--- title: "This week's Ruby news, issue 311" publication: "Ruby Weekly" issue: 311 published_at: "2016-08-18" canonical_url: "https://rubyweekly.com/issues/311" --- This week's Ruby news, issue 311 This week's Ruby and Rails news[Read this e-mail on the Web](http://rubyweekly.com/issues/311) Ruby WeeklyIssue 311 — August 18, 2016 Timo Rößner[A Deep Dive Into Mutation Testing and The Mutant Gem](https://troessner.svbtle.com/kill-all-the-mutants-a-deep-dive-into-mutation-testing-and-how-the-mutant-gem-works)Mutant is the most advanced system for doing mutation testing in Ruby. Mutation testing is where code is changed (mutated) in minor ways to see how robust the existing tests are. David Bush[The Ins and Outs of Debugging Ruby with Byebug](https://www.sitepoint.com/the-ins-and-outs-of-debugging-ruby-with-byebug/)[Byebug](https://github.com/deivid-rodriguez/byebug) is a debugger for Ruby 2 that uses [TracePoint.](http://ruby-doc.org/core-2.0.0/TracePoint.html) Yehonathan Sharvit[Lambda Calculus: The Y Combinator in Ruby](http://blog.klipse.tech/lambda/2016/08/10/pure-y-combinator-ruby.html)The Y combinator is a function that allows the generation of recursive functions without using names. This post introduces it in Ruby with live, editable demos. HerokuSponsored[Container Ready Rails 5](https://blog.heroku.com/container_ready_rails_5?c=7013A000000NnBtQAK&utm_campaign=Display%20-%20Endemic%20-%20Cooper%20-%20Ruby%20-%20Blog%20-%20Real-Time-Rails&utm_medium=display&utm_source=cooperpress&utm_content=blog&utm_term=ruby)Explore the interfaces that make it easy to deploy your app on any container platform. [Read more.](https://blog.heroku.com/container_ready_rails_5?c=7013A000000NnBtQAK&utm_campaign=Display%20-%20Endemic%20-%20Cooper%20-%20Ruby%20-%20Blog%20-%20Real-Time-Rails&utm_medium=display&utm_source=cooperpress&utm_content=blog&utm_term=ruby) [![Heroku\](https://copm.s3.amazonaws.com/137e521e.png)](https://blog.heroku.com/container_ready_rails_5?c=7013A000000NnBtQAK&utm_campaign=Display%20-%20Endemic%20-%20Cooper%20-%20Ruby%20-%20Blog%20-%20Real-Time-Rails&utm_medium=display&utm_source=cooperpress&utm_content=blog&utm_term=ruby) Andrew Allen[human_time: Ruby Time and Date Comparisons for Humans](https://github.com/allenan/human_time)A gem that makes time and date comparisons more readable, e.g. `more_recent_than_or_equal_to?` and `earlier_than?` methods. Leo Laporte[An Interview with DHH](https://twit.tv/shows/triangulation/episodes/259)Rails creator David Heinemeier Hansson (DHH) talks about programming as art, how he got started coding, his love of photography, and racing in Le Mans. _70 minutes._ Alex Taylor[Advanced SQL in Rails: A 2 Part Series](http://brewhouse.io/2016/08/04/sql-in-rails.html)A look at taking advantage of more powerful SQL features (like window functions and views) from Rails. [Part 2 here.](http://brewhouse.io/2016/08/12/sql-in-rails-part2.html) Sitepoint[Asynchronous Multiple File Upload with Rails and Dropzone.js](https://www.sitepoint.com/asynchronous-multiple-file-upload-with-rails-and-dropzone-js/)A walkthrough of implementing a drag and droppable file upload mechanism within a Rails 4.2 app. Jobs - [Sr. Javascript / Ruby Developer](https://www.stickermule.com/jobs?job=714da6cc-dc8b-4453-8bd6-7b0fa41ebd37&title=sr-javascript--ruby-developer)Sticker Mule is looking for passionate engineers to join our remote team. Come help us build the best e-commerce experience using Ruby, Rails, React, Node, Docker and more. Sticker Mule - [Ruby on Rails Engineer at Instacart (San Francisco)](https://inst.cr/t/TGxJVdHj1?utm_source=rubyweekly&utm_medium=email)Less than 2% of US grocery spend last year was online. We're going to change that. Come work with us on its fun, challenging problems. Instacart - [Get 5+ Engineering Job Offers in 1 Week](https://hired.com/?utm_source=newsletters&utm_medium=petercooperpress&utm_campaign=q3-16-rubyweekly)With Hired, companies apply to hire you - get salary and equity offers before you interview from companies like Facebook, Postmates, & Square Hired.com In brief - [Daniel Kehoe's Learn Ruby on Rails 5 Kickstarter](https://www.kickstarter.com/projects/909377477/learn-ruby-on-rails-5?ref=ruby_weekly) news Daniel is updating his popular Rails intro book to Rails 5. Kickstarter - [New Framework Defaults in Rails 5 to Make Upgrade Easier](http://blog.bigbinary.com/2016/08/18/new-framework-defaults-in-rails-5-to-make-upgrade-easier.html?utm_source=rubyweekly&utm_medium=email) news Rails 5 adds feature flags for all the breaking changes to make the upgrade process easier. Srihari K - [Find and Fix Ruby Errors Faster (and have fun doing it)](https://rollbar.com/?utm_source=rubyweekly&utm_medium=email-nl&utm_term=rubyweekly_8_18&utm_campaign=nl_sponsorship) Quickly pinpoint what’s broken and why. Get the context and insights to defeat all Ruby errors. ROLLBARSponsored - [Exporting Data to a XLSX Spreadsheet from Rails](https://blog.codeminer42.com/exporting-data-to-a-xlsx-spreadsheet-on-rails-7322d1c2c0e7?utm_source=rubyweekly&utm_medium=email) tutorial Igor Marques da Silva - [Rake Explained: A Primer for Ruby's Task Management Tool](https://medium.com/@rudyyazdi/rake-gem-explained-ebee7e6e6f72?utm_source=rubyweekly&utm_medium=email) tutorial Rudy Yazdi - [Run Rails Migrations Automatically on Heroku](http://aspiringwebdev.com/run-rails-migrations-automatically-on-heroku/?utm_source=rubyweekly&utm_medium=email) tutorial Corey Martin - [How to Scrape Web Sites with Ruby and Watir](http://readysteadycode.com/howto-scrape-websites-with-ruby-and-watir?utm_source=rubyweekly&utm_medium=email) tutorial A very basic intro. Watir is powered by Selenium, so you can even use it to interact with on-page JavaScript. TIMCRAFT - [Rails and Webpack: No Gem Required](http://blog.iempire.ru/2016/07/09/webpack-and-rails/?utm_source=rubyweekly&utm_medium=email) tutorial Kir Shatrov - [A Look Into Bloom Filters with Ruby](https://subvisual.co/blog/posts/96-a-look-into-bloom-filters-with-ruby?utm_source=rubyweekly&utm_medium=email) tutorial Fernando Mendes - [Rails 5 Allows Wildcard For Specifying Template Dependencies For Cache Digests](http://blog.bigbinary.com/2016/08/17/rails-5-allows-wildcard-for-specifying-template-dependencies.html?utm_source=rubyweekly&utm_medium=email) tutorial Abhishek Jain - [Spy vs Double vs Instance Double](http://www.ombulabs.com/blog/rspec/ruby/spy-vs-double-vs-instance-double.html?utm_source=rubyweekly&utm_medium=email) tutorial Mauro Otonelli - [Elixir for Rubyists: A Simple, Accessible 13 Minute Intro](https://www.youtube.com/watch?v=L0qC97ytMjQ) video Tute Costa - [The Upgrade Trails: Tips for Upgrading Rails Apps](http://olivierlacan.com/posts/the-upgrade-trails/?utm_source=rubyweekly&utm_medium=email) opinion Lessons learnt from a Rails 3 to Rails 4 migration that took two years. Olivier Lacan - [Thoughts on Ruby’s Reputation](http://www.alanbradburne.com/Rubys-reputation/?utm_source=rubyweekly&utm_medium=email) opinion Reflections inspired by Adam Hawkins’ [2015 post on the future of the Ruby community.](http://hawkins.io/2015/05/the-ruby-community-the-next-version/) Alan Bradburne - [Semaphore Test Boosters: Cut Your Build Time to ~ 3 Minutes](https://semaphoreci.com/product/test-boosters?utm_source=rubyweekly&utm_medium=email&utm_content=20160817&utm_campaign=testboosters) tools Automatically parallelize your Ruby test suite, no matter its size. Book a personal demo today. SemaphoreSponsored - [A PDF Minitest Cheat Sheet](http://chriskottom.com/blog/2016/08/minitest-cheat-sheet/?utm_source=rubyweekly&utm_medium=email) tools A reference to the basic methods and syntax for `Minitest` and `Minitest::Spec` as well as a full listing of all assertions and expectations. Chris Kottom - [Oprah: Opinionated Presenters for Rails 5](https://github.com/endofunky/oprah?utm_source=rubyweekly&utm_medium=email) code Designed to be very lightweight, easy to est, and with no monkey patching. Tobias Svensson - [emittr: A Ruby Event Emitter Implementation](https://github.com/talyssonoc/emittr?utm_source=rubyweekly&utm_medium=email) code Talysson de Oliveira Cassiano Curated by [Peter Cooper](https://twitter.com/peterc) and [Glenn Goodrich](https://twitter.com/ruprict), and published by [Cooperpress](https://cooperpress.com/). Send feedback by simply replying to this mail. Want to sponsor an issue? See our [media kit.](https://cooperpress.com/mediakit) Want to post a job? Email us or [use our self-serve system.](https://booking.cooperpress.com/jobs) [Unsubscribe](*|UNSUB|*) | [Change email address](*|UPDATE_PROFILE|*) | [Read this issue on the Web](http://rubyweekly.com/issues/311) © Cooperpress Ltd. 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