While having typing information in an ambient module (d.ts) is great for most use cases it doesn't cover the following two problems:

• Using enums declared in an ambient module: The enums are not compiled to JavaScript objects and can therefore not be used
• Creating instances of DTOs: You cannot create an instance of a DTO if it is an interface.

My suggestion is to have the possibility to create a normal TypeScript module with classes instead of interfaces and exported enums which can be compiled to JavaScript.

Currently the following ambient module is created

declare module api
{
interface MyDTO
{
foo: string;
bar: MyEnum;
}

enum MyEnum
{
    foo,
    bar,
    baz,
}

This is what should be possible to create:

module api
{
export class MyDTO
{
foo: string;
bar: MyEnum;
}

export const enum MyEnum
{
    foo,
    bar,
    baz,
}

This is what we currently want to do, but are not able to:

class Foo
{
constructor()
{
var dto = new MyDTO(); // not possible because MyDTO is an interface
dto.bar = MyEnum.foo; // not possible because MyEnum is not compiled to a JavaScript object
}
}