🔎 Search Terms

type named undefined

🕗 Version & Regression Information

• This is the behavior in every version I tried, and I reviewed the FAQ

⏯ Playground Link

Playground Link

💻 Code

namespace ns {
    export type undefined = "";
    export function x(p: undefined): undefined { // global undefined
        
    }
}

function x(p: ns.undefined) { // undefined from the namespace

}

🙁 Actual behavior

Inside the namespace undefined is the global undefined type. We can access the type if we qualify it with the namespace

🙂 Expected behavior

undefined should not be allowed as a type name. (null is not)

Additional information about the issue

No response