confirmation: Move one_click_unsubscribe_link out of notifications.py.

This helps prevent a problematic import sequence when we start using
it from signals.py.

confirmation/models.py

@@ -123,6 +123,15 @@ _properties = {
     Confirmation.REALM_CREATION: ConfirmationType('check_prereg_key_and_redirect'),
 }
 
+def one_click_unsubscribe_link(user_profile: UserProfile, email_type: str) -> str:
+    """
+    Generate a unique link that a logged-out user can visit to unsubscribe from
+    Zulip e-mails without having to first log in.
+    """
+    return create_confirmation_link(user_profile, user_profile.realm.host,
+                                    Confirmation.UNSUBSCRIBE,
+                                    url_args = {'email_type': email_type})
+
 # Functions related to links generated by the generate_realm_creation_link.py
 # management command.
 # Note that being validated here will just allow the user to access the create_realm

zerver/lib/digest.py

@@ -10,7 +10,8 @@ from django.template import loader
 from django.conf import settings
 from django.utils.timezone import now as timezone_now
 
-from zerver.lib.notifications import build_message_list, one_click_unsubscribe_link
+from confirmation.models import one_click_unsubscribe_link
+from zerver.lib.notifications import build_message_list
 from zerver.lib.send_email import send_future_email, FromAddress
 from zerver.lib.url_encoding import encode_stream
 from zerver.models import UserProfile, UserMessage, Recipient, Stream, \

zerver/lib/notifications.py

@@ -1,7 +1,7 @@
 
 from typing import cast, Any, Dict, Iterable, List, Mapping, Optional, Sequence, Tuple
 
-from confirmation.models import Confirmation, create_confirmation_link
+from confirmation.models import Confirmation, one_click_unsubscribe_link
 from django.conf import settings
 from django.template import loader
 from django.utils.timezone import now as timezone_now
@@ -37,15 +37,6 @@ import ujson
 from collections import defaultdict
 import pytz
 
-def one_click_unsubscribe_link(user_profile: UserProfile, email_type: str) -> str:
-    """
-    Generate a unique link that a logged-out user can visit to unsubscribe from
-    Zulip e-mails without having to first log in.
-    """
-    return create_confirmation_link(user_profile, user_profile.realm.host,
-                                    Confirmation.UNSUBSCRIBE,
-                                    url_args = {'email_type': email_type})
-
 def relative_to_full_url(base_url: str, content: str) -> str:
     # Convert relative URLs to absolute URLs.
     fragment = lxml.html.fromstring(content)

zerver/tests/test_signup.py

@@ -17,7 +17,8 @@ from mock import patch, MagicMock
 from zerver.lib.test_helpers import MockLDAP, get_test_image_file, avatar_disk_path
 
 from confirmation.models import Confirmation, create_confirmation_link, MultiuseInvite, \
-    generate_key, confirmation_url, get_object_from_key, ConfirmationKeyException
+    generate_key, confirmation_url, get_object_from_key, ConfirmationKeyException, \
+    one_click_unsubscribe_link
 from confirmation import settings as confirmation_settings
 
 from zerver.forms import HomepageForm, WRONG_SUBDOMAIN_ERROR, check_subdomain_available
@@ -55,7 +56,7 @@ from zerver.lib.avatar import avatar_url
 from zerver.lib.mobile_auth_otp import xor_hex_strings, ascii_to_hex, \
     otp_encrypt_api_key, is_valid_otp, hex_to_ascii, otp_decrypt_api_key
 from zerver.lib.notifications import enqueue_welcome_emails, \
-    one_click_unsubscribe_link, followup_day2_email_delay
+    followup_day2_email_delay
 from zerver.lib.subdomains import is_root_domain_available
 from zerver.lib.test_helpers import find_key_by_email, queries_captured, \
     HostRequestMock, load_subdomain_token