Test parallel push doesn't lead mismatched sha

transactional_test is set to false because general test flow doesn't
clear records created in Thread.new which use different db connection.

test/unit/parallel_pusher_test.rb

@@ -0,0 +1,46 @@
+require 'test_helper'
+require 'concurrent/atomics'
+
+class ParallelPusherTest < ActiveSupport::TestCase
+  self.use_transactional_tests = false
+
+  context "when pushing gems in parallel" do
+    setup do
+      @fs = RubygemFs.mock!
+      @user = create(:user, email: "user@example.com")
+    end
+
+    teardown do
+      @user.destroy
+      @rubygem = Rubygem.find_by(name: 'hola')
+      @rubygem.versions.destroy_all
+      @rubygem.destroy
+      Delayed::Job.delete_all
+      GemDownload.delete_all
+    end
+
+    should "not lead to sha mismatch between gem file and db" do
+      @gem1 = gem_file("hola-0.0.0.gem")
+      @gem2 = gem_file("hola/hola-0.0.0.gem")
+      @cutter1 = Pusher.new(@user, @gem1)
+      @cutter2 = Pusher.new(@user, @gem2)
+      latch = Concurrent::CountDownLatch.new(2)
+
+      Thread.new do
+        @cutter1.process
+        ActiveRecord::Base.connection.close
+        latch.count_down
+      end
+
+      Thread.new do
+        @cutter2.process
+        ActiveRecord::Base.connection.close
+        latch.count_down
+      end
+
+      latch.wait
+      expected_sha = Digest::SHA2.base64digest(@fs.get('gems/hola-0.0.0.gem'))
+      assert_equal expected_sha, Version.last.sha256
+    end
+  end
+end

test/unit/pusher_test.rb

@@ -338,4 +338,22 @@ class PusherTest < ActiveSupport::TestCase
       assert_equal 'new summary', response['_source']['summary']
     end
   end
+
+  context "pushing to s3 fails" do
+    setup do
+      @gem = gem_file("test-1.0.0.gem")
+      @cutter = Pusher.new(@user, @gem)
+      @fs = RubygemFs.s3!('https://some.host')
+      s3_exception = Aws::S3::Errors::ServiceError.new("stub raises", "something went wrong")
+      Aws::S3::Client.any_instance.stubs(:put_object).with(any_parameters).raises(s3_exception)
+      @cutter.process
+    end
+
+    should "not create version" do
+      rubygem = Rubygem.find_by(name: 'test')
+      expected_message = "There was a problem saving your gem. Please try again."
+      assert_equal expected_message, @cutter.message
+      assert_equal 0, rubygem.versions.count
+    end
+  end
 end