Past Meetup

GraphQL with Sangria and Property Driven Tests

This Meetup is past

66 people went

Location image of event venue


UPDATE: Watch this event line online using Hangouts on Air!


We're going for broke and hosting a 3rd event in a row at Paytm Labs. Adam & Harinder, thanks for putting up with us!

It's been awhile since our last event and that's totally unacceptable. We are going to commit to more regular meetups and we have a bunch of ideas on how to do it. We'll be socializing some of these ideas in the coming weeks, but Katrin and I will also share a short summary with everyone at the event too.

For this event we have two guest speakers. Marconi Lanna, a world class Scala speaker extraordinaire will be paying us a visit. If you weren't able to attend Scala Up North (co-organized by Marconi), then you should check out his talk on Scala One Liners ( ), it was a classic! For this event Marconi is to give a talk on F-Bounded polymorphism.

Our second speaker is relatively new to the Scala community, but I have no doubt will have lots to contribute in years to come (if he's not totally swooned by Haskell first). I hired David Nadeau at Ethoca and I've been impressed with his passion for technology and all things programming related. He recently gave a good presentation to our colleagues on Property Driven Testing and I've invited him to present it to you fine people.


Cancelled - F-Bounded Polymorphism - Marconi Lanna, Originate

This talk will be rescheduled in the new year!

GraphQL with Sangria (remote) - Oleg Ilyenko, ( commercetools GmbH

Facebook released the first draft of GraphQL specification this past July. GraphQL provides an alternative to the REST API with high emphasis on efficient data retrieval and introspection. It becomes even more powerful when combined with client-side frameworks like React and Relay, allowing you to build an application based on highly decoupled components without sacrificing performance or over-/under-fetching a data needed for the views. Web application development is not the only area where GraphQL can excel. Any area that requires very precise and performant data fetching/manipulation, like mobile application development, can profit from GraphQL. In this talk I would like to give an introduction to GraphQL ( ) and Sangria ( ) - a scala GraphQL implementation.

(Organizer note: Oleg is the author of Sangria and this wil be his first talk on the subject! He will present via Google Hangout live from Berlin. It will be recorded and we'll do our best to accommodate questions at the end.)

Property Driven Testing - David Nadeau, Ethoca

We've all come to accept that properly tested code is less susceptible to bugs (especially regression bugs), however writing meaningful unit tests is a difficult and tedious task. In this talk I will briefly discuss some ways to write more meaningful unit tests, and then discuss a testing concept taken from the Haskell communities: property based testing.

Property based testing is a nice compromise between unit testing and a mathematical proof. It proposes the idea that we should not only be testing our functions by asserting a known output given some known input, but also, that we should test behaviours (properties) that we desire our function to always exhibit. If unit tests make us think about our code, property based testing makes us think a lot harder.

I hope to show that this form of testing has practical value, which will not only increase the quality of your code, but also the enjoyment of testing it.

Tentative schedule

6:30 Doors Open

7:00 A meetup update from Sean and Katrin

7:15 Oleg Ilyenko, ( commercetools Gmb, GraphQL with Sangria

7:55 David Nadeau, Ethoca, Property Driven Testing

8:20 Raffle for IntelliJ license

8:25 Social. Stick around and get to know your fellow Scala peers

Hope to see you there!


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