Update username validator (#1865)

* update username validator

* lint fix

care/users/migrations/0014_alter_user_username.py

@@ -0,0 +1,26 @@
+# Generated by Django 4.2.8 on 2024-01-31 14:00
+
+from django.db import migrations, models
+
+import care.utils.models.validators
+
+
+class Migration(migrations.Migration):
+    dependencies = [
+        ("users", "0013_staff_to_nurse"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="user",
+            name="username",
+            field=models.CharField(
+                error_messages={"unique": "A user with that username already exists."},
+                help_text="Username must be 4 to 16 characters long. It may only contain lowercase alphabets, numbers, underscores, hyphens and dots. It shouldn't start or end with underscores, hyphens or dots. It shouldn't contain consecutive underscores, hyphens or dots.",
+                max_length=150,
+                unique=True,
+                validators=[care.utils.models.validators.UsernameValidator()],
+                verbose_name="username",
+            ),
+        ),
+    ]

care/users/models.py

@@ -1,7 +1,6 @@
 import uuid
 
 from django.contrib.auth.models import AbstractUser, UserManager
-from django.contrib.auth.validators import UnicodeUsernameValidator
 from django.core.validators import MaxValueValidator, MinValueValidator
 from django.db import models
 from django.urls import reverse
@@ -10,6 +9,7 @@
 
 from care.utils.models.base import BaseModel
 from care.utils.models.validators import (
+    UsernameValidator,
     mobile_or_landline_number_validator,
     mobile_validator,
 )
@@ -147,13 +147,6 @@ def __str__(self):
         return self.name
 
 
-class UsernameValidator(UnicodeUsernameValidator):
-    regex = r"^[\w.@+-]+[^.@+_-]$"
-    message = _(
-        "Please enter letters, digits and @ . + - _ only and username should not end with @ . + - or _"
-    )
-
-
 class UserSkill(BaseModel):
     user = models.ForeignKey("User", on_delete=models.CASCADE, null=True, blank=True)
     skill = models.ForeignKey("Skill", on_delete=models.CASCADE, null=True, blank=True)
@@ -175,7 +168,7 @@ class User(AbstractUser):
         _("username"),
         max_length=150,
         unique=True,
-        help_text=_("150 characters or fewer. Letters, digits and @/./+/-/_ only."),
+        help_text=username_validator.message,
         validators=[username_validator],
         error_messages={"unique": _("A user with that username already exists.")},
     )

care/utils/models/validators.py

@@ -1,9 +1,12 @@
+import re
 from typing import Iterable, List
 
 import jsonschema
+from django.core import validators
 from django.core.exceptions import ValidationError
 from django.core.validators import RegexValidator
 from django.utils.deconstruct import deconstructible
+from django.utils.translation import gettext_lazy as _
 
 
 @deconstructible
@@ -44,6 +47,18 @@ def _extract_errors(
             container.append(ValidationError(message))
 
 
+@deconstructible
+class UsernameValidator(validators.RegexValidator):
+    regex = r"^(?!.*[._-]{2})[a-z0-9](?:[a-z0-9._-]{2,14}[a-z0-9])$"
+    message = _(
+        "Username must be 4 to 16 characters long. "
+        "It may only contain lowercase alphabets, numbers, underscores, hyphens and dots. "
+        "It shouldn't start or end with underscores, hyphens or dots. "
+        "It shouldn't contain consecutive underscores, hyphens or dots."
+    )
+    flags = re.ASCII
+
+
 @deconstructible
 class PhoneNumberValidator(RegexValidator):
     """

care/utils/tests/test_username_validator.py

@@ -0,0 +1,49 @@
+from django.core.exceptions import ValidationError
+from django.test import TestCase
+
+from care.utils.models.validators import UsernameValidator
+
+
+class UsernameValidatorTests(TestCase):
+    username_validator = UsernameValidator()
+
+    valid_usernames = [
+        "user",
+        "user123",
+        "user_123",
+        "user_123-456",
+        "useruseruseruser",
+        "11useruseruser11",
+    ]
+
+    invalid_characters = ["user@123", "user#123", "user?123", "user!123"]
+
+    consecutive_characters = ["user__123", "user--123", "user..123", "user__" "..user"]
+
+    invalid_case = ["User", "USER", "uSeR"]
+
+    invalid_length = ["usr", "user12345678901234567890", "useruseruseruseru"]
+
+    def test_valid_usernames(self):
+        for username in self.valid_usernames:
+            self.assertIsNone(self.username_validator(username))
+
+    def test_invalid_characters(self):
+        for username in self.invalid_characters:
+            with self.assertRaises(ValidationError):
+                self.username_validator(username)
+
+    def test_consecutive_characters(self):
+        for username in self.consecutive_characters:
+            with self.assertRaises(ValidationError):
+                self.username_validator(username)
+
+    def test_invalid_case(self):
+        for username in self.invalid_case:
+            with self.assertRaises(ValidationError):
+                self.username_validator(username)
+
+    def test_invalid_length(self):
+        for username in self.invalid_length:
+            with self.assertRaises(ValidationError):
+                self.username_validator(username)

pyproject.toml

@@ -55,12 +55,3 @@ known_third_party = [
   "sentry_sdk",
   "simple_history"
 ]
-extend_skip=["migrations"]
-
-[tool.black]
-extend-exclude = """
-/(
-  | migrations
-)/
-
-"""