Add name collision ID to User model.

openlobby/core/migrations/0010_user_name_collision_id.py

+# Generated by Django 2.0.2 on 2018-02-20 20:28
+
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('core', '0009_auto_20180217_1850'),
+    ]
+
+    operations = [
+        migrations.AddField(
+            model_name='user',
+            name='name_collision_id',
+            field=models.IntegerField(default=0),
+        ),
+    ]

openlobby/core/models.py

@@ -13,6 +13,15 @@ class User(AbstractUser):
     openid_uid = models.CharField(max_length=255, null=True)
     extra = JSONField(null=True, blank=True)
     is_author = models.BooleanField(default=False)
+    name_collision_id = models.IntegerField(default=0)
+
+    def save(self, *args, **kwargs):
+        # deal with first name and last name collisions
+        collisions = User.objects.filter(first_name=self.first_name, last_name=self.last_name)\
+            .order_by('-name_collision_id')[:1]
+        if len(collisions) > 0:
+            self.name_collision_id = collisions[0].name_collision_id + 1
+        super().save(*args, **kwargs)
 
 
 class OpenIdClient(models.Model):

tests/test_models.py

@@ -74,3 +74,19 @@ def test_login_attempt__default_expiration():
         attempt = LoginAttempt.objects.create(openid_client=client, state='foo',
             app_redirect_uri='http://openlobby/app')
     assert attempt.expiration == 10000 + settings.LOGIN_ATTEMPT_EXPIRATION
+
+
+def test_user__no_name_collision():
+    User.objects.create(username='a', first_name='Ryan', last_name='Gosling')
+    User.objects.create(username='b', first_name='Burt', last_name='Reynolds')
+    user = User.objects.create(username='c', first_name='Ryan', last_name='Reynolds')
+    assert user.name_collision_id == 0
+
+
+def test_user__name_collision():
+    u1 = User.objects.create(username='a', first_name='Ryan', last_name='Gosling')
+    u2 = User.objects.create(username='b', first_name='Ryan', last_name='Gosling')
+    u3 = User.objects.create(username='c', first_name='Ryan', last_name='Gosling')
+    assert u1.name_collision_id == 0
+    assert u2.name_collision_id == 1
+    assert u3.name_collision_id == 2