+-->
+<!--
+### Fixed
+
+- A bullet item for the Fixed category.
+
+-->
+<!--
+### Security
+
+- A bullet item for the Security category.
+
+-->

src/mitol/common/models.py

@@ -9,9 +9,11 @@
 from django.db import transaction
 from django.db.models import (
     PROTECT,
+    BooleanField,
     DateTimeField,
     ForeignKey,
     JSONField,
+    Manager,
     Model,
     prefetch_related_objects,
 )
@@ -47,6 +49,22 @@ class Meta:
         abstract = True
 
 
+class SoftDeleteModel(Model):
+    """Model that blocks delete and instead marks the items is_active flag as false"""
+
+    is_active = BooleanField(default=True)
+
+    def delete(self):
+        """Mark items inactive instead of deleting them"""
+        self.is_active = False
+        self.save(update_fields=["is_active"])
+
+    class Meta:
+        """Meta options for SoftDeleteTimestampModel"""
+
+        abstract = True
+
+
 class AuditModel(TimestampedModel):
     """An abstract base class for audit models"""
 
@@ -235,3 +253,11 @@ def _clone(self):
             self._prefetch_generic_related_lookups
         )
         return c
+
+
+class ActiveUndeleteManager(Manager):
+    """Query manager for models with soft-delete that excludes inactive records"""
+
+    def get_queryset(self):
+        """Get the active queryset for manager"""
+        return QuerySet(self.model, using=self._db).filter(is_active=True)

tests/mitol/common/test_models.py

@@ -13,6 +13,8 @@
     Root,
     SecondLevel1,
     SecondLevel2,
+    TestSoftDelete,
+    TestSoftDeleteTimestamped,
     Updateable,
 )
 
@@ -102,3 +104,33 @@ def test_auditable_model():
     # auditable_instance.status = FinancialAidStatus.AUTO_APPROVED
     auditable_instance.save_and_log(user)
     assert AuditableTestModelAudit.objects.count() == 1
+
+
+def test_soft_delete_model():
+    """Verify that soft delete models work"""
+
+    soft_delete_record = TestSoftDelete.objects.create(test_data="Test Deletion")
+
+    assert TestSoftDelete.objects.count() == 1
+
+    soft_delete_record.delete()
+
+    assert TestSoftDelete.objects.count() == 0
+    assert TestSoftDelete.all_objects.count() == 1
+
+
+def test_soft_delete_model_with_timestamps():
+    """Verify that the updated_on timestamp gets updated too when deleting"""
+
+    soft_delete_record = TestSoftDeleteTimestamped.objects.create(
+        test_data="Test Deletion"
+    )
+    pk = soft_delete_record.id
+
+    assert TestSoftDeleteTimestamped.objects.count() == 1
+
+    soft_delete_record.delete()
+
+    soft_delete_record = TestSoftDeleteTimestamped.all_objects.get(pk=pk)
+
+    assert soft_delete_record.created_on != soft_delete_record.updated_on

tests/testapp/migrations/0004_add_soft_delete_models_update_ids.py

@@ -0,0 +1,123 @@
+# Generated by Django 4.2.8 on 2024-01-08 17:19
+
+import django.db.models.manager
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("testapp", "0003_auditabletestmodelaudit"),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name="TestSoftDelete",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("is_active", models.BooleanField(default=True)),
+                ("test_data", models.CharField(max_length=100)),
+            ],
+            options={
+                "abstract": False,
+            },
+            managers=[
+                ("all_objects", django.db.models.manager.Manager()),
+            ],
+        ),
+        migrations.CreateModel(
+            name="TestSoftDeleteTimestamped",
+            fields=[
+                (
+                    "id",
+                    models.BigAutoField(
+                        auto_created=True,
+                        primary_key=True,
+                        serialize=False,
+                        verbose_name="ID",
+                    ),
+                ),
+                ("created_on", models.DateTimeField(auto_now_add=True)),
+                ("updated_on", models.DateTimeField(auto_now=True)),
+                ("is_active", models.BooleanField(default=True)),
+                ("test_data", models.CharField(max_length=100)),
+            ],
+            options={
+                "abstract": False,
+            },
+            managers=[
+                ("all_objects", django.db.models.manager.Manager()),
+            ],
+        ),
+        migrations.AlterField(
+            model_name="auditabletestmodel",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="auditabletestmodelaudit",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="democourseware",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="firstlevel1",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="firstlevel2",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="root",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="secondlevel1",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="secondlevel2",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+        migrations.AlterField(
+            model_name="updateable",
+            name="id",
+            field=models.BigAutoField(
+                auto_created=True, primary_key=True, serialize=False, verbose_name="ID"
+            ),
+        ),
+    ]

tests/testapp/models.py

@@ -5,9 +5,11 @@
 from django.db import models
 
 from mitol.common.models import (
+    ActiveUndeleteManager,
     AuditableModel,
     AuditModel,
     PrefetchGenericQuerySet,
+    SoftDeleteModel,
     TimestampedModel,
 )
 from mitol.common.utils.serializers import serialize_model_object
@@ -85,3 +87,21 @@ class DemoCourseware(models.Model):
     description = models.TextField()
 
     learner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE)
+
+
+class TestSoftDelete(SoftDeleteModel):
+    """Test model for soft deletion"""
+
+    test_data = models.CharField(max_length=100)
+
+    all_objects = models.Manager()
+    objects = ActiveUndeleteManager()
+
+
+class TestSoftDeleteTimestamped(SoftDeleteModel, TimestampedModel):
+    """Test model for soft deletions with timestamps"""
+
+    test_data = models.CharField(max_length=100)
+
+    all_objects = models.Manager()
+    objects = ActiveUndeleteManager()