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Sebastian McKenzie, the original creator of Yarn and Babel and a member of the React Native team at Facebook, has been working on an “all-in-one” solution for JavaScript and TypeScript development. The Rome project, a reference to “all roads lead to Rome”, was made public on Feb 26th 2020. What is Rome? Rome is a from-scratch implementation of a complete JavaScript toolchain. It compiles and bundl

Serving the right code to the right browsers can be tricky. Here are some options. Serving modern code to modern browsers can be great for performance. Your JavaScript bundles can contain more compact or optimized modern syntax, while still supporting older browsers. The tooling ecosystem has consolidated on using the module/nomodule pattern for declaratively loading modern VS legacy code, which p

Modern JavaScript syntax lets you do more with less code, but how much of the JavaScript we ship to users is actually modern? For the past few years we’ve been writing modern JavaScript (or TypeScript), which is then transpiled to ES5 as a build step. This has let the “state of the art” of JavaScript move forward at a faster pace than could have otherwise been achieved while supporting older brows

Analyzing the characteristics of real-world applications is difficult. We often make generalizations about applications we see in the wild, both anecdotal and statistical: "Single-Page Applications are slower than multipage" or "apps with low TTI loaded fast". However, the extent to which these generalizations hold for the performance and architectural characteristics we care about varies. I belie

JSX is actually quite straightforward: take 1 minute and read this, and you'll understand everything there is to know about this interesting alternative to templates. Alternative title: "Living with JSX" The Pragma You declare this per-file or per-function to tell your transpiler (eg: Babel) the name of a function that should be called at runtime for each node (see Transpilation). In the example b