UMD re-export incorrect after re-exporting an external module

[christopherthielen]

Re-export an external module. Then re-export an internal module. Generate a UMD bundle. The internal module symbols are exported as if they came from the external module.

Minimal reproduction: https://github.com/christopherthielen/rollup-bug

git clone https://github.com/christopherthielen/rollup-bug
cd rollup-bug
yarn install
yarn build
cat _bundles/rollup-bug.js

---

localmodule.js

export const FOO = "foo";

index.js

export * from "ui-router-core";
export * from "./localmodule";

UMD bundle

Object.keys(uiRouterCore).forEach(function (key) { exports[key] = uiRouterCore[key]; });
exports.FOO = uiRouterCore.FOO; // FOO is not on uiRouterCore, it's an internal module.
Object.defineProperty(exports, '__esModule', { value: true });

---

Interestingly, swapping the order of re-exports seems to work (re-export external modules last)

index.js

export * from "./localmodule";
export * from "ui-router-core";

[guybedford]

This is an interesting bug and unfortunately there's nothing that can really be done here as we don't know if UI-Router-Core does export a FOO or not, so we have to assume it does.

Changing the export order sounds like the right fix here to me.

Marking as a wontfix.