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Elements of Ruby Style

This is a scratchpad of style guidelines for Ruby. When undefined, there are multiple ways that are acceptable and dependent on context.

Returning values

• Never use explicit return when intent is clear
• Use as a short circuit guard statement

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Gemfile.lock

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require 'net/http'

module Net
  module DefaultProxy
    # Defaults all requests through Net::HTTP through an http proxy.
    # Example:
    #   require 'net/http'
    #   require 'net/http_extensions'
    #   Net::HTTP.set_http_proxy!
    #

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• cilantro (after cooking)
• onion (before and after, small cubes after for crunch and sharp)
• tomatos
• celery
• chicken (strips, small)
• carrots (cubed)
• green bell pepper (cooked very soft)
• zucchini

very thin consistency, strong tomato flavor (maybe canned tomatos with juice?). chicken broth and tomato base.

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Hunting Down Execution Order Test Failures

Unit tests should pass when run in random order. But for an existing legacy project, certain tests might depend on the execution order. One test might run perfectly fine by itself, but fail miserably when run after another test. Rather than running different combinations manually, RSpec 2.8 has the option to run specs in random order with the --order random flag. But even with this, it can be hard to determine which specific test is causing the dependency. For example:

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      class << self
        # Define an attr_accessor, but the reader method will
        # set the variable if there is a first argument
        def dsl_accessor(*args)
          args.each do |name|
            class_eval <<-ACCESSORS
              attr_writer :#{name}
              def #{name}(*args)
                send("#{name}=", args.first) if !args.empty?
                @#{name}

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# http://danielmiessler.com/study/lsof/
sudo lsof -c haproxy
sudo lsof -iTCP | grep LISTEN

# http://danielmiessler.com/study/tcpdump/
# capture unlimited length, on loopback device, don't resolve hostname, absolute sequence numbers, tcp, src or dst port == 443
sudo tcpdump -s 0 -i lo0 -n -S tcp port 443

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RSpec Performance Module

Port http://guides.rubyonrails.org/performance_testing.html to RSpec. Add as another example group or add to existing controller example group

describe SomeController, :performance => true do
  # someway to load seed data for these sets of tests
  fixtures      :production_dump
  use_database  :production

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def commit_for(pathspec = "HEAD")
  `git log -1 --format=%H #{pathspec}`.chomp
end

def oneline_for(pathspec = "HEAD")
  `git log -1 --oneline #{args[:good]}`.chomp
end

# remember what HEAD is so we can jump back to it
START = commit_for('HEAD')

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require 'new_relic'
require 'faraday'
require 'active_support'

class InstrumentationMiddleware < Faraday::Middleware
  extend NewRelic::Agent::MethodTracer
  def call(env)
    uri = env[:url]
    method = env[:method]
    metrics = ["External/#{uri.host}/Faraday/#{method}", "External/#{uri.host}/all"]