kenichi

require 'sinatra/base'

class App < Sinatra::Base
  get '/' do
    "hello!\n"
  end
  post '/exit' do
    Thread.new { sleep 1; exit }
    "exiting!\n"
  end

kenichi

require 'newrelic_rpm'

class Err
  def self.do
    raise 'here is an error'
  end
end

desc 'test notice error'
task :error do

kenichi

def bam(*a, baz:, bat:, **h, &block)
  [*a, block.parameters, baz: baz, bat: bat, **h]
end

__END__

> bam 1, 2, 'a', 'b' => 'c', d: 0xe, baz: 'mno', bat: 'jkl' do |*ar, foo:, **hash|; end
=> [1, 2, "a", {"b"=>"c"}, [[:rest, :ar], [:keyreq, :foo], [:keyrest, :hash]], {:baz=>"mno", :bat=>"jkl", :d=>14}]

kenichi

require 'newrelic_rpm'

class A
  include NewRelic::Agent::Instrumentation::ControllerInstrumentation
  
  # if this was removed, B.foo would not be instrumented, because B's definitiion overrides #foo
  def self.inherited subclass
    subclass.add_method_tracer :foo
  end

kenichi

First, I switch to JRuby 1.7 running in 1.9 mode

knakamura:test $ chruby jruby-1.7
knakamura:test $ wr
/Users/knakamura/.rubies/jruby-1.7.25/bin/ruby
jruby 1.7.25 (1.9.3p551) 2016-04-13 867cb81 on Java HotSpot(TM) 64-Bit Server VM 1.8.0_102-b14 +jit [darwin-x86_64]

Then I write out a simple Gemfile, no ruby directive

kenichi

NoMethodError: Couldn't find Member with [WHERE "members"."deleted_at" IS NULL AND (lower(sponsor_id) = '22403602')]

kenichi

$ rails new asset_hosted 2>&1 1>/dev/null

$ cd asset_hosted

$ echo 'Rails.application.config.action_controller.asset_host = "example.com"' >> config/initializers/assets.rb

$ be rails runner 'puts ApplicationController.asset_host'
Running via Spring preloader in process 56593
example.com

kenichi

Rails.application.configure do
  # ...

  config.action_controller.asset_host = Proc.new do |source|
    if source.ends_with?(".jpg") || source.ends_with?(".gif") || source.ends_with?(".png")
      "https://cdn-images.example.com"
    else
      "https://cdn.example.com"
    end
  end

kenichi

$ chruby 2.3.3
$ irb
irb(main):001:0> [].concat [1,2,3].map {|x| x.** 2}.select do |x|; x%2==0; end
=> [4]

irb(main):002:0> [].concat [1,2,3].map {|x| x.**(2)}.select do |x|; x%2==0; end
TypeError: no implicit conversion of Enumerator into Array
        from (irb):2:in `concat'
        from (irb):2
        from /Users/knakamura/.rubies/ruby-2.3.3/bin/irb:11:in `<main>'

kenichi

require 'benchmark/ips'

i, o = IO.pipe
rs = [i]

Benchmark.ips do |x|

  x.report :exceptions do
    begin
      i.read_nonblock 1