How To Strongly Type process.env
Learn how to strongly type process.env in TypeScript by either augmenting global type or validating it at runtime with t3-env.
TypeScript 5.0 has made it to Total TypeScript!
It brought a lot of improvements - you can learn all about it in our 5.0 breakdown.
The most exciting feature for Total TypeScript was const type parameters.
It lets you specify a type parameter as const
- meaning that everything that gets passed to that parameter gets inferred as if it were as const
.
const routes = <const TRoutes>( routes: TRoutes ) => { return routes; }; const myRoutes = routes({ user: "/user", createUser: "/user/create", }); Object.values(myRoutes); // ['/user', '/user/create'] // Before 5.0, myRoutes would be inferred as string[]
Before 5.0, you needed to use a hack in TypeScript to get this behaviour - the F.Narrow type helper from ts-toolbelt
. I even taught this in Total TypeScript!
No longer - I've re-recorded 3 exercises in TT's Advanced Patterns workshop to take advantage of const type annotations.
I can't wait to see what you build with them!
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Learn how to strongly type process.env in TypeScript by either augmenting global type or validating it at runtime with t3-env.
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