Tools: Cannot convert Polymer 2 starter-kit example successfully

[dsyrstad]

I tried to convert the Polymer 2 stater-kit example to Polymer 3 and it fails to load in the browser. I'm using

polymer --version: 1.7.7
node --version: v8.11.3
npm --version: 6.3.0
bower --version: 1.8.4
Ubuntu 16.04.1

I followed these instructions to create the Polymer 2 start-kit app: https://www.polymer-project.org/2.0/start/toolbox/set-up

mkdir polymer2-3-upgrade-app
cd polymer2-3-upgrade-app
polymer init

I chose polymer-2-starter-kit

When I ran: polymer serve, it worked fine. I was up and running with Polymer 2 successfully.

Then I followed this guide: https://www.polymer-project.org/3.0/docs/upgrade to convert to Polymer 3:

modulizer --out . --npm-version 1.0.0
(Omitted --import-style name as recommended for application projects.)

[1/2] 🌀  Converting Package...
Out directory: /home/dsyrstad/IdeaProjects/polymer2-3-upgrade-app
Failed to read entrypoints of package 'shadycss' because the package does not have a 'bower.json' file.
polymer-starter-kit: Did not find an HTML main in bower.json. A main was not added to package.json, so this package will not be directly importable by name. Manually update main in your bower.json or package.json to fix.
[2/2] 🎉  Conversion Complete!

Then I ran:
npm install

Which told me:

npm WARN deprecated [email protected]: This package is unmaintained. Use @sinonjs/formatio instead
npm WARN [email protected] No repository field.

added 65 packages from 482 contributors and audited 575 packages in 4.091s
found 4 vulnerabilities (3 low, 1 critical)
  run `npm audit fix` to fix them, or `npm audit` for details

It appeared the conversion basically worked, so I ran: polymer serve
I opened http://127.0.0.1:8081 in Chrome.
Chrome Dev console reported:

webcomponents-loader.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
polymer-element.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
app-drawer.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
app-drawer-layout.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
app-header.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
app-header-layout.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
app-scroll-effects.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
app-toolbar.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
app-location.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
app-route.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
iron-pages.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
iron-selector.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
paper-icon-button.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
settings.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
html-tag.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)
import-href.js:1 Failed to load resource: the server responded with a status of 404 (Not Found)

Only index.html, my-*.js, and service-worker.js were loaded by the browser. None of the node_modules loaded, probably because of imports like this:

import { PolymerElement } from '../../@polymer/polymer/polymer-element.js';

And this line in index.html:

<script src="../@webcomponents/webcomponentsjs/webcomponents-loader.js"></script>

Also tried:

polymer serve --npm
polymer serve --npm --module-resolution="node"
polymer serve --npm --module-resolution="none"
polymer serve --module-resolution="none"

All give the same result.

Help? I also cannot get my current Polymer 2 app to convert because of spread operators.

Note: I originally raised this issue in https://github.com/Polymer/polymer-modulizer/issues/461 not knowing that project is defunct. It would be good if someone monitored the issues there. There's another new one after mine...

[MacTheZazou]

This issue is more than 1 month old and blocking a lot of people. Can we have a little help regarding how to fix it?

[ivegotwings]

I have exact same errors-

polymer --version: 2.0
node --version: v10.11.0
npm --version: 6.4.1
bower --version: 1.8.4
OS- windows 10

Also I used to get the JAVASCRIPT HEAP OUT OF MEMORY, I used the command SET NODE_OPTIONS "--max-old-space-size=8192". Then this error stoped.

After receiving the errors mentioned above. Polymer generated around 39 files all related to coverage and tests, but no polymer file is converted. I also tried supplying a main in bower.json but it did not help either.

[ivegotwings]

It seems the conversion works without errors on Mac OS but fails on widows and ubuntu.

[dsyrstad]

It seems the conversion works without errors on Mac OS.

This issue was reported against Ubuntu.

[dsyrstad]

Is the modulizer even being maintained anymore? Apparently no response from the team here. I mean, it's a sad state of things if it won't even convert the Polymer 2 sample app.

[MacTheZazou]

I agree! We need a bug free tool to upgrade to P3 & lit-element!

[MacTheZazou]

Help me, Obi-Wan Kenobi. You're my only hope.

[stale[bot]]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.