Bundling with rollup - Uncaught TypeError: Class constructor LitElement cannot be invoked without 'new'

Description

Bundling with rollup - Uncaught TypeError: Class constructor LitElement cannot be invoked without ‘new’

Live Demo

https://github.com/johnlim/my-element.git

Steps to Reproduce

1. Clone the repo
2. npm install
3. ./node_modules/.bin rollup -c
4. Serve index.html
5. console error Uncaught TypeError: Class constructor LitElement cannot be invoked without 'new'

Expected Results

Custom lit-element should be rendered

Actual Results

Console error Uncaught TypeError: Class constructor LitElement cannot be invoked without 'new'

Browsers Affected

• [ *] Chrome
• Firefox
• Edge
• Safari 11
• Safari 10
• IE 11

[johnlim]

@Noooil Thanks! That works!

[patrickkuhlmann]

inline your babelrc into rollup.config.js like this

babel({
    // babelrc: false is needed to prevent reading broken .babelrc files from
    // dependencies (we have to process node_modules). Thats why we also need
    // to inline our own .babelrc file
    babelrc: false,
    presets: [["@babel/es2015", { modules: false }]]
})