For a long time, JavaScript developers have relied on instanceof to figure out, “Is this an error?” err instanceof Error // true...usually In normal code, that works fine. You rarely think about it. But once values come from other realms, things get weird, and the failures are silent. Everything “works”...

Writing JavaScript that opens something (a file, a stream, a lock, a database connection) also means remembering to clean it up. And if we’re being honest, that cleanup doesn’t always happen. I know I’ve missed it more than once. JavaScript has always made this our problem. We reach for try...

Most front-end code processes data long before it ever hits the screen. We fetch a list, tweak it, trim it down, and repeat. And usually without thinking too hard about how much work we’re doing along the way. For years, modern JavaScript has pushed us toward a familiar pattern: data...