api: Add an endpoint for listing the user groups in realm.

Adds endpoint for listing the user groups in realm.
Provides "description", "members", "name" and "id" for each user group.

Fixes #10298

zerver/tests/test_user_groups.py

@@ -117,6 +117,14 @@ class UserGroupAPITestCase(ZulipTestCase):
         self.assert_json_error(result, "User group 'support' already exists.")
         self.assert_length(UserGroup.objects.all(), 2)
 
+    def test_user_group_get(self) -> None:
+        # Test success
+        user_profile = self.example_user('hamlet')
+        self.login(user_profile.email)
+        result = self.client_get('/json/user_groups')
+        self.assert_json_success(result)
+        self.assert_length(result.json()['user_groups'], UserGroup.objects.filter(realm=user_profile.realm).count())
+
     def test_user_group_create_by_guest_user(self) -> None:
         guest_user = self.example_user('polonius')
 

zerver/views/user_groups.py

@@ -14,7 +14,8 @@ from zerver.lib.response import json_success, json_error
 from zerver.lib.users import user_ids_to_users
 from zerver.lib.validator import check_list, check_string, check_int, \
     check_short_string
-from zerver.lib.user_groups import access_user_group_by_id, get_memberships_of_users, get_user_group_members
+from zerver.lib.user_groups import access_user_group_by_id, get_memberships_of_users, \
+    get_user_group_members, user_groups_in_realm_serialized
 from zerver.models import UserProfile, UserGroup, UserGroupMembership
 from zerver.views.streams import compose_views, FuncKwargPair
 
@@ -28,6 +29,12 @@ def add_user_group(request: HttpRequest, user_profile: UserProfile,
     check_add_user_group(user_profile.realm, name, user_profiles, description)
     return json_success()
 
+@require_non_guest_human_user
+@has_request_variables
+def get_user_group(request: HttpRequest, user_profile: UserProfile) -> HttpResponse:
+    user_groups = user_groups_in_realm_serialized(user_profile.realm)
+    return json_success({"user_groups": user_groups})
+
 @require_non_guest_human_user
 @has_request_variables
 def edit_user_group(request: HttpRequest, user_profile: UserProfile,

zproject/urls.py

@@ -251,6 +251,8 @@ v1_api_and_json_patterns = [
          'DELETE': 'zerver.views.push_notifications.remove_android_reg_id'}),
 
     # user_groups -> zerver.views.user_groups
+    url(r'^user_groups$', rest_dispatch,
+        {'GET': 'zerver.views.user_groups.get_user_group'}),
     url(r'^user_groups/create$', rest_dispatch,
         {'POST': 'zerver.views.user_groups.add_user_group'}),
     url(r'^user_groups/(?P<user_group_id>\d+)$', rest_dispatch,