Merge and re-export module in external module declaration

[jbrantly]

Let's say I'm writing a declaration file for a library that exports two external modules: myLib and myLibWithExtras. The myLibWithExtras module is exactly myLib but with some additional items.

As an example of what I'm trying to do:

// myLib.d.ts
declare module "myLib" {
  function doSomething(): void;
}

declare module "myLibWithExtras" {
  // this doesn't work 
  import myLib= require("myLib");
  module myLib {
    function doSomethingElse(): void;
  }
  export = myLib;
}

// consumer.ts
import myLib = require("myLib")
import myLibWithExtras = require("myLibWithExtras")
myLib.doSomething();
myLib.doSomethingElse(); // should not compile
myLibWithExtras.doSomething();
myLibWithExtras.doSomethingElse();

Is there any way to accomplish this?

[danquirk]

You need a /// reference to myLib.d.ts in consumer.ts so that it knows where to find the quoted names (myLib, myLibWithExtras). Otherwise this is all correct and works for me with the latest bits.

[jbrantly]

Hmm. I built off master and modified consumer.ts and got this:

/// <reference path="myLib.d.ts" />

import myLib = require("myLib")
import myLibWithExtras = require("myLibWithExtras")
myLib.doSomething();
//myLib.doSomethingElse(); // should not compile
myLibWithExtras.doSomething();
myLibWithExtras.doSomethingElse(); // should compile but doesnt

~/tstest$ node ../TypeScript/built/local/tsc.js consumer.ts --module commonjs
consumer.ts(8,17): error TS2339: Property 'doSomethingElse' does not exist on type 'typeof "myLib"'.

Perhaps I'm missing something simple?

[mhegazy]

Your doSomethingElse function is not exported in the d.ts file:

  module myLib {
    export function doSomethingElse(): void;
  }

[jbrantly]

@mhegazy Adding export did not change the output in my test.

[mhegazy]

Oh.. my bad. this is actually a bug, import declarations can not merge with other declarations. The bug is to get an error message in mylib.d.ts to not export the import but complain that it is merged with the module. The compiler shows the error correctly in non-ambient declarations but not here.

I think your scenario would work well with the new import syntax:#1983, this will be in our next release (1.5).

so your code will look like:

// myLib.d.ts
declare module "myLib" {
  export function doSomething(): void;
}

declare module "myLibWithExtras" {
  export * from "myLib";
  export function doSomethingElse(): void;
}

[jbrantly]

Ah! Very good, thanks!

[danquirk]

Re-opening, sounds like we do want to fix today's error message.

[jbrantly]

Ah right, sorry about that.