Add bookmark sharing (#311)

* Allow marking bookmarks as shared

* Add basic share view

* Ensure tag names in tag cloud are unique

* Filter shared bookmarks by user

* Add link for filtering by user

* Prevent n+1 queries when rendering bookmark list

* Prevent empty query params in return URL

* Fix user select template tag name

* Create shared bookmarks through API

* List shared bookmarks through API

* Show bookmark suggestions for shared view

* Show unique tags in search suggestions

* Sort user options

* Add bookmark sharing feature flag

* Add test for share setting default

* Simplify settings view

bookmarks/tests/test_bookmark_shared_view_performance.py

@@ -0,0 +1,44 @@
+from django.contrib.auth.models import User
+from django.test import TransactionTestCase
+from django.test.utils import CaptureQueriesContext
+from django.urls import reverse
+from django.db import connections
+from django.db.utils import DEFAULT_DB_ALIAS
+
+from bookmarks.tests.helpers import BookmarkFactoryMixin
+
+
+class BookmarkSharedViewPerformanceTestCase(TransactionTestCase, BookmarkFactoryMixin):
+
+    def setUp(self) -> None:
+        user = self.get_or_create_test_user()
+        self.client.force_login(user)
+
+    def get_connection(self):
+        return connections[DEFAULT_DB_ALIAS]
+
+    def test_should_not_increase_number_of_queries_per_bookmark(self):
+        # create initial users and bookmarks
+        num_initial_bookmarks = 10
+        for index in range(num_initial_bookmarks):
+            user = self.setup_user(enable_sharing=True)
+            self.setup_bookmark(user=user, shared=True)
+
+        # capture number of queries
+        context = CaptureQueriesContext(self.get_connection())
+        with context:
+            response = self.client.get(reverse('bookmarks:shared'))
+            self.assertContains(response, 'data-is-bookmark-item', num_initial_bookmarks)
+
+        number_of_queries = context.final_queries
+
+        # add more users and bookmarks
+        num_additional_bookmarks = 10
+        for index in range(num_additional_bookmarks):
+            user = self.setup_user(enable_sharing=True)
+            self.setup_bookmark(user=user, shared=True)
+
+        # assert num queries doesn't increase
+        with self.assertNumQueries(number_of_queries):
+            response = self.client.get(reverse('bookmarks:shared'))
+            self.assertContains(response, 'data-is-bookmark-item', num_initial_bookmarks + num_additional_bookmarks)