feat: Add social media username validation

web/forms.py

@@ -58,6 +58,7 @@
     WaitingRoom,
 )
 from .referrals import handle_referral
+from .validators import validate_discord_username, validate_github_username, validate_slack_username
 from .widgets import (
     TailwindCaptchaTextInput,
     TailwindCheckboxInput,
@@ -746,6 +747,31 @@ def clean_username(self):
             raise forms.ValidationError("This username is already taken. Please choose a different one.")
         return username
 
+    def _clean_social_media_username(self, field_name, validator):
+        """
+        Helper method to validate social media usernames.
+
+        Reduces code duplication by centralizing the validation logic
+        for all social media platform usernames.
+        """
+        username = self.cleaned_data.get(field_name, "")
+        if username:
+            try:
+                validator(username)
+            except ValidationError as e:
+                # Preserve error codes and full error structure
+                raise forms.ValidationError(e.message, code=e.code if hasattr(e, 'code') else None)
+        return username
+
+    def clean_discord_username(self):
+        return self._clean_social_media_username("discord_username", validate_discord_username)
+
+    def clean_slack_username(self):
+        return self._clean_social_media_username("slack_username", validate_slack_username)
+
+    def clean_github_username(self):
+        return self._clean_social_media_username("github_username", validate_github_username)
+
     def save(self, commit=True):
         user = super().save(commit=False)
         if commit:

web/migrations/0064_cleanup_social_media_usernames.py

@@ -0,0 +1,65 @@
+# Generated migration to clean up social media usernames before enforcing new length constraints
+
+from django.db import migrations
+
+
+def cleanup_social_media_usernames(apps, schema_editor):
+    """
+    Clean up social media usernames that exceed new length limits:
+    - discord_username: 37 chars (down from 50)
+    - slack_username: 21 chars (down from 50)
+    - github_username: 39 chars (down from 50)
+
+    This migration truncates over-limit usernames to fit the new constraints.
+    """
+    Profile = apps.get_model("web", "Profile")
+    updated_count = 0
+
+    for profile in Profile.objects.all():
+        modified = False
+
+        # Truncate discord_username to 37 chars
+        if profile.discord_username and len(profile.discord_username) > 37:
+            profile.discord_username = profile.discord_username[:37]
+            modified = True
+
+        # Truncate slack_username to 21 chars
+        if profile.slack_username and len(profile.slack_username) > 21:
+            profile.slack_username = profile.slack_username[:21]
+            modified = True
+
+        # Truncate github_username to 39 chars
+        if profile.github_username and len(profile.github_username) > 39:
+            profile.github_username = profile.github_username[:39]
+            modified = True
+
+        if modified:
+            # Use update() to bypass validators and Profile.save() with full_clean()
+            Profile.objects.filter(pk=profile.pk).update(
+                discord_username=profile.discord_username,
+                slack_username=profile.slack_username,
+                github_username=profile.github_username,
+            )
+            updated_count += 1
+
+    if updated_count > 0:
+        print(f"✓ Cleaned up {updated_count} profiles with over-limit usernames")
+
+
+def reverse_cleanup(apps, schema_editor):
+    """
+    Reverse migration - no action needed as truncation is one-way.
+    Original usernames are lost, so we cannot restore them.
+    """
+    pass
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("web", "0063_virtualclassroom_virtualclassroomcustomization_and_more"),
+    ]
+
+    operations = [
+        migrations.RunPython(cleanup_social_media_usernames, reverse_cleanup),
+    ]

web/migrations/0065_alter_profile_social_username_fields.py

@@ -0,0 +1,44 @@
+# Schema migration to enforce new field length constraints on social media usernames
+
+from django.db import migrations, models
+import web.validators
+
+
+class Migration(migrations.Migration):
+
+    dependencies = [
+        ("web", "0064_cleanup_social_media_usernames"),
+    ]
+
+    operations = [
+        migrations.AlterField(
+            model_name="profile",
+            name="discord_username",
+            field=models.CharField(
+                blank=True,
+                help_text="Your Discord username (e.g., User#1234)",
+                max_length=37,
+                validators=[web.validators.validate_discord_username],
+            ),
+        ),
+        migrations.AlterField(
+            model_name="profile",
+            name="slack_username",
+            field=models.CharField(
+                blank=True,
+                help_text="Your Slack username",
+                max_length=21,
+                validators=[web.validators.validate_slack_username],
+            ),
+        ),
+        migrations.AlterField(
+            model_name="profile",
+            name="github_username",
+            field=models.CharField(
+                blank=True,
+                help_text="Your GitHub username (without @)",
+                max_length=39,
+                validators=[web.validators.validate_github_username],
+            ),
+        ),
+    ]

web/models.py

@@ -26,6 +26,7 @@
 from PIL import Image
 
 from web.utils import calculate_and_update_user_streak
+from web.validators import validate_discord_username, validate_github_username, validate_slack_username
 
 
 class Notification(models.Model):
@@ -62,9 +63,24 @@ class Profile(models.Model):
     )
     is_teacher = models.BooleanField(default=False)
     is_social_media_manager = models.BooleanField(default=False)
-    discord_username = models.CharField(max_length=50, blank=True, help_text="Your Discord username (e.g., User#1234)")
-    slack_username = models.CharField(max_length=50, blank=True, help_text="Your Slack username")
-    github_username = models.CharField(max_length=50, blank=True, help_text="Your GitHub username (without @)")
+    discord_username = models.CharField(
+        max_length=37,  # 32 (username) + 1 (#) + 4 (discriminator)
+        blank=True,
+        validators=[validate_discord_username],
+        help_text="Your Discord username (e.g., User#1234)",
+    )
+    slack_username = models.CharField(
+        max_length=21,  # Matches Slack's 21 character limit
+        blank=True,
+        validators=[validate_slack_username],
+        help_text="Your Slack username",
+    )
+    github_username = models.CharField(
+        max_length=39,  # Matches GitHub's 39 character limit
+        blank=True,
+        validators=[validate_github_username],
+        help_text="Your GitHub username (without @)",
+    )
     referral_code = models.CharField(max_length=20, unique=True, blank=True)
     referred_by = models.ForeignKey("self", on_delete=models.SET_NULL, null=True, blank=True, related_name="referrals")
     referral_earnings = models.DecimalField(max_digits=10, decimal_places=2, default=0)
@@ -102,6 +118,8 @@ def __str__(self):
     def save(self, *args, **kwargs):
         if not self.referral_code:
             self.referral_code = self.generate_referral_code()
+        # Validate social media usernames and other field constraints
+        self.full_clean()
         # Skip image processing for SVG files
         super().save(*args, **kwargs)