[Web Components | Lit] Investigate upgrade to Lit 2.x

The problem

Blocked by https://github.com/carbon-design-system/carbon-for-ibm-dotcom/issues/9767

Carbon Web Components is currently running on v1.x of lit-element / lit-html. This is one of the fundamental libraries used for rendering web components within this repository.

The solution

Investigate the level of effort for upgrading carbon-web-components to Lit 2.x.

Additional information

• Investigation should consider users that are currently on lit-html/lit-element, and if there is any messaging necessary to have users upgrade to lit 2.
• Corresponding upgrade issue for carbon-web-components: https://github.com/carbon-design-system/carbon-web-components/issues/657
• Upgrade documentation: https://lit.dev/docs/releases/upgrade/
• Additional information regarding the update is captured in this issue.

[abdonrd]

@jeffchew more good news!

@open-wc/lit-helpers@0.5.0 just released with spread, spreadEvents, and spreadProps directives! https://github.com/open-wc/open-wc/releases/tag/%40open-wc/lit-helpers%400.5.0

[jeffchew]

Hi @1ucian0 ! Right now the bump for lit 2 is slated for this quarter (Q4 2022). Note that this also is in tandem with an upgrade to Carbon v11 so this will be a major release to Carbon Web Components v2!

We will have some other announcements regarding Carbon Web Components as part of this, so stay tuned!