Add Participant::from_email

gratipay/models/participant/__init__.py

@@ -102,6 +102,20 @@ def from_session_token(cls, token):
 
         return participant
 
+    @classmethod
+    def from_email(cls, email_address):
+        """Return an existing participant based on email.
+        """
+        return cls.db.one("""
+
+            SELECT participants.*::participants
+              FROM participants
+              JOIN emails ON emails.participant_id = participants.id
+             WHERE emails.address=%s
+               AND emails.verified IS true
+
+        """, (email_address, ))
+
     @classmethod
     def _from_thing(cls, thing, value):
         assert thing in ("id", "username_lower", "session_token", "api_key")

tests/py/test_participant_emails.py

@@ -0,0 +1,31 @@
+# -*- coding: utf-8 -*-
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+from gratipay.testing import Harness
+from gratipay.models.participant import Participant
+
+
+class TestFromEmail(Harness):
+
+    def test_returns_participant_by_primary_email(self):
+        alice = self.make_participant('alice')
+        self.add_and_verify_email(alice, '[email protected]')
+
+        assert Participant.from_email('[email protected]').username == 'alice'
+
+    def test_returns_participant_by_non_primary_email(self):
+        alice = self.make_participant('alice')
+        self.add_and_verify_email(alice, '[email protected]')
+        self.add_and_verify_email(alice, '[email protected]')
+
+        assert Participant.from_username('alice').email_address == '[email protected]'
+        assert Participant.from_email('[email protected]').username == 'alice'
+
+    def test_returns_none_for_unverified_email(self):
+        alice = self.make_participant('alice')
+        alice.start_email_verification('[email protected]')
+
+        assert Participant.from_email('[email protected]') is None
+
+    def test_returns_none_if_no_email_exists(self):
+        assert Participant.from_email('[email protected]') is None