UI = f(data)(state ..read more

The limits of my language mean the limits of my world ..read more

Security is important. Nobody wants to be the person advocating for less security. So nobody wants to say it. But somebody has to say it. So I guess I’ll say it. The way npm audit works is broken. Its rollout as a default after every npm install was rushed, inconsiderate, and inadequate for the front-end tooling. Have you heard the story about the boy who cried wolf? Spoiler alert: the wolf eats the sheep. If we don’t want our sheep to be eaten, we need better tools. As of today, npm audit is a stain on the entire npm ecosystem. The best time to fix it was before rolling it out as a default. T ..read more

There are many articles written about React performance optimizations. In general, if some state update is slow, you need to: Verify you’re running a production build. (Development builds are intentionally slower, in extreme cases even by an order of magnitude.) Verify that you didn’t put the state higher in the tree than necessary. (For example, putting input state in a centralized store might not be the best idea.) Run React DevTools Profiler to see what gets re-rendered, and wrap the most expensive subtrees with memo(). (And add useMemo() where needed.) This last step is annoying, especia ..read more

The Don’t Repeat Yourself Wikipedia article states: Violations of DRY are typically referred to as WET solutions, which is commonly taken to stand for “write every time”, “write everything twice”, “we enjoy typing” or “waste everyone’s time”. But as any Phish fan can tell you, wasting time is actually good! A year ago, I gave a conference talk, and I want to share it today with those of you who haven’t watched it. This talk isn’t about React, or even JavaScript. Watch: The Wet Codebase (includes transcript) In this talk, my aim was to show why strict adherence to writing code that is free o ..read more

It was a late evening. My colleague has just checked in the code that they’ve been writing all week. We were working on a graphics editor canvas, and they implemented the ability to resize shapes like rectangles and ovals by dragging small handles at their edges. The code worked. But it was repetitive. Each shape (such as a rectangle or an oval) had a different set of handles, and dragging each handle in different directions affected the shape’s position and size in a different way. If the user held Shift, we’d also need to preserve proportions while resizing. There was a bunch of math. The co ..read more

I started this decade as a first-year college student fresh out of high school. I was 17, didn’t have a job, didn’t have any industry connections, and really didn’t know shit. And now you’re reading my blog! I would have been proud. I’ve told bits and pieces of my story on different podcasts. Now feels like an appropriate time to write down the parts that were most memorable to me. Every person’s story is unique and not directly reproducible. I’ve benefited immensely from the privilege of being born in an upper middle class family and looking like a typical coder stereotype. People took chance ..read more

During my time on the React team, I’ve been lucky to see how Jordan, Sebastian, Sophie and other tenured team members approach problems. In this post, I’m distilling what I learned from them into a few high-level technical principles. These principles aren’t meant to be exhaustive. This is my personal attempt to formalize observations about how the React team operates — other team members may have different perspectives. UI Before API Every abstraction has its own quirks when deployed at scale. How do those quirks manifest themselves in the user interfaces? Can you tell when an app is built w ..read more

My previous post included this paragraph: let vs const vs var: Usually you want let. If you want to forbid assignment to this variable, you can use const. (Some codebases and coworkers are pedantic and force you to use const when there is only one assignment.) This turned out to be very controversial, sparking conversations on Twitter and Reddit. It seems that the majority view (or at least, the most vocally expressed view) is that one should use const wherever possible, only falling back to let where necessary, as can be enforced with the prefer-const ESLint rule. In this post, I will brief ..read more

During my first few years of using JavaScript, I felt like a fraud. Even though I could build websites with frameworks, something was missing. I dreaded JavaScript job interviews because I didn’t have a solid grasp on fundamentals. Over the years, I’ve formed a mental model of JavaScript that gave me confidence. Here, I’m sharing a very compressed version of it. It’s structured like a glossary, with each topic getting a few sentences. As you read through this post, try to mentally keep score about how confident you feel about each topic. I won’t judge you if quite a few of them are a miss! At ..read more