Merging declarations of namespace and variable

Question

I'm trying to create declaration file for a third-party library node-tap. The simplified problem is: for a library

// node_modules/a/index.js function A() { /* ... */ } module.exports = new A(); module.exports.A = A;

what would be a correct *.d.ts declaration file to allow the following code to compile successfully?

// test.ts import * as a from 'a'; import {A} from 'a'; function f(): A { return a; }

Mention that having A as type is important, even though it could be omitted in this simple example.

3 revs, 2 users 65% · Accepted Answer · 2017-05-17 17:49:58Z

If you need to be able to call new a.A(), do:

declare class A { A: typeof A; } declare const a: A; declare namespace a { export type A = A; } export = a;

If you only need the type a.A accessible, do:

declare const a: a.A; declare namespace a { interface A {} } export = a

I think you need to keep declare class A { A: typeof A }, otherwise you can't do new a.A(), as a.A only refers to a type.

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