export import generates no code (perhaps due optimization)

[Evgenus]

TLDR: TypeScript does not generate JS code for exported variables when they are not used in current compilation scope, only the declarations (.d.ts)

Example

---

source files

// a.ts
import b = require("b");
b.c.say();

// b.ts
export import c = require("c");

// c.ts
export function say() {
    console.log("Hello World!");
}

---

Success scenario. We are using a.ts directly. tsc a.ts --module commonjs

generated files

// a.js
var b = require("b");
b.c.say();

// b.js
var c = require("c");
exports.c = c;

// c.js
function say() {
    console.log("Hello World!");
}
exports.say = say;

---

Failure scenario. Imagine if a.ts is placed into another project and uses b.ts as external dependency. In that case we need to compile b.ts with declarations for it. tsc b.ts --module commonjs --declaration

// c.js
function say() {
    console.log("Hello World!");
}
exports.say = say;

// c.d.ts
export declare function say(): void;

// b.d.ts
export import c = require("c");

// b.js   IT IS EMPTY!

---

First, this behavior is strongly inconsistent since generated declarations contains definitions for code that does not exist in generated JS.
Also, the fact that the JS code does not get generated at all is a blocker for our current use cases.
We need this fixed as soon as possible.

[ahejlsberg]

This appears to be a bug in the old compiler. The new compiler generates the following b.js in both cases:

// b.js
exports.c = require("c");

[Evgenus]

What version have you mentioned? npm version is 1.0.1 and it has that bug.

[RyanCavanaugh]

The compiler version in the master branch right now. It is not published in npm yet.

[nexussays]

I spent several hours tonight dealing with this problem and trying to track it down online, so +1 for getting it to prod ASAP.

Is there an ETA for public release of this version? I couldn't find anything on the roadmap or elsewhere.

[basarat]

@nexussays I would say soon https://github.com/Microsoft/TypeScript/milestones

[nexussays]

Are new versions cut from master, so this fix will be part of 1.1? There's no milestone on this issue and no associated changelog.

[mhegazy]

@nexussays, yes master would be the right place to grab the fix for this.

[nexussays]

Great. Can't wait for 1.1 :)