Add benchmark (#2855)

* Add benchmark gem to Faker

* Fix #2851

Add benchmark rake task for evaluating time execution. Fixes

Co-authored-by: Rubens Fernandes <rubens.fernandes97@gmail.com>

* Commit PR suggestions by Thiago.
- Build all_methods outside the benchmark since we don't want to measure that.

* Commit PR suggestions by Steffani.

- Avoid calling the same object twice

---------

Co-authored-by: Rubens Fernandes <rubens.fernandes97@gmail.com>

Gemfile

@@ -5,6 +5,7 @@ source 'https://rubygems.org'
 # Specify your gem's dependencies in faker.gemspec
 gemspec
 
+gem 'benchmark'
 gem 'minitest', '5.20.0'
 gem 'pry', '0.14.2'
 gem 'rake', '13.1.0'

Gemfile.lock

@@ -8,6 +8,7 @@ GEM
   remote: https://rubygems.org/
   specs:
     ast (2.4.2)
+    benchmark (0.3.0)
     coderay (1.1.3)
     concurrent-ruby (1.2.2)
     docile (1.4.0)
@@ -64,6 +65,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  benchmark
   faker!
   minitest (= 5.20.0)
   pry (= 0.14.2)

tasks/benchmark.rake

@@ -0,0 +1,43 @@
+# frozen_string_literal: true
+
+# rubocop:disable Security/Eval,Style/EvalWithLocation
+
+require 'benchmark'
+require 'faker'
+
+desc 'Benchmarking every Faker generator'
+task :benchmark do
+  all_methods = BenchmarkHelper.all_methods
+  count = all_methods.count
+
+  Benchmark.bmbm do |x|
+    x.report("Number of generators: #{count}") do
+      100.times do
+        all_methods.each { |method_name| eval(method_name) }
+      end
+    end
+  end
+end
+
+class BenchmarkHelper
+  class << self
+    def all_methods
+      subclasses.map do |subclass|
+        subclass_methods(subclass).flatten
+      end.flatten.sort
+    end
+
+    def subclasses
+      Faker.constants.delete_if do |subclass|
+        %i[Base Bank Books Cat Char Base58 ChileRut CLI Config Creature Date Dog DragonBall Dota ElderScrolls Fallout Games GamesHalfLife HeroesOfTheStorm Internet JapaneseMedia LeagueOfLegends Movies Myst Overwatch OnePiece Pokemon Religion Sports SwordArtOnline TvShows Time VERSION Witcher WorldOfWarcraft Zelda].include?(subclass)
+      end.sort
+    end
+
+    def subclass_methods(subclass)
+      eval("Faker::#{subclass}.public_methods(false) - Faker::Base.public_methods(false)").sort.map do |method|
+        "Faker::#{subclass}.#{method}"
+      end.sort
+    end
+  end
+end
+# rubocop:enable Security/Eval,Style/EvalWithLocation