RSpec profiling with RubyProf and StackProf

Readme.md

Profile your specs

Instructions

• Ensure that you have required gems ('ruby-prof' >= 0.16, 'stackprof')

• Require spec_profiling.rb in your spec_helper.rb (or whereever you like)

• To profile the whole suite run:

# Profile with ruby-prof
RUBYPROF=1 rspec ...

# Profile with stackprof
STACKPROF=1 rspec ...

• To profile a separate example mark it with the corresponding tag:

# Profile with StackProf
it "is too slow", :sprof do
 ...
end

# Profile with RubyProf
it "is too slow", :rprof do
  ...
end

Gemfile

gem 'stackprof', require: false
gem 'ruby-prof', require: false

spec_profiling.rb

module SpecProfiling
  class << self
    def init
      ruby_prof if ENV['RUBYPROF']
      stack_prof if ENV['STACKPROF']
    end

    def ruby_prof
      require 'ruby-prof'
      $stdout.puts "RubyProf enabled"

      profiler = RubyProf::Profile.new(
        merge_fibers: true,
        include_threads: [Thread.current]
      )

      profiler.start

      at_exit do
        result = profiler.stop
        
        # Common RSpec methods
        result.eliminate_methods!(
          [
            /instance_exec/,
            /Example(Group)?>?#run(_examples)?/,
            /Procsy/,
            /AroundHook#execute_with/,
            /HookCollections/,
            /Array#(map|each)/
          ]
        )
        printer_type = ENV['RPRINTER'] || 'call_stack'
        printer = "RubyProf::#{printer_type.camelize}Printer".constantize
        path = Rails.root.join("tmp", "ruby-prof-report-#{printer_type}-#{RubyProf.measure_mode}-total.html")
        File.open(path.to_s, 'w') { |f| printer.new(result).print(f, min_percent: 1) }
      end
    end

    def stack_prof
      require 'stackprof'
      mode = ENV['RMODE'] || 'wall'
      $stdout.puts "StackProf enabled (mode: #{mode})"
      path = Rails.root.join("tmp", "stackprof-#{mode}-test-total.dump")
      # we use raw to make it possible to generate flamegraphs
      StackProf.start(mode: mode.to_sym, raw: true)

      at_exit do
        StackProf.stop
        StackProf.results path.to_s
      end
    end
  end
end

RSpec.configure do |config|
  config.around(:each, :sprof) do |ex|
    require 'stackprof'
    mode = ENV['RMODE'] || 'wall'
    path = Rails.root.join("tmp", "stackprof-#{mode}-test-#{ex.full_description.parameterize}.dump")
    StackProf.run(mode: mode, out: path.to_s, raw: true) do
      ex.run
    end
  end

  config.around(:each, :rprof) do |ex|
    require 'ruby-prof'
    
    result = RubyProf.profile { ex.run }
    
    printer_type = ENV['RPRINTER'] || 'call_stack'
    printer = "RubyProf::#{printer_type.camelize}Printer".constantize
    
    path = Rails.root.join("tmp", "ruby-prof-report-#{printer_type}-#{RubyProf.measure_mode}-#{ex.full_description.parameterize}.html")
    File.open(path.to_s, 'w') { |f| printer.new(result).print(f, min_percent: 1) }
  end
end

SpecProfiling.init

See https://choosealicense.com/ for tl;dr

Please, please add a license. The fact none is listed makes using this software a legal quagmire. Currently it is not legal to use this code or its derivatives in any useful software. I may be mistaken but hopefully this is not the intended effect.

Currently no license is mentioned anywhere, what makes this code fully copyrighted, like any other creative work.

It limits usefulness of this project - and I hope that it is unintentional. For example it seems that it would solve my problem of profiling hilariously slow rspec tests (2036.33 seconds ./spec/word_processor_spec.rb:43), in current situation I would be unable to legally publish project that would use this solution.

Obviously, please do not release it under any license if you are not the author (that would be even worse legal quagmire)