Testing: Fix false positive and cover edge case for Channel::Driver::Twitter#fetch

Originally, a spec for race condition handling
in Channel::Driver::Twitter#fetch
used a `travel_back` call in the wrong place:
it needed to be called _after_ `subject!(:channel)` was created,
but since it was placed in an `around` block,
it ran before all preceding setup blocks.

Moving it to a `before` block changed the order in which it was called,
thus fixing a false positive in the test.

An additional expectation was added
to prevent this false positive in the future,
and a new test case was added to capture yet another edge case.

spec/models/channel/driver/twitter_spec.rb

@@ -934,12 +934,25 @@ RSpec.describe Channel::Driver::Twitter do
                      search_term:    'zammadzammadzammad',
                      custom_options: {
                        user: {
-                         # Must match outgoing tweet author Twitter user ID
+                         # "outgoing" tweets = authored by this Twitter user ID
                          id: '1205290247124217856',
                        },
                      })
             end
 
+            # This test case requires the use_vcr: :time_sensitive option
+            # to travel_to(when the VCR cassette was recorded).
+            #
+            # This ensures that #fetch doesn't ignore
+            # the "older" tweets stored in the VCR cassette,
+            # but it also freezes time,
+            # which breaks this test expectation logic:
+            #
+            #     expect { channel.fetch }.to change(Time, :current).by_at_least(5)
+            #
+            # So, we unfreeze time here.
+            before { travel_back }
+
             let!(:tweet) { create(:twitter_article, body: 'zammadzammadzammad') }
 
             context '(i.e., after the BG job has posted the article to Twitter…' do
@@ -954,19 +967,6 @@ RSpec.describe Channel::Driver::Twitter do
                 YML
 
                 around do |example|
-                  # This test case requires the use_vcr: :time_sensitive option
-                  # to travel_to(when the VCR cassette was recorded).
-                  #
-                  # This ensures that #fetch doesn't ignore
-                  # the "older" tweets stored in the VCR cassette,
-                  # but it also freezes time,
-                  # which breaks this race condition handling logic:
-                  #
-                  #     break if Delayed::Job.where('created_at < ?', Time.current).none?
-                  #
-                  # So, we unfreeze time here.
-                  travel_back
-
                   # Run BG job (Why not use Scheduler.worker?
                   # It led to hangs & failures elsewhere in test suite.)
                   Thread.new do
@@ -978,9 +978,18 @@ RSpec.describe Channel::Driver::Twitter do
                 it 'does not import the duplicate tweet (waits up to 60s for BG job to finish)' do
                   expect { channel.fetch }
                     .to not_change(Ticket::Article, :count)
+                    .and change(Time, :current).by_at_least(5)
                 end
               end
             end
+
+            # To reproduce this test case, the VCR cassette has been modified
+            # so that the fetched tweet has a different ("incoming") author user ID.
+            it 'skips race condition handling for incoming tweets' do
+              expect { channel.fetch }
+                .to change(Ticket::Article, :count)
+                .and change(Time, :current).by_at_most(1)
+            end
           end
         end
 

test/data/vcr_cassettes/models/channel/driver/twitter/race_condition_when_fetch_finds_a_half-processed_outgoing_tweet_skips_race_condition_handling_for_incoming_tweets.yml

@@ -0,0 +1,84 @@
+---
+http_interactions:
+- request:
+    method: get
+    uri: https://api.twitter.com/1.1/search/tweets.json?count=100&q=zammadzammadzammad&result_type=mixed
+    body:
+      encoding: UTF-8
+      string: ''
+    headers:
+      User-Agent:
+      - TwitterRubyGem/6.2.0
+      Authorization:
+      - OAuth oauth_consumer_key="REDACTED", oauth_nonce="37876a49fa0c474bd7732dea70083056",
+        oauth_signature="f159trPoyOipHcp%2BPlL33Kh2nO4%3D", oauth_signature_method="HMAC-SHA1",
+        oauth_timestamp="1583840887", oauth_token="REDACTED",
+        oauth_version="1.0"
+      Connection:
+      - close
+      Host:
+      - api.twitter.com
+  response:
+    status:
+      code: 200
+      message: OK
+    headers:
+      Cache-Control:
+      - no-cache, no-store, must-revalidate, pre-check=0, post-check=0
+      Connection:
+      - close
+      Content-Disposition:
+      - attachment; filename=json.json
+      Content-Length:
+      - '2346'
+      Content-Type:
+      - application/json;charset=utf-8
+      Date:
+      - Tue, 10 Mar 2020 11:48:07 GMT
+      Expires:
+      - Tue, 31 Mar 1981 05:00:00 GMT
+      Last-Modified:
+      - Tue, 10 Mar 2020 11:48:07 GMT
+      Pragma:
+      - no-cache
+      Server:
+      - tsa_m
+      Set-Cookie:
+      - guest_id=v1%3A158384088754038008; Max-Age=63072000; Expires=Thu, 10 Mar 2022
+        11:48:07 GMT; Path=/; Domain=.twitter.com; Secure; SameSite=None
+      - lang=en; Path=/
+      - personalization_id="v1_N5oIKIuBSmkhNAVvuM7dWQ=="; Max-Age=63072000; Expires=Thu,
+        10 Mar 2022 11:48:07 GMT; Path=/; Domain=.twitter.com; Secure; SameSite=None
+      Status:
+      - 200 OK
+      Strict-Transport-Security:
+      - max-age=631138519
+      X-Access-Level:
+      - read-write-directmessages
+      X-Connection-Hash:
+      - a615db05b45fdf48368de9e967c599c2
+      X-Content-Type-Options:
+      - nosniff
+      X-Frame-Options:
+      - SAMEORIGIN
+      X-Rate-Limit-Limit:
+      - '180'
+      X-Rate-Limit-Remaining:
+      - '177'
+      X-Rate-Limit-Reset:
+      - '1583841131'
+      X-Response-Time:
+      - '134'
+      X-Transaction:
+      - '004926c000957504'
+      X-Twitter-Response-Tags:
+      - BouncerCompliant
+      X-Xss-Protection:
+      - '0'
+    body:
+      encoding: UTF-8
+      string: '{"statuses":[{"created_at":"Tue Mar 10 11:48:05 +0000 2020","id":1237344473199153152,"id_str":"1237344473199153152","text":"zammadzammadzammad","truncated":false,"entities":{"hashtags":[],"symbols":[],"user_mentions":[],"urls":[]},"metadata":{"iso_language_code":"lv","result_type":"recent"},"source":"\u003ca
+        href=\"https:\/\/zammad.com\/\" rel=\"nofollow\"\u003ezammad\u003c\/a\u003e","in_reply_to_status_id":null,"in_reply_to_status_id_str":null,"in_reply_to_user_id":null,"in_reply_to_user_id_str":null,"in_reply_to_screen_name":null,"user":{"id":1205290247124217857,"id_str":"1205290247124217857","name":"pennbrooke","screen_name":"pennbrooke1","location":"","description":"","url":null,"entities":{"description":{"urls":[]}},"protected":false,"followers_count":0,"friends_count":1,"listed_count":0,"created_at":"Fri
+        Dec 13 00:56:10 +0000 2019","favourites_count":0,"utc_offset":null,"time_zone":null,"geo_enabled":false,"verified":false,"statuses_count":19,"lang":null,"contributors_enabled":false,"is_translator":false,"is_translation_enabled":false,"profile_background_color":"F5F8FA","profile_background_image_url":null,"profile_background_image_url_https":null,"profile_background_tile":false,"profile_image_url":"http:\/\/abs.twimg.com\/sticky\/default_profile_images\/default_profile_normal.png","profile_image_url_https":"https:\/\/abs.twimg.com\/sticky\/default_profile_images\/default_profile_normal.png","profile_link_color":"1DA1F2","profile_sidebar_border_color":"C0DEED","profile_sidebar_fill_color":"DDEEF6","profile_text_color":"333333","profile_use_background_image":true,"has_extended_profile":false,"default_profile":true,"default_profile_image":true,"following":false,"follow_request_sent":false,"notifications":false,"translator_type":"none"},"geo":null,"coordinates":null,"place":null,"contributors":null,"is_quote_status":false,"retweet_count":0,"favorite_count":0,"favorited":false,"retweeted":false,"lang":"lv"}],"search_metadata":{"completed_in":0.017,"max_id":1237344473199153152,"max_id_str":"1237344473199153152","next_results":"?max_id=1237344473199153151&q=zammadzammadzammad&count=100&include_entities=1&result_type=mixed","query":"zammadzammadzammad","refresh_url":"?since_id=1237344473199153152&q=zammadzammadzammad&result_type=mixed&include_entities=1","count":100,"since_id":0,"since_id_str":"0"}}'
+    http_version: 
+  recorded_at: Tue, 10 Mar 2020 11:48:07 GMT