Mark ProcessCommitWorker as idempotent

The ProcessCommitWorker processed 1 million "duplicate"
jobs the past 7 days, and spent 120 hours on that.

Duplicate jobs are jobs that get scheduled when there
is already a job in the queue for the same worker with
the same arguments.

If the job was (marked as) idempotent,
we would be able to deduplicate those jobs automatically
when they get scheduled.

app/workers/all_queues.yml

@@ -1234,7 +1234,7 @@
   :urgency: :high
   :resource_boundary: :unknown
   :weight: 3
-  :idempotent: 
+  :idempotent: true
 - :name: project_cache
   :feature_category: :source_code_management
   :has_external_dependencies: 

app/workers/process_commit_worker.rb

@@ -7,13 +7,15 @@
 # result of this the workload of this worker should be kept to a bare minimum.
 # Consider using an extra worker if you need to add any extra (and potentially
 # slow) processing of commits.
-class ProcessCommitWorker # rubocop:disable Scalability/IdempotentWorker
+class ProcessCommitWorker
   include ApplicationWorker
 
   feature_category :source_code_management
   urgency :high
   weight 3
 
+  idempotent!
+
   # project_id - The ID of the project this commit belongs to.
   # user_id - The ID of the user that pushed the commit.
   # commit_hash - Hash containing commit details to use for constructing a

spec/services/git/branch_push_service_spec.rb

@@ -291,7 +291,7 @@ describe Git::BranchPushService, services: true do
       execute_service(project, user, oldrev: oldrev, newrev: newrev, ref: ref)
     end
 
-    it "defaults to the pushing user if the commit's author is not known", :sidekiq_might_not_need_inline do
+    it "defaults to the pushing user if the commit's author is not known", :sidekiq_inline, :use_clean_rails_redis_caching do
       allow(commit).to receive_messages(
         author_name: 'unknown name',
         author_email: 'unknown@email.com'
@@ -336,7 +336,7 @@ describe Git::BranchPushService, services: true do
     end
 
     context "while saving the 'first_mentioned_in_commit_at' metric for an issue" do
-      it 'sets the metric for referenced issues', :sidekiq_might_not_need_inline do
+      it 'sets the metric for referenced issues', :sidekiq_inline, :use_clean_rails_redis_caching do
         execute_service(project, user, oldrev: oldrev, newrev: newrev, ref: ref)
 
         expect(issue.reload.metrics.first_mentioned_in_commit_at).to be_like_time(commit_time)
@@ -397,7 +397,7 @@ describe Git::BranchPushService, services: true do
         allow(project).to receive(:default_branch).and_return('not-master')
       end
 
-      it "creates cross-reference notes", :sidekiq_might_not_need_inline do
+      it "creates cross-reference notes", :sidekiq_inline, :use_clean_rails_redis_caching do
         expect(SystemNoteService).to receive(:cross_reference).with(issue, closing_commit, commit_author)
         execute_service(project, user, oldrev: oldrev, newrev: newrev, ref: ref)
       end
@@ -438,7 +438,7 @@ describe Git::BranchPushService, services: true do
       context "mentioning an issue" do
         let(:message) { "this is some work.\n\nrelated to JIRA-1" }
 
-        it "initiates one api call to jira server to mention the issue", :sidekiq_might_not_need_inline do
+        it "initiates one api call to jira server to mention the issue", :sidekiq_inline, :use_clean_rails_redis_caching do
           execute_service(project, user, oldrev: oldrev, newrev: newrev, ref: ref)
 
           expect(WebMock).to have_requested(:post, jira_api_comment_url('JIRA-1')).with(

spec/workers/process_commit_worker_spec.rb

@@ -22,16 +22,26 @@ describe ProcessCommitWorker do
       worker.perform(project.id, -1, commit.to_hash)
     end
 
+    include_examples 'an idempotent worker' do
+      subject do
+        perform_multiple([project.id, user.id, commit.to_hash], worker: worker)
+      end
+
       it 'processes the commit message' do
-      expect(worker).to receive(:process_commit_message).and_call_original
+        expect(worker).to receive(:process_commit_message)
+          .exactly(IdempotentWorkerHelper::WORKER_EXEC_TIMES)
+          .and_call_original
 
-      worker.perform(project.id, user.id, commit.to_hash)
+        subject
       end
 
       it 'updates the issue metrics' do
-      expect(worker).to receive(:update_issue_metrics).and_call_original
+        expect(worker).to receive(:update_issue_metrics)
+          .exactly(IdempotentWorkerHelper::WORKER_EXEC_TIMES)
+          .and_call_original
 
-      worker.perform(project.id, user.id, commit.to_hash)
+        subject
+      end
     end
   end