Use API helper to send artifact file through Workhorse

lib/api/helpers.rb

@@ -432,6 +432,10 @@ module API
       header(*Gitlab::Workhorse.send_git_archive(repository, ref: ref, format: format))
     end
 
+    def send_artifacts_entry(build, entry)
+      header(*Gitlab::Workhorse.send_artifacts_entry(build, entry))
+    end
+
     # The Grape Error Middleware only has access to env but no params. We workaround this by
     # defining a method that returns the right value.
     def define_params_for_grape_middleware

lib/api/jobs.rb

@@ -101,7 +101,7 @@ module API
         entry = build.artifacts_metadata_entry(params[:artifact_path])
         not_found! unless entry.exists?
 
-        Gitlab::Workhorse.send_artifacts_entry(build, entry)
+        send_artifacts_entry(build, entry)
       end
 
       desc 'Download the artifacts file from a job' do

spec/requests/api/jobs_spec.rb

@@ -215,10 +215,9 @@ describe API::Jobs do
           get_artifact_file(artifact)
 
           expect(response).to have_http_status(200)
-          expect(response.body)
-            .to include 'Gitlab-Workhorse-Send-Data', 'artifacts-entry'
           expect(response.headers)
-            .to include('Content-Type' => 'application/json')
+            .to include('Content-Type' => 'application/json',
+                        'Gitlab-Workhorse-Send-Data' => /artifacts-entry/)
         end
       end