feat(compiler): support for CustomStateSet

[pfteter]

Ticket: #6285

Stencil Version

4.33

Current Behavior

@AttachInternals() internals!: ElementInternals;

cannot be used without
formAssociated: true in the metadata.

because of a condition in the compiler

Expected Behavior

@AttachInternals() internals!: ElementInternals;

should work without formAssociated: true in the metadata.

CustomStateSet can now be used without formAssociated for components that are not formAssociated.

Improvement: Add stencil support for custom state.

System Info

Steps to Reproduce

add

@AttachInternals() internals!: ElementInternals;

to a component, an console error will be shown

Code Reproduction URL

Additional Information

Will commit a fix for it, the solution is quite easy:
https://developer.mozilla.org/en-US/docs/Web/API/HTMLElement/attachInternals

Does this introduce a breaking change?

• Yes
• No

Testing

Manual testing / changing code in node_modules

[christian-bromann]

Thanks for raising this PR.

Can we create a test for this? I suggest a WDIO e2e test that verifies that a component without the formAssociated flag can use element internals.

[christian-bromann]

Also could we update the docs as they should be clarify that element internals can be used without form association.

[christian-bromann]

@pfteter mind running npm run prettier and check in the changes?

[christian-bromann]

Thanks a lot 👍