From 4083be8e8cb1412f8fff33062b660a67e9187f28 Mon Sep 17 00:00:00 2001
From: Tom Hacohen <tom@stosb.com>
Date: Fri, 15 May 2020 11:01:56 +0300
Subject: [PATCH] Username: disallow @ in usernames.

---
 myauth/migrations/0002_auto_20200515_0801.py | 19 ++++++++++++++
 myauth/models.py                             | 27 +++++++++++++++++++-
 2 files changed, 45 insertions(+), 1 deletion(-)
 create mode 100644 myauth/migrations/0002_auto_20200515_0801.py

diff --git a/myauth/migrations/0002_auto_20200515_0801.py b/myauth/migrations/0002_auto_20200515_0801.py
new file mode 100644
index 0000000..3ce02b2
--- /dev/null
+++ b/myauth/migrations/0002_auto_20200515_0801.py
@@ -0,0 +1,19 @@
+# Generated by Django 3.0.3 on 2020-05-15 08:01
+
+from django.db import migrations, models
+import myauth.models
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ('myauth', '0001_initial'),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name='user',
+            name='username',
+            field=models.CharField(error_messages={'unique': 'A user with that username already exists.'}, help_text='Required. 150 characters or fewer. Letters, digits and ./+/-/_ only.', max_length=150, unique=True, validators=[myauth.models.UnicodeUsernameValidator()], verbose_name='username'),
+        ),
+    ]
diff --git a/myauth/models.py b/myauth/models.py
index 3d30525..4afc27c 100644
--- a/myauth/models.py
+++ b/myauth/models.py
@@ -1,5 +1,30 @@
 from django.contrib.auth.models import AbstractUser
+from django.core import validators
+from django.db import models
+from django.utils.deconstruct import deconstructible
+from django.utils.translation import gettext_lazy as _
+
+
+@deconstructible
+class UnicodeUsernameValidator(validators.RegexValidator):
+    regex = r'^[\w.+-]+\Z'
+    message = _(
+        'Enter a valid username. This value may contain only letters, '
+        'numbers, and ./+/-/_ characters.'
+    )
+    flags = 0
 
 
 class User(AbstractUser):
-    pass
+    username_validator = UnicodeUsernameValidator()
+
+    username = models.CharField(
+        _('username'),
+        max_length=150,
+        unique=True,
+        help_text=_('Required. 150 characters or fewer. Letters, digits and ./+/-/_ only.'),
+        validators=[username_validator],
+        error_messages={
+            'unique': _("A user with that username already exists."),
+        },
+    )