React Suspense, Unit testing side effects & Writing better experiments

The summer is almost over, and it's time to get back to work! 💪 We're here with another edition of React Open Source Meetup, and we hope you're ready for another exciting event. This time, we're going to discuss unit testing side effects and writing better experiments using React Render Props.

Big thanks to Hello Fresh (https://www.hellofresh.de) for hosting us again and for supporting the local community.

To participate in interesting discussions and keep in touch with fellow attendees and speakers, join our Slack workspace: http://bit.ly/rdb-slack-2018

If you're starving for more in-depth talks and hands-on workshops, make sure you check out the first speakers at React Day Berlin conference, returning on November 30, 2018 – https://reactday.berlin

# Event Schedule

18:30 – Doors open: snacks, drinks, networking
19:00 – Introduction
19:10 – 🗣"Unit testing side effects with Jest and Introscope" by Peter Leonov
19:40 – 🗣"Write better experiments using React Render Props"
by José Mussa
20:10 – 🗣"React Suspense Deep Dive" by Tejas Kumar
20:40 – Finishing beers and more networking

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## Unit testing side effects with Jest and Introscope
by Peter Leonov

Testing ES6 modules can be tough, esp. if the module has a small public API with rich internals. We developed a babel plugin (called Introscope) helping to look inside any module turning it into a factory function. This helps us develop some cool techniques for more or less robust side effects based testing with mocks, spies, and Jest snapshots.

About Peter (https://twitter.com/peterleonov)

Peter works as a Senior JavaScript Engineer at Zalando. He's a full-stack developer with 10 years of backend and 15 years of front-end experience. In frontend, he loves React/Redux and functional ES6. He's gone from telnet to Docker, from CGI scripts to nginx C modules, from onmouseover to reactive cross-platform apps, from to semantic SCSS + BEM, from solving quadratic equations to a high-performance Ruby LALR1 parser, from BASIC to Haskell, from joy to happiness.

## Write better experiments using React Render Props
by José Mussa

A/B testing allows us to test a hypothesis on a small sample of users without affecting all of them. Wouldn’t it be awesome if we could apply the same principle to our codebase?

About José (https://twitter.com/jcmussa)

A front-end driven JavaScript developer. His main focus is on customer-facing applications, and he loves to write code used directly by HelloFresh customers all around the globe. He has always dreamt of contributing to a codebase that could reach many users, so working on HelloFresh every day is definitely awesome!

## React Suspense Deep Dive
by Tejas Kumar

Suspense is an exciting new fundamental arriving soon in React. This talk explores this interesting new paradigm in-depth on the client and on the server, outlining its implications for current and future front-end development.

About Tejas (https://twitter.com/tejaskumar_)

Tejas enjoys code. And people. And talking about code to people.

# Contact

If you have any questions about the React Open Source community, or willing to support us as a company and sponsor the next event – reach us at hi@reactday.berlin

# Social

Check out last events talk recordings https://www.youtube.com/ReactDayBerlin
Follow updates on twitter https://twitter.com/reactdayberlin