London React Meetup – April 2016

An evening of testing workflows and dynamically built forms awaited visitors to Code Node last Wednesday when the London React Meetup was once again in town. Tom Duncalf kicked things off by describing what he has found to be effective unit and integration testing strategies for React applications.

Tom explained his rationale for writing tests and in particular unit tests. In addition to verifying the application behaves as expected and providing a useful set of automated regression tests (allowing you to refactor with confidence), he pointed out how well written tests can act as documentation for the code and enable faster debugging with less dependency on end-to-end tests (be they automated or manual) to expose errors.

Taking this testing philosophy, Tom went on to discuss how this applies to testing applications built with React and listed the qualities he looks to test in his components (e.g. do they render correctly, can you interact with them as expected and how do the integrate with the rest of the application).

The talk was full of code examples of how Tom went about implementing his tests using his toolchain of choice: Mocha, Chai and Enzyme.

Next up was Anna Doubkova discussing her experiences with Redux Form and how useful it was in developing a CMS application she was involved in with her team here at Red Badger. One aim of the project was to deliver a CMS with less dependency on developer input to extend. Anna noted how great it would be for the customer to alter their CMS just by changing the data structure. i.e. have fields added by the CMS administrator automatically render on the page without the need to bring the development team in.

A combination of JSON SchemaRedux Form and React enabled the team to do just that. Anna took us through the journey of developing the solution and the reasons for the technical choices made.

Anna ended by listing the pros and cons of working with redux form, expressing overall how easy the team found it to use.

Rounding the evening off was Arnaud Rinquin who shared his journey of reducing the friction he was feeling around testing in the javascript ecosystem. It’s no secret that the toolchain takes a bit of setting up, leading to developers experiencing what has been politely termed Javascript Fatigue.

Inspired by Dan Abramov’s Redux tutorial,  Arnaud aimed to recreate the feel of Dan’s environment in his own workspace. That being: run the tests in the browser, have tests alongside the production code (in the same file), have the tests run automatically on a code change and have the tests execute in the shell  (to facilitate continuous integration).

He successfully achieved this through a combination of a babel plugin (to remove the test code and any dependencies from the code files) and a specially written chrome plugin (to control the test runs). This achievement has enabled Arnaud to enjoy what is for him “a proper TDD workflow”. He can now keep coding and stop worrying.

The success of these meetups (all the 300 tickets for this event were snapped up within an hour) demonstrates the popularity of React in the London software community and the quality of the talks highlights how open the React community is to exploring and embracing new techniques. Everyone’s already looking forward to what fresh insights May’s meetup will provide.

Hear about when new events are announced first by joining the meetup group here.