TypeScript Tricks I Actually Use Day to Day

I've been writing TypeScript for a few years now across React Native, Node.js, and a bunch of different product types. And there's a gap between what the docs teach you and what you actually end up reaching for every day. Here are the patterns I keep coming back to. Discriminated unions for state management This one changed how I model data. Instead of a bunch of optional fields that may or may not exist, you define each state explicitly. type RequestState = | { status: "idle" } | { status: "loading" } | { status: "success"; data: User } | { status: "error"; message: string }; Now TypeScript knows exactly what's available in each case. No more data might be undefined checks scattered everywhere. satisfies instead of direct type annotation This one's newer but I use it a lot now. The difference is subtle but useful. const config = { theme: "dark", language: "en", } satisfies Record<string, string>; With satisfies, you get type checking without losing the literal types. If you anno