TypeScript: compiling removes unreferenced imports

Question

In our project we're using RequireJS as our module loader. Some of our modules will influence global libraries, and hence won't be directly used within the module they are referenced in.

Example:

define(['definitely/goingto/usethis/','just/referencingthis/forpackaging'], function(useThis) {
    useThis.likeIPromised();

    // the following call can only be made when the second required file is available
    someGlobalAvailableVariable.someMethod();
});

This works as expected when writing my modules in JavaScript. However, we're translating our project step by step to TypeScript. Given the example above, this results in:

import useThis = module("definitely/goingto/usethis/");
import whatever = module("just/referencingthis/forpackaging");

useThis.likeIPromised();

// I've written a definition file so the following statement will evaluate
someGlobalAvailableVariable.someMethod();

And when compiling this to JavaScript, the compiler wants to be helpful and removes any unused imports. As such, this breaks my code, cause the second imported module isn't available.

My current work around is to include a redundant assignment, but this looks ugly:

import whatever = module("just/referencingthis/forpackaging");
var a = whatever; // a is never ever used further down this module

Does anyone know if it's possible to configure the TypeScript compiler to not optimize modules during compile?

I'm assuming you couldn't just move the import to the appropriate module? — Fenton, Mar 07 '13 at 13:29
They are in the appropriate module. My project consists mainly out of widgets. Each widget is packed in its own module. I'm using Handlebars for templating and want to pack the resulting views together with my widget definition files. When referencing such a view, it will expose a method with the same name on the global variable 'Handlebars'. Hence I don't need to reference the module as it will have defined the method for me. — thomaux, Mar 07 '13 at 13:54

score 26 · Answer 1 · answered Mar 07 '13 at 17:05

26

You can do this at the top of your file (instead of import):

/// <amd-dependency path="just/referencingthis/forpackaging" />

answered Mar 07 '13 at 17:05

Ryan Cavanaugh

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agree, wish it was documented – JasonS Jun 26 '13 at 01:53
7

What do I do if I'm using commonjs? I wish there was a command-line flag to turn this off :-( – obe Jul 18 '15 at 23:14
2

This answer does not appear to work if using commonjs or systemjs – lightswitch05 Sep 02 '15 at 14:38
this was added with alias in Typescript 1.5 -> https://github.com/Microsoft/TypeScript/wiki/What's-new-in-TypeScript#amd-dependency-optional-names – ruifn Sep 16 '15 at 17:04
FYI - this has been deprectated: https://www.typescriptlang.org/docs/handbook/triple-slash-directives.html – Ryan Posener Aug 25 '16 at 17:08

score 11 · Accepted Answer · answered Apr 27 '16 at 16:14

A nicer solution (tested with TS 1.8):

import 'just/referencingthis/forpackaging';

The amd-dependency triple-slash-directive seems to only work if there are other require imports; only having amd-dependency directives results in the TypeScript compiler generating JavaScript completely without a module definition.

TypeScript: compiling removes unreferenced imports

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