AMD modules in --module=umd are named at usage site but not at declaration site

[alexeagle]

$ ./node_modules/.bin/tsc -v
Version 2.5.2

$ cat a.ts
/// <amd-module name="a"/>
export const a = 1;

$ cat b.ts
/// <amd-module name="b"/>
import {a} from './a';
console.log(a);

$ cat tsconfig.json
{
  "compilerOptions": {
    "module": "umd"
  }
}

$ ./node_modules/.bin/tsc

$ cat a.js
(function (factory) {
    if (typeof module === "object" && typeof module.exports === "object") {
        var v = factory(require, exports);
        if (v !== undefined) module.exports = v;
    }
    else if (typeof define === "function" && define.amd) {
        define(["require", "exports"], factory);
    }
})(function (require, exports) {
    "use strict";
    exports.__esModule = true;
    /// <amd-module name="a"/>
    exports.a = 1;
});

$ cat b.js
(function (factory) {
    if (typeof module === "object" && typeof module.exports === "object") {
        var v = factory(require, exports);
        if (v !== undefined) module.exports = v;
    }
    else if (typeof define === "function" && define.amd) {
        define(["require", "exports", "a"], factory);
    }
})(function (require, exports) {
    "use strict";
    exports.__esModule = true;
    /// <amd-module name="b"/>
    var a_1 = require("a");
    console.log(a_1.a);
});

The AMD output embedded in these UMD modules doesn't work, because the modules are declared anonymous (define(["require", "exports"], factory);), but require'd by name (var a_1 = require("a");).

Require.js gives error: Uncaught Error: Mismatched anonymous define() module

Changing the --module flag to amd makes the code work.

I'm aware that /// <amd-module/> directive is intended for --module=amd but since umd modules wrap an amd module, I think this ought to be supported.

Note: internally at Google, we use goog.module as a format that can be concatenated onto a webpage, since modules are named. This named umd proposal allows us to do the same thing for external users, part of http://g.co/ng/abc .

[alexeagle]

Note, it's fine that the commonjs modules embedded in the umd modules are unnamed, we'll still load those from individual paths.
It's just for Require.js that we want to be able to concatenate the sources together.

[alexeagle]

FYI, as a workaround I use this AfterTransformer
alexeagle/rules_typescript@adaf532#diff-a35a66f3760905e2e8a6f1f168d11f05

[kitsonk]

While I don't need it, it does seem appropriate that if:

/// <amd-module name="a"/>
export const a = 1;

Emits the following when targeting amd:

define("a", ["require", "exports"], function (require, exports) {
    "use strict";
    Object.defineProperty(exports, "__esModule", { value: true });
    /// <amd-module name="a"/>
    exports.a = 1;
});

That the following would be emitted when targeting umd:

(function (factory) {
    if (typeof module === "object" && typeof module.exports === "object") {
        var v = factory(require, exports);
        if (v !== undefined) module.exports = v;
    }
    else if (typeof define === "function" && define.amd) {
-        define(["require", "exports"], factory);
+        define("a", ["require", "exports"], factory);
    }
})(function (require, exports) {
    "use strict";
    exports.__esModule = true;
    /// <amd-module name="a"/>
    exports.a = 1;
});

Semi related is good ole #8436 which is to have a global fallback to UMD modules.

[mhegazy]

should be in typescript@next tomorrow.