Page reload doesn't work with lit-element

[LasseRosenow]

🐛 bug report

Im working on a simple single page application build with lit-element. I bundle everything together using parcel and that works pretty good. But in live development, whenever I change something inside of a custom element, the page won't refresh and I geht this issue:
"Uncaught DOMException: Failed to execute 'define' on 'CustomElementRegistry': this name has already been used with this registry"

🎛 Configuration (.babelrc, package.json, cli command)

{
  "scripts": {
    "dev": "parcel watch src/index.html",
    "start": "parcel src/index.html",
    "build": "parcel build src/index.html"
  },
  "dependencies": {
    "lit-element": "^2.0.1",
    "lit-element-router": "^1.0.0"
  },
  "devDependencies": {
    "parcel-bundler": "^1.11.0"
  },
  "browserslist": [
    "Chrome 72"
  ]
}

🤔 Expected Behavior

The custom element should be reloaded and I should just see the changes I made.

😯 Current Behavior

I get this error message instead:
"Uncaught DOMException: Failed to execute 'define' on 'CustomElementRegistry': this name has already been used with this registry"
And there is no reload. If I refresh the page myself, everything works just fine... until I change something else.

💁 Possible Solution

No idea :(

🔦 Context

I also tried out my project on webpack and everything works there, except I don't like how webpack manages assets etc.
So it seems to be a parcel issue.

💻 Code Sample

🌍 Your Environment

Software	Version(s)
Parcel	1.11.0
Node	11.10.0
npm	6.7.0
Operating System	Windows 10

[mischnic]

I'm guessing you have a call like this somewhere in your project: customElements.define('popup-info', PopUpInfo); and don't have hot module reloading enabled in your webpack config.

I think webpack reloads the whole page by default while Parcel does hot reloading (in this case re-execute the Javascript). #289 (comment) describes how to setup your project to reload the page completely without HMR: add this

if (module.hot) {
  module.hot.accept(function () {
    window.location.reload();
  });
}