Fix organizer username in participation request emails

src/apps/competitions/emails.py

@@ -14,13 +14,16 @@ def send_participation_requested_emails(participant):
         'user': participant.user
     }
     # Notify Organizers
-    codalab_send_mail(
-        context_data=context,
-        subject=f'{participant.user.username} applied to your competition',
-        html_file="emails/participation/organizer/participation_requested.html",
-        text_file="emails/participation/organizer/participation_requested.txt",
-        to_email=get_organizer_emails(participant.competition)
-    )
+    for organizer in participant.competition.all_organizers:
+        if organizer.is_deleted:
+            continue
+        codalab_send_mail(
+            context_data={**context, 'user': organizer},
+            subject=f'{participant.user.username} applied to your competition',
+            html_file="emails/participation/organizer/participation_requested.html",
+            text_file="emails/participation/organizer/participation_requested.txt",
+            to_email=organizer.email
+        )
 
     # Notify User
     codalab_send_mail(

src/apps/competitions/tests/test_emails.py

@@ -0,0 +1,33 @@
+from types import SimpleNamespace
+from unittest import mock
+
+from competitions.emails import send_participation_requested_emails
+
+
+def test_participation_request_uses_each_recipient_as_email_user():
+    participant_user = SimpleNamespace(
+        username='participant', email='participant@example.com', is_deleted=False
+    )
+    organizers = [
+        SimpleNamespace(username='owner', email='owner@example.com', is_deleted=False),
+        SimpleNamespace(username='collaborator', email='collaborator@example.com', is_deleted=False),
+        SimpleNamespace(username='deleted', email='deleted@example.com', is_deleted=True),
+    ]
+    participant = SimpleNamespace(
+        user=participant_user,
+        competition=SimpleNamespace(title='Competition', all_organizers=organizers),
+    )
+
+    with mock.patch('competitions.emails.codalab_send_mail') as send_mail:
+        send_participation_requested_emails(participant)
+
+    assert [call.kwargs['to_email'] for call in send_mail.call_args_list] == [
+        'owner@example.com',
+        'collaborator@example.com',
+        'participant@example.com',
+    ]
+    assert [call.kwargs['context_data']['user'] for call in send_mail.call_args_list] == [
+        organizers[0],
+        organizers[1],
+        participant_user,
+    ]