Allow deleting last elsewhere if email attached

gratipay/models/participant/__init__.py

@@ -519,9 +519,16 @@ def delete_elsewhere(self, platform, user_id):
         user_id = unicode(user_id)
         with self.db.get_cursor() as c:
             accounts = self.get_elsewhere_logins(c)
-            assert len(accounts) > 0
-            if len(accounts) == 1 and accounts[0] == (platform, user_id):
-                raise LastElsewhere()
+
+            # A user who signed up via a third-party provider might not have
+            # and email attached. They must maintain at least one elsewhere
+            # account until they provide an email.
+            assert self.email_address or (len(accounts) > 0)
+
+            is_last = len(accounts) == 1 and accounts[0] == (platform, user_id)
+            if is_last and not self.email_address:
+                raise LastElsewhereAndNoEmail()
+
             c.one("""
                 DELETE FROM elsewhere
                 WHERE participant=%s
@@ -1432,7 +1439,7 @@ def __nonzero__(self):
         A, B, C = self._all
         return A or C
 
-class LastElsewhere(Exception): pass
+class LastElsewhereAndNoEmail(Exception): pass
 
 class NonexistingElsewhere(Exception): pass
 

tests/py/test_participant.py

@@ -19,7 +19,7 @@
 )
 from gratipay.models.exchange_route import ExchangeRoute
 from gratipay.models.participant import (
-    LastElsewhere, NeedConfirmation, NonexistingElsewhere, Participant
+    LastElsewhereAndNoEmail, NeedConfirmation, NonexistingElsewhere, Participant
 )
 from gratipay.testing import Harness, D,P,T
 
@@ -69,12 +69,16 @@ def test_comparison(self):
         assert not (self.alice == None)
 
     def test_delete_elsewhere_last(self):
-        with pytest.raises(LastElsewhere):
+        with pytest.raises(LastElsewhereAndNoEmail):
             self.alice.delete_elsewhere('twitter', self.alice.id)
 
+    def test_delete_elsewhere_last_works_if_email_present(self):
+        self.add_and_verify_email(self.alice, '[email protected]')
+        self.alice.delete_elsewhere('twitter', self.alice.id)
+
     def test_delete_elsewhere_last_signin(self):
         self.make_elsewhere('bountysource', self.alice.id, 'alice')
-        with pytest.raises(LastElsewhere):
+        with pytest.raises(LastElsewhereAndNoEmail):
             self.alice.delete_elsewhere('twitter', self.alice.id)
 
     def test_delete_elsewhere_nonsignin(self):

www/~/%username/delete-elsewhere.json.spt

@@ -1,5 +1,5 @@
 from aspen import Response
-from gratipay.models.participant import LastElsewhere, NonexistingElsewhere
+from gratipay.models.participant import LastElsewhereAndNoEmail, NonexistingElsewhere
 [-----------------------------------------------------------------------------]
 if user.ANON:
     raise Response(403)
@@ -10,10 +10,16 @@ user_id = request.body["user_id"]
 
 try:
     user.participant.delete_elsewhere(platform, user_id)
-except LastElsewhere:
-    raise Response(400, "Cannot delete last login account. If you want to merge this login account to a different Gratipay account: log out of this account; log into the other account using another method; and then add this authentication provider to it. The two Gratipay accounts will be merged.")
+except LastElsewhereAndNoEmail:
+    msg = _("Cannot delete last login account since you don't have an email "
+            "address attached. If you want to merge this login account to a "
+            "different Gratipay account: log out of this account; log into the "
+            "other account using another method; and then add this "
+            "authentication provider to it. The two Gratipay accounts "
+            "will be merged.")
+    raise Response(400, msg)
 except NonexistingElsewhere:
-    raise Response(400, "Account does not exist.")
+    raise Response(400, _("Account does not exist."))
 
 [---] application/json via json_dump
 { "msg": "OK" }