[bundler] Multiple import() statements for the same fragment breaks bundles

[keanulee]

When I edit:

https://github.com/Polymer/pwa-starter-kit/blob/b50a93748677c8be0bdcdc5ed71a03747628fc57/src/actions/app.js#L31-L39

  switch(page) {
    case 'view1':
      import('../components/my-view1.js').then((module) => {
        // Put code in here that you want to run every time when
        // navigating to view1 after my-view1.js is loaded.
      });
      break;
    case 'view2':
      import('../components/my-view2.js');
      break;

To:

    case 'view1':
      import('../components/my-view1.js').then((module) => {
        // Put code in here that you want to run every time when
        // navigating to view1 after my-view1.js is loaded.
      });

      import('../components/my-view2.js');

      break;
    case 'view2':
      import('../components/my-view2.js');
      break;

The resulting shell bundle (my-app.js) doesn't export some identifiers used by the fragments like LitElement and html.

Ref Polymer/pwa-starter-kit#190

[abdonrd]

@usergenic any news about this? 🙂

[LarsDenBakker]

This is a serious bug, not very encouraging that it's been open since july :(

[RobMaskell]

Strangely hit this two days ago and it took a while to unwind it

[usergenic]

FWIW, working on this via #722 - rollup has some unfortunate assumptions and its own new logic around deduplicating dynamic imports that I'm attempting to get around. Solution soon.

[usergenic]

Filed a bug on rollup rollup/rollup#2487

[usergenic]

Filed a bug on rollup rollup/rollup#2487

[usergenic]

Filed another bug on rollup rollup/rollup#2489

[usergenic]

Fixed by #722