From 0e9c1a297aa15570d87da356f2ac908f1fd433a3 Mon Sep 17 00:00:00 2001
From: Eugen Rochko <eugen@zeonfederated.com>
Date: Sat, 17 Sep 2016 17:03:36 +0200
Subject: [PATCH] Improved error handling for FollowRemoteService

---
 .../components/reducers/timelines.jsx          | 14 +++++++++-----
 app/controllers/api_controller.rb              |  8 ++++++++
 app/services/follow_remote_account_service.rb  | 18 ++++++++++++------
 3 files changed, 29 insertions(+), 11 deletions(-)

diff --git a/app/assets/javascripts/components/reducers/timelines.jsx b/app/assets/javascripts/components/reducers/timelines.jsx
index 79d7d1f7d..462c10733 100644
--- a/app/assets/javascripts/components/reducers/timelines.jsx
+++ b/app/assets/javascripts/components/reducers/timelines.jsx
@@ -1,8 +1,9 @@
-import { TIMELINE_SET, TIMELINE_UPDATE, TIMELINE_DELETE } from '../actions/timelines';
-import { REBLOG_SUCCESS, FAVOURITE_SUCCESS }              from '../actions/interactions';
-import { ACCOUNT_SET_SELF, ACCOUNT_FETCH_SUCCESS }        from '../actions/accounts';
-import { STATUS_FETCH_SUCCESS }                           from '../actions/statuses';
-import Immutable                                          from 'immutable';
+import { TIMELINE_SET, TIMELINE_UPDATE, TIMELINE_DELETE }                                            from '../actions/timelines';
+import { REBLOG_SUCCESS, FAVOURITE_SUCCESS }                                                         from '../actions/interactions';
+import { ACCOUNT_SET_SELF, ACCOUNT_FETCH_SUCCESS, ACCOUNT_FOLLOW_SUCCESS, ACCOUNT_UNFOLLOW_SUCCESS } from '../actions/accounts';
+import { STATUS_FETCH_SUCCESS }                                                                      from '../actions/statuses';
+import { FOLLOW_SUBMIT_SUCCESS }                                                                     from '../actions/follow';
+import Immutable                                                                                     from 'immutable';
 
 const initialState = Immutable.Map({
   home: Immutable.List([]),
@@ -97,6 +98,9 @@ export default function timelines(state = initialState, action) {
         map.set('me', action.account.id);
       });
     case ACCOUNT_FETCH_SUCCESS:
+    case FOLLOW_SUBMIT_SUCCESS:
+    case ACCOUNT_FOLLOW_SUCCESS:
+    case ACCOUNT_UNFOLLOW_SUCCESS:
       return accountToMaps(state, Immutable.fromJS(action.account));
     case STATUS_FETCH_SUCCESS:
       return contextToMaps(state, Immutable.fromJS(action.status), Immutable.fromJS(action.context.ancestors), Immutable.fromJS(action.context.descendants));
diff --git a/app/controllers/api_controller.rb b/app/controllers/api_controller.rb
index bacdd997b..cbe7141b9 100644
--- a/app/controllers/api_controller.rb
+++ b/app/controllers/api_controller.rb
@@ -10,6 +10,14 @@ class ApiController < ApplicationController
     render json: { error: 'Record not found' }, status: 404
   end
 
+  rescue_from Goldfinger::Error do
+    render json: { error: 'Remote account could not be resolved' }, status: 422
+  end
+
+  rescue_from HTTP::Error do
+    render json: { error: 'Remote data could not be fetched' }, status: 503
+  end
+
   protected
 
   def current_resource_owner
diff --git a/app/services/follow_remote_account_service.rb b/app/services/follow_remote_account_service.rb
index 0e23ed7d2..00285f47a 100644
--- a/app/services/follow_remote_account_service.rb
+++ b/app/services/follow_remote_account_service.rb
@@ -31,9 +31,12 @@ class FollowRemoteAccountService < BaseService
     feed = get_feed(account.remote_url)
     hubs = feed.xpath('//xmlns:link[@rel="hub"]')
 
-    if hubs.empty? || hubs.first.attribute('href').nil? || feed.at_xpath('/xmlns:feed/xmlns:author/xmlns:uri').nil?
-      Rails.logger.debug "Cannot find PuSH hub or author for #{uri}"
-      return nil
+    if hubs.empty? || hubs.first.attribute('href').nil?
+      raise Goldfinger::Error, "No PubSubHubbub hubs found"
+    end
+
+    if feed.at_xpath('/xmlns:feed/xmlns:author/xmlns:uri').nil?
+      raise Goldfinger::Error, "No author URI found"
     end
 
     account.uri     = feed.at_xpath('/xmlns:feed/xmlns:author/xmlns:uri').content
@@ -53,9 +56,6 @@ class FollowRemoteAccountService < BaseService
     end
 
     return account
-  rescue Goldfinger::Error, HTTP::Error
-    Rails.logger.debug "Error while fetching data for #{uri}"
-    nil
   end
 
   private
@@ -89,3 +89,9 @@ class FollowRemoteAccountService < BaseService
     HTTP
   end
 end
+
+class NoAuthorFeedError < StandardError
+end
+
+class NoHubError < StandardError
+end