add custom save validations

codeforlife/user/migrations/0001_initial.py

@@ -1,4 +1,4 @@
-# Generated by Django 3.2.20 on 2023-12-11 14:36
+# Generated by Django 3.2.20 on 2023-12-11 17:42
 
 from django.conf import settings
 import django.core.validators
@@ -60,7 +60,7 @@ class Migration(migrations.Migration):
                 ('id', models.CharField(editable=False, help_text='Uniquely identifies a class.', max_length=5, primary_key=True, serialize=False, validators=[django.core.validators.MinLengthValidator(5), django.core.validators.RegexValidator(code='id_not_upper_alphanumeric', message='ID must be alphanumeric with upper case characters.', regex='^[0-9A-Z]*$')], verbose_name='identifier')),
                 ('name', models.CharField(max_length=200, verbose_name='name')),
                 ('read_classmates_data', models.BooleanField(default=False, help_text="Designates whether students in this class can see their fellow classmates' data.", verbose_name='read classmates data')),
-                ('receive_requests_until', models.DateTimeField(blank=True, help_text="A point in the future until which the class can receive requests from students to join. Set to null if it's not accepting requests.", null=True, verbose_name='accept student join requests until')),
+                ('receive_requests_until', models.DateTimeField(help_text="A point in the future until which the class can receive requests from students to join. Set to null if it's not accepting requests.", null=True, verbose_name='accept student join requests until')),
             ],
             options={
                 'verbose_name': 'class',
@@ -99,7 +99,7 @@ class Migration(migrations.Migration):
                 ('session_key', models.CharField(max_length=40, primary_key=True, serialize=False, verbose_name='session key')),
                 ('session_data', models.TextField(verbose_name='session data')),
                 ('expire_date', models.DateTimeField(db_index=True, verbose_name='expire date')),
-                ('user', models.OneToOneField(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
+                ('user', models.OneToOneField(null=True, on_delete=django.db.models.deletion.CASCADE, to=settings.AUTH_USER_MODEL)),
             ],
             options={
                 'verbose_name': 'session',

codeforlife/user/models/klass.py

@@ -77,7 +77,6 @@ class Manager(WarehouseModel.Manager["Class"]):
     receive_requests_until = models.DateTimeField(
         _("accept student join requests until"),
         null=True,
-        blank=True,
         help_text=_(
             "A point in the future until which the class can receive requests"
             " from students to join. Set to null if it's not accepting"

codeforlife/user/models/session.py

@@ -34,7 +34,6 @@ class Session(AbstractBaseSession):
     ] = models.OneToOneField(  # type: ignore[assignment]
         "user.User",
         null=True,
-        blank=True,
         on_delete=models.CASCADE,
     )
 

codeforlife/user/models/user.py

@@ -60,7 +60,7 @@ def _create_user(
                 password=make_password(password),
                 email=email,
             )
-            user.save(using=self._db)
+            user.save(using=self._db, _from_manager=True)
             return user
 
         def create_user(self, password: str, first_name: str, **fields):
@@ -261,3 +261,21 @@ def is_authenticated(self):
             return not self.session.session_auth_factors.exists()
         except _session.Session.DoesNotExist:
             return False
+
+    def save(self, *args, **kwargs):
+        if self.id is None and not kwargs.pop("_from_manager", False):
+            raise IntegrityError("Must call create_user instead.")
+
+        if (
+            self.student
+            # pylint: disable-next=no-member
+            and self.student.klass.students.filter(
+                user__first_name=self.first_name
+            ).exists()
+        ):
+            raise IntegrityError(
+                "Another student in the class already has first name"
+                f' "{self.first_name}".'
+            )
+
+        super().save(*args, **kwargs)

codeforlife/user/tests/models/test_user.py

@@ -21,9 +21,41 @@ class TestUser(ModelTestCase[User]):
     def setUp(self):
         self.klass__AB123 = Class.objects.get(pk="AB123")
         self.school__1 = School.objects.get(pk=1)
+        self.student__1 = Student.objects.get(pk=1)
 
     # TODO: test docstrings.
 
+    def test_save__create(self):
+        """
+        Cannot create a user calling save.
+        """
+
+        with self.assert_raises_integrity_error():
+            User(
+                first_name="first_name",
+                last_name="last_name",
+                email="[email protected]",
+                password="password",
+            ).save()
+
+    def test_save__first_name__student(self):
+        """
+        Students must have a unique name per class.
+        """
+
+        student = Student.objects.create(
+            auto_gen_password="password",
+            klass=self.student__1.klass,
+            school=self.student__1.school,
+        )
+
+        with self.assert_raises_integrity_error():
+            User.objects.create_user(
+                first_name=self.student__1.user.first_name,
+                password="password",
+                student=student,
+            )
+
     def test_constraints__profile(self):
         """
         Cannot be a student and a teacher.