1 files changed, 107 insertions, 0 deletions
diff --git a/spec/support/rspec_run_time.rb b/spec/support/rspec_run_time.rb
new file mode 100644
index 00000000000..977d4885624
--- /dev/null
+++ b/spec/support/rspec_run_time.rb
@@ -0,0 +1,107 @@
+# frozen_string_literal: true
+
+require 'os'
+require 'yaml'
+require 'rspec/core/formatters/base_formatter'
+require_relative '../../tooling/lib/tooling/helpers/duration_formatter'
+
+module Support
+  module RSpecRunTime
+    class RSpecFormatter < RSpec::Core::Formatters::BaseFormatter
+      include Tooling::Helpers::DurationFormatter
+
+      TIME_LIMIT_IN_MINUTES = 80
+
+      RSpec::Core::Formatters.register self, :example_group_started, :example_group_finished
+
+      def start(_notification)
+        @group_level = 0
+        @rspec_test_suite_start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+        output.puts "\n# [RSpecRunTime] Starting RSpec timer..."
+
+        init_expected_duration_report
+      end
+
+      def example_group_started(notification)
+        if @last_elapsed_seconds && @last_elapsed_seconds > TIME_LIMIT_IN_MINUTES * 60
+          RSpec::Expectations.fail_with(
+            "Rspec suite is exceeding the #{TIME_LIMIT_IN_MINUTES} minute limit and is forced to exit with error.")
+        end
+
+        if @group_level == 0
+          @current_group_start_time = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          file_path = spec_file_path(notification)
+          output.puts "# [RSpecRunTime] Starting example group #{file_path}. #{expected_run_time(file_path)}"
+        end
+
+        @group_level += 1
+      end
+
+      def example_group_finished(notification)
+        @group_level -= 1 if @group_level > 0
+
+        if @group_level == 0
+          file_path = spec_file_path(notification)
+          time_now = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+          actual_duration = time_now - @current_group_start_time
+
+          output.puts "\n# [RSpecRunTime] Finishing example group #{file_path}. " \
+                      "It took #{readable_duration(actual_duration)}. " \
+                      "#{expected_run_time(file_path)}"
+        end
+
+        output_elapsed_time
+      end
+
+      private
+
+      def expected_duration_report
+        report_path = ENV['KNAPSACK_RSPEC_SUITE_REPORT_PATH']
+
+        return unless report_path && File.exist?(report_path)
+
+        # rubocop:disable Gitlab/Json -- regular JSON is sufficient
+        @expected_duration_report ||= JSON.parse(File.read(report_path))
+        # rubocop:enable Gitlab/Json
+      end
+      alias_method :init_expected_duration_report, :expected_duration_report
+
+      def spec_file_path(notification)
+        notification.group.metadata[:file_path].sub('./', '')
+      end
+
+      def expected_run_time(spec_file_path)
+        return '' unless expected_duration_report
+
+        expected_duration = expected_duration_report[spec_file_path]
+        return "Missing expected duration from Knapsack report for #{spec_file_path}." unless expected_duration
+
+        "Expected to take #{readable_duration(expected_duration)}."
+      end
+
+      def output_elapsed_time
+        time_now = Process.clock_gettime(Process::CLOCK_MONOTONIC)
+        elapsed_seconds = time_now - @rspec_test_suite_start_time
+
+        # skip the output unless the duration increased by at least 1 second
+        unless @last_elapsed_seconds.nil? || elapsed_seconds - @last_elapsed_seconds < 1
+          output.puts \
+            "# [RSpecRunTime] RSpec elapsed time: #{readable_duration(elapsed_seconds)}. " \
+            "#{current_rss_in_megabytes}\n\n"
+        end
+
+        @last_elapsed_seconds = elapsed_seconds
+      end
+
+      def current_rss_in_megabytes
+        rss_in_megabytes = OS.rss_bytes / 1024 / 1024
+
+        "Current RSS: ~#{rss_in_megabytes.round}M"
+      end
+    end
+  end
+end
+
+RSpec.configure do |config|
+  config.add_formatter Support::RSpecRunTime::RSpecFormatter if ENV['GITLAB_CI']
+end