This article surveys the current state of JavaScript tooling for a class of testing techniques which address something called “the oracle problem”. The class is coextensive with fuzz testing broadly defined, including mutational fuzzing, generative testing, property-based testing, model-based testing and mutation testing. While these ways of testing have found devotees in other ecosystems, none are much used or even known about in the JavaScript community. Not so long ago one could have said the same about unit testing. When will fuzz testing get its unit testing moment?

JavaScript libraries to enable these sorts of testing are still immature, but now reaching a point where it is possible for developers to try them out and come to their own opinions about the value of these testing approaches. It is time to start trialling these libraries on real applications so that we can better gauge the value of the techniques they make possible. …

The name Kubernetes originates from Greek, meaning helmsman or pilot, and is the root of governor and cybernetic.

(Kubernetes documentation)

The term “cybernetics” conjures up images of Cold War control rooms, creepy physiological experiments and old-timey transistors. Yet, as hinted by the hat-tip concealed in the naming of Google’s container orchestration platform, the discipline is the source of key concepts underlying modern DevOps. What can we gain from paying more attention to this strand in the history of our craft?

“Cybernetics” was coined from the Greek word κυβερνήτης in the 40s by one of the pioneers of high-speed digital computing, Norbert Wiener, to describe “the entire field of control and communication theory, whether in the machine or in the animal” (Cybernetics, 1948). …

Theory and practice in React 16

If you have been keeping tabs on React’s progress using GitHub or Twitter, you will have encountered a number of curious and tantalising words: continuations, algebraic effects, coroutines… and of course, fibers. …


Sam Galson

Software Engineer at YLD, connoisseur of curiosities.

Get the Medium app

A button that says 'Download on the App Store', and if clicked it will lead you to the iOS App store
A button that says 'Get it on, Google Play', and if clicked it will lead you to the Google Play store