[Cancelled] An introduction to mutation testing in Ruby

Tue, 10 Mar 2020 19:00 - 21:30 JST

Impact Hub Tokyo

東京都目黒区目黒2-11-3 印刷工場1階


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Free admission
Drinks and a light meal will be provided


In light of the coronavirus disease (COVID-19) outbreak, this event is cancelled. Once the situation stabilizes, we'll hold another event that will feature Amol's presentation "An introduction to mutation testing in Ruby".


19:00 〜 19:30 Doors open

Grab a drink and catch up with your fellow Rubyists.

19:30 〜 20:00 An introduction to mutation testing in Ruby - Amol Verma

How do you know if your tests have good coverage? Does 100% code coverage guarantee protection against anything other than some simple runtime exceptions? How often does your coverage metric prompt you to make meaningful changes to your production code?

Code coverage tools like simplecov are commonly used by Rubyists, but can distract from the point of testing: making sure production code is robust and error-free. Mutation testing can be a sensible alternative (or addition) to your current code coverage strategy.

In this presentation, I'll introduce the concept of mutation testing, demonstrate the process of mutation testing Ruby code, and talk about its pros, cons, and appropriate usecases.


Started using Ruby in 2016. I enjoy writing tests, arguing about process, and deleting large redundant sections of our codebase. I develop software at MediWeb, Inc.

20:00 〜 20:30 Rubyist show and tell

Do you have a cool snippet of Ruby code that you'd like to share, but it doesn't warrant an entire presentation? A challenge with your Ruby application you've been struggling with, and would like some advice? A helpful library or tool you've come across? This is your chance to share it.

For those who'd like to participate, you'll have up to five minutes. There's no need to create a slide deck, but you'll be able to use the projector if you have a code sample or something else to share. While we'll ask you if you'd like to participate when signing up, this is just to gauge interest, and you can change your mind on the day of the event.

20:30 〜 21:30 Open Networking

Discuss the presentations or anything else Ruby related with the other attendees.

Food Sponsor

tokyodev helps international developers start and grow their career in Japan. We curate a list of developer jobs in Japan that don't require Japanese, write articles about being a developer here (including our recently published developer salary survey), and provide a forum to discuss the challenges of being a developer here.

Drink and Venue Sponsor

Le Wagon Tokyo is a coding school for startups, creative people and tech entrepreneurs. Our 9-week full-time or 24-week part-time Coding Bootcamps are designed for complete beginners or "half-beginners" who really want to dive into programming and, above all, change their mindset. Learn to think like a developer, consider issues with new insight, and become more autonomous thanks to these newly acquired abilities.

Code of Conduct

Tokyo Rubyist Meetup is a safe and inclusive event. By attending, you agree to our code of conduct.

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Tokyo Rubyist Meetup

Tokyo Rubyist Meetup

Tokyo Rubyist Meetup (trbmeetup) is an event that seeks to help bridge the Japan and international ruby and ruby on rails community. It will hold regular meetings where Japanese Rubyists can commun...

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