This should help everyone who has special needs and use cases around custom elements. Since Svelte components are wrapped and only run on connectedCallback, it makes sense to expose the custom element class for modification before that.
- fixes#8954 / closes#8955 - use extend to attach the function manually and save possible values to a prop
- closes#8473 / closes#4168 - use extend to set the proper static attribute and then call attachInternals in the constructor
- closes#8472 - use extend to attach anything custom you need
- closes#3091 - pass `this` to a prop of your choice and use it inside your component
- add some doc for #8987
Simon H