I’ve been involved with the development of the pipe operator (|>) in JavaScript for 4 years, going all the way back to 2017 when it was just a humble pipeline that did basic function application. Over the course of the discussion, the proposal evolved into two competing syntaxes, F# & Smart-Mix, exploring different ways of […]

At work, we recently decided to adopt Next.js to decouple our React front-end application from our Django API, so I’ve been working with it extensively over the past few weeks. In parallel, I’ve been working to migrate this very site to Gatsby, pulling in my reading list and my resume onto a new foundation, since […]

useEffect is a powerful hook provided in React 16.8, allowing you to sync data with the outside world. One of the minor annoyances with useEffect is its dependency array, which indicates to useEffect when it should rerun. Adding a function to the dependency array can cause major problems with useEffect. Let’s take a look at […]

I recently extracted and released kefir-ajax, a fetch-like ajax library for Kefir. While I wrote the library in plain JavaScript, the library generates TypeScript typings from its JSDocs. As you can see here, the json method of the ObsResponse class returns TypeScript unknown, rather than the much more common any. Using unknown instead of any […]

Whenever you write new tests for your React components, you’ll probably find your tests reusing the same interactions as tests you’ve already written. In multiple tests, you’ll click a button or change an input and assert that the React component you’re testing updates as expected. This comes up often enough when testing that I like […]

Last week, Babel released version 7.5.0, which included our implementation of the F#-style pipeline operator. If you’re not already aware, TC39 is exploring the potential of a pipeline operator in JavaScript. You can learn more about what’s going on with the operator here. At this point, we’ve got all 3 proposals in Babel, so the […]

Dealing with loading state is a core requirement of most apps you build. Every app needs data, that data almost always needs to be loaded from somewhere, so you need to manage your loading state. Redux doesn’t provide any particular structure for this, but combining it with TypeScript enables some useful patterns. Let’s take a […]

When I was in 4th grade, a yo-yo fad passed through my middle school. Because they were cheap, we all got one, and we were obsessed. We debated which brands were the best, which yo-yo style worked well, and how to do tricks. This was all pre-Internet and entirely word of mouth. We’d hang out […]