Augmentations for the global scope can only be directly nested in external modules or ambient module declarations(2669)

Question

I would like to store my NodeJS config in the global scope.

I tried to follow this => Extending TypeScript Global object in node.js and other solution on stackoverflow,

I made a file called global.d.ts where I have the following code

declare global {
    namespace NodeJS {
      interface Global {
          config: MyConfigType
      }
    }
  }

Augmentations for the global scope can only be directly nested in external modules or ambient module declarations.ts(2669)

but doing this works fine =>

declare module NodeJS  {
    interface Global {
        config: MyConfigType
    }
}

the problem is, I need to import the file MyConfigType to type the config, but the second option do not allow that.

Understand that an "external module" is a file containing an import or export statement, that an "ambient module declaration" reads declare module "m" {} (note the quotes), and reread the error message. — Aluan Haddad
In an ambient decl. file that's not been turned into a module you are already operating in the global scope (outside of declare module {} braces) so you can just omit declare global — Dominic

sshh sshh · Accepted Answer · 2019-12-27T11:10:16

You can indicate that the file is a module like so:

export {};

declare global {
    namespace NodeJS {
        interface Global {
            config: MyConfigType
        }
    }
}