Create loop_runner module to run test repeatedly

Create QA::Specs::LoopRunner
Call LoopRunner with --loop CLI option
Allow loop duration to be set with an ENV var

qa/qa.rb

@@ -419,6 +419,7 @@ module QA
     autoload :Config, 'qa/specs/config'
     autoload :Runner, 'qa/specs/runner'
     autoload :ParallelRunner, 'qa/specs/parallel_runner'
+    autoload :LoopRunner, 'qa/specs/loop_runner'
 
     module Helpers
       autoload :Quarantine, 'qa/specs/helpers/quarantine'

qa/qa/runtime/env.rb

@@ -261,6 +261,10 @@ module QA
         ENV['QA_RUNTIME_SCENARIO_ATTRIBUTES']
       end
 
+      def gitlab_qa_loop_runner_minutes
+        ENV.fetch('GITLAB_QA_LOOP_RUNNER_MINUTES', 1).to_i
+      end
+
       private
 
       def remote_grid_credentials

qa/qa/scenario/shared_attributes.rb

@@ -8,6 +8,7 @@ module QA
       attribute :gitlab_address, '--address URL', 'Address of the instance to test'
       attribute :enable_feature, '--enable-feature FEATURE_FLAG', 'Enable a feature before running tests'
       attribute :parallel, '--parallel', 'Execute tests in parallel'
+      attribute :loop, '--loop', 'Execute test repeatedly'
     end
   end
 end

qa/qa/specs/loop_runner.rb

+# frozen_string_literal: true
+
+module QA
+  module Specs
+    module LoopRunner
+      module_function
+
+      def run(args)
+        start = Time.now
+        loop_duration = 60 * QA::Runtime::Env.gitlab_qa_loop_runner_minutes
+
+        while Time.now - start < loop_duration
+          RSpec::Core::Runner.run(args.flatten, $stderr, $stdout).tap do |status|
+            abort if status.nonzero?
+          end
+          RSpec.clear_examples
+        end
+      end
+    end
+  end
+end

qa/qa/specs/runner.rb

@@ -63,6 +63,8 @@ module QA
 
         if Runtime::Scenario.attributes[:parallel]
           ParallelRunner.run(args.flatten)
+        elsif Runtime::Scenario.attributes[:loop]
+          LoopRunner.run(args.flatten)
         else
           RSpec::Core::Runner.run(args.flatten, $stderr, $stdout).tap do |status|
             abort if status.nonzero?