check email toxic domain at model-level

antispam/models/__init__.py

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+from antispam.models.fields import AntiSpamEmailField
+from antispam.models.models import ToxicDomain
+
+__all__ = ["AntiSpamEmailField", "ToxicDomain"]

antispam/models/fields.py

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+from django.conf import settings
+from django.db import models
+
+from antispam import forms
+
+
+class AntiSpamEmailField(models.EmailField):
+    """An email field that forbids email addresses with a known toxic domain."""
+
+    default_validators = [forms.validate_antispam_email]
+
+
+if settings.TESTING:
+    from model_bakery import baker
+
+    baker.generators.add(
+        AntiSpamEmailField, lambda: baker.random_gen.gen_email(max_length=100)
+    )
+else:  # pragma: no cover
+    # baker is only used in tests, so we don't need coverage for this part
+    pass

antispam/models/models.py

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+from django.db import models
+from django.utils.translation import gettext_lazy as _
+
+
+class ToxicDomain(models.Model):
+    """Domain marked as spam in public databases"""
+
+    domain = models.URLField(_("domain"), max_length=253, primary_key=True)
+    created = models.DateTimeField(auto_now_add=True)
+    is_externally_managed = models.BooleanField(
+        _("is externally managed"),
+        default=False,
+        help_text=_(
+            "True if kept up-to-date using external toxic domain providers, else False"
+        ),
+    )
+
+    def __str__(self) -> str:
+        return self.domain