Valid email domains added and tests passing.

app/main/validators.py

@@ -1,3 +1,4 @@
+import re
 from wtforms import ValidationError
 from datetime import datetime
 from app.main.encryption import check_hash
@@ -22,3 +23,18 @@ class CsvFileValidator(object):
     def __call__(self, form, field):
         if not form.file.data.mimetype == 'text/csv':
             raise ValidationError(self.message)
+
+
+class ValidEmailDomainRegex(object):
+
+    def __call__(self, form, field):
+        from flask import (current_app, url_for)
+        message = (
+            'Enter a central government email address.'
+            ' If you think you should have access'
+            ' <a href="{}">contact us</a>').format(
+                "https://docs.google.com/forms/d/1AL8U-xJX_HAFEiQiJszGQw0PcEaEUnYATSntEghNDGo/viewform")
+        valid_domains = current_app.config.get('EMAIL_DOMAIN_REGEXES', [])
+        email_regex = "(^[^@^\\s]+@[^@^\\.^\\s]+(\\.[^@^\\.^\\s]*)*.({}))".format("|".join(valid_domains))
+        if not re.match(email_regex, field.data):
+            raise ValidationError(message)