Version

3.2.19

Reproduction link

github.com

Steps to reproduce

General

1. Create a custom element
2. Try using the life-cycle hooks to access the props.

Reproduction through the example

1. Clone the repo provided
2. Run npm i --save
3. Run npm run build:wc
4. Copy the output into lab directory
5. cd lab then run npx http-server

What is expected?

Expected props to be available in created/mounted/before mount hooks.

What is actually happening?

Props are undefined in setup/onMounted/onBeforeMount or created hooks

This is happening in the defineCustomElement API. Also, it says the attributes have not been passed in console warning, even though the attributes have been passed in.

Anything on this?

I believe I'm seeing the same problem: https://github.com/vuejs/vue-next/issues/4789

I'll send a PR in a few hours

fixed by 3ca8317