added helper function for public email domain check

baseframe/forms/helper.py

@@ -0,0 +1,24 @@
+from .validators import IsPublicEmailDomain, ValidationError
+
+__all__ = ['is_public_email_domain']
+
+
+class DummyField(object):
+    # Validators need a field param to work, we're going to pass a dummy
+    # https://github.com/wtforms/wtforms/blob/master/tests/validators.py#L14
+    def __init__(self, data):
+        self.data = data
+
+
+def is_public_email_domain(email_or_domain):
+    """
+    Checks if the given email address or domain belongs to a public email domain
+    """
+    try:
+        validator = IsPublicEmailDomain()
+        # custom validators need to accept a form and field to work
+        # as our validator doesn't do anything with the form, can just pass a dummy object
+        validator(dict(), DummyField(email_or_domain))
+    except ValidationError:
+        return False
+    return True

tests/test_validators.py

@@ -2,6 +2,7 @@
 
 import warnings
 import urllib3
+from baseframe.forms.helper import is_public_email_domain
 from .fixtures import TestCaseBaseframe, UrlFormTest, AllUrlsFormTest, OptionalIfFormTest, OptionalIfNotFormTest, PublicEmailDomainFormTest
 
 
@@ -72,6 +73,15 @@ def test_public_email_domain(self):
             self.assertIn('webmail_domain', self.webmail_form.errors)
             self.assertNotIn('not_webmail_domain', self.webmail_form.errors)
 
+    def test_public_email_domain_helper(self):
+        with self.app.test_request_context('/'):
+            self.assertEqual(is_public_email_domain(u'gmail.com'), True)
+            self.assertEqual(is_public_email_domain(u'i❤.ws'), False)
+            # this domain lookup fails, so the helper should return False
+            self.assertEqual(
+                is_public_email_domain(u'www.abcdefghijklmnopqrstuvwxyzabcdefghijklmnopqrstuvwxyzabcdefghijks.com'),
+                False)
+
     def test_url_without_protocol(self):
         with self.app.test_request_context('/'):
             url = 'hasgeek.com'