benchmark merge_vs_square_accessor

merge_vs_merge_bang_vs_square_accessor.rb

require 'benchmark/ips'

foo = { foo_1: 'one', foo_2: 'two' }
bar = { bar_1: 'one', bar_2: 'two' }

Benchmark.ips do |x|
  x.config(:time => 5, :warmup => 2)

  x.report('merge!') do |times|
    foo = { foo_1: 'one', foo_2: 'two' }
    bar = { bar_1: 'one', bar_2: 'two' }
    foo.merge!(bar)
  end

  x.report('square_accessor') do |times|
    foo = { foo_1: 'one', foo_2: 'two' }
    bar = { bar_1: 'one', bar_2: 'two' }
    foo[:bar_1] = 'one'
    foo[:bar_2] = 'two'
  end
  
  x.report('merge') do |times|
    foo = { foo_1: 'one', foo_2: 'two' }
    bar = { bar_1: 'one', bar_2: 'two' }
    foo.merge(bar)
  end

  x.compare!
end

results:

ruby merge_vs_merge_bang_vs_square_accessor.rb
Warming up --------------------------------------
              merge!    52.247k i/100ms
     square_accessor    50.111k i/100ms
               merge    32.190k i/100ms
Calculating -------------------------------------
              merge!     46.961B (±31.4%) i/s -     79.139B
     square_accessor     45.220B (±31.7%) i/s -     76.270B
               merge     17.328B (±43.9%) i/s -     35.860B

Comparison:
              merge!: 46961394641.1 i/s
     square_accessor: 45220484056.7 i/s - same-ish: difference falls within error
               merge: 17328443767.5 i/s - 2.71x slower