lint: Ban use of json_success({}) instead of json_success().

tools/lint-all

@@ -253,6 +253,8 @@ def build_custom_checkers(by_lang):
              ('tools/tests/test_template_parser.py', '{% foo'),
          ]),
          'description': 'Used % comprehension without a tuple'},
+        {'pattern': 'json_success\({}\)',
+         'description': 'Use json_success() to return nothing'},
         # To avoid json_error(_variable) and json_error(_(variable))
         {'pattern': '\Wjson_error\(_\(?\w+\)',
          'exclude': set(['tools/lint-all']),

zerver/tests/test_subs.py

@@ -979,7 +979,7 @@ class SubscriptionRestApiTest(ZulipTestCase):
             # type: (HttpRequest, UserProfile) -> HttpResponse
             user_profile.full_name = 'Should not be committed'
             user_profile.save()
-            return json_success({})
+            return json_success()
 
         def method2(req, user_profile):
             # type: (HttpRequest, UserProfile) -> HttpResponse

zerver/views/realm_emoji.py

@@ -25,4 +25,4 @@ def upload_emoji(request, user_profile):
 def delete_emoji(request, user_profile, emoji_name):
     # type: (HttpRequest, UserProfile, text_type) -> HttpResponse
     do_remove_realm_emoji(user_profile.realm, emoji_name)
-    return json_success({})
+    return json_success()

zerver/views/streams.py

@@ -132,7 +132,7 @@ def deactivate_stream_backend(request, user_profile, stream_name):
         return json_error(_('Cannot administer invite-only streams this way'))
 
     do_deactivate_stream(target)
-    return json_success({})
+    return json_success()
 
 @require_realm_admin
 @has_request_variables
@@ -174,7 +174,7 @@ def update_stream_backend(request, user_profile, stream_name,
         do_change_stream_description(user_profile.realm, stream_name, description)
     if stream_name is not None and new_name is not None:
         do_rename_stream(user_profile.realm, stream_name, new_name)
-    return json_success({})
+    return json_success()
 
 def list_subscriptions_backend(request, user_profile):
     # type: (HttpRequest, UserProfile) -> HttpResponse

zerver/views/users.py

@@ -40,7 +40,7 @@ def deactivate_user_own_backend(request, user_profile):
     if user_profile.is_realm_admin and len(admins) == 1:
         return json_error(_('Cannot deactivate the only admin'))
     do_deactivate_user(user_profile)
-    return json_success({})
+    return json_success()
 
 def deactivate_bot_backend(request, user_profile, email):
     # type: (HttpRequest, UserProfile, text_type) -> HttpResponse
@@ -58,7 +58,7 @@ def _deactivate_user_profile_backend(request, user_profile, target):
         return json_error(_('Insufficient permission'))
 
     do_deactivate_user(target)
-    return json_success({})
+    return json_success()
 
 def reactivate_user_backend(request, user_profile, email):
     # type: (HttpRequest, UserProfile, text_type) -> HttpResponse
@@ -71,7 +71,7 @@ def reactivate_user_backend(request, user_profile, email):
         return json_error(_('Insufficient permission'))
 
     do_reactivate_user(target)
-    return json_success({})
+    return json_success()
 
 @has_request_variables
 def update_user_backend(request, user_profile, email,
@@ -98,7 +98,7 @@ def update_user_backend(request, user_profile, email,
             return json_error(_("Name too long!"))
         do_change_full_name(target, new_full_name)
 
-    return json_success({})
+    return json_success()
 
 def avatar(request, email):
     # type: (HttpRequest, str) -> HttpResponse