Benchmark script from Ruby Performance Optimization (https://pragprog.com/book/adrpo/ruby-performance-optimization)

measure.rb

require "json"
require "benchmark"

class Measure
  def self.run(&block)
    no_gc = (ARGV[0] == "--no-gc")
    if no_gc
      GC.disable
    else
    # collect memory allocated during library loading # and our own code before the measurement
    GC.start
    end
    memory_before = `ps -o rss= -p #{Process.pid}`.to_i/1024
    gc_stat_before = GC.stat
    time = Benchmark.realtime do
      yield
    end
    gc_stat_after = GC.stat
    GC.start unless no_gc
    memory_after = `ps -o rss= -p #{Process.pid}`.to_i/1024

    puts({
        RUBY_VERSION => {
          gc: no_gc ? 'disabled' : 'enabled',
          time: time.round(2),
          gc_count: gc_stat_after[:count] - gc_stat_before[:count],
          memory: "%dM" % (memory_after - memory_before)
          }
        }.to_json)
  end
end

Call it like this:

Measure.run do
  #whatever code you want to test
end

The output will look like this:

{"2.2.2":{"gc":"enabled","time":0.04,"gc_count":0,"memory":"0M"}}