TypeScript - 在 object 使用别名解构时指定类型

Question

He everybody, I'm refactoring an NodeJS app to TypeScript. And I was making always object destructuring and also for the code block below I'm making and alias while object destructuring as you see. And how can I specify type here?

const {length: isRegistered}  = await User.countDocuments({email: emailTo});

Answer 1

I would favour typing the return type of User.countDocuments({email: emailTo}) , which should be similar to Promise<{ length: number, ... }> . That way, TypeScript will infer the type of the destructed properties.

Another way is to be more explicit by typing const {length: isRegistered}: {length: number} .