Log RSS when we're printing RSpec elapsed time

Gemfile

@@ -492,6 +492,7 @@ group :test do
   gem 'rspec_profiling', '~> 0.0.6', feature_category: :tooling
   gem 'rspec-benchmark', '~> 0.6.0', feature_category: :tooling
   gem 'rspec-parameterized', '~> 1.0', require: false, feature_category: :tooling
+  gem 'os', '~> 1.1', feature_category: :tooling
 
   gem 'capybara', '~> 3.39', '>= 3.39.2' # rubocop:todo Gemfile/MissingFeatureCategory
   gem 'capybara-screenshot', '~> 1.0.26' # rubocop:todo Gemfile/MissingFeatureCategory

Gemfile.lock

@@ -1997,6 +1997,7 @@ DEPENDENCIES
   openid_connect (= 1.3.0)
   openssl (~> 3.0)
   org-ruby (~> 0.9.12)
+  os (~> 1.1)
   pact (~> 1.63)
   parallel (~> 1.19)
   parser (~> 3.2, >= 3.2.2.4)

spec/support/rspec_run_time.rb

 # frozen_string_literal: true
 
+require 'os'
 require 'yaml'
 require 'rspec/core/formatters/base_formatter'
 require_relative '../../tooling/lib/tooling/helpers/duration_formatter'
@@ -84,11 +85,19 @@ def output_elapsed_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)}.\n\n"
+          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